Parker Solar Probe Completes 24th Close Approach to Sun (News Release - June 23)
NASA’s Parker Solar Probe completed its 24th close approach to the Sun on Thursday, June 19, matching its record distance of 3.8 million miles (6.1 million kilometers) from the solar surface. Following this flyby — the last of the spacecraft’s baseline mission plan — Parker Solar Probe will remain in orbit around the Sun and continue making observations until next steps for the mission are formally reviewed in 2026.
Parker Solar Probe checked in with mission operators at the Johns Hopkins Applied Physics Laboratory (APL) in Maryland — where it was also designed and built — on Sunday, June 22, reporting that all systems are healthy and operating normally. The spacecraft was out of contact with Earth and operating autonomously during the close approach.
During this flyby, the spacecraft also equaled its record-setting speed of 430,000 miles per hour (687,000 kilometers per hour) — a mark that, like the distance, was set and subsequently matched during close approaches on December 24, 2024, and March 22, 2025.
This close to the Sun, the spacecraft relied on its innovative carbon foam shield, known simply as the Thermal Protection System, to protect itself from the intense heat. Spacecraft operators expect that the shield faced temperatures of between 1,600 to 1,700°F (870 to 930°C) at closest approach.
During the solar encounter — which began on June 14 and ends June 24 — Parker’s four scientific instrument packages are gathering unique observations from inside the Sun’s corona. The flyby, as the third at this distance and speed, is allowing the spacecraft to conduct unrivaled measurements of the solar wind and solar activity while the Sun is in a more active phase of its 11-year cycle.
Parker’s observations of the solar wind and solar events, such as flares and coronal mass ejections, are critical to advancing humankind’s understanding of the Sun and phenomena that drive high-energy space weather events that pose risks to astronauts, satellites, air travel and even power grids on Earth. Understanding the fundamental physics of space weather enables more reliable prediction of astronaut safety during future deep-space missions to the Moon and Mars.
“Parker Solar Probe remains in excellent health, with both the spacecraft and its instruments ready to continue their groundbreaking mission,” said Arik Posner, Parker Solar Probe program scientist at NASA Headquarters in Washington. “The spacecraft will keep exploring the solar atmosphere as the Sun enters the declining phase of its 11-year cycle, providing a unique opportunity to study how solar activity evolves and shapes the heliosphere during this pivotal period.”
Parker Solar Probe was developed as a part of NASA’s Living With a Star (LWS) program to explore aspects of the Sun-Earth system that directly affect life and society. The LWS program is managed by the agency’s Goddard Space Flight Center in Greenbelt, Maryland, for NASA’s Science Mission Directorate in Washington. APL manages Parker Solar Probe for NASA and designed, built and operates the mission.
NASA’s Parker Solar Probe Reports Healthy Status After Solar Encounter (News Release)
Eight days after its record-breaking closest approach to the Sun’s surface on December 24, 2024, NASA’s Parker Solar Probe has confirmed that the spacecraft’s systems and science instruments are healthy and operating normally, including collecting science data as it swung around our star.
Breaking its previous record by flying just 3.8 million miles above the surface of the Sun, Parker Solar Probe hurtled through the solar atmosphere at 430,000 miles per hour — faster than any human-made object has ever moved. A beacon tone, received in the mission operations center at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, late in the evening of Thursday, December 26, confirmed that the spacecraft had made it through the encounter safely.
The telemetry (or housekeeping data) that APL began receiving on January 1 provided more detail on the spacecraft’s operating status and condition. It showed, for example, that Parker had executed the commands that had been programmed into its flight computers before the flyby, and that its science instruments were operational during the flyby itself.
Telemetry transmission, through NASA’s Deep Space Network, continues through Thursday. Science data transmission will begin later this month, when the spacecraft and its most powerful onboard antenna are in better alignment with Earth to transmit at higher data rates. Parker Solar Probe’s next two close passes of the Sun, at approximately the same distance and speed, will occur on March 22 and June 19.
Parker Solar Probe was developed as part of NASA’s Living With a Star program to explore aspects of the Sun-Earth system that directly affect life and society. The Living With a Star program is managed by the agency’s Goddard Space Flight Center in Greenbelt, Maryland, for NASA’s Science Mission Directorate in Washington. The Applied Physics Laboratory designed, built and operates the spacecraft and manages the mission for NASA.
NASA’s Parker Solar Probe Reports Successful Closest Approach to Sun (News Release)
Following its record-breaking closest approach to the Sun, NASA’s Parker Solar Probe has transmitted a beacon tone back to Earth indicating that it’s in good health and operating normally.
The mission operations team at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland received the signal just before midnight EST, on the night of December 26. The team was out of contact with the spacecraft during closest approach, which occurred on December 24, with Parker Solar Probe zipping just 3.8 million miles from the solar surface while moving about 430,000 miles per hour.
The spacecraft is expected to send back detailed telemetry data about its status on January 1.
This close-up study of the Sun allows Parker Solar Probe to take measurements that help scientists better understand how material in this region gets heated to millions of degrees, trace the origin of the solar wind (a continuous flow of material escaping from the Sun), and discover how energetic particles are accelerated to near light speed. Previous close passes have helped scientists pinpoint the origins of structures in the solar wind and map the outer boundary of the Sun’s atmosphere.
Parker Solar Probe was developed as part of NASA’s Living With a Star program to explore aspects of the Sun-Earth system that directly affect life and society. The Living With a Star program is managed by the agency’s Goddard Space Flight Center in Greenbelt, Maryland, for NASA’s Science Mission Directorate in Washington. APL designed, built and operates the spacecraft, and manages the mission for NASA.
Parker Solar Probe Begins Record-Setting Closest Approach to the Sun (News Release - December 20)
NASA’s Parker Solar Probe is in good health and operating normally as it speeds toward its closest-ever flight around the Sun on Christmas Eve.
Mission operators at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, received a beacon transmission from Parker, through NASA’s Deep Space Network complex in Canberra, Australia, at 7:20 p.m. EST today indicating that all spacecraft systems were operating normally.
“This is one example of NASA’s bold missions, doing something that no one else has ever done before to answer longstanding questions about our Universe,” said Arik Posner, Parker Solar Probe program scientist at NASA Headquarters in Washington. “We can’t wait to receive that first status update from the spacecraft and start receiving the science data in the coming weeks.”
Parker is now on course to fly just 3.8 million miles (around 6.1 million kilometers) from the surface of the Sun on Tuesday, December 24, at 6:53 a.m. EST. During closest approach, or perihelion, mission operations will be out of contact with the spacecraft, and Parker will transmit another beacon tone on Friday, December 27, to confirm its health following the close flyby.
“No human-made object has ever passed this close to a star, so Parker will truly be returning data from uncharted territory” said Nick Pinkine, Parker Solar Probe mission operations manager at APL. “We’re excited to hear back from the spacecraft when it swings back around the Sun.”
Parker Solar Probe was developed as a part of NASA’s Living With a Star program to explore aspects of the Sun-Earth system that directly affect life and society. The Living With a Star program is managed by the agency’s Goddard Space Flight Center in Greenbelt, Maryland, for NASA’s Science Mission Directorate in Washington. APL manages Parker Solar Probe for NASA and designed, built and operates the mission.
NASA’s Sun-Bound Parker Solar Probe Swings Through Final Venus Flyby (News Release)
Gravity-Assist Maneuver Sets Up Record Close Approach to Our Star
On November 6, NASA’s Parker Solar Probe completed its seventh and final Venus gravity-assist maneuver, passing within 240 miles (about 387 kilometers) of Venus’ surface. The flyby adjusted Parker’s trajectory into the final orbital configuration of its primary mission, bringing the spacecraft to within an unprecedented 3.8 million miles of the solar surface on December 24, 2024.
Monitoring the maneuver through NASA’s Deep Space Network, the mission operations team at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland — where Parker Solar Probe was designed and built — confirmed that Parker was operating normally as it reached closest approach to Venus at 1:43 p.m. EST, flew precisely through its planned “aim point” and then began its swing in toward the Sun.
“We’re reaching the crescendo of Parker’s incredible voyage through the inner Solar System,” said Yanping Guo, Parker Solar Probe mission design and navigation manager in APL’s Space Exploration Sector. “More than six years after launch, this incredible spacecraft continues to exceed all expectations, and we can’t wait to see what Parker uncovers on its closest approaches to the Sun.”
Parker is now on course to reach the final objective of a historic mission conceived over 65 years ago: flying within 3.8 million miles (around 6.1 million kilometers) of the surface of the Sun. No human-made object has ever passed this close to a star, so Parker will be returning data from uncharted territory. As Parker passes through the Sun’s atmosphere, it will cut through plumes of plasma still connected to the Sun.
It will be close enough to pass inside a solar eruption, like a surfer diving under a crashing ocean wave.
“This is the vision generations of scientists have dreamed of realizing since 1958,” said Nour Rawafi, the Parker Solar Probe project scientist at APL.
During its Christmas Eve closest approach, or perihelion, mission control will be out of contact with the spacecraft, although Parker will transmit beacon tones on December 21 and December 27 to confirm its health. The spacecraft will remain in this orbit for the remainder of its primary mission, completing two more perihelia at about the same distance and speed — a record 430,000 miles (692,018 kilometers) per hour — in March and June 2025. After that, the team will decide whether to keep the spacecraft in that orbit or reposition it.
New Science
Early mission plans didn’t include any planetary science at Venus. But that changed shortly after launch in 2018, and Parker’s better-than-expected performance allowed the team to adjust its observational programs.
One reason why Parker’s Venus flybys have become boons for new science is a chance discovery from the spacecraft’s Wide-Field Imager for Parker Solar Probe, called WISPR. The instrument peers out from Parker and away from the Sun to see fine details in the solar wind. But on July 11, 2020, during Parker’s third Venus flyby, scientists turned WISPR toward Venus in hopes of tracking changes in the planet’s thick cloud cover. The images revealed a surprise: WISPR, which captures visible and near infrared light, seemed to see the Venusian surface.
“The WISPR cameras can see through the clouds to the surface of Venus, which glows in the near-infrared because it’s so hot,” said APL planetary scientist Noam Izenberg.
Venus, sizzling at approximately 869° Fahrenheit (about 465° Celsius), was radiating through the clouds.
The WISPR images from the 2020 flyby, as well as the next flyby in 2021, revealed Venus’ surface in a new light. But they also raised puzzling questions, and scientists devised the final flyby to help answer them.
The Venus images correlate well with data from the Magellan spacecraft, showing dark and light patterns that line up with surface regions that Magellan captured when it mapped Venus’ surface using radar from 1990 to 1994. Yet some parts of the WISPR images appear brighter than expected, hinting at extra information captured by WISPR.
Is WISPR picking up on chemical differences on the surface, where the ground is made of different material? Perhaps it’s seeing variations in age, where more recent lava flows added a fresh coat to the Venusian surface.
“Because it flies over a number of similar and different landforms compared to the previous Venus flybys, the November 6 flyby will give us more context to evaluate whether WISPR can help us distinguish physical or even chemical properties of Venus’ surface,” Izenberg said.
Rawafi said that imaging was just part of the flyby’s science agenda. Shaped under Rawafi’s direction for more than a year, the comprehensive plan also included a look at the different components of Venus’ exosphere and their interactions with the Sun. The Parker team expects to begin receiving the first bits of that data later this month, he added, with plans to present some of its findings at the American Geophysical Union’s Fall Meeting the week of December 9 to 13.
“The science data we’ve gathered over these seven Venus flybys is a real tribute to Parker’s versatility, and have enabled new avenues for research on Venus,” Rawafi said. “The seventh Venus flyby, however, was especially unique, in that spacecraft flew through the planet’s nightside and plunged deep into its atmosphere. We’re anticipating some exciting surprises when the data comes down.”
NASA’s Parker Solar Probe Completes 20th Close Approach to the Sun (News Release)
NASA’s Parker Solar Probe completed its 20th close approach to the Sun on June 30, 2024, matching its own distance record by coming about 4.51 million miles (7.26 million kilometers) from the solar surface.
The close approach (known as perihelion) occurred at 3:47 UTC (11:47 p.m. EDT on June 29), with Parker Solar Probe moving 394,736 miles per hour (635,266 kilometers per hour) around the Sun, again matching its own record. On July 2, the spacecraft checked in with mission operators at the Johns Hopkins University's Applied Physics Laboratory in Laurel, Maryland (where the spacecraft was also designed and built), with a beacon tone indicating that it was in good health and all systems were operating normally.
The milestone also marked the midpoint in the mission’s 20th solar encounter, which began on June 25 and continues through July 5.
Parker will fly around the Sun at the same distance and speed one more time this year — on September 30 — before making the first of its three final planned closest approaches on December 24. At that point, with Parker’s orbit shaped by the mission’s final Venus gravity assist-flyby on November 6, the spacecraft will zoom just 3.8 million miles from the solar surface, moving about 430,000 miles per hour.
NASA’s Deep Space Network Ground Testing with Peregrine a Success (Press Release)
Pittsburgh, PA – Last month, the Deep Space Network (DSN) from NASA’s Jet Propulsion Laboratory (JPL) successfully completed an end-to-end communications test with Astrobotic’s Peregrine lunar lander. These tests demonstrated compatibility with space-to-ground communications that will occur during Peregrine’s mission to the Moon.
After the Peregrine spacecraft separates from United Launch Alliance's (ULA)Vulcan Centaur rocket, Peregrine will be utilizing DSN’s 34-meter dishes at Canberra, Australia; Madrid, Spain; and Goldstone, California. These dishes are the same suite used to communicate with the James Webb Space Telescope, as well as historic missions such as New Horizons, Solar Parker Probe, InSight, Juno, and MAVEN.
”Our team has completed a major test with the DSN global network and Astrobotic’s communication systems including flight avionics, ground support software, and mission ops infrastructure. We successfully passed commands, received telemetry, and determined ranging performance. The sense of accomplishment was palpable when the screens of our Mission Control center were illuminated by real telemetry coming from our spacecraft,” said Eduardo Lugo, Astrobotic Lead RF Engineer.
Testing with Peregrine and DSN was conducted over two weeks, culminating in confirmation that Peregrine can successfully transmit data and receive commands through DSN and to Astrobotic’s Mission Control Center in Pittsburgh, Pennsylvania.
“This success marks a major program milestone for Peregrine mission as well as for Astrobotic as a company. Confirming the technical capabilities of our team and our custom-built avionics and communications systems in a sophisticated, system-level spacecraft test was a tremendous success. Seeing the entire team overcome test challenges felt close to flying the actual mission. This is a great accomplishment for our historic trip to the Moon,” says Ander Solorzano, Astrobotic’s Lead Systems Engineer and one of the Flight Directors for Peregrine Mission One.
Peregrine’s progress continues as its Space Robotics team also successfully integrated the OPAL Terrain Relative Navigation (TRN) compute hardware and associated camera to Peregrine’s flight decks. TRN is designed to enable precise and safe landings on the Moon, Mars, and beyond. The system will be leveraged again on Astrobotic’s Griffin Mission One. In addition to TRN, all twenty-four of Peregrine’s payloads have also been integrated with its flight decks.
The Peregrine spacecraft continues its final assembly at Astrobotic’s headquarters and is currently on schedule for final environmental testing before delivery to the launch site in Cape Canaveral, Florida.
Parker Solar Probe Captures its First Images of Venus' Surface in Visible Light, Confirmed (News Release)
NASA’s Parker Solar Probe has taken its first visible-light images of the surface of Venus from space.
Smothered in thick clouds, Venus’ surface is usually shrouded from sight. But in two recent flybys of the planet, Parker used its Wide-Field Imager, or WISPR, to image the entire nightside in wavelengths of the visible spectrum – the type of light that the human eye can see – and extending into the near-infrared.
The images, combined into a video, reveal a faint glow from the surface that shows distinctive features like continental regions, plains, and plateaus. A luminescent halo of oxygen in the atmosphere can also be seen surrounding the planet.
“We’re thrilled with the science insights Parker Solar Probe has provided thus far,” said Nicola Fox, division director for the Heliophysics Division at NASA Headquarters. “Parker continues to outperform our expectations, and we are excited that these novel observations taken during our gravity-assist maneuver can help advance Venus research in unexpected ways.”
Such images of the planet, often called Earth’s twin, can help scientists learn more about Venus’ surface geology, what minerals might be present there, and the planet’s evolution. Given the similarities between the planets, this information can help scientists on the quest to understand why Venus became inhospitable and Earth became an oasis.
“Venus is the third brightest thing in the sky, but until recently we have not had much information on what the surface looked like because our view of it is blocked by a thick atmosphere,” said Brian Wood, lead author on the new study and physicist at the Naval Research Laboratory in Washington, DC. “Now, we finally are seeing the surface in visible wavelengths for the first time from space.”
Unexpected Capabilities
The first WISPR images of Venus were taken in July 2020 as Parker embarked on its third flyby, which the spacecraft uses to bend its orbit closer to the Sun. WISPR was designed to see faint features in the solar atmosphere and wind, and some scientists thought they might be able to use WISPR to image the cloud tops veiling Venus as Parker passed the planet.
“The objective was to measure the speed of the clouds,” said WISPR project scientist Angelos Vourlidas, co-author on the new paper and researcher at Johns Hopkins University Applied Physics Laboratory.
But instead of just seeing clouds, WISPR also saw through to the surface of the planet. The images were so striking that the scientists turned on the cameras again during the fourth pass in February 2021. During the 2021 flyby, the spacecraft’s orbit lined up perfectly for WISPR to image Venus’ nightside in entirety.
“The images and video just blew me away,” Wood said.
Glowing like an Iron from the Forge
Clouds obstruct most of the visible light coming from Venus’ surface, but the very-longest visible wavelengths, which border the near-infrared wavelengths, make it through. On the dayside, this red light gets lost amid the bright sunshine reflected off Venus’ cloud tops, but in the darkness of night, the WISPR cameras were able to pick up this faint glow caused by the incredible heat emanating from the surface.
“The surface of Venus, even on the nightside, is about 860 degrees,” Wood said. “It's so hot that the rocky surface of Venus is visibly glowing, like a piece of iron pulled from a forge.”
As it passed by Venus, WISPR picked up a range of wavelengths from 470 nanometers to 800 nanometers. Some of that light is in the near-infrared – wavelengths that we cannot see, but sense as heat – and some is in the visible range, between 380 nanometers and about 750 nanometers.
Venus in a New Light
In 1975, the Venera 9 lander sent the first tantalizing glimpses of the surface after landing on Venus. Since then, Venus’ surface has been revealed further with radar and infrared instruments, which can peer through the thick clouds by using wavelengths of light invisible to the human eye. NASA’s Magellan mission created the first maps in the 1990s using radar and JAXA’s Akatsuki spacecraft gathered infrared images after reaching orbit around Venus in 2015. The new images from Parker add to these findings by extending the observations to red wavelengths at the edge of what we can see.
The WISPR images show features on the Venusian surface, such as the continental region Aphrodite Terra, the Tellus Regio plateau, and the Aino Planitia plains. Since higher-altitude regions are about 85 degrees Fahrenheit cooler than lower areas, they show up as dark patches amidst the brighter lowlands. These features can also be seen in previous radar images, such as those taken by Magellan.
Beyond looking at surface features, the new WISPR images will help scientists better understand the geology and mineral make-up of Venus. When heated, materials glow at unique wavelengths. By combining the new images with previous ones, scientists now have a wider range of wavelengths to study, which can help identify what minerals are on the surface of the planet. Such techniques have previously been used to study the surface of the Moon. Future missions will continue to expand this range of wavelengths, which will contribute to our understanding of habitable planets.
This information could also help scientists understand the planet’s evolution. While Venus, Earth, and Mars all formed around the same time, they are very different today. The atmosphere on Mars is a fraction of Earth’s while Venus has a much thicker atmosphere. Scientists suspect volcanism played a role in creating the dense Venusian atmosphere, but more data are needed to know how. The new WISPR images might provide clues about how volcanos may have affected the planet’s atmosphere.
In addition to the surface glow, the new images show a bright ring around the edge of the planet caused by oxygen atoms emitting light in the atmosphere. Called airglow, this type of light is also present in Earth’s atmosphere, where it’s visible from space and sometimes from the ground at night.
Flyby Science
While Parker Solar Probe’s primary goal is solar science, the Venusian flybys are providing exciting opportunities for bonus data that wasn’t expected at the mission’s launch.
WISPR has also imaged Venus’ orbital dust ring – a doughnut-shaped track of microscopic particles strewn in the wake of Venus’ orbit around the Sun – and the FIELDS instrument made direct measurements of radio waves in the Venusian atmosphere, helping scientists understand how the upper atmosphere changes during the Sun’s 11-year cycle of activity.
In December 2021, researchers published new findings about the rediscovery of the comet-like tail of plasma streaming out behind Venus, called a “tail ray”. The new results showed this tail of particles extending nearly 5,000 miles out from the Venusian atmosphere. This tail could be how Venus’ water escaped from the planet, contributing to its current dry and inhospitable environment.
While the geometry of the next two flybys likely won’t allow Parker to image the nightside, scientists will continue to use Parker’s other instruments to study Venus’ space environment. In November 2024, the spacecraft will have a final chance to image the surface on its seventh and final flyby.
NASA Enters the Solar Atmosphere for the First Time, Bringing New Discoveries (News Release - December 14)
For the first time in history, a spacecraft has touched the Sun. NASA’s Parker Solar Probe has now flown through the Sun’s upper atmosphere – the corona – and sampled particles and magnetic fields there.
The new milestone marks one major step for Parker Solar Probe and one giant leap for solar science. Just as landing on the Moon allowed scientists to understand how it was formed, touching the very stuff the Sun is made of will help scientists uncover critical information about our closest star and its influence on the solar system.
"Parker Solar Probe 'touching the Sun' is a monumental moment for solar science and a truly remarkable feat," said Thomas Zurbuchen, the associate administrator for the Science Mission Directorate at NASA Headquarters in Washington. "Not only does this milestone provide us with deeper insights into our Sun's evolution and its impacts on our solar system, but everything we learn about our own star also teaches us more about stars in the rest of the universe.”
As it circles closer to the solar surface, Parker is making new discoveries that other spacecraft were too far away to see, including from within the solar wind – the flow of particles from the Sun that can influence us at Earth. In 2019, Parker discovered that magnetic zig-zag structures in the solar wind, called switchbacks, are plentiful close to the Sun. But how and where they form remained a mystery. Halving the distance to the Sun since then, Parker Solar Probe has now passed close enough to identify one place where they originate: the solar surface.
The first passage through the corona – and the promise of more flybys to come – will continue to provide data on phenomena that are impossible to study from afar.
“Flying so close to the Sun, Parker Solar Probe now senses conditions in the magnetically-dominated layer of the solar atmosphere – the corona – that we never could before,” said Nour Raouafi, the Parker project scientist at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. “We see evidence of being in the corona in magnetic field data, solar wind data, and visually in images. We can actually see the spacecraft flying through coronal structures that can be observed during a total solar eclipse.”
Closer Than Ever Before
Parker Solar Probe launched in 2018 to explore the mysteries of the Sun by traveling closer to it than any spacecraft before. Three years after launch and decades after first conception, Parker has finally arrived.
Unlike Earth, the Sun doesn’t have a solid surface. But it does have a superheated atmosphere, made of solar material bound to the Sun by gravity and magnetic forces. As rising heat and pressure push that material away from the Sun, it reaches a point where gravity and magnetic fields are too weak to contain it.
“We were fully expecting that, sooner or later, we would encounter the corona for at least a short duration of time,” said Justin Kasper, lead author on a new paper about the milestone published in Physical Review Letters, and deputy chief technology officer at BWX Technologies, Inc. and University of Michigan professor. “But it is very exciting that we’ve already reached it.”
At one point, as Parker Solar Probe dipped to just beneath 15 solar radii (around 6.5 million miles) from the Sun’s surface, it transited a feature in the corona called a pseudostreamer. Pseudostreamers are massive structures that rise above the Sun’s surface and can be seen from Earth during solar eclipses.
Passing through the pseudostreamer was like flying into the eye of a storm. Inside the pseudostreamer, the conditions quieted, particles slowed, and number of switchbacks dropped – a dramatic change from the busy barrage of particles the spacecraft usually encounters in the solar wind.
The first passage through the corona, which lasted only a few hours, is one of many planned for the mission. Parker will continue to spiral closer to the Sun, eventually reaching as close as 8.86 solar radii (3.83 million miles) from the surface. Upcoming flybys, the next of which is happening in January 2022, will likely bring Parker Solar Probe through the corona again.
“I’m excited to see what Parker finds as it repeatedly passes through the corona in the years to come,” said Nicola Fox, division director for the Heliophysics Division at NASA Headquarters. “The opportunity for new discoveries is boundless.”
The size of the corona is also driven by solar activity. As the Sun’s 11-year activity cycle – the solar cycle – ramps up, the outer edge of the corona will expand, giving Parker Solar Probe a greater chance of being inside the corona for longer periods of time.
“It is a really important region to get into because we think all sorts of physics potentially turn on,” Kasper said. “And now we're getting into that region and hopefully going to start seeing some of these physics and behaviors.”
Narrowing Down Switchback Origins
Even before the first trips through the corona, some surprising physics was already surfacing. On recent solar encounters, Parker Solar Probe collected data pinpointing the origin of zig-zag-shaped structures in the solar wind, called switchbacks. The data showed one spot that switchbacks originate is at the visible surface of the Sun – the photosphere.
By the time it reaches Earth, 93 million miles away, the solar wind is an unrelenting headwind of particles and magnetic fields. But as it escapes the Sun, the solar wind is structured and patchy. In the mid-1990s, the NASA-European Space Agency mission Ulysses flew over the Sun’s poles and discovered a handful of bizarre S-shaped kinks in the solar wind’s magnetic field lines, which detoured charged particles on a zig-zag path as they escaped the Sun. For decades, scientists thought these occasional switchbacks were oddities confined to the Sun’s polar regions.
In 2019, at 34 solar radii from the Sun, Parker discovered that switchbacks were not rare, but common in the solar wind. This renewed interest in the features and raised new questions: Where were they coming from? Were they forged at the surface of the Sun, or shaped by some process kinking magnetic fields in the solar atmosphere?
The new findings, in press at the Astrophysical Journal, finally confirm one origin point is near the solar surface.
The clues came as Parker orbited closer to the Sun on its sixth flyby, less than 25 solar radii out. Data showed switchbacks occur in patches and have a higher percentage of helium – known to come from the photosphere – than other elements. The switchbacks’ origins were further narrowed when the scientists found the patches aligned with magnetic funnels that emerge from the photosphere between convection cell structures called supergranules.
In addition to being the birthplace of switchbacks, the scientists think the magnetic funnels might be where one component of the solar wind originates. The solar wind comes in two different varieties – fast and slow – and the funnels could be where some particles in the fast solar wind come from.
“The structure of the regions with switchbacks matches up with a small magnetic funnel structure at the base of the corona,” said Stuart Bale, professor at the University of California, Berkeley, and lead author on the new switchbacks paper. “This is what we expect from some theories, and this pinpoints a source for the solar wind itself.”
Understanding where and how the components of the fast solar wind emerge, and if they’re linked to switchbacks, could help scientists answer a longstanding solar mystery: how the corona is heated to millions of degrees, far hotter than the solar surface below.
While the new findings locate where switchbacks are made, the scientists can’t yet confirm how they’re formed. One theory suggests they might be created by waves of plasma that roll through the region like ocean surf. Another contends they’re made by an explosive process known as magnetic reconnection, which is thought to occur at the boundaries where the magnetic funnels come together.
“My instinct is, as we go deeper into the mission and lower and closer to the Sun, we're going to learn more about how magnetic funnels are connected to the switchbacks,” Bale said. “And hopefully resolve the question of what process makes them.”
Now that researchers know what to look for, Parker’s closer passes may reveal even more clues about switchbacks and other solar phenomena. The data to come will allow scientists a glimpse into a region that’s critical for superheating the corona and pushing the solar wind to supersonic speeds. Such measurements from the corona will be critical for understanding and forecasting extreme space weather events that can disrupt telecommunications and damage satellites around Earth.
“It’s really exciting to see our advanced technologies succeed in taking Parker Solar Probe closer to the Sun than we’ve ever been, and to be able to return such amazing science,” said Joseph Smith, Parker program executive at NASA Headquarters. "We look forward to seeing what else the mission discovers as it ventures even closer in the coming years."
Parker Solar Probe is part of NASA’s Living with a Star program to explore aspects of the Sun-Earth system that directly affect life and society. The Living with a Star program is managed by the agency’s Goddard Space Flight Center in Greenbelt, Maryland, for NASA’s Science Mission Directorate in Washington. The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, manages the Parker Solar Probe mission for NASA and designed, built, and operates the spacecraft.
So for much of today, I've been reading online articles—like this one—about an intriguing deep space mission that's been under study by the Johns Hopkins University Applied Physics Laboratory (JHUAPL) for quite some time now. Known as the Interstellar Probe, this spacecraft would launch in the early 2030s, possibly pass by the distant dwarf planets Quaoar or Gonggong during its voyage, and reach our solar system's heliosphere boundary just 15 years after lift-off. By comparison, it took the twin Voyager robotic probes 35 years to reach the same location. And once all is said and done, the Interstellar Probe will have traveled as far as 1,000 astronomical units (the Earth is 1 astronomical unit, or 93 million miles, from the Sun) by the time its planned 50-year mission comes to an end.
It's only fitting that JHUAPL would be the organization that's doing a study on this fascinating project. It was, after all, this laboratory that built a spacecraft which gave us our first close-up glimpse of Pluto (New Horizons) and constructed another probe that traveled to the opposite end of our solar system...literally towards the Sun (the Parker Solar Probe). Scientists say that NASA's powerful Space Launch System rocket (which will soon be prepped for its maiden flight to the Moon as we speak) will make this cosmic sojourn possible. The SLS will not be launching the Europa Clipper to Jupiter's icy moon Europa as originally intended, but this launch vehicle will have been operational for about a decade by the time it's ready to hurl the Interstellar Probe to the edge of our solar system and beyond. We'll overlook the fact that SpaceX fanboys will be foaming at the mouth to get this trailblazing explorer to depart Earth on a Starship rocket instead. I prefer SLS.
JHUAPL should complete its study of the Interstellar Probe within a year...and then submit it to NASA for consideration soon afterward. Let's cross our fingers that this project gets greenlit! Happy Monday.
NASA / Johns Hopkins APL / Naval Research Laboratory / Guillermo Stenborg and Brendan Gallagher
Parker Solar Probe Offers Stunning View of Venus (News Release)
NASA’s Parker Solar Probe captured stunning views of Venus during its close flyby of the planet in July 2020.
Though Parker Solar Probe’s focus is the Sun, Venus plays a critical role in the mission: The spacecraft whips by Venus a total of seven times over the course of its seven-year mission, using the planet’s gravity to bend the spacecraft’s orbit. These Venus gravity assists allow Parker Solar Probe to fly closer and closer to the Sun on its mission to study the dynamics of the solar wind close to its source.
But — along with the orbital dynamics — these passes can also yield some unique and even unexpected views of the inner solar system. During the mission’s third Venus gravity assist on July 11, 2020, the onboard Wide-field Imager for Parker Solar Probe, or WISPR, captured a striking image of the planet’s nightside from 7,693 miles away.
WISPR is designed to take images of the solar corona and inner heliosphere in visible light, as well as images of the solar wind and its structures as they approach and fly by the spacecraft. At Venus, the camera detected a bright rim around the edge of the planet that may be nightglow — light emitted by oxygen atoms high in the atmosphere that recombine into molecules in the nightside. The prominent dark feature in the center of the image is Aphrodite Terra, the largest highland region on the Venusian surface. The feature appears dark because of its lower temperature, about 85 degrees Fahrenheit (30 degrees Celsius) cooler than its surroundings.
That aspect of the image took the team by surprise, said Angelos Vourlidas, the WISPR project scientist from the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, who coordinated a WISPR imaging campaign with Japan’s Venus-orbiting Akatsuki mission. “WISPR is tailored and tested for visible light observations. We expected to see clouds, but the camera peered right through to the surface.”
“WISPR effectively captured the thermal emission of the Venusian surface,” said Brian Wood, an astrophysicist and WISPR team member from the U.S. Naval Research Laboratory in Washington, D.C. “It’s very similar to images acquired by the Akatsuki spacecraft at near-infrared wavelengths.”
This surprising observation sent the WISPR team back to the lab to measure the instrument’s sensitivity to infrared light. If WISPR can indeed pick up near-infrared wavelengths of light, the unforeseen capability would provide new opportunities to study dust around the Sun and in the inner solar system. If it can’t pick up extra infrared wavelengths, then these images — showing signatures of features on Venus’ surface — may have revealed a previously unknown “window” through the Venusian atmosphere.
For more insight into the July 2020 images, the WISPR team planned a set of similar observations of the Venusian nightside during Parker Solar Probe’s latest Venus flyby on Feb. 20, 2021. Mission team scientists expect to receive and process that data for analysis by the end of April.
“We are really looking forward to these new images,” said Javier Peralta, a planetary scientist from the Akatsuki team, who first suggested a Parker Solar Probe campaign with Akatsuki, which has been orbiting Venus since 2015. “If WISPR can sense the thermal emission from the surface of Venus and nightglow — most likely from oxygen — at the limb of the planet, it can make valuable contributions to studies of the Venusian surface.”
Parker Solar Probe is part of NASA’s Living with a Star program to explore aspects of the Sun-Earth system that directly affect life and society. The Living with a Star program is managed by the agency’s Goddard Space Flight Center in Greenbelt, Maryland, for NASA’s Science Mission Directorate in Washington. Johns Hopkins APL designed, built and operates the spacecraft.
NASA / Johns Hopkins APL / Naval Research Lab / Parker Solar Probe / Brendan Gallagher
NASA’s Parker Solar Probe Spies Newly-Discovered Comet NEOWISE (News Release - July 10)
NASA’s Parker Solar Probe was at the right place at the right time to capture a unique view of comet NEOWISE on July 5, 2020. Parker Solar Probe’s position in space gave the spacecraft an unmatched view of the comet’s twin tails when it was particularly active just after its closest approach to the Sun, called perihelion.
The comet was discovered by NASA’s Near-Earth Object Wide-field Infrared Survey Explorer, or NEOWISE, on March 27. Since then, the comet — called comet C/2020 F3 NEOWISE and nicknamed comet NEOWISE — has been spotted by several NASA spacecraft, including Parker Solar Probe, NASA’s Solar and Terrestrial Relations Observatory, the ESA/NASA Solar and Heliospheric Observatory, and astronauts aboard the International Space Station.
The image above is unprocessed data from Parker Solar Probe’s WISPR instrument, which takes images of the Sun’s outer atmosphere and solar wind in visible light. WISPR’s sensitivity also makes it well-suited to see fine detail in structures like comet tails. Parker Solar Probe collected science data through June 28 for its fifth solar flyby, but the availability of additional downlink time allowed the team to take extra images, including this image of comet NEOWISE.
The twin tails of comet NEOWISE are seen more clearly in this image from the WISPR instrument, which has been processed to increase contrast and remove excess brightness from scattered sunlight, revealing more detail in the comet tails.
The lower tail, which appears broad and fuzzy, is the dust tail of comet NEOWISE — created when dust lifts off the surface of the comet’s nucleus and trails behind the comet in its orbit. Scientists hope to use WISPR’s images to study the size of dust grains within the dust tail, as well as the rate at which the comet sheds dust.
The upper tail is the ion tail, which is made up of gases that have been ionized by losing electrons in the Sun’s intense light. These ionized gases are buffeted by the solar wind — the Sun’s constant outflow of magnetized material — creating the ion tail that extends directly away from the Sun. Parker Solar Probe’s images appear to show a divide in the ion tail. This could mean that comet NEOWISE has two ion tails, in addition to its dust tail, though scientists would need more data and analysis to confirm this possibility.
NASA / Naval Research Laboratory / Parker Solar Probe
First Parker Solar Probe Science Data Released to Public (News Release - November 12)
On Nov. 12, 2019, NASA’s Parker Solar Probe team released scientific data collected during the spacecraft's first two solar orbits to the general public.
The released encounter data encompasses measurements made during the first two solar encounters, spanning the time between Oct. 31 and Nov. 12, 2018, and March 30 and April 19, 2019, when the spacecraft was within 0.25 AU of the Sun, as well as data collected at farther distances. One AU, or astronomical unit, is about 93 million miles, the average distance between the Sun and Earth.
Science teams led by principal investigators from partner institutions have been busy poring over the wealth of information collected by Parker Solar Probe in preparation for the mission's first science results, to be released later this year. The four instrument suites onboard – FIELDS, ISʘIS, SWEAP, and WISPR – have been observing the characteristics of the solar wind (fields, waves, flows, and particles) in the immediate environment surrounding the Sun, called the corona.
“Parker Solar Probe is crossing new frontiers of space exploration, giving us so much new information about the Sun,” said Parker Solar Probe Project Scientist Nour E. Raouafi, from the Johns Hopkins Applied Physics Laboratory, or APL, in Laurel, Maryland, which manages the mission for NASA. “Releasing this data to the public will allow them not only to contribute to the success of the mission along with the scientific community, but also to raise the opportunity for new discoveries to the next level.”
With three of 24 planned solar orbits under its belt, Parker Solar Probe will continue to get closer to the Sun in the coming years, eventually swooping to within 4 million miles of the Sun's surface, facing heat and radiation like no spacecraft before it. The mission seeks to provide new data on solar activity and how the solar corona works, which contributes significantly to our ability to forecast major space weather events that impact life on Earth. The mission launched in 2018 and is slated to perform its primary science mission until 2025.
NASA / Naval Research Laboratory / Parker Solar Probe
Space enthusiasts everywhere were treated to amazing new images taken by the recently-launchedParker Solar Probe and the Transiting Exoplanet Survey Satellite(TESS) this week. In the snapshot above, you see our Milky Way galaxy as it was glimpsed by Parker's Wide-field Imager on September 9. In the snapshot below, you see the 'first light' science image that was taken by TESS on August 7 (the satellite's first light test image was publicly released a few months ago). In other amazing TESS-related news, NASA announced that its newest planet hunter has already pinpointed two new exoplanet candidates: a super-Earth orbiting around the bright star Pi Mensae about 60 light-years away, and a 'hot Earth' revolving around LHS 3844—an M dwarf star 49 light-years away. Astronomers need to confirm these two planetary discoveries with follow-up observations, but all signs point to TESS beginning to live up to expectations about five months after its launch!
The Parker Solar Probe, meanwhile, is expected to make its first flyby of Venus on October 3 before cruising through the Sun's corona for the first time in November. Stay tuned.
NASA, ULA Launch Parker Solar Probe on Historic Journey to Touch Sun (Press Release)
Hours before the rise of the very star it will study, NASA’s Parker Solar Probe launched from Florida Sunday to begin its journey to the Sun, where it will undertake a landmark mission. The spacecraft will transmit its first science observations in December, beginning a revolution in our understanding of the star that makes life on Earth possible.
Roughly the size of a small car, the spacecraft lifted off at 3:31 a.m. EDT on a United Launch Alliance Delta IV Heavy rocket from Space Launch Complex-37 at Cape Canaveral Air Force Station. At 5:33 a.m., the mission operations manager reported that the spacecraft was healthy and operating normally.
The mission’s findings will help researchers improve their forecasts of space weather events, which have the potential to damage satellites and harm astronauts on orbit, disrupt radio communications and, at their most severe, overwhelm power grids.
“This mission truly marks humanity’s first visit to a star that will have implications not just here on Earth, but how we better understand our universe,” said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate. “We’ve accomplished something that decades ago, lived solely in the realm of science fiction.”
During the first week of its journey, the spacecraft will deploy its high-gain antenna and magnetometer boom. It also will perform the first of a two-part deployment of its electric field antennas. Instrument testing will begin in early September and last approximately four weeks, after which Parker Solar Probe can begin science operations.
“Today’s launch was the culmination of six decades of scientific study and millions of hours of effort,” said project manager Andy Driesman, of the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland. “Now, Parker Solar Probe is operating normally and on its way to begin a seven-year mission of extreme science.”
Over the next two months, Parker Solar Probe will fly towards Venus, performing its first Venus gravity assist in early October – a maneuver a bit like a handbrake turn – that whips the spacecraft around the planet, using Venus’s gravity to trim the spacecraft’s orbit tighter around the Sun. This first flyby will place Parker Solar Probe in position in early November to fly as close as 15 million miles from the Sun – within the blazing solar atmosphere, known as the corona – closer than anything made by humanity has ever gone before.
Throughout its seven-year mission, Parker Solar Probe will make six more Venus flybys and 24 total passes by the Sun, journeying steadily closer to the Sun until it makes its closest approach at 3.8 million miles. At this point, the probe will be moving at roughly 430,000 miles per hour, setting the record for the fastest-moving object made by humanity.
Parker Solar Probe will set its sights on the corona to solve long-standing, foundational mysteries of our Sun. What is the secret of the scorching corona, which is more than 300 times hotter than the Sun’s surface, thousands of miles below? What drives the supersonic solar wind – the constant stream of solar material that blows through the entire solar system? And finally, what accelerates solar energetic particles, which can reach speeds up to more than half the speed of light as they rocket away from the Sun?
Scientists have sought these answers for more than 60 years, but the investigation requires sending a probe right through the unrelenting heat of the corona. Today, this is finally possible with cutting-edge thermal engineering advances that can protect the mission on its daring journey.
“Exploring the Sun’s corona with a spacecraft has been one of the hardest challenges for space exploration,” said Nicola Fox, project scientist at APL. “We’re finally going to be able to answer questions about the corona and solar wind raised by Gene Parker in 1958 – using a spacecraft that bears his name – and I can’t wait to find out what discoveries we make. The science will be remarkable.”
Parker Solar Probe carries four instrument suites designed to study magnetic fields, plasma and energetic particles, and capture images of the solar wind. The University of California, Berkeley, U.S. Naval Research Laboratory in Washington, University of Michigan in Ann Arbor, and Princeton University in New Jersey lead these investigations.
Parker Solar Probe is part of NASA’s Living with a Star program to explore aspects of the Sun-Earth system that directly affect life and society. The Living with a Star program is managed by the agency’s Goddard Space Flight Center in Greenbelt, Maryland, for NASA’s Science Mission Directorate in Washington. APL designed and built, and operates the spacecraft.
The mission is named for Eugene Parker, the physicist who first theorized the existence of the solar wind in 1958. It’s the first NASA mission to be named for a living researcher.
A plaque dedicating the mission to Parker was attached to the spacecraft in May. It includes a quote from the renowned physicist – “Let’s see what lies ahead.” It also holds a memory card containing more than 1.1 million names submitted by the public to travel with the spacecraft to the Sun.
Prepping to Launch for the Sun (News Release - July 31)
NASA’s Parker Solar Probe has cleared the final procedures in the clean room before its move to the launch pad, where it will be integrated onto its launch vehicle, a United Launch Alliance Delta IV Heavy. This is an historic mission that will revolutionize our understanding of the Sun, where changing conditions can propagate out into the solar system, affecting Earth and other worlds. Parker Solar Probe will travel through the Sun’s atmosphere, closer to the surface than any spacecraft before it, facing brutal heat and radiation conditions — and ultimately providing humanity with the closest-ever observations of a star.
Seen here inside one half of its 62.7-foot tall fairing, the Parker Solar Probe was encapsulated on July 16, 2018, in preparation for the move from Astrotech Space Operations in Titusville, Florida, to Space Launch Complex 37 on Cape Canaveral Air Force Station, where it will be integrated onto its launch vehicle for its launch that is targeted for August 11, 2018.
Earlier today, NASA announced that the impending launch of its Parker Solar Probehas been delayed from August 6 to August 11 (after having an original flight date of August 3)...due to a piece of foam that technicians at Astrotech Space Operations (in Titusville, Florida) found inside the Delta IV Heavy payload fairing after Parker was recently encapsulated inside it. This is good news to me—as I probably would've missed the launch if it took place on August 6 (Monday) due to work. The Delta IV Heavy rocket that will send Parker towards the Sun is now set to depart from Cape Canaveral Air Force Station in Florida on August 11 at 3:48 AM, Eastern Daylight Time (12:48 AM, Pacific Daylight Time). I can live with that!
Cutting-Edge Heat Shield Installed on NASA’s Parker Solar Probe (News Release - July 5)
The launch of Parker Solar Probe, the mission that will get closer to the Sun than any human-made object has ever gone, is quickly approaching, and on June 27, 2018, Parker Solar Probe’s heat shield — called the Thermal Protection System, or TPS — was installed on the spacecraft.
A mission 60 years in the making, Parker Solar Probe will make a historic journey to the Sun’s corona, a region of the solar atmosphere. With the help of its revolutionary heat shield, now permanently attached to the spacecraft in preparation for its August 2018 launch, the spacecraft’s orbit will carry it to within 4 million miles of the Sun's fiercely hot surface, where it will collect unprecedented data about the inner workings of the corona.
The eight-foot-diameter heat shield will safeguard everything within its umbra, the shadow it casts on the spacecraft. At Parker Solar Probe’s closest approach to the Sun, temperatures on the heat shield will reach nearly 2,500 degrees Fahrenheit, but the spacecraft and its instruments will be kept at a relatively comfortable temperature of about 85 degrees Fahrenheit.
The heat shield is made of two panels of superheated carbon-carbon composite sandwiching a lightweight 4.5-inch-thick carbon foam core. The Sun-facing side of the heat shield is also sprayed with a specially formulated white coating to reflect as much of the Sun’s energy away from the spacecraft as possible.
The heat shield itself weighs only about 160 pounds — here on Earth, the foam core is 97 percent air. Because Parker Solar Probe travels so fast — 430,000 miles per hour at its closest approach to the Sun, fast enough to travel from Philadelphia to Washington, D.C., in about one second — the shield and spacecraft have to be light to achieve the needed orbit.
The reinstallation of the Thermal Protection System — which was briefly attached to the spacecraft during testing at the Johns Hopkins Applied Physics Lab in Laurel, Maryland, in fall 2017 — marks the first time in months that Parker Solar Probe has been fully integrated. The heat shield and spacecraft underwent testing and evaluation separately at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, before shipping out to Astrotech Space Operations in Titusville, Florida, in April 2018. With the recent reunification, Parker Solar Probe inches closer to launch and toward the Sun.
Parker Solar Probe is part of NASA’s Living with a Star Program, or LWS, to explore aspects of the Sun-Earth system that directly affect life and society. LWS is managed by Goddard for the Heliophysics Division of NASA’s Science Mission Directorate in Washington, D.C. The Johns Hopkins Applied Physics Laboratory manages the Parker Solar Probe mission for NASA. APL designed and built the spacecraft and will also operate it.
Power Up: Solar Arrays Installed on NASA’s Mission to Touch the Sun (News Release)
NASA’s Parker Solar Probe depends on the Sun, not just as an object of scientific investigation, but also for the power that drives its instruments and systems. On Thursday, May 31, 2018, the spacecraft’s solar arrays were installed and tested. These arrays will power all of the spacecraft’s systems, including the suites of scientific instruments studying the solar wind and the Sun’s corona as well as the Solar Array Cooling System (SACS) that will protect the arrays from the extreme heat at the Sun.
“Unlike solar-powered missions that operate far from the Sun and are focused only on generating power from it, we need to manage the power generated along with the substantial heat that comes from being so close to the Sun,” said Andy Driesman, project manager from the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. “When we’re out around the orbit of Venus, we fully extend the arrays to get the power we need. But when we’re near the Sun, we tuck the arrays back until only a small wing is exposed, and that portion is enough to provide needed electrical power.”
The solar arrays are cooled by a gallon of water that circulates through tubes in the arrays and into large radiators at the top of the spacecraft. They are just over three and a half feet (1.12 meters) long and nearly two and a half feet (0.69 meters) wide. Mounted on motorized arms, the arrays will retract almost all of their surface behind the Thermal Protection System – the heat shield – when the spacecraft is close to the Sun. The solar array installation marks some of the final preparation and testing of Parker Solar Probe leading up to the mission’s July 31 launch date.
More Than 1.1 Million Names Installed on NASA’s Parker Solar Probe (News Release)
Throughout its seven-year mission, NASA’s Parker Solar Probe will swoop through the Sun’s atmosphere 24 times, getting closer to our star than any spacecraft has gone before. The spacecraft will carry more than scientific instruments on this historic journey — it will also hold more than 1.1 million names submitted by the public to go to the Sun.
“Parker Solar Probe is going to revolutionize our understanding of the Sun, the only star we can study up close,” said Nicola Fox, project scientist for Parker Solar Probe at the Johns Hopkins Applied Physics Lab in Laurel, Maryland. “It’s fitting that as the mission undertakes one of the most extreme journeys of exploration ever tackled by a human-made object, the spacecraft will also carry along the names of so many people who are cheering it on its way.”
Back in March 2018, the public were invited to send their names to the Sun aboard humanity’s first mission to “touch” a star. A total of 1,137,202 names were submitted and confirmed over the seven-and-a-half-week period, and a memory card containing the names was installed on the spacecraft on May 18, 2018, three months before the scheduled launch on July 31, 2018, from NASA’s Kennedy Space Center in Florida. The card was mounted on a plaque bearing a dedication to and a quote from the mission’s namesake, heliophysicist Eugene Parker, who first theorized the existence of the solar wind. This is the first NASA mission to be named for a living individual.
This memory card also carries photos of Parker, professor emeritus at the University of Chicago, and a copy of his groundbreaking 1958 scientific paper. Parker proposed a number of concepts about how stars — including our Sun — give off material. He called this cascade of energy and particles the solar wind, a constant outflow of material from the Sun that we now know shapes everything from the habitability of worlds to our solar system’s interaction with the rest of the galaxy.
Parker Solar Probe will explore the Sun’s outer atmosphere and make critical observations to answer decades-old questions about the physics of stars. The resulting data may also improve forecasts of major eruptions on the Sun and subsequent space weather events that impact life on Earth, as well as satellites and astronauts in space.
Though our understanding of the Sun and the solar wind has vastly improved since Parker first theorized the solar wind, there are still questions left unanswered. Two of the most fundamental mysteries – which scientists hope Parker Solar Probe will help solve – are the coronal heating problem and the mechanism behind solar wind acceleration.
The coronal heating problem is what scientists call the apparent mismatch between the temperature of the Sun’s photosphere — the visible “surface,” measuring about 10,000 degrees Fahrenheit — and the much higher temperature of the corona — the Sun’s atmosphere, which reaches temperatures of up to 10 million degrees Fahrenheit. Since the Sun’s energy source is at its core, this increase is similar to walking away from a campfire and suddenly feeling a thousand times hotter — completely counterintuitive. This implies that some other process is continually adding more heat to that solar atmosphere.
Scientists think that the mechanism behind this as-yet unexplained heating happens in the lower corona — and Parker Solar Probe will get closer to this region than any spacecraft has before. Getting a closer look at this region should help scientists identify the source of this coronal heating, along with pinpointing the process that accelerates the solar wind to enormous speeds as it leaves the Sun.
A commemorative reproduction of the plaque bearing an identical memory card — minus the submitted names — was presented to Parker at the Johns Hopkins University Applied Physics Lab in October 2017 by the mission team.
"From the experience of seeing the probe up close, I understand now the difficult task you are undertaking, and I am sure you will succeed,” said Parker after visiting the spacecraft in the clean room.
Parker Solar Probe is part of NASA’s Living with a Star Program, or LWS, to explore aspects of the Sun-Earth system that directly affect life and society. LWS is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland, for the Heliophysics Division of NASA’s Science Mission Directorate in Washington. Johns Hopkins APL manages the Parker Solar Probe mission for NASA. APL designed and built the spacecraft and will also operate it.
