Wednesday, April 26, 2017
NASA / JPL -Caltech
NASA Spacecraft Dives Between Saturn and Its Rings (News Release)
NASA's Cassini spacecraft is back in contact with Earth after its successful first-ever dive through the narrow gap between the planet Saturn and its rings on April 26, 2017. The spacecraft is in the process of beaming back science and engineering data collected during its passage, via NASA's Deep Space Network Goldstone Complex in California's Mojave Desert. The DSN acquired Cassini's signal at 11:56 p.m. PDT on April 26, 2017 (2:56 a.m. EDT on April 27) and data began flowing at 12:01 a.m. PDT (3:01 a.m. EDT) on April 27.
"In the grandest tradition of exploration, NASA's Cassini spacecraft has once again blazed a trail, showing us new wonders and demonstrating where our curiosity can take us if we dare," said Jim Green, director of the Planetary Science Division at NASA Headquarters in Washington.
As it dove through the gap, Cassini came within about 1,900 miles (3,000 kilometers) of Saturn's cloud tops (where the air pressure is 1 bar -- comparable to the atmospheric pressure of Earth at sea level) and within about 200 miles (300 kilometers) of the innermost visible edge of the rings.
While mission managers were confident Cassini would pass through the gap successfully, they took extra precautions with this first dive, as the region had never been explored.
"No spacecraft has ever been this close to Saturn before. We could only rely on predictions, based on our experience with Saturn's other rings, of what we thought this gap between the rings and Saturn would be like," said Cassini Project Manager Earl Maize of NASA's Jet Propulsion Laboratory in Pasadena, California. "I am delighted to report that Cassini shot through the gap just as we planned and has come out the other side in excellent shape."
The gap between the rings and the top of Saturn's atmosphere is about 1,500 miles (2,000 kilometers) wide. The best models for the region suggested that if there were ring particles in the area where Cassini crossed the ring plane, they would be tiny, on the scale of smoke particles. The spacecraft zipped through this region at speeds of about 77,000 mph (124,000 kph) relative to the planet, so small particles hitting a sensitive area could potentially have disabled the spacecraft.
As a protective measure, the spacecraft used its large, dish-shaped high-gain antenna (13 feet or 4 meters across) as a shield, orienting it in the direction of oncoming ring particles. This meant that the spacecraft was out of contact with Earth during the ring-plane crossing, which took place at 2 a.m. PDT (5 a.m. EDT) on April 26. Cassini was programmed to collect science data while close to the planet and turn toward Earth to make contact about 20 hours after the crossing.
Cassini's next dive through the gap is scheduled for May 2.
Launched in 1997, Cassini arrived at Saturn in 2004. Following its last close flyby of the large moon Titan on April 21 PDT (April 22 EDT), Cassini began what mission planners are calling its "Grand Finale." During this final chapter, Cassini loops Saturn approximately once per week, making a total of 22 dives between the rings and the planet. Data from this first dive will help engineers understand if and how they will need to protect the spacecraft on its future ring-plane crossings. The spacecraft is on a trajectory that will eventually plunge into Saturn's atmosphere -- and end Cassini's mission -- on Sept. 15, 2017.
NASA / JPL - Caltech / Space Science Institute
Monday, April 24, 2017
NASA / JPL - Caltech / Space Science Institute
Cassini Completes Final -- and Fateful -- Titan Flyby (Press Release)
NASA's Cassini spacecraft has had its last close brush with Saturn's hazy moon Titan and is now beginning its final set of 22 orbits around the ringed planet.
The spacecraft made its 127th and final close approach to Titan on April 21 at 11:08 p.m. PDT (2:08 a.m. EDT on April 22), passing at an altitude of about 608 miles (979 kilometers) above the moon's surface.
Cassini transmitted its images and other data to Earth following the encounter. Scientists with Cassini's radar investigation will be looking this week at their final set of new radar images of the hydrocarbon seas and lakes that spread across Titan's north polar region. The planned imaging coverage includes a region previously seen by Cassini's imaging cameras, but not by radar. The radar team also plans to use the new data to probe the depths and compositions of some of Titan's small lakes for the first (and last) time, and look for further evidence of the evolving feature researchers have dubbed the "magic island."
"Cassini's up-close exploration of Titan is now behind us, but the rich volume of data the spacecraft has collected will fuel scientific study for decades to come," said Linda Spilker, the mission's project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California.
Gateway to the Grand Finale
The flyby also put Cassini on course for its dramatic last act, known as the Grand Finale. As the spacecraft passed over Titan, the moon's gravity bent its path, reshaping the robotic probe's orbit slightly so that instead of passing just outside Saturn's main rings, Cassini will begin a series of 22 dives between the rings and the planet on April 26. The mission will conclude with a science-rich plunge into Saturn's atmosphere on Sept. 15.
"With this flyby we're committed to the Grand Finale," said Earl Maize, Cassini project manager at JPL. "The spacecraft is now on a ballistic path, so that even if we were to forgo future small course adjustments using thrusters, we would still enter Saturn's atmosphere on Sept. 15 no matter what."
Cassini received a large increase in velocity of approximately 1,925 mph (precisely 860.5 meters per second) with respect to Saturn from the close encounter with Titan.
After buzzing Titan, Cassini coasted onward, reaching the farthest point in its orbital path around Saturn at 8:46 p.m. PDT (11:46 p.m. EDT) on April 22. This point, called apoapse, is where each new Cassini lap around Saturn begins. Technically, Cassini began its Grand Finale orbits at this time, but since the excitement of the finale begins in earnest on April 26 with the first ultra-close dive past Saturn, the mission is celebrating the latter milestone as the formal beginning of the finale.
The spacecraft's first finale dive will take place on April 26 at 2 a.m. PDT (5 a.m. EDT). The spacecraft will be out of contact during the dive and for about a day afterward while it makes science observations from close to the planet. The earliest time Cassini is scheduled to make radio contact with Earth is 12:05 a.m. PDT (3:05 a.m. EDT) on April 27. Images and other data are expected to begin flowing in shortly after communication is established.
A new narrated, 360-degree animated video gives viewers a sense of what it might be like to fly alongside Cassini as it makes one of its Grand Finale dives.
Thursday, April 13, 2017
An Astrobiologist's Dream: The Subsurface Oceans of Europa and Enceladus May Bear the Ingredients Necessary for Life...
NASA / JPL - Caltech
NASA Missions Provide New Insights into 'Ocean Worlds' in Our Solar System (Press Release)
Two veteran NASA missions are providing new details about icy, ocean-bearing moons of Jupiter and Saturn, further heightening the scientific interest of these and other "ocean worlds" in our solar system and beyond. The findings are presented in papers published Thursday by researchers with NASA’s Cassini mission to Saturn and Hubble Space Telescope.
In the papers, Cassini scientists announce that a form of chemical energy that life can feed on appears to exist on Saturn's moon Enceladus, and Hubble researchers report additional evidence of plumes erupting from Jupiter's moon Europa.
“This is the closest we've come, so far, to identifying a place with some of the ingredients needed for a habitable environment,” said Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate at Headquarters in Washington. ”These results demonstrate the interconnected nature of NASA's science missions that are getting us closer to answering whether we are indeed alone or not.”
The paper from researchers with the Cassini mission, published in the journal Science, indicates hydrogen gas, which could potentially provide a chemical energy source for life, is pouring into the subsurface ocean of Enceladus from hydrothermal activity on the seafloor.
The presence of ample hydrogen in the moon's ocean means that microbes – if any exist there – could use it to obtain energy by combining the hydrogen with carbon dioxide dissolved in the water. This chemical reaction, known as "methanogenesis" because it produces methane as a byproduct, is at the root of the tree of life on Earth, and could even have been critical to the origin of life on our planet.
Life as we know it requires three primary ingredients: liquid water; a source of energy for metabolism; and the right chemical ingredients, primarily carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. With this finding, Cassini has shown that Enceladus – a small, icy moon a billion miles farther from the Sun than Earth – has nearly all of these ingredients for habitability. Cassini has not yet shown phosphorus and sulfur are present in the ocean, but scientists suspect them to be, since the rocky core of Enceladus is thought to be chemically similar to meteorites that contain the two elements.
"Confirmation that the chemical energy for life exists within the ocean of a small moon of Saturn is an important milestone in our search for habitable worlds beyond Earth," said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California.
The Cassini spacecraft detected the hydrogen in the plume of gas and icy material spraying from Enceladus during its last, and deepest, dive through the plume on Oct. 28, 2015. Cassini also sampled the plume's composition during flybys earlier in the mission. From these observations scientists have determined that nearly 98 percent of the gas in the plume is water, about 1 percent is hydrogen and the rest is a mixture of other molecules including carbon dioxide, methane and ammonia.
The measurement was made using Cassini's Ion and Neutral Mass Spectrometer (INMS) instrument, which sniffs gases to determine their composition. INMS was designed to sample the upper atmosphere of Saturn's moon Titan. After Cassini's surprising discovery of a towering plume of icy spray in 2005, emanating from hot cracks near the south pole, scientists turned its detectors toward the small moon.
Cassini wasn't designed to detect signs of life in the Enceladus plume – indeed, scientists didn't know the plume existed until after the spacecraft arrived at Saturn.
"Although we can't detect life, we've found that there's a food source there for it. It would be like a candy store for microbes," said Hunter Waite, lead author of the Cassini study.
The new findings are an independent line of evidence that hydrothermal activity is taking place in the Enceladus ocean. Previous results, published in March 2015, suggested hot water is interacting with rock beneath the sea; the new findings support that conclusion and add that the rock appears to be reacting chemically to produce the hydrogen.
The paper detailing new Hubble Space Telescope findings, published in The Astrophysical Journal Letters, reports on observations of Europa from 2016 in which a probable plume of material was seen erupting from the moon’s surface at the same location where Hubble saw evidence of a plume in 2014. These images bolster evidence that the Europa plumes could be a real phenomenon, flaring up intermittently in the same region on the moon's surface.
The newly imaged plume rises about 62 miles (100 kilometers) above Europa’s surface, while the one observed in 2014 was estimated to be about 30 miles (50 kilometers) high. Both correspond to the location of an unusually warm region that contains features that appear to be cracks in the moon’s icy crust, seen in the late 1990s by NASA's Galileo spacecraft. Researchers speculate that, like Enceladus, this could be evidence of water erupting from the moon’s interior.
“The plumes on Enceladus are associated with hotter regions, so after Hubble imaged this new plume-like feature on Europa, we looked at that location on the Galileo thermal map. We discovered that Europa’s plume candidate is sitting right on the thermal anomaly," said William Sparks of the Space Telescope Science Institute in Baltimore, Maryland. Sparks led the Hubble plume studies in both 2014 and 2016.
The researchers say if the plumes and the warm spot are linked, it could mean water being vented from beneath the moon's icy crust is warming the surrounding surface. Another idea is that water ejected by the plume falls onto the surface as a fine mist, changing the structure of the surface grains and allowing them to retain heat longer than the surrounding landscape.
For both the 2014 and 2016 observations, the team used Hubble's Space Telescope Imaging Spectrograph (STIS) to spot the plumes in ultraviolet light. As Europa passes in front of Jupiter, any atmospheric features around the edge of the moon block some of Jupiter’s light, allowing STIS to see the features in silhouette. Sparks and his team are continuing to use Hubble to monitor Europa for additional examples of plume candidates and hope to determine the frequency with which they appear.
NASA's future exploration of ocean worlds is enabled by Hubble's monitoring of Europa's putative plume activity and Cassini's long-term investigation of the Enceladus plume. In particular, both investigations are laying the groundwork for NASA's Europa Clipper mission, which is planned for launch in the 2020s.
“If there are plumes on Europa, as we now strongly suspect, with the Europa Clipper we will be ready for them,” said Jim Green, Director of Planetary Science, at NASA Headquarters.
Hubble's identification of a site which appears to have persistent, intermittent plume activity provides a tempting target for the Europa mission to investigate with its powerful suite of science instruments. In addition, some of Sparks' co-authors on the Hubble Europa studies are preparing a powerful ultraviolet camera to fly on Europa Clipper that will make similar measurements to Hubble's, but from thousands of times closer. And several members of the Cassini INMS team are developing an exquisitely sensitive, next-generation version of their instrument for flight on Europa Clipper.
NASA / ESA / K. Retherford / SWRI
Tuesday, April 11, 2017
Check out this pic and YouTube video showing a dockworker feeding raw meat to a flock of bald eagles in Dutch Harbor, Alaska last summer. It's amazing that America's national bird is as common in The Last Frontier as coyotes are here in Los Angeles! Anyways, enjoy the video.
(Ignore the brief profanity at the beginning of this clip.)
Friday, April 07, 2017
Department of Defense
Just thought I'd share these pics that were released by the Pentagon last night showing Tomahawk missiles being launched from U.S. warships to supposedly hit a Syrian airbase that was used to deploy aircraft that carried out a heinous chemical weapons attack on Syrian civilians three days ago. I say 'supposedly' because based on reports that I've read online (yes, I know that the key word here is 'online'), President Trump went out of his way to not cause any real damage to the al-Shayrat military airfield to prevent antagonizing Trump's good friend and puppet master in Moscow, Vladimir Putin. According to said reports, Putin wanted to help Trump get back on his feet after his approval rating dipped to historic levels by creating an event that would distract the media from continuing to focus on Trump's ties to Russia. (Word has it that Trump's rating dipped to 35% only after 74 days in office, whereas it took the rating of fellow GOP'er George W. Bush about 1,947 days to fall that low. Bill Clinton and Barack Obama's ratings have never sunk to that level...because Democrats!)
What better way to create a distraction than to have Bashar al-Assad, Syria's own leader and Putin's other puppet, stage a chemical attack on his own people at the behest of Putin that would force Trump to react? By giving a military response to such an atrocity, Trump would supposedly receive the sympathy of the same mainstream media that lambasted him for the last two or so years. And this is despite the fact that Trump wanted to avenge the "beautiful" Syrian babies that he tried through two failed Muslim bans to keep out of the United States. And I won't even delve into other reports mentioning that Trump has been secretly amassing U.S. ground forces inside Syria weeks before last night's missile strike.
Just how much more does Trump's approval rating need to drop for him to send our soldiers into battle on Syrian soil to fight anyone other than the Islamic State (who is the foe we should be focusing on) as a way to take our attention away from the fact that he's a terrible president doing Putin's bidding? I could type a lot more on this charade that Trump and Putin are trying to play, but I won't. Don't know if I should hope or dread that Trump will finally prove to the fools who voted for him that Trump's presidency poses as an existential threat not just to America but to the whole world in general... We shall see. Or hopefully we won't.
Department of Defense
Department of Defense
Thursday, April 06, 2017
NASA / JPL - Caltech / UCLA / MPS / DLR / IDA / PSI
Ceres' Temporary Atmosphere Linked to Solar Activity (Press Release)
Scientists have long thought that Ceres may have a very weak, transient atmosphere, but mysteries lingered about its origin and why it's not always present. Now, researchers suggest that this temporary atmosphere appears to be related to the behavior of the Sun, rather than Ceres' proximity to the Sun. The study was conducted by scientists from NASA's Dawn mission and others who previously identified water vapor at Ceres using other observatories.
"We think the occurrence of Ceres' transient atmosphere is the product of solar activity," said Michaela Villarreal, lead author of the new study in the Astrophysical Journal Letters and researcher at the University of California, Los Angeles.
Ceres is the largest object in the asteroid belt that lies between Mars and Jupiter. When energetic particles from the Sun hit exposed ice and ice near the surface of the dwarf planet, it transfers energy to the water molecules as they collide. This frees the water molecules from the ground, allowing them to escape and create a tenuous atmosphere that may last for a week or so.
"Our results also have implications for other airless, water-rich bodies of the solar system, including the polar regions of the Moon and some asteroids," said Chris Russell, principal investigator of the Dawn mission, also at UCLA. "Atmospheric releases might be expected from their surfaces, too, when solar activity erupts." Before Dawn arrived in orbit at Ceres in 2015, evidence for an atmosphere had been detected by some observatories at certain times, but not others, suggesting that it is a transient phenomenon. In 1991, the International Ultraviolet Explorer satellite detected hydroxyl emission from Ceres, but not in 1990. Then, in 2007, the European Southern Observatory's Very Large Telescope searched for a hydroxide emission, but came up empty. The European Space Agency's Herschel Space Observatory detected water in the possible weak atmosphere, or "exosphere," of Ceres on three occasions, but did not on a fourth attempt.
As Dawn began its thorough study of Ceres in March 2015, scientists found ample evidence for water in the form of ice. The spacecraft's gamma ray and neutron detector (GRaND) has found that the uppermost surface is rich in hydrogen, which is consistent with broad expanses of water ice. This ice is nearer to the surface at higher latitudes, where temperatures are lower, a 2016 study published in the journal Science found. Ice has been detected directly at the small bright crater called Oxo and in at least one of the craters that are persistently in shadow in the northern hemisphere. Other research has suggested that persistently shadowed craters are likely to harbor ice. Additionally, the shapes of craters and other features are consistent with significant water-ice content in the crust.
Because of this evidence for abundant ice, many scientists think that Ceres' exosphere is created in a process similar to what occurs on comets, even though they are much smaller. In that model, the closer Ceres gets to the Sun, the more water vapor is released because of ice sublimating near or at the surface.
But the new study suggests comet-like behavior may not explain the mix of detections and non-detections of a weak atmosphere.
"Sublimation probably is present, but we don't think it's significant enough to produce the amount of exosphere that we're seeing," Villarreal said.
Villarreal and colleagues showed that past detections of the transient atmosphere coincided with higher concentrations of energetic protons from the Sun. Non-detections coincided with lower concentrations of these particles. What's more, the best detections of Ceres' atmosphere did not occur at its closest approach to the Sun. This suggests that solar activity, rather than Ceres' proximity to the Sun, is a more important factor in generating an exosphere.
The research began with a 2016 Science study led by Chris Russell. The study, using GRaND data, suggested that, during a six-day period in 2015, Ceres had accelerated electrons from the solar wind to very high energies.
In its orbital path, Ceres is currently getting closer to the Sun. But the Sun is now in a particularly quiet period, expected to last for several more years. Since their results indicate Ceres' exosphere is related to solar activity, study authors are predicting that the dwarf planet will have little to no atmosphere for some time. However, they recommend that other observatories monitor Ceres for future emissions.
Dawn is now in its extended mission and studying Ceres in a highly elliptical orbit. Engineers are maneuvering the spacecraft to a different orbital plane so that Ceres can be viewed in a new geometry. The primary science objective is to measure cosmic rays to help determine which chemical elements lie near the surface of Ceres. As a bonus, in late April, the Sun will be directly behind Dawn, when the spacecraft is at an altitude of about 12,300 miles (20,000 kilometers). Ceres will appear brighter than before in that configuration, and perhaps reveal more secrets about its composition and history.
The Dawn mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.
Source: Jet Propulsion Laboratory
Tuesday, April 04, 2017
NASA / JPL -Caltech
NASA’s Cassini Mission Prepares for 'Grand Finale' at Saturn (Press Release)
NASA's Cassini spacecraft, in orbit around Saturn since 2004, is about to begin the final chapter of its remarkable story. On Wednesday, April 26, the spacecraft will make the first in a series of dives through the 1,500-mile-wide (2,400-kilometer) gap between Saturn and its rings as part of the mission’s grand finale.
"No spacecraft has ever gone through the unique region that we'll attempt to boldly cross 22 times," said Thomas Zurbuchen, associate administrator for the Science Mission Directorate at NASA Headquarters in Washington. "What we learn from Cassini’s daring final orbits will further our understanding of how giant planets, and planetary systems everywhere, form and evolve. This is truly discovery in action to the very end."
During its time at Saturn, Cassini has made numerous dramatic discoveries, including a global ocean that showed indications of hydrothermal activity within the icy moon Enceladus, and liquid methane seas on its moon Titan.
Now 20 years since launching from Earth, and after 13 years orbiting the ringed planet, Cassini is running low on fuel. In 2010, NASA decided to end the mission with a purposeful plunge into Saturn this year in order to protect and preserve the planet's moons for future exploration – especially the potentially habitable Enceladus.
But the beginning of the end for Cassini is, in many ways, like a whole new mission. Using expertise gained over the mission's many years, Cassini engineers designed a flight plan that will maximize the scientific value of sending the spacecraft toward its fateful plunge into the planet on Sept. 15. As it ticks off its terminal orbits during the next five months, the mission will rack up an impressive list of scientific achievements.
"This planned conclusion for Cassini's journey was far and away the preferred choice for the mission's scientists," said Linda Spilker, Cassini project scientist at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California. "Cassini will make some of its most extraordinary observations at the end of its long life."
The mission team hopes to gain powerful insights into the planet's internal structure and the origins of the rings, obtain the first-ever sampling of Saturn's atmosphere and particles coming from the main rings, and capture the closest-ever views of Saturn's clouds and inner rings. The team currently is making final checks on the list of commands the robotic probe will follow to carry out its science observations, called a sequence, as it begins the finale. That sequence is scheduled to be uploaded to the spacecraft on Tuesday, April 11.
Cassini will transition to its grand finale orbits, with a last close flyby of Saturn's giant moon Titan, on Saturday, April 22. As it has many times over the course of the mission, Titan's gravity will bend Cassini's flight path. Cassini's orbit then will shrink so that instead of making its closest approach to Saturn just outside the rings, it will begin passing between the planet and the inner edge of its rings.
"Based on our best models, we expect the gap to be clear of particles large enough to damage the spacecraft. But we're also being cautious by using our large antenna as a shield on the first pass, as we determine whether it's safe to expose the science instruments to that environment on future passes," said Earl Maize, Cassini project manager at JPL. "Certainly there are some unknowns, but that's one of the reasons we're doing this kind of daring exploration at the end of the mission."
In mid-September, following a distant encounter with Titan, the spacecraft's path will be bent so that it dives into the planet. When Cassini makes its final plunge into Saturn's atmosphere on Sept. 15, it will send data from several instruments – most notably, data on the atmosphere's composition – until its signal is lost.
"Cassini's grand finale is so much more than a final plunge," said Spilker. "It's a thrilling final chapter for our intrepid spacecraft, and so scientifically rich that it was the clear and obvious choice for how to end the mission."
Monday, April 03, 2017
NASA / JHUAPL / SWRI
New Horizons Halfway from Pluto to Next Flyby Target (News Release)
How time and our spacecraft fly – especially when you’re making history at 32,000 miles (51,500 kilometers) per hour.
Continuing on its path through the outer regions of the solar system, NASA’s New Horizons spacecraft has now traveled half the distance from Pluto – its storied first target – to 2014 MU69, the Kuiper Belt Object (KBO) it will fly past on Jan. 1, 2019. The spacecraft reached that milestone at midnight (UTC) on April 3 – or 8 p.m. ET on April 2 – when it was 486.19 million miles (782.45 million kilometers) beyond Pluto and the same distance from MU69.
“It’s fantastic to have completed half the journey to our next flyby; that flyby will set the record for the most distant world ever explored in the history of civilization,” said Alan Stern, New Horizons principal investigator from the Southwest Research Institute in Boulder, Colorado.
Later this week – at 21:24 UTC (or 5:24 p.m. ET) on April 7 – New Horizons will also reach the halfway point in time between closest approaches to Pluto, which occurred at 7:48 a.m. ET on July 14, 2015, and MU69, predicted for 2 a.m. ET on New Year’s Day 2019. The nearly five-day difference between the halfway markers of distance and time is due to the gravitational tug of the Sun. The spacecraft is actually getting slightly slower as it pulls away from the Sun’s gravity, so the spacecraft crosses the midpoint in distance a bit before it passes the midpoint in time.
Ready for a Rest
New Horizons will begin a new period of hibernation later this week. In fact, the spacecraft will be sleeping through the April 7 halfway timing marker to MU69, because mission operators at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, will have put the spacecraft into hibernation two hours beforehand.
The scheduled 157-day hibernation is well-deserved; New Horizons has been “awake” for almost two and a half years, since Dec. 6, 2014. Since then, in addition to its historic Pluto encounter and 16 subsequent months of relaying the data from that encounter back to Earth, New Horizons has made breakthrough, distant observations of a dozen Kuiper Belt Objects (KBOs), collected unique data on the dust and charged-particle environment of the Kuiper Belt, and studied the hydrogen gas that permeates the vast space surrounding the Sun, called the heliosphere.
“The January 2019 MU69 flyby is the next big event for us, but New Horizons is truly a mission to more broadly explore the Kuiper Belt,” said Hal Weaver, New Horizons project scientist from APL, in Laurel, Maryland. “In addition to MU69, we plan to study more than two-dozen other KBOs in the distance and measure the charged particle and dust environment all the way across the Kuiper Belt.”
New Horizons is currently 3.5 billion miles (5.7 billion kilometers) from Earth; at that distance, a radio signal sent from the operations team – and traveling at light speed – needs about five hours and 20 minutes to reach the spacecraft. All spacecraft systems are healthy and operating normally, and the spacecraft is on course for its MU69 flyby.
NASA / JHUAPL / SWRI / Steve Gribben
Saturday, April 01, 2017
Just thought I'd share this hilarious pic that I recently found on Twitter. Well... Hilarious if you're not a red baseball cap-wearing, MAGA-spewing troglodyte who voted for anyone in the Republican Party. This "logo" applies to the GOP as long as Donald Trump or at least his elk like Steve Bannon, Sean Spicer or Jeff Sessions are still in office. Until then, expect more illustrations like this that poke fun at America's Islamophobic, racist, environment-polluting, fanatically-Christian, xenophobic, universal healthcare-threatening, Russia-loving and Holocaust-denying regime to pop up on social media. Carry on!
Friday, March 31, 2017
Just thought I'd share these pics that I took at STAPLES Center in Los Angeles two days ago—when I visited the new bronze statue of 4-time NBA champion Shaquille O'Neal that is now on display at Star Plaza outside the arena. The statue, which is 9-feet-tall and weighs 1,200 pounds, was unveiled before the Lakers' home game against the Minnesota Timberwolves on March 24 (the Lakers won that game in overtime, 130-119). It's only a matter of time till Kobe Bryant himself gets his own statue outside STAPLES Center...and I'll be dishin' out 7 dollars (like I did on Wednesday) for parking before I walk over to the stadium to see the Black Mamba immortalized at Star Plaza as well. Happy Friday!
Thursday, March 30, 2017
NASA / GSFC
NASA's MAVEN Reveals Most of Mars' Atmosphere Was Lost to Space (Press Release)
Solar wind and radiation are responsible for stripping the Martian atmosphere, transforming Mars from a planet that could have supported life billions of years ago into a frigid desert world, according to new results from NASA's MAVEN spacecraft.
"We've determined that most of the gas ever present in the Mars atmosphere has been lost to space," said Bruce Jakosky, principal investigator for the Mars Atmosphere and Volatile Evolution Mission (MAVEN), University of Colorado in Boulder. The team made this determination from the latest results, which reveal that about 65 percent of the argon that was ever in the atmosphere has been lost to space. Jakosky is lead author of a paper on this research to be published in Science on Friday, March 31.
In 2015, MAVEN team members previously announced results that showed atmospheric gas is being lost to space today and described how atmosphere is stripped away. The present analysis uses measurements of today’s atmosphere for the first estimate of how much gas was lost through time.
Liquid water, essential for life, is not stable on Mars' surface today because the atmosphere is too cold and thin to support it. However, evidence such as features resembling dry riverbeds and minerals that only form in the presence of liquid water indicates the ancient Martian climate was much different – warm enough for water to flow on the surface for extended periods.
“This discovery is a significant step toward unraveling the mystery of Mars' past environments,“ said Elsayed Talaat, MAVEN Program Scientist, at NASA Headquarters in Washington. “In a broader context, this information teaches us about the processes that can change a planet’s habitability over time.”
There are many ways a planet can lose some of its atmosphere. For example, chemical reactions can lock gas away in surface rocks, or an atmosphere can be eroded by radiation and a stellar wind from a planet's parent star. The new result reveals that solar wind and radiation were responsible for most of the atmospheric loss on Mars, and the depletion was enough to transform the Martian climate. The solar wind is a thin stream of electrically conducting gas constantly blowing out from the surface of the Sun.
The early Sun had far more intense ultraviolet radiation and solar wind, so atmospheric loss by these processes was likely much greater in Mars' history. According to the team, these processes may have been the dominant ones controlling the planet's climate and habitability. It's possible microbial life could have existed at the surface early in Mars’ history. As the planet cooled off and dried up, any life could have been driven underground or forced into rare surface oases.
Jakosky and his team got the new result by measuring the atmospheric abundance of two different isotopes of argon gas. Isotopes are atoms of the same element with different masses. Since the lighter of the two isotopes escapes to space more readily, it will leave the gas remaining behind enriched in the heavier isotope. The team used the relative abundance of the two isotopes measured in the upper atmosphere and at the surface to estimate the fraction of the atmospheric gas that has been lost to space.
As a "noble gas" argon cannot react chemically, so it cannot be sequestered in rocks; the only process that can remove noble gases into space is a physical process called "sputtering" by the solar wind. In sputtering, ions picked up by the solar wind can impact Mars at high speeds and physically knock atmospheric gas into space. The team tracked argon because it can be removed only by sputtering. Once they determined the amount of argon lost by sputtering, they could use this information to determine the sputtering loss of other atoms and molecules, including carbon dioxide (CO2).
CO2 is of interest because it is the major constituent of Mars' atmosphere and because it's an efficient greenhouse gas that can retain heat and warm the planet. "We determined that the majority of the planet's CO2 was also lost to space by sputtering," said Jakosky. "There are other processes that can remove CO2, so this gives the minimum amount of CO2 that's been lost to space."
The team made its estimate using data from the Martian upper atmosphere, which was collected by MAVEN's Neutral Gas and Ion Mass Spectrometer (NGIMS). This analysis included measurements from the Martian surface made by NASA's Sample Analysis at Mars (SAM) instrument on board the Curiosity rover.
"The combined measurements enable a better determination of how much Martian argon has been lost to space over billions of years," said Paul Mahaffy of NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Using measurements from both platforms points to the value of having multiple missions that make complementary measurements." Mahaffy, a co-author of the paper, is principal investigator on the SAM instrument and lead on the NGIMS instrument, both of which were developed at NASA Goddard.
The research was funded by the MAVEN mission. MAVEN's principal investigator is based at the University of Colorado's Laboratory for Atmospheric and Space Physics, Boulder, and NASA Goddard manages the MAVEN project. MSL/Curiosity is managed by NASA's Jet Propulsion Laboratory, Pasadena, California.
Monday, March 27, 2017
NASA / JPL - Caltech / SwRI / MSSS / Roman Tkachenko
Dark Spot and Jovian ‘Galaxy’ (News Release)
This enhanced-color image of a mysterious dark spot on Jupiter seems to reveal a Jovian “galaxy” of swirling storms.
Juno acquired this JunoCam image on Feb. 2, 2017, at 5:13 a.m. PDT (8:13 a.m. EDT), at an altitude of 9,000 miles (14,500 kilometers) above the giant planet’s cloud tops. This publicly selected target was simply titled “Dark Spot.” In ground-based images it was difficult to tell that it is a dark storm.
Citizen scientist Roman Tkachenko enhanced the color to bring out the rich detail in the storm and surrounding clouds. Just south of the dark storm is a bright, oval-shaped storm with high, bright, white clouds, reminiscent of a swirling galaxy. As a final touch, he rotated the image 90 degrees, turning the picture into a work of art.
JunoCam's raw images are available at www.missionjuno.swri.edu/junocam for the public to peruse and process into image products.
Friday, March 24, 2017
Despite having seven years to craft an alternative healthcare bill that wouldn't suck, the GOP dropped the ball anyway when it couldn't muster enough votes needed to pass the American Health Care Act (AHCA) earlier today. I would like to thank the Freedom Caucus (an ultra-conservative group of Republicans in the House of Representatives) for being so heartless in their attempt to strip away components of AHCA that would provide basic medical needs to pregnant women and sick individuals that sensible Republicans (yes, I too can't believe that such a group exists in the U.S. government) couldn't support the legislation if the Freedom Caucus had its way. I would also like to thank Donald Trump for undermining his presidency by not being able to repeal and replace the Affordable Care Act (a.k.a. Obamacare) 64 days after he was sworn into the White House...despite saying during his presidential campaign that he would accomplish the feat on Day One of his first (and only?) term in office. And House Speaker Paul Ryan showed that he is as ineffective a leader in his party as he is a spineless patsy to Trump.
NASA / Bill Ingalls
But if I'm gonna say some nice things about Trump, it's that at least he signed the NASA Transition Authorization Act of 2017 last Tuesday. This bill calls for a $19.5 billion budget for NASA in 2018...which supports the Europa Clipper mission to Jupiter, the Mars 2020 rover that is Curiosity's successor, and a manned mission to the Red Planet by 2033. So thanks to Obamacare being left intact (and in Paul Ryan's words, remaining "the law of the land"), 24 million Americans who would've lost their health coverage under AHCA by 2026 will (hopefully) be alive to see humans set foot on (or at least orbit) the Red Planet in a little over 15 years! Awesome.
And of course, thanks to the demise of AHCA, I'll still be able to take medication without any issues for the illness, known as Valley Fever (or Coccidioidomycosis), that I contracted five years ago. To the Republican Party: Your utter incompetence saved the lives of many Americans today...including possibly mine. Thank you.
Wednesday, March 22, 2017
NASA / JPL - Caltech / UCLA / MPS / DLR / IDA
Ice in Ceres' Shadowed Craters Linked to Tilt History (News Release)
Dwarf planet Ceres may be hundreds of millions of miles from Jupiter, and even farther from Saturn, but the tremendous influence of gravity from these gas giants has an appreciable effect on Ceres' orientation. In a new study, researchers from NASA's Dawn mission calculate that the axial tilt of Ceres -- the angle at which it spins as it journeys around the Sun -- varies widely over the course of about 24,500 years. Astronomers consider this to be a surprisingly short period of time for such dramatic deviations.
Changes in axial tilt, or "obliquity," over the history of Ceres are related to the larger question of where frozen water can be found on Ceres' surface, scientists report in the journal Geophysical Research Letters. Given conditions on Ceres, ice would only be able to survive at extremely cold temperatures -- for example, in areas that never see the Sun.
"We found a correlation between craters that stay in shadow at maximum obliquity, and bright deposits that are likely water ice," said Anton Ermakov, postdoctoral researcher at NASA's Jet Propulsion Laboratory, Pasadena, California, and lead author of the study. "Regions that never see sunlight over millions of years are more likely to have these deposits."
Cycles of Obliquity
Throughout the last 3 million years, Ceres has gone through cycles where its tilt ranges from about 2 degrees to about 20 degrees, calculations indicate.
"We cannot directly observe the changes in Ceres' orientation over time, so we used the Dawn spacecraft's measurements of shape and gravity to precisely reconstruct what turned out to be a dynamic history," said Erwan Mazarico, a co-author at NASA's Goddard Space Flight Center in Greenbelt, Maryland.
The last time the dwarf planet reached a maximum tilt, which was about 19 degrees, was 14,000 years ago, researchers said. For comparison, Earth is tilted 23.5 degrees. This significant tilt causes our planet to experience seasons: The northern hemisphere experiences summer when it is oriented toward the Sun, and winter when it's pointed away from the Sun. By contrast, Ceres' current tilt is about 4 degrees, so it will not have such strong seasonal effects over the course of a year there (which is about 4.6 Earth years).
How Obliquity Relates to Ice
When the axial tilt is small, relatively large regions on Ceres never receive direct sunlight, particularly at the poles. These persistently shadowed regions occupy an area of about 800 square miles (2,000 square kilometers). But when the obliquity increases, more of the craters in the polar regions receive direct exposure to the Sun, and persistently shadowed areas only occupy 0.4 to 4 square miles (1 to 10 square kilometers). These areas on Ceres' surface, which stay in shadow even at high obliquity, may be cold enough to maintain surface ice, Dawn scientists said.
These craters with areas that stay in shadow over long periods of time are called "cold traps," because they are so cold and dark that volatiles -- substances easily vaporized -- that migrate into these areas can't escape, even over a billion years. A 2016 study by the Dawn team in Nature Astronomy found bright material in 10 of these craters, and data from Dawn's visible and infrared mapping spectrometer indicate that one of them contains ice.
The new study focused on polar craters and modeled how shadowing progresses as Ceres' axial tilt varies. In the northern hemisphere, only two persistently shadowed regions remain in shadow at the maximum 20-degree tilt. Both of these regions have bright deposits today. In the southern hemisphere, there are also two persistently shadowed regions at highest obliquity, and one of them clearly has a bright deposit.
Shadowed Regions in Context
Ceres is the third body in the solar system found to have permanently shadowed regions. Mercury and Earth's Moon are the other two, and scientists believe they received their ice from impacting bodies. However, Mercury and the Moon do not have such wide variability in their tilts because of the stabilizing gravitational influence of the Sun and Earth, respectively. The origin of the ice in Ceres' cold traps is more mysterious -- it may come from Ceres itself, or may be delivered by impacts from asteroids and comets. Regardless, the presence of ice in cold traps could be related to a tenuous water atmosphere, which was detected by ESA's Herschel Space Observatory in 2012-13. Water molecules that leave the surface would fall back onto Ceres, with some landing in cold traps and accumulating there.
"The idea that ice could survive on Ceres for long periods of time is important as we continue to reconstruct the dwarf planet's geological history, including whether it has been giving off water vapor," said Carol Raymond, deputy principal investigator of the Dawn mission and study co-author, based at JPL.
Dawn's mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.
Source: Jet Propulsion Laboratory
Friday, March 17, 2017
Happy St. Patrick's Day! Just thought I'd share these photos that I took of the Shamrock Shake that I bought at McDonald's a little over two weeks ago. It's totally delicious! I've been meaning to try out this minty beverage since 2012...but was unable to due to this unfortunate situation that I was in during March of that year. Well, better late than never!
Thursday, March 16, 2017
ESA / AOESImage
ESA’s Jupiter Mission Moves Off the Drawing Board (Press Release)
Demanding electric, magnetic and power requirements, harsh radiation, and strict planetary protection rules are some of the critical issues that had to be tackled in order to move ESA’s Jupiter Icy Moons Explorer – Juice – from the drawing board and into construction.
Scheduled for launch in 2022, with arrival in the Jovian system in 2029, Juice will spend three-and-a-half years examining the giant planet’s turbulent atmosphere, enormous magnetosphere, its set of tenuous dark rings and its satellites.
It will study the large icy moons Ganymede, Europa and Callisto, which are thought to have oceans of liquid water beneath their icy crusts – perhaps even harbouring habitable environments.
The mission will culminate in a dedicated, eight-month tour around Ganymede, the first time any moon beyond our own has been orbited by a spacecraft.
Juice will be equipped with 10 state-of-the-art instruments, including cameras, an ice-penetrating radar, an altimeter, radio-science experiments, and sensors to monitor the magnetic fields and charged particles in the Jovian system.
In order to ensure it can address these goals in the challenging Jovian environment, the spacecraft’s design has to meet stringent requirements.
An important milestone was reached earlier this month, when the preliminary design of Juice and its interfaces with the scientific instruments and the ground stations were fixed, which will now allow a prototype spacecraft to be built for rigorous testing.
The review also confirmed that the 5.3 tonne spacecraft will be compatible with its Ariane 5 launcher.
Operating in the outer Solar System, far from the Sun, means that Juice needs a large solar array: two wings of five panels each are foreseen, which will cover a total surface area of nearly 100 square metres, capable of providing 820 Watts at Jupiter by the end of the mission.
After launch, Juice will make five gravity-assist flybys in total: one each at Mars and Venus, and three at Earth, to set it on course for Jupiter. Its solar panels will have to cope with a range of temperatures such that when it is flying closer to the Sun during the Venus flyby, the solar wings will be tilted to avoid excessive temperatures damaging the solar cells.
The spacecraft’s main engine will be used to enter orbit around the giant planet, and later around Jupiter’s largest moon, Ganymede. As such, the engine design has also been critically reviewed at this stage.
Special measures will allow Juice to cope with the extremely harsh radiation that it must endure for several years around Jupiter. This means careful selection of components and materials, as well as radiation shielding.
One particularly important topic is Juice’s electromagnetic ‘cleanliness’. Because a key goal is to monitor the magnetic fields and charged particles at Jupiter, it is imperative that any electromagnetic fields generated by the spacecraft itself do not interfere with the sensitive scientific measurements.
This will be achieved by the careful design of the solar array electrical architecture, the power distribution unit, and the reaction wheels – a type of flywheel that stabilises the attitude.
The review also ensured that Juice will meet strict planetary protection guidelines, because it is imperative to minimise the risk that the potentially habitable ocean moons, particularly Europa, might be contaminated by viruses, bacteria or spores carried by the spacecraft from Earth. Therefore, mission plans ensure that Juice will not crash into Europa, on a timescale of hundreds of years.
“The spacecraft design has been extensively and positively reviewed, and confirmed to address the many critical mission requirements,” says Giuseppe Sarri, Juice project manager. “So far we are on schedule, and are delighted to begin the development stage of this ambitious large-class mission.”
ESA’s industrial partners, led by Airbus, now have the go-ahead to start building the prototype spacecraft units that will subjected to tough tests to simulate the conditions expected during launch, as well as the extreme range of environmental conditions.
Once the design is proved beyond doubt, the flight model – the one that will actually go into space – will be built.
Source: European Space Agency
Sunday, March 12, 2017
Yesterday, I went to The Grove near Beverly Hills to attend a discussion and book signing by Lily Collins...the daughter of music legend Phil Collins and an up-and-coming actress who appeared in such films as last year's Rules Don't Apply, 2013's The Mortal Instruments: City of Bones and the 2009 Oscar-nominated movie The Blind Side. Ms. Collins was totally awesome in person. She read an excerpt from her new book Unfiltered before giving her take on it and talking about what motivated her to write her first publication. Afterwards, she spent the next two hours signing copies of her book and taking pics with around 300 fans who drove to Barnes & Noble to see her in person. Some attendees even flew 2,000 miles to see Ms. Collins in Los Angeles... Pretty cool!
There are two other book signings that I plan to attend this May—but I won't mention the people appearing since I don't want to jinx these events. Carry on!
Friday, March 10, 2017
NASA / JPL - Caltech / Space Science Institute
Cassini Reveals Strange Shape of Saturn's Moon Pan (Press Release - March 9)
These raw, unprocessed images of Saturn's tiny moon, Pan, were taken on March 7, 2017, by NASA's Cassini spacecraft. The flyby had a close-approach distance of 24,572 kilometers (15,268 miles).
These images are the closest images ever taken of Pan and will help to characterize its shape and geology.
Additional raw images from Cassini are available at:
The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA's Jet Propulsion Laboratory in Pasadena, California, manages the mission for the agency's Science Mission Directorate in Washington. The Cassini imaging operations center is based at the Space Science Institute in Boulder, Colorado. Caltech in Pasadena manages JPL for NASA.
Source: Jet Propulsion Laboratory
NASA / JPL - Caltech / Space Science Institute
Thursday, March 09, 2017
NASA / JPL - Caltech
NASA Mission Named 'Europa Clipper' (News Release)
NASA's upcoming mission to investigate the habitability of Jupiter's icy moon Europa now has a formal name: Europa Clipper.
The moniker harkens back to the clipper ships that sailed across the oceans of Earth in the 19th century. Clipper ships were streamlined, three-masted sailing vessels renowned for their grace and swiftness. These ships rapidly shuttled tea and other goods back and forth across the Atlantic Ocean and around globe.
In the grand tradition of these classic ships, the Europa Clipper spacecraft would sail past Europa at a rapid cadence, as frequently as every two weeks, providing many opportunities to investigate the moon up close. The prime mission plan includes 40 to 45 flybys, during which the spacecraft would image the moon's icy surface at high resolution and investigate its composition and the structure of its interior and icy shell.
Europa has long been a high priority for exploration because it holds a salty liquid water ocean beneath its icy crust. The ultimate aim of Europa Clipper is to determine if Europa is habitable, possessing all three of the ingredients necessary for life: liquid water, chemical ingredients, and energy sources sufficient to enable biology.
"During each orbit, the spacecraft spends only a short time within the challenging radiation environment near Europa. It speeds past, gathers a huge amount of science data, then sails on out of there," said Robert Pappalardo, Europa Clipper project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California.
Previously, when the mission was still in the conceptual phase, it was sometimes informally called Europa Clipper, but NASA has now adopted that name as the former title for the mission.
The mission is being planned for launch in the 2020s, arriving in the Jupiter system after a journey of several years.
JPL manages the mission for the agency's Science Mission Directorate in Washington.
Tuesday, February 28, 2017
NASA / Goddard Space Flight Center
Just thought I'd end this month by pointing out that NASA is currently inviting the public to submit artwork (via e-mail) that will fly aboard the Transiting Exoplanet Survey Satellite (TESS)...which is scheduled to launch aboard SpaceX's Falcon 9 rocket from Florida in March of 2018. Click on this page for more details. Right now, there is no limit as to how many artwork you can submit to fly aboard TESS; this campaign either ends on November 20, 2017, or when the drive (Hard drive? Flash drive? The site doesn't say—though it's most likely the latter) that will carry the submissions reaches full capacity. The artwork below are the ones that I myself sent in as of today. I created a couple of more illustrations that I plan to submit over the next few weeks... I'll post them in a future Blog entry. If you have your own drawings to send into the cosmos, submit now!
Thursday, February 23, 2017
Lakers Name Earvin "Magic" Johnson President of Basketball Operations (Press Release - February 21)
Magic to run Lakers Basketball Front Office as part of restructuring.
LOS ANGELES -- Los Angeles Lakers Governor Jeanie Buss announced today that the team has named Earvin "Magic" Johnson as President of Basketball Operations. In addition, General Manager Mitch Kupchak has been relieved of his duties, effective immediately. Furthermore, Jim Buss will no longer hold his role as Lakers Executive Vice President of Basketball Operations.
"Today I took a series of actions I believe will return the Lakers to the heights Dr. Jerry Buss demanded and our fans rightly expect," Jeanie Buss said. "Effective immediately, Earvin Johnson will be in charge of all basketball operations and will report directly to me. Our search for a new General Manager to work with Earvin and Coach Luke Walton is well underway and we hope to announce a new General Manager in short order. Together, Earvin, Luke and our new General Manager will establish the foundation for the next generation of Los Angeles Lakers greatness."
"It's a dream come true to return to the Lakers as President of Basketball Operations working closely with Jeanie Buss and the Buss family," said Earvin "Magic" Johnson. "Since 1979, I've been a part of the Laker Nation and I'm passionate about this organization. I will do everything I can to build a winning culture on and off the court. We have a great coach in Luke Walton and good young players. We will work tirelessly to return our Los Angeles Lakers to NBA champions."
Jeanie Buss added, "I took these actions today to achieve one goal: Everyone associated with the Lakers will now be pulling in the same direction, the direction established by Earvin and myself. We are determined to get back to competing to win NBA championships again."
Regarding Mitch Kupchak, Jeanie Buss stated, "We are grateful for the many contributions Mitch has made to the Lakers over the years and we wish him all the best."
With regard to fellow owner and brother, Jim Buss, Ms. Buss said, "Jim loves the Lakers. Although he will no longer be responsible for basketball personnel decisions, he is an owner of this team and we share the same goal: returning the Lakers to the level of greatness our father demanded. Our fans deserve no less."
In addition to the changes made within the basketball department, the Lakers also announced they have parted ways with John Black who had been the Lakers Vice President of Public Relations. Chief Operating Officer Tim Harris will immediately begin a search for a replacement. Jeanie Buss added, "We thank John for his many years of service."
Wednesday, February 22, 2017
(Three Earth-Like Worlds with Liquid Water on Them? Yes, Please!) NASA Announces a Stellar Exoplanet Discovery...
NASA / JPL - Caltech
NASA Telescope Reveals Largest Batch of Earth-Size, Habitable-Zone Planets Around Single Star (Press Release)
NASA's Spitzer Space Telescope has revealed the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in the habitable zone, the area around the parent star where a rocky planet is most likely to have liquid water.
The discovery sets a new record for greatest number of habitable-zone planets found around a single star outside our solar system. All of these seven planets could have liquid water – key to life as we know it – under the right atmospheric conditions, but the chances are highest with the three in the habitable zone.
“This discovery could be a significant piece in the puzzle of finding habitable environments, places that are conducive to life,” said Thomas Zurbuchen, associate administrator of the agency’s Science Mission Directorate in Washington. “Answering the question ‘are we alone’ is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step forward toward that goal.”
At about 40 light-years (235 trillion miles) from Earth, the system of planets is relatively close to us, in the constellation Aquarius. Because they are located outside of our solar system, these planets are scientifically known as exoplanets.
This exoplanet system is called TRAPPIST-1, named for The Transiting Planets and Planetesimals Small Telescope (TRAPPIST) in Chile. In May 2016, researchers using TRAPPIST announced they had discovered three planets in the system. Assisted by several ground-based telescopes, including the European Southern Observatory's Very Large Telescope, Spitzer confirmed the existence of two of these planets and discovered five additional ones, increasing the number of known planets in the system to seven.
The new results were published Wednesday in the journal Nature, and announced at a news briefing at NASA Headquarters in Washington.
Using Spitzer data, the team precisely measured the sizes of the seven planets and developed first estimates of the masses of six of them, allowing their density to be estimated.
Based on their densities, all of the TRAPPIST-1 planets are likely to be rocky. Further observations will not only help determine whether they are rich in water, but also possibly reveal whether any could have liquid water on their surfaces. The mass of the seventh and farthest exoplanet has not yet been estimated – scientists believe it could be an icy, "snowball-like" world, but further observations are needed.
"The seven wonders of TRAPPIST-1 are the first Earth-size planets that have been found orbiting this kind of star," said Michael Gillon, lead author of the paper and the principal investigator of the TRAPPIST exoplanet survey at the University of Liege, Belgium. "It is also the best target yet for studying the atmospheres of potentially habitable, Earth-size worlds."
In contrast to our sun, the TRAPPIST-1 star – classified as an ultra-cool dwarf – is so cool that liquid water could survive on planets orbiting very close to it, closer than is possible on planets in our solar system. All seven of the TRAPPIST-1 planetary orbits are closer to their host star than Mercury is to our sun. The planets also are very close to each other. If a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth's sky.
The planets may also be tidally locked to their star, which means the same side of the planet is always facing the star, therefore each side is either perpetual day or night. This could mean they have weather patterns totally unlike those on Earth, such as strong winds blowing from the day side to the night side, and extreme temperature changes.
Spitzer, an infrared telescope that trails Earth as it orbits the sun, was well-suited for studying TRAPPIST-1 because the star glows brightest in infrared light, whose wavelengths are longer than the eye can see. In the fall of 2016, Spitzer observed TRAPPIST-1 nearly continuously for 500 hours. Spitzer is uniquely positioned in its orbit to observe enough crossing – transits – of the planets in front of the host star to reveal the complex architecture of the system. Engineers optimized Spitzer’s ability to observe transiting planets during Spitzer’s “warm mission,” which began after the spacecraft’s coolant ran out as planned after the first five years of operations.
"This is the most exciting result I have seen in the 14 years of Spitzer operations," said Sean Carey, manager of NASA's Spitzer Science Center at Caltech/IPAC in Pasadena, California. "Spitzer will follow up in the fall to further refine our understanding of these planets so that the James Webb Space Telescope can follow up. More observations of the system are sure to reveal more secrets.”
Following up on the Spitzer discovery, NASA's Hubble Space Telescope has initiated the screening of four of the planets, including the three inside the habitable zone. These observations aim at assessing the presence of puffy, hydrogen-dominated atmospheres, typical for gaseous worlds like Neptune, around these planets.
In May 2016, the Hubble team observed the two innermost planets, and found no evidence for such puffy atmospheres. This strengthened the case that the planets closest to the star are rocky in nature.
"The TRAPPIST-1 system provides one of the best opportunities in the next decade to study the atmospheres around Earth-size planets," said Nikole Lewis, co-leader of the Hubble study and astronomer at the Space Telescope Science Institute in Baltimore, Maryland. NASA's planet-hunting Kepler space telescope also is studying the TRAPPIST-1 system, making measurements of the star's minuscule changes in brightness due to transiting planets. Operating as the K2 mission, the spacecraft's observations will allow astronomers to refine the properties of the known planets, as well as search for additional planets in the system. The K2 observations conclude in early March and will be made available on the public archive.
Spitzer, Hubble, and Kepler will help astronomers plan for follow-up studies using NASA's upcoming James Webb Space Telescope, launching in 2018. With much greater sensitivity, Webb will be able to detect the chemical fingerprints of water, methane, oxygen, ozone, and other components of a planet's atmosphere. Webb also will analyze planets' temperatures and surface pressures – key factors in assessing their habitability.
NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate. Science operations are conducted at the Spitzer Science Center, at Caltech, in Pasadena, California. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at Caltech/IPAC. Caltech manages JPL for NASA.
NASA / JPL - Caltech
Tuesday, February 21, 2017
NASA / JPL - Caltech
NASA's Europa Flyby Mission Moves into Design Phase (News Release)
A mission to examine the habitability of Jupiter's ocean-bearing moon Europa is taking one step closer to the launch pad, with the recent completion of a major NASA review.
On Feb. 15, NASA's Europa multiple-flyby mission successfully completed its Key Decision Point-B review. This NASA decision permits the mission to move forward into its preliminary design phase, known as "Phase B," beginning on Feb. 27.
A highlight of Phase A was the selection and accommodation of 10 instruments being developed to study the scientific mysteries of Europa. The new mission phase is planned to continue through September 2018, and will result in the completion of a preliminary design for the mission's systems and subsystems. Some testing of spacecraft components, including solar cells and science instrument detectors, has already been underway during Phase A, and this work is planned to continue into Phase B.
In addition, during Phase B subsystem vendors will be selected, as well as prototype hardware elements for the science instruments. Spacecraft subassemblies will be built and tested as well.
The Europa mission spacecraft is being planned for launch in the 2020s, arriving in the Jupiter system after a journey of several years. The spacecraft would orbit Jupiter as frequently as every two weeks, providing many opportunities for close flybys of Europa. The mission plan includes 40 to 45 flybys in the prime mission, during which the spacecraft would image the moon's icy surface at high resolution and investigate its composition and the structure of its interior and icy shell.
The life cycle of a NASA science mission includes several key phases. At each step, missions must successfully demonstrate that they have met the agency's requirements in order to indicate readiness to move forward into the next phase. Phase B includes preliminary design work, while phases C and D include final design, spacecraft fabrication, assembly and testing, and launch.
Sunday, February 19, 2017
USAF / R. Nial Bradshaw
F-35A Stealth Brings Flexibility to Battlespace (News Release - February 13)
NELLIS AIR FORCE BASE, Nev. (AFNS) -- Stealth isn’t new in the Air Force; but, stealth combined with the multirole capabilities of the F-35A Lightning II is proving to be a game changer in the Nevada desert.
Units from across the Air Force have converged here for Red Flag 17-1, the Air Force’s premier air combat exercise, which pits a friendly force against an aggressor force in scenarios designed to give pilots true-to-life experiences before heading into actual combat.
Military strategists have long noted that while the United States has invested heavily in combat aircraft technology, potential adversaries have pushed their capital toward advanced surface-to-air missiles in integrated air defense systems. Planners say any realistic large-force exercise must test the Air Force’s ability to survive and suppress these sophisticated systems.
That is what the Airmen of the 388th and 419th Fighter Wings from Hill Air Force Base, Utah, bring to the fight with the combat-capable F-35A.
“During this Red Flag we’re training against the highest level threats we know exist,” said Lt. Col. George Watkins, the 34th Fighter Squadron commander. “Just as we’re getting new systems and technology, the adversary’s threats are becoming more sophisticated and capable.”
Fourth-generation aircraft, such as the F-16 Fighting Falcon, F-15 Eagle, F/A-18 Hornet, A-10 Thunderbolt II and others, cannot operate in an environment where they are targeted by advanced anti-air systems with sophisticated radar and infrared capabilities.
Red Flag planners are tasking the F-35A with taking out these threats and the aircraft’s stealth capability is proving pilots can survive and operate effectively where others cannot.
“I flew a mission the other day where our four-ship formation of F-35As destroyed five surface-to-air threats in a 15-minute period without being targeted once,” said Maj. James Schmidt, a former A-10 pilot. “It’s pretty cool to come back from a mission where we flew right over threats knowing they could never see us.”
In past Red Flags, the friendly force did not have the capability to directly target advanced surface-to-air missile threats with an aircraft like the F-35A. Exercise planners would engage the targets with long range “standoff” weapons – like Tomahawk missiles – before sending aircraft in to the fight.
“We would shoot everything we had at that one threat just to take it out. Now between us and the (F-22) Raptor, we are able to geo-locate them and precision target them.” Watkins said. “With the stealth capability of the F-35A we can get close enough to put a bomb right on them. That would be impossible with a fourth-generation aircraft.”
After taking out the ground threats, the multirole F-35A is able to “pitch back into the fight” with air-to-air missiles, taking out aircraft that don’t even know they’re there, Schmidt said.
This is the largest exercise to date for the combat pilots of Hill’s 34th Fighter Squadron and they’re learning to believe in what the multirole fighter can do in combat, said Maj. Shad Stromberg, a 419th FW Reserve F-35 pilot.
“After almost every mission, we shake our heads and smile, saying 'We can't believe we just did that',” Schmidt said. “We flew right into the heart of the threat and were able to bring all of our jets back out with successful strikes. It's like we hit the 'I Believe' button again after every sortie.”
Source: Nellis Air Force Base