Thursday, January 30, 2020

NASA Makes Way for the James Webb Space Telescope as a 'Great Observatory' Goes Silent...

An artist's concept of NASA's Spitzer Space Telescope gazing at the heavens while floating through deep space.
NASA / JPL - Caltech

NASA’s Spitzer Space Telescope Ends Mission of Astronomical Discovery (Press Release)

After more than 16 years studying the universe in infrared light, revealing new wonders in our solar system, our galaxy, and beyond, NASA's Spitzer Space Telescope's mission has come to an end.

Mission engineers confirmed at 2:30 p.m. PST (5:30 p.m. EST) Thursday the spacecraft was placed in safe mode, ceasing all science operations. After the decommissioning was confirmed, Spitzer Project Manager Joseph Hunt declared the mission had officially ended.

Launched in 2003, Spitzer was one of NASA's four Great Observatories, along with the Hubble Space Telescope, the Chandra X-ray Observatory and the Compton Gamma Ray Observatory. The Great Observatories program demonstrated the power of using different wavelengths of light to create a fuller picture of the universe.

"Spitzer has taught us about entirely new aspects of the cosmos and taken us many steps further in understanding how the universe works, addressing questions about our origins, and whether or not are we alone," said Thomas Zurbuchen, associate administrator of NASA's Science Mission Directorate in Washington. "This Great Observatory has also identified some important and new questions and tantalizing objects for further study, mapping a path for future investigations to follow. Its immense impact on science certainly will last well beyond the end of its mission."

Among its many scientific contributions, Spitzer studied comets and asteroids in our own solar system and found a previously unidentified ring around Saturn. It studied star and planet formation, the evolution of galaxies from the ancient universe to today, and the composition of interstellar dust. It also proved to be a powerful tool for detecting exoplanets and characterizing their atmospheres. Spitzer's best-known work may be detecting the seven Earth-size planets in the TRAPPIST-1 system – the largest number of terrestrial planets ever found orbiting a single star – and determining their masses and densities.

In 2016, following a review of operating astrophysics missions, NASA made a decision to close out the Spitzer mission in 2018 in anticipation of the launch of the James Webb Space Telescope, which also will observe the universe in infrared light. When Webb's launch was postponed, Spitzer was granted an extension to continue operations until this year. This gave Spitzer additional time to continue producing transformative science, including insights that will pave the way for Webb, which is scheduled to launch in 2021.

"Everyone who has worked on this mission should be extremely proud today," Hunt said. "There are literally hundreds of people who contributed directly to Spitzer's success, and thousands who used its scientific capabilities to explore the universe. We leave behind a powerful scientific and technological legacy."

Keeping Cool

Though it was not NASA's first space-based infrared telescope, Spitzer was the most sensitive infrared telescope in history when it launched, and it delivered a deeper and more far-reaching view of the infrared cosmos than its predecessors. Above Earth's atmosphere, Spitzer could detect some wavelengths that cannot be observed from the ground. The spacecraft's Earth-trailing orbit placed it far away from our planet's infrared emissions, which also gave Spitzer better sensitivity than was possible for larger telescopes on Earth.

Spitzer's prime mission came to an end in 2009, when the telescope exhausted its supply of the liquid helium coolant necessary for operating two of its three instruments – the Infrared Spectrograph (IRS) and Multiband Imaging Photometer for Spitzer (MIPS). The mission was deemed a success, having achieved all of its primary science objectives and more. But Spitzer's story wasn't over. Engineers and scientists were able to keep the mission going using only two out of four wavelength channels on the third instrument, the Infrared Array Camera (IRAC). Despite increasing engineering and operations challenges, Spitzer continued to produce transformational science for another 10 1/2 years – far longer than mission planners anticipated.

During its extended mission, Spitzer continued to make significant scientific discoveries. In 2014, it detected evidence of asteroid collisions in a newly formed planetary system, providing evidence that such smash-ups might be common in early solar systems and crucial to the formation of some planets. In 2016, Spitzer worked with Hubble to image the most distant galaxy ever detected. From 2016 onward, Spitzer studied the TRAPPIST-1 system for more than 1,000 hours. All of Spitzer's data are free and available to the public in the Spitzer data archive. Mission scientists say they expect researchers to continue making discoveries with Spitzer long after the spacecraft’s decommissioning.

"I think that Spitzer is an example of the very best that people can achieve," said Spitzer Project Scientist Michael Werner. "I feel very fortunate to have worked on this mission, and to have seen the ingenuity, doggedness and brilliance that people on the team showed. When you tap into those things and empower people to use them, then truly incredible things will happen."

NASA's Jet Propulsion Laboratory (JPL) near Pasadena, California, conducts mission operations and manages the Spitzer Space Telescope mission for the agency's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena. Spacecraft operations are based at Lockheed Martin Space in Littleton, Colorado. Data are archived at the Infrared Science Archive housed at IPAC at Caltech. Caltech manages JPL for NASA.

Lockheed Martin in Sunnyvale, California, built the Spitzer spacecraft, and during development served as lead for systems and engineering, and integration and testing. Ball Aerospace and Technologies Corporation in Boulder, Colorado provided the optics, cryogenics and thermal shells and shields for Spitzer.

Ball developed the IRS instrument, with science leadership based at Cornell University, and the MIPS instrument, with science leadership based at the University of Arizona in Tucson. NASA's Goddard Space Flight Center in Greenbelt, Maryland, developed the IRAC instrument, with science leadership based at the Harvard Smithsonian Astrophysics Observatory in Cambridge, Massachusetts.​

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Inside the Space Flight Operations Facility at NASA's Jet Propulsion Laboratory near Pasadena, California, project members applaud after the mission came to an end on January 30, 2020.
NASA / JPL - Caltech

Sunday, January 26, 2020

ABSOLUTELY DEVASTATED.

As his wife and two daughters stand nearby, Kobe Bryant hoists up the NBA championship trophy after he leads the Los Angeles Lakers to its 15th title, on June 14, 2009.
Getty Images

Rest In Peace, Kobe. It was an honor meeting you at The Grove in Los Angeles back on October 23, 2018. It is totally surreal and heartbreaking that you are no longer with us. May you, your beautiful daughter Gianna, and the seven other wonderful people you were with when today's unthinkable tragedy took place now look down upon us from Heaven. We will surely continue to look up to you as a legend whose legacy will forever transcend the sport of basketball. Mamba out.

Posing with Kobe Bryant during a photo op inside Barnes & Noble bookstore at The Grove in Los Angeles...on October 23, 2018.

Monday, January 13, 2020

Photo of the Day: VIPER's Engineering Model Goes Through the Motions...

Two technicians look on as an engineering model of NASA's VIPER lunar rover is tested at NASA's Glenn Research Center in Cleveland, Ohio.
NASA / Bridget Caswell, Alcyon Technical Services

NASA’s New Moon Rover Tested in Lunar Operations Lab (News Release)

An engineering model of the Volatiles Investigating Polar Exploration Rover, or VIPER, is tested in the Simulated Lunar Operations Laboratory at NASA’s Glenn Research Center in Cleveland, Ohio. About the size of a golf cart, VIPER is a mobile robot that will roam around the Moon’s South Pole looking for water ice in the region and for the first time ever, actually sample the water ice at the same pole where the first woman and next man will land in 2024 under the Artemis program.

The large, adjustable soil bin contains lunar simulant and allows engineers to mimic the Moon’s terrain. Engineers from NASA’s Johnson Space Center in Houston, where the rover was designed and built, joined the Glenn team to complete the tests. Test data will be used to evaluate the traction of the vehicle and wheels, determine the power requirements for a variety of maneuvers and compare methods of traversing steep slopes. Respirators are worn by researchers to protect against the airborne silica that is present during testing.

VIPER is a collaboration within and beyond the agency. NASA's Ames Research Center in Silicon Valley is managing the project, leading the mission’s science, systems engineering, real-time rover surface operations and software. The rover’s instruments are provided by Ames, NASA’s Kennedy Space Center in Florida and commercial partner, Honeybee Robotics in California. The spacecraft, lander and launch vehicle that will deliver VIPER to the surface of the Moon will be provided through NASA’s Commercial Lunar Payload Services program, delivering science and technology payloads to and near the Moon.  

Source: NASA.Gov

Tuesday, January 07, 2020

TESS Update #2: Kepler's Successor Finds Its First Potentially-Habitable Exoplanet...

An artist's concept of three exoplanets orbiting within the TOI 700 star system.
NASA's Goddard Space Flight Center / Chris Smith

NASA Planet Hunter Finds its 1st Earth-size Habitable-zone World (News Release - January 6)

NASA’s Transiting Exoplanet Survey Satellite (TESS) has discovered its first Earth-size planet in its star’s habitable zone, the range of distances where conditions may be just right to allow the presence of liquid water on the surface. Scientists confirmed the find, called TOI 700 d, using NASA’s Spitzer Space Telescope and have modeled the planet’s potential environments to help inform future observations.

TOI 700 d is one of only a few Earth-size planets discovered in a star's habitable zone so far. Others include several planets in the TRAPPIST-1 system and other worlds discovered by NASA’s Kepler Space Telescope.

“TESS was designed and launched specifically to find Earth-sized planets orbiting nearby stars,” said Paul Hertz, astrophysics division director at NASA Headquarters in Washington. “Planets around nearby stars are easiest to follow-up with larger telescopes in space and on Earth. Discovering TOI 700 d is a key science finding for TESS. Confirming the planet’s size and habitable zone status with Spitzer is another win for Spitzer as it approaches the end of science operations this January."

TESS monitors large swaths of the sky, called sectors, for 27 days at a time. This long stare allows the satellite to track changes in stellar brightness caused by an orbiting planet crossing in front of its star from our perspective, an event called a transit.

TOI 700 is a small, cool M dwarf star located just over 100 light-years away in the southern constellation Dorado. It’s roughly 40% of the Sun’s mass and size and about half its surface temperature. The star appears in 11 of the 13 sectors TESS observed during the mission’s first year, and scientists caught multiple transits by its three planets.

The star was originally misclassified in the TESS database as being more similar to our Sun, which meant the planets appeared larger and hotter than they really are. Several researchers, including Alton Spencer, a high school student working with members of the TESS team, identified the error.

“When we corrected the star’s parameters, the sizes of its planets dropped, and we realized the outermost one was about the size of Earth and in the habitable zone,” said Emily Gilbert, a graduate student at the University of Chicago. “Additionally, in 11 months of data we saw no flares from the star, which improves the chances TOI 700 d is habitable and makes it easier to model its atmospheric and surface conditions.”

Gilbert and other researchers presented the findings at the 235th meeting of the American Astronomical Society in Honolulu, and three papers — one of which Gilbert led — have been submitted to scientific journals.

The innermost planet, called TOI 700 b, is almost exactly Earth-size, is probably rocky and completes an orbit every 10 days. The middle planet, TOI 700 c, is 2.6 times larger than Earth — between the sizes of Earth and Neptune — orbits every 16 days and is likely a gas-dominated world. TOI 700 d, the outermost known planet in the system and the only one in the habitable zone, measures 20% larger than Earth, orbits every 37 days and receives from its star 86% of the energy that the Sun provides to Earth. All of the planets are thought to be tidally locked to their star, which means they rotate once per orbit so that one side is constantly bathed in daylight.

A team of scientists led by Joseph Rodriguez, an astronomer at the Center for Astrophysics | Harvard & Smithsonian in Cambridge, Massachusetts, requested follow-up observations with Spitzer to confirm TOI 700 d.

“Given the impact of this discovery — that it is TESS’s first habitable-zone Earth-size planet — we really wanted our understanding of this system to be as concrete as possible,” Rodriguez said. “Spitzer saw TOI 700 d transit exactly when we expected it to. It’s a great addition to the legacy of a mission that helped confirm two of the TRAPPIST-1 planets and identify five more.”

The Spitzer data increased scientists’ confidence that TOI 700 d is a real planet and sharpened their measurements of its orbital period by 56% and its size by 38%. It also ruled out other possible astrophysical causes of the transit signal, such as the presence of a smaller, dimmer companion star in the system.

Rodriguez and his colleagues also used follow-up observations from a 1-meter ground-based telescope in the global Las Cumbres Observatory network to improve scientists’ confidence in the orbital period and size of TOI 700 c by 30% and 36%, respectively.

Because TOI 700 is bright, nearby, and shows no sign of stellar flares, the system is a prime candidate for precise mass measurements by current ground-based observatories. These measurements could confirm scientists’ estimates that the inner and outer planets are rocky and the middle planet is made of gas.

Future missions may be able to identify whether the planets have atmospheres and, if so, even determine their compositions.

While the exact conditions on TOI 700 d are unknown, scientists can use current information, like the planet’s size and the type of star it orbits, to generate computer models and make predictions. Researchers at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, modeled 20 potential environments of TOI 700 d to gauge if any version would result in surface temperatures and pressures suitable for habitability.

Their 3D climate models examined a variety of surface types and atmospheric compositions typically associated with what scientists regard to be potentially habitable worlds. Because TOI 700 d is tidally locked to its star, the planet’s cloud formations and wind patterns may be strikingly different from Earth’s.

One simulation included an ocean-covered TOI 700 d with a dense, carbon-dioxide-dominated atmosphere similar to what scientists suspect surrounded Mars when it was young. The model atmosphere contains a deep layer of clouds on the star-facing side. Another model depicts TOI 700 d as a cloudless, all-land version of modern Earth, where winds flow away from the night side of the planet and converge on the point directly facing the star.

When starlight passes through a planet’s atmosphere, it interacts with molecules like carbon dioxide and nitrogen to produce distinct signals, called spectral lines. The modeling team, led by Gabrielle Engelmann-Suissa, a Universities Space Research Association visiting research assistant at Goddard, produced simulated spectra for the 20 modeled versions of TOI 700 d.

“Someday, when we have real spectra from TOI 700 d, we can backtrack, match them to the closest simulated spectrum, and then match that to a model,” Engelmann-Suissa said. “It’s exciting because no matter what we find out about the planet, it’s going to look completely different from what we have here on Earth.”

TESS is a NASA Astrophysics Explorer mission led and operated by MIT in Cambridge, Massachusetts, and managed by NASA's Goddard Space Flight Center. Additional partners include Northrop Grumman, based in Falls Church, Virginia; NASA’s Ames Research Center in California’s Silicon Valley; the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts; MIT’s Lincoln Laboratory; and the Space Telescope Science Institute in Baltimore. More than a dozen universities, research institutes and observatories worldwide are participants in the mission.

The Jet Propulsion Laboratory in Pasadena, California, manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at Caltech in Pasadena. Space operations are based at Lockheed Martin Space in Littleton, Colorado. Data are archived at the Infrared Science Archive housed at IPAC at Caltech. Caltech manages JPL for NASA.

The modeling work was funded through the Sellers Exoplanet Environments Collaboration at Goddard, a multidisciplinary collaboration that brings together experts to build comprehensive and sophisticated computer models to better analyze current and future exoplanet observations.

Source: NASA.Gov

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Monday, January 06, 2020

TESS Update: 2020 Begins with an Amazing Discovery Made by Kepler's Successor...

An artist's concept of the exoplanet TOI 1338 b orbiting its two parent stars.
NASA's Goddard Space Flight Center / Chris Smith

NASA’s TESS Mission Uncovers Its 1st World With Two Stars (News Release)

In 2019, when Wolf Cukier finished his junior year at Scarsdale High School in New York, he joined NASA’s Goddard Space Flight Center in Greenbelt, Maryland, as a summer intern. His job was to examine variations in star brightness captured by NASA’s Transiting Exoplanet Survey Satellite (TESS) and uploaded to the Planet Hunters TESS citizen science project.

“I was looking through the data for everything the volunteers had flagged as an eclipsing binary, a system where two stars circle around each other and from our view eclipse each other every orbit,” Cukier said. “About three days into my internship, I saw a signal from a system called TOI 1338. At first I thought it was a stellar eclipse, but the timing was wrong. It turned out to be a planet.”

TOI 1338 b, as it is now called, is TESS’s first circumbinary planet, a world orbiting two stars. The discovery was featured in a panel discussion on Monday, Jan. 6, at the 235th American Astronomical Society meeting in Honolulu. A paper, which Cukier co-authored along with scientists from Goddard, San Diego State University, the University of Chicago and other institutions, has been submitted to a scientific journal.

The TOI 1338 system lies 1,300 light-years away in the constellation Pictor. The two stars orbit each other every 15 days. One is about 10% more massive than our Sun, while the other is cooler, dimmer and only one-third the Sun’s mass.

TOI 1338 b is the only known planet in the system. It’s around 6.9 times larger than Earth, or between the sizes of Neptune and Saturn. The planet orbits in almost exactly the same plane as the stars, so it experiences regular stellar eclipses.

TESS has four cameras, which each take a full-frame image of a patch of the sky every 30 minutes for 27 days. Scientists use the observations to generate graphs of how the brightness of stars change over time. When a planet crosses in front of its star from our perspective, an event called a transit, its passage causes a distinct dip in the star’s brightness.

But planets orbiting two stars are more difficult to detect than those orbiting one. TOI 1338 b’s transits are irregular, between every 93 and 95 days, and vary in depth and duration thanks to the orbital motion of its stars. TESS only sees the transits crossing the larger star; the transits of the smaller star are too faint to detect.

“These are the types of signals that algorithms really struggle with,” said lead author Veselin Kostov, a research scientist at the SETI Institute and Goddard. “The human eye is extremely good at finding patterns in data, especially non-periodic patterns like those we see in transits from these systems.”

This explains why Cukier had to visually examine each potential transit. For example, he initially thought TOI 1338 b’s transit was a result of the smaller star in the system passing in front of the larger one — both cause similar dips in brightness. But the timing was wrong for an eclipse.

After identifying TOI 1338 b, the research team used a software package called eleanor, named after Eleanor Arroway, the central character in Carl Sagan’s novel “Contact,” to confirm the transits were real and not a result of instrumental artifacts.

“Throughout all of its images, TESS is monitoring millions of stars,” said co-author Adina Feinstein, a graduate student at the University of Chicago. “That’s why our team created eleanor. It’s an accessible way to download, analyze and visualize transit data. We designed it with planets in mind, but other members of the community use it to study stars, asteroids and even galaxies.”

TOI 1338 had already been studied from the ground by radial velocity surveys, which measure motion along our line of sight. Kostov’s team used this archival data to analyze the system and confirm the planet. Its orbit is stable for at least the next 10 million years. The orbit’s angle to us, however, changes enough that the planet transit will cease after November 2023 and resume eight years later.

NASA’s Kepler and K2 missions previously discovered 12 circumbinary planets in 10 systems, all similar to TOI 1338 b. Observations of binary systems are biased toward finding larger planets, Kostov said. Transits of smaller bodies don’t have as big an effect on the stars’ brightness. TESS is expected to observe hundreds of thousands of eclipsing binaries during its initial two-year mission, so many more of these circumbinary planets should be waiting for discovery.

TESS is a NASA Astrophysics Explorer mission led and operated by MIT in Cambridge, Massachusetts, and managed by NASA's Goddard Space Flight Center. Additional partners include Northrop Grumman, based in Falls Church, Virginia; NASA’s Ames Research Center in California’s Silicon Valley; the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts; MIT’s Lincoln Laboratory; and the Space Telescope Science Institute in Baltimore. More than a dozen universities, research institutes and observatories worldwide are participants in the mission.

Source: NASA.Gov

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Wednesday, December 18, 2019

Photos of the Day: IMPEACHED!!!

The New York Time's front page article on Donald Trump's impeachment...for December 19, 2019.

Today is the day that was over two years in the making. The U.S. House of Representatives officially voted—on two articles that involved the abuse of power and obstruction of justice—to impeach Donald Trump. About damn time! The articles of impeachment will soon be transferred over to the U.S. Senate...which will begin Trump's trial next month.

The Washington Post's front page article on Donald Trump's impeachment...for December 19, 2019.

On the downside, the Senate is currently controlled by the Republican party—so Mitch "Complicit turtle-faced traitorous bastard" McConnell, Lindsey "I am compromised like you wouldn't believe" Graham and all of the other cowardly GOP lackwits will ensure that Trump will be acquitted when the trial reaches the verdict phase. On the upside, though, Trump will forever be lumped together with Bill Clinton, Andrew Johnson and Richard Nixon...even though the latter resigned before he was impeached. So much for your legacy, Trump—and you still have to deal with the criminal charges wrought upon you by the state of New York after your reign of ineptitude inevitably reaches its long-awaited conclusion. You're fired!

HEY LOOK— Trump finally won the popular vote!

Monday, December 16, 2019

NASA's Next X-Plane Moves a Step Closer to Reality...

An artist's concept of NASA's X-59 QueSST aircraft landing at Edwards Air Force Base in California.
Lockheed Martin

NASA’s X-59 Quiet Supersonic Research Aircraft Cleared for Final Assembly (Press Release)

NASA’s first large scale, piloted X-plane in more than three decades is cleared for final assembly and integration of its systems following a major project review by senior managers held Thursday at NASA Headquarters in Washington.

The management review, known as Key Decision Point-D (KDP-D), was the last programmatic hurdle for the X-59 Quiet SuperSonic Technology (QueSST) aircraft to clear before officials meet again in late 2020 to approve the airplane’s first flight in 2021.

“With the completion of KDP-D we’ve shown the project is on schedule, it’s well planned and on track. We have everything in place to continue this historic research mission for the nation’s air-traveling public,” said Bob Pearce, NASA’s associate administrator for Aeronautics.

The X-59 is shaped to reduce the loudness of a sonic boom reaching the ground to that of a gentle thump, if it is heard at all. It will be flown above select U.S. communities to generate data from sensors and people on the ground in order to gauge public perception. That data will help regulators establish new rules to enable commercial supersonic air travel over land.

Construction of the X-59, under a $247.5 million cost-plus-incentive-fee contract, is continuing at Lockheed Martin Aeronautics Company’s Skunk Works factory in Palmdale, California.

Three major work areas are actively set up for building the airplane’s main fuselage, wing and empennage. Final assembly and integration of the airplane’s systems – including an innovative cockpit eXternal Visibility System – is targeted for late 2020.

Management of the X-59 QueSST development and construction falls under the Low Boom Flight Demonstrator project, which is part of NASA’s Integrated Aviation Systems Program.

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Different parts of the X-59's main fuselage begin to take shape at Lockheed Martin's Skunk Works factory in Palmdale, California.
Lockheed Martin

Saturday, December 14, 2019

Hubble Photographs Our Newest Interstellar Interloper...

Two images of interstellar comet 2I/Borisov that were taken by NASA's Hubble Space Telescope...on November 16 (left) and December 9, 2019 (right), respectively.
NASA, ESA and D. Jewitt (UCLA)

Interstellar Comet 2I/Borisov Swings Past Sun (News Release - December 12)

When astronomers see something in the universe that at first glance seems like one-of-a-kind, it's bound to stir up a lot of excitement and attention. Enter comet 2I/Borisov. This mysterious visitor from the depths of space is the first identified comet to arrive here from another star. We don't know from where or when the comet started heading toward our Sun, but it won't hang around for long. The Sun's gravity is slightly deflecting its trajectory, but can't capture it because of the shape of its orbit and high velocity of about 100,000 miles per hour.

Telescopes around the world have been watching the fleeting visitor. NASA's Hubble Space Telescope has provided the sharpest views as the comet skirts by our Sun. Since October the space telescope has been following the comet like a sports photographer following horses speeding around a racetrack. Hubble revealed that the heart of the comet, a loose agglomeration of ices and dust particles, is likely no more than about 3,200 feet across, about the length of nine football fields. Though comet Borisov is the first of its kind, no doubt there are many other comet vagabonds out there, plying the space between stars. Astronomers will eagerly be on the lookout for the next mysterious visitor from far beyond.

These two images (above), taken by Hubble, capture comet 2I/Borisov streaking though our solar system and on its way back to interstellar space. It is only the second interstellar object known to have passed through the solar system.

Nov. 16, 2019, Photo (Above Left)

The comet appears in front of a distant background spiral galaxy (2MASX J10500165-0152029). The galaxy's bright central core is smeared in the image because Hubble was tracking the comet. Comet Borisov was approximately 203 million miles from Earth in this exposure. Its tail of ejected dust streaks off to the upper right. The comet has been artificially colored blue to discriminate fine detail in the halo of dust, or coma, surrounding the central nucleus. It also helps to visually separate the comet from the background galaxy.

Dec. 9, 2019, Photo (Above Right)

Hubble revisited the comet shortly after its closest approach to the Sun where it received maximum heating after spending most of its life in frigid interstellar space. The comet also reached a breathtaking maximum speed of about 100,000 miles per hour. Comet Borisov is 185 million miles from Earth in this photo, near the inner edge of the Asteroid Belt but below it. The nucleus, an agglomeration of ices and dust, is still too small to be resolved. The bright central portion is a coma made up of dust leaving the surface. The comet will make its closest approach to Earth in late December at a distance of 180 million miles.

"Hubble gives us the best upper limit of the size of comet Borisov's nucleus, which is the really important part of the comet," said David Jewitt, a UCLA professor of planetary science and astronomy, whose team has captured the best and sharpest look at this first confirmed interstellar comet. "Surprisingly, our Hubble images show that its nucleus is more than 15 times smaller than earlier investigations suggested it might be. Our Hubble images show that the radius is smaller than half a kilometer. Knowing the size is potentially useful for beginning to estimate how common such objects may be in the solar system and our galaxy. Borisov is the first known interstellar comet, and we would like to learn how many others there are."

Crimean amateur astronomer Gennady Borisov discovered the comet on Aug. 30, 2019, and reported the position measurements to the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts. The Center for Near-Earth Object Studies at NASA's Jet Propulsion Laboratory in Pasadena, California, working with the Minor Planet Center, computed an orbit for the comet, which shows that it came from elsewhere in our Milky Way galaxy, point of origin unknown.

Nevertheless, observations by numerous telescopes show that the comet's chemical composition is similar to the comets found inside our solar system, providing evidence that comets also form around other stars. By the middle of 2020 the comet will have already zoomed past Jupiter's distance of 500 million miles on its way back into the frozen abyss of interstellar space.

The Hubble Space Telescope is a project of international cooperation between ESA (the European Space Agency) and NASA. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C. The Minor Planet Center and the Center for Near-Earth Orbit Studies are projects of NASA’s Near-Earth Object Observations Program of the Planetary Defense Coordination Office at NASA Headquarters.

Source: NASA.Gov

Friday, December 13, 2019

Another Mars 2020 Flight Component Arrives in Cape Canaveral, Florida...

The backshell and heat shield (background) for NASA's Mars 2020 rover...which is scheduled to launch to the Red Planet next July.
Lockheed Martin

Lockheed Martin Delivers Mars 2020 Rover Aeroshell To Launch Site (Press Release)

Heat Shield and Backshell Will Protect NASA's Rover During Descent to Mars

DENVER, Dec. 13, 2019 -- The capsule-shaped aeroshell that will protect NASA's Mars 2020 rover was delivered to NASA's Kennedy Space Center, Florida yesterday. Built by Lockheed Martin, the aeroshell will encapsulate and protect the Mars 2020 rover during its deep space cruise to Mars, and from the intense heat as the entry system descends through the Martian atmosphere to the surface of Mars.

Because of the large mass and unique entry trajectory profile that could create external temperatures up to 3,800 degrees Fahrenheit, the heat shield uses a tiled Phenolic Impregnated Carbon Ablator (PICA) thermal protection system instead of the Mars heritage Super Lightweight Ablator (SLA) 561V. This will only be the second time PICA has flown on a Mars mission.

"Even though we have the experience of building the nearly identical aeroshell for the Curiosity Rover, the almost 15-foot diameter composite structure was just as big a challenge to build and test 10 years later," said Neil Tice, Mars 2020 aeroshell program manager at Lockheed Martin Space. "We've built every Mars aeroshell entry system for NASA of its 40 years of exploring Mars, so we pulled from that experience to build this important system."

Along with the Curiosity mission, this is the largest aeroshell/heat shield ever built for a planetary mission at 4.5 meters (nearly 15 feet) in diameter. In contrast, the aeroshell/heat shield of the InSight lander measured 8.6 feet and Apollo capsule heat shields measured just less than 13 feet.

The backshell and heat shield were transported from Lockheed Martin's Waterton facility in Littleton, Colorado where they were built, to nearby Buckley Air Force Base. They were then loaded onto an Air Force transport plane and flown to NASA's Kennedy Space Center.

Recently, Lockheed Martin integrated the MSL Entry Descent and Landing Instrument (MEDLI2) onto the heat shield and backshell. Provided by NASA's Langley and Ames Research Centers, MEDLI2 will collect temperature and pressure data during the spacecraft's descent through the Martian atmosphere.

The Mars 2020 rover is in testing at NASA's Jet Propulsion Laboratory, Pasadena, California., which manages the Mars 2020 project for the NASA Science Mission Directorate, Washington. The mission will launch in July 2020 and land on Mars in February 2021 at the Jezero Crater.

Source: Lockheed Martin

Thursday, December 12, 2019

Hello, Nightingale: OSIRIS-REx Has Found Its Landing Spot on Asteroid Bennu!

An image of the site on asteroid Bennu's surface (dubbed Nightingale) where NASA's OSIRIS-REx spacecraft will touch down to collect a soil sample in August of 2020.
NASA / Goddard / University of Arizona

X Marks the Spot: NASA Selects Site for Asteroid Sample Collection (Press Release)

After a year scoping out asteroid Bennu’s boulder-scattered surface, the team leading NASA’s first asteroid sample return mission has officially selected a sample collection site.

The Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-Rex) mission team concluded a site designated “Nightingale” – located in a crater high in Bennu’s northern hemisphere – is the best spot for the OSIRIS-REx spacecraft to snag its sample.

The OSIRIS-REx team spent the past several months evaluating close-range data from four candidate sites in order to identify the best option for the sample collection. The candidate sites – dubbed Sandpiper, Osprey, Kingfisher, and Nightingale – were chosen for investigation because, of all the potential sampling regions on Bennu, these areas pose the fewest hazards to the spacecraft’s safety while still providing the opportunity for great samples to be gathered.

“After thoroughly evaluating all four candidate sites, we made our final decision based on which site has the greatest amount of fine-grained material and how easily the spacecraft can access that material while keeping the spacecraft safe,” said Dante Lauretta, OSIRIS-REx principal investigator at the University of Arizona in Tucson. “Of the four candidates, site Nightingale best meets these criteria and, ultimately, best ensures mission success.”

Site Nightingale is located in a northern crater 230 feet (70 meters) wide. Nightingale’s regolith – or rocky surface material – is dark, and images show that the crater is relatively smooth. Because it is located so far north, temperatures in the region are lower than elsewhere on the asteroid and the surface material is well-preserved. The crater also is thought to be relatively young, and the regolith is freshly exposed. This means the site would likely allow for a pristine sample of the asteroid, giving the team insight into Bennu’s history.

Although Nightingale ranks the highest of any location on Bennu, the site still poses challenges for sample collection. The original mission plan envisioned a sample site with a diameter of 164 feet (50 meters). While the crater that hosts Nightingale is larger than that, the area safe enough for the spacecraft to touch is much smaller – approximately 52 feet (16 meters) in diameter, resulting in a site that is only about one-tenth the size of what was originally envisioned. This means the spacecraft has to very accurately target Bennu’s surface. Nightingale also has a building-size boulder situated on the crater’s eastern rim, which could pose a hazard to the spacecraft while backing away after contacting the site.

The mission also selected site Osprey as a backup sample collection site. The spacecraft has the capability to perform multiple sampling attempts, but any significant disturbance to Nightingale’s surface would make it difficult to collect a sample from that area on a later attempt, making a backup site necessary. The spacecraft is designed to autonomously “wave-off” from the site if its predicted position is too close to a hazardous area. During this maneuver, the exhaust plumes from the spacecraft’s thrusters could potentially disturb the surface of the site, due to the asteroid’s microgravity environment. In any situation where a follow-on attempt at Nightingale is not possible, the team will try to collect a sample from site Osprey instead.

"Bennu has challenged OSIRIS-REx with extraordinarily rugged terrain," said Rich Burns, OSIRIS-REx project manager at NASA’s Goddard Space Flight Center. "The team has adapted by employing a more accurate, though more complex, optical navigation technique to be able to get into these small areas. We'll also arm OSIRIS-REx with the capability to recognize if it is on course to touch a hazard within or adjacent to the site and wave-off before that happens."

With the selection of final primary and backup sites, the mission team will undertake further reconnaissance flights over Nightingale and Osprey, beginning in January and continuing through the spring. Once these flyovers are complete, the spacecraft will begin rehearsals for its first "touch-and-go" sample collection attempt, which is scheduled for August. The spacecraft will depart Bennu in 2021 and is scheduled to return to Earth in September 2023.

NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona, Tucson, is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Denver built the spacecraft and provides flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which is managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.

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