Volcanoes on Mars Could be Active, Raising Possibility that the Planet was Recently Habitable
New observations reveal that Mars could still be volcanically active, raising the possibility for habitable conditions below the surface of Mars in recent history.
By Daniel Stolte, University Communications, and Alan Fischer, Planetary Science Institute - May 6, 2021
Evidence of recent volcanic activity on Mars shows that eruptions could have taken place in the past 50,000 years, according to new study by researchers at the University of Arizona's Lunar and Planetary Laboratory and the Planetary Science Institute.
Most volcanism on the Red Planet occurred between 3 and 4 billion years ago, with smaller eruptions in isolated locations continuing perhaps as recently as 3 million years ago. But, until now, there was no evidence to indicate Mars could still be volcanically active.
Using data from satellites orbiting Mars, researchers discovered a previously unknown volcanic deposit. They detail their findings in the paper "Evidence for geologically recent explosive volcanism in Elysium Planitia, Mars," published in the journal Icarus.
"This may be the youngest volcanic deposit yet documented on Mars," said lead study author David Horvath, who did the research as a postdoctoral researcher at UArizona and is now a research scientist at the Planetary Science Institute. “If we were to compress Mars' geologic history into a single day, this would have occurred in the very last second.”
The volcanic eruption produced an 8-mile-wide, smooth, dark deposit surrounding a 20-mile-long volcanic fissure.
"When we first noticed this deposit, we knew it was something special," said study co-author Jeff Andrews-Hanna, an associate professor at the UArizona Lunar and Planetary Laboratory and the senior author on the study. "The deposit was unlike anything else found in the region, or indeed on all of Mars, and more closely resembled features created by older volcanic eruptions on the Moon and Mercury."
Further investigation showed that the properties, composition and distribution of material match what would be expected for a pyroclastic eruption – an explosive eruption of magma driven by expanding gasses, not unlike the opening of a shaken can of soda.
The majority of volcanism in the Elysium Planitia region and elsewhere on Mars consists of lava flowing across the surface, similar to recent eruptions in Iceland being studied by co-author Christopher Hamilton, a UArizona associate professor of lunar and planetary sciences. Although there are numerous examples of explosive volcanism on Mars, they occurred long ago. However, this deposit appears to be different.
"This feature overlies the surrounding lava flows and appears to be a relatively fresh and thin deposit of ash and rock, representing a different style of eruption than previously identified pyroclastic features," Horvath said. "This eruption could have spewed ash as high as 6 miles into Mars' atmosphere. It is possible that these sorts of deposits were more common but have been eroded or buried."
The site of the recent eruption is about 1,000 miles (1,600 kilometers) from NASA's InSight lander, which has been studying seismic activity on Mars since 2018. Two Marsquakes, the Martian equivalent of earthquakes, were found to originate in the region around the Cerberus Fossae, and recent work has suggested the possibility that these could be due to the movement of magma deep underground.
"The young age of this deposit absolutely raises the possibility that there could still be volcanic activity on Mars, and it is intriguing that recent Marsquakes detected by the InSight mission are sourced from the Cerberus Fossae," Horvath said. In fact, the team of researchers predicted this to be a likely location for Marsquakes several months before NASA's InSight lander touched down on Mars.
A volcanic deposit such as this one also raises the possibility for habitable conditions below the surface of Mars in recent history, Horvath said.
"The interaction of ascending magma and the icy substrate of this region could have provided favorable conditions for microbial life fairly recently and raises the possibility of extant life in this region," he said.
Similar volcanic fissures in this region were the source of enormous floods, perhaps as recently as 20 million years ago, as groundwater erupted out onto the surface.
Elysium Planitia, the region of recent explosive volcanism (white box) and NASA's InSight lander. Overlooking the plain is Elysium Mons, a volcano towering nearly 8 miles above its base.MOLA Science Team
Andrews-Hanna's research group continues to investigate the causes of the eruption. Pranabendu Moitra, a research scientist in the UArizona Department of Geosciences, has been probing the mechanism behind the eruption.
An expert in similar explosive eruptions on Earth, Moitra developed models to look at the possible cause of the Martian eruption. In a forthcoming paper in the journal Earth and Planetary Science Letters, he suggests that the explosion either could have been a result of gases already present in the Martian magma, or it could have happened when the magma came into contact with Martian permafrost.
"The ice melts to water, mixes with the magma and vaporizes, forcing a violent explosion of the mixture," Moitra said. "When water mixes with magma, it's like pouring gasoline on a fire."
He also points out that the youngest volcanic eruption on Mars happened only 6 miles (10 kilometers) from the youngest large-impact crater on the planet – a 6-mile-wide crater named Zunil.
"The ages of the eruption and the impact are indistinguishable, which raises the possibility, however speculative, that the impact actually triggered the volcanic eruption," Moitra said.
Several studies have found evidence that large quakes on Earth can cause magma stored beneath the surface to erupt. The impact that formed the Zunil crater on Mars would have shaken the Red Planet just like an earthquake, Moitra explained.
While the more dramatic giant volcanoes elsewhere on Mars – such as Olympus Mons, the tallest mountain in the solar system – tell a story of the planet's ancient dynamics, the current hotspot of Martian activity seems to be in the relatively featureless plains of the planet's Elysium region.
Andrews-Hanna said it's remarkable that one region hosts the epicenters of present-day earthquakes, the most recent floods of water, the most recent lava flows, and now an even more recent explosive volcanic eruption.
"This may be the most recent volcanic eruption on Mars," he said, "but I think we can rest assured that it won't be the last."
The volcanic deposit described in this study, along with ongoing seismic rumbling in the planet's interior detected by InSight and possible evidence for releases of methane plumes into the atmosphere detected by NASA's MAVEN orbiter, suggest that Mars is far from a cold, inactive world, Andrews-Hanna said.
"All these data seem to be telling the same story," he said. "Mars isn't dead."
Behind the Scenes with Carina Bennett
In 2019, the University of Arizona rolled out a new brand, Wonder, rooted in the university’s purpose and values and designed to capture the spirit of curiosity that powers Wildcat creativity and ingenuity.
By Carina Bennett, Alumni Association - Spring 2021
I get a lot of fulfillment from my education. I love learning about new things. Chasing down the truth behind the things I wonder about is a huge driving force in my life.
I went into the Wonder animation work without expectations. They listened to my story and specifically chose an artist whose style would match mine. I wasn’t expecting that amount of care and attention.
They couldn’t have picked a better artist. The final animation was so imaginative — they created a whole world for me. During the voiceover I riffed on scripts like I was describing my work to somebody at a party. I used my creative writing background to contribute to the vision of the piece and tell stories. It was so cool.
Beyond Ordinary
Mapping Bennu: UArizona alumna’s wonder moment begins with the OSIRIS-REx mission and a pinpoint of light.
By Sarah Beaudry, Alumni Association - Spring 2021
Carina Bennett remembers her first day working on the OSIRIS-REx mission: She found herself among space scientists with years of experience. It was rocket science, but she was a filmmaker.
“There was a ton of vocabulary people threw around,” Bennett says. “I kept a list and would Google words I didn’t know.”
That determination to figure it out started early on in her University of Arizona experience. After earning bachelor’s degrees in creative writing and media arts, she earned a master’s in film production at the University of Iowa before returning to Tucson to begin her career. She started in video communications at UArizona, then joined the OSIRIS-REx imaging team.
Bennett describes herself as an “asteroid cartographer.” As she explains, all the images used for OSIRIS-REx science came through the imaging team, which removed dead or hot pixels, corrected any geometry information and ensured that pixels denoted, as accurately as possible, the latitude and longitude of points on the asteroid.
Bennett developed the main global map of Bennu, a mosaic composed of thousands of images taken from around the asteroid which were map projected into 2D space, carefully corrected, and layered together to make the map as seamless as possible.
Now that OSIRIS-REx is scheduled to leave Bennu in May with the sample it collected from the surface, the mission team will prepare for sample analysis. Bennett, too, has transitioned: to project manager and software engineer. She will be part of the team that builds a software system to pass data among scientists around the world.
“I just love my job,” Bennett says. “There’s a lot of young women on the team and people who were students hired on afterwards. I love nurturing the future generation of scientists.”
A total of 150 UArizona undergraduate and graduate students have worked on OSIRIS-REx, and more than 30 alumni have been hired to join the mission as staff. While working on the mission, Bennett continued to build her skills with another bachelor’s degree and a master’s degree, both in computer science.
Back in the days when Bennett was Googling unfamiliar science terms, she found inspiration during a meeting with Dante Lauretta. The OSIRIS-REx principal investigator Googled his own unknown words.
“I was sitting next to Dante in a meeting when somebody said something and he Googled it. I was like, ‘Oh my God, everybody’s constantly learning.’ It was a pivotal moment,” Bennett says. “There’s an empowerment in being proud that you don’t know something and wanting to figure it out. You should embrace the fact that you are always learning, instead of trying to hide it.”
Lauretta has also encouraged Bennett in her new role. “It’s intimidating to manage people who have so many years of experience,” Bennett says. “But Dante was immediately supportive. He said, ‘Well, if I thought that way when I was 35, or when I became PI of the OSIRIS-REx mission, I wouldn’t be in this position.’ “He was basically like, No, you can do this.”
Bennett is still discovering what else she can do.
“One of the things that I have learned to love about my life is that I can pivot. I don’t want to start thinking that I do space science now, and that’s all I’m going to do,” she says. “I don’t want to limit myself. I hope I don’t know where I’m going next or what the next opportunity is going to be.”
Masters of Space
Research from UArizona scientists has shaped our understanding of our solar system and universe - beginning with the Apollo 11 mission more than 50 years ago.
By University Communications - Spring 2021
When the first humans stepped onto the moon just over a half-century ago, on July 20, 1969, they knew they were venturing into the unknown. Some had feared the lander would be swallowed up by bottomless layers of dust, as almost nothing was known about the moon’s surface at the time. But they had the courage to trust the Apollo 11 mission team and the groundbreaking research being performed at the University of Arizona’s then-fledgling Lunar and Planetary Laboratory, or LPL.
When Gerard P. Kuiper founded the laboratory nine years earlier, in 1960, there was skepticism and a lack of interest in humans visiting the moon. But reaching the moon soon became a priority as the space race ramped up in the early ’60s. Kuiper and his UArizona laboratory were suddenly in demand.
“The UA has been a part of nearly every NASA planetary exploration mission — and with leadership roles on many of them,” says Tim Swindle, director of the UArizona Department of Planetary Sciences and LPL. “Our graduates and alumni have also been involved in many missions. That is our goal.”
William K. Hartmann, an Arizona alumnus who studied with Kuiper, was instrumental in creating some of the first maps of the moon.
“We projected photos of the moon onto a white globe, then photographed the globe from different angles to make an atlas of lunar features from overhead, as they would be seen by astronauts orbiting the moon,” Hartmann says.
Over the course of his scientific career, Hartmann discovered several impact basins on the moon. During the 1960s, he correctly predicted the age of the lunar lava plains, confirmed through samples returned by the Apollo missions.
UArizona’s LPL legacy continues today with a journey to asteroid Bennu, through the OSIRIS-REx mission and, more recently, with testing Mars exploration drones in Iceland and a mission to build a space telescope that will map vast regions of star-forming gas.
A Celestial Detective Makes Her Way From the UK to Investigate Space Rocks at Arizona
Jessica Barnes calls herself a cosmic detective. Her career path began to take shape when she discovered geosciences as an undergraduate at the University of St. Andrews in Scotland.
By Katy Smith, Alumni Association - Spring 2021
Jessica Barnes calls herself a cosmic detective. Her career path began to take shape when she discovered geosciences as an undergraduate at the University of St. Andrews in Scotland.
“I decided I love rocks and knowing the rocks around me tell a story of how we got here and millions of years of history,” says Barnes, an assistant professor at the University of Arizona’s Lunar and Planetary Laboratory.
As Barnes developed a concurrent interest in the planetary sciences, she chose to focus on space rocks. Their stories go even further back, as far as the origination of the solar system billions of years ago. Now, as a cosmochemist, she looks for answers to questions like: How did Earth become habitable? On what other planets might life be sustainable?
What’s Now, What’s Next
Barnes joined the LPL in 2019 following a postdoctoral fellowship at NASA’s Johnson Space Center in Houston.
“I was really excited when we were able to hire Dr. Jessica Barnes. We had identified her as somebody we wanted to recruit. I’m trying to assemble the cosmochemistry supergroup, and I knew Dr. Barnes was going to be a central member of that team,” says LPL professor Dante Lauretta.
Barnes began her work at Arizona with her current project: leading a team of researchers in examining lunar samples as part of NASA’s Apollo Next Generation Sample Analysis, or ANGSA, Program. She’s excited to work with rocks from the moon because it’s her favorite planetary body.
“It’s always there; we’re naturally curious about it. The moon is steeped in our culture and history. It’s in references in music and literature,” she says.
From a more clinical standpoint, the moon’s rocks are full of information that can be interpreted to reach a better understanding of Earth’s history. Cosmochemists believe other planetary bodies crashed into our planet, delivering water and carbon. Records of these impacts can be read in minerals, but the rocks on Earth aren’t as old as those from the moon, which was hit with the same materials.
This project will lead to another that Barnes and Lauretta both anticipate eagerly. Starting in 2023, they’ll analyze the sample returned by the OSIRIS-REx mission. NASA invested more than $1 billion on the mission, which is bringing a sample of Bennu, a hydrated carbonaceous asteroid, to Earth for analysis. Asteroids like Bennu likely played a major role in giving Earth its water.
“We’re going to bring these samples back to Earth, we’re going to bring them to our laboratories, and we’re going to unravel the early history of our solar system,” says Lauretta, the mission’s principal investigator.
The chance to be part of the OSIRIS-REx mission was one of the factors that drew Barnes to Arizona, as was the university’s history of working with NASA.
“LPL was built 50 years ago using NASA funds, and its history goes all the way back to Gerard Kuiper. It’s one of the most well-renowned planetary sciences departments in the world,” Barnes says. “And the mission is a big draw. Who gets to orbit an asteroid, essentially pogo sticking off the surface, collecting samples, bringing them back?
It’s just awesome.”
Barnes has found a supportive network of mentors and peers at Arizona and throughout her career journey as she completed her doctoral degree and made a permanent move from England. Now, she’s become a role model to others.
“I’ve been given lots of opportunities and support, and that’s what I what I hope to do for my students. I want to pay that experience forward. We’re trying to bring forward more female voices and more diversity in other ways.”
Iceland: The Wildcat Testing Ground
UArizona’s Lunar and Planetary Laboratory programs are influenced by early Apollo missions and Gerard Kuiper’s approach to teaching. He took his students on field trips to places on Earth that he felt were representative of what students might see on the moon or in the solar system.
By Daniel Stolte, Alumni Association - Spring 2021
UArizona’s Lunar and Planetary Laboratory programs are influenced by early Apollo missions and Gerard Kuiper’s approach to teaching. He took his students on field trips to places on Earth that he felt were representative of what students might see on the moon or in the solar system, such as Meteor Crater in northern Arizona, dune fields or the extensive lava flows blanketing the Big Island of Hawaii.
Those types of instructive field trips continue today. “During our field trips, students visit planetary analog sites,” says Tim Swindle, director of the UArizona Department of Planetary Sciences and LPL. “It’s an important part of our department culture.
“We can send a robotic spacecraft to places in our solar system and beyond, but we’ll never be able to see them as well as we can see places on Earth,” Swindle says. “By comparing those sites using every scientific technique we can think of, we can learn what those places out there in space might be like.”
The latest explorations will include a team of scientists led by LPL’s Christopher Hamilton, an associate professor. They are gearing up to send drones on exploration missions across a vast lava field in Iceland to test a next-generation Mars exploration concept.
Hamilton is the principal investigator on a project that has been awarded a $3.1 million NASA grant to develop a new concept combining rovers and unmanned aerial systems, commonly known as drones, to explore regions of the red planet that have been previously inaccessible. These new Rover–Aerial Vehicle Exploration Networks will be tested in Iceland to explore volcanic terrains similar to those observed on Mars.
RAVEN adds an entirely new approach to NASA’s paradigm of planetary exploration, which traditionally has centered around four steps, each building on the scientific findings of the previous one: flyby, orbit, land and rove, according to Hamilton.
The first spacecraft sent to a previously unvisited body in the solar system commonly executes a flyby pass to collect as many data as possible to inform subsequent robotic missions, which consist of another space probe placed into orbit, then a lander, which studies the surface in one place, and, finally, a rover built to move around and analyze various points of scientific interest.
“With RAVEN, we’re adding ‘fly’ to that list,” Hamilton says. “The concept is geared toward building new technology for two robots to work together on an extraterrestrial body. We are going to look at how a rover and a drone can work together to maximize the scientific output of such a mission.”
Previous analog research at UArizona includes preparation for the 2008 Phoenix Mars mission, the first planetary mission led by a university. Then, a UArizona team traveled to Antarctica to study how the instruments they had developed would work in what is considered the most Mars-like environment on Earth.
New Images: OSIRIS-REx Leaves its Mark on Bennu
New images of Bennu's surface captured during the final flyover reveal dramatic changes to the sample site.
By Mikayla Mace Kelley, University Communications - April 15, 2021
Like boot prints on the moon, the University of Arizona-led OSIRIS-REx spacecraft left its mark on asteroid Bennu. Now, new images – taken during the spacecraft's final flyover on April 7 — reveal the aftermath of the historic encounter with the asteroid.
The spacecraft flew within 2.3 miles of the asteroid – the closest it has been since the touch-and-go, or TAG, sample collection event on Oct. 20. During TAG, the spacecraft's sampling head sunk 1.6 feet into the asteroid's surface and simultaneously fired a pressurized charge of nitrogen gas, churning up surface material and driving it into the collection chamber. The spacecraft's thrusters also launched rocks and dust during the maneuver to reverse course and back away from the asteroid.
Comparison of the two images reveal surface disturbance. At the sample site, there appears to be a depression, with several large boulders evident at the bottom, suggesting that they were exposed by sampling. There is a noticeable increase in the amount of highly reflective material near the TAG point against the mostly dark background of the surface, and many rocks were moved around.
Where thrusters fired against the surface, scientists found more substantial movement. Multiple small boulders were mobilized by the plumes into a shape similar to a campfire ring – similar to rings of boulders seen around small craters pocking the surface.
Jason Dworkin, the mission's project scientist at Goddard Space Flight Center, noticed that one boulder measuring 4 feet across on the edge of the sampling site seemed to appear only in the post-TAG image.
"The rock probably weighs around a ton, with a mass somewhere between a cow and a car," he said.
Dante Lauretta, UArizona planetary sciences professor and mission principal investigator, believes that this boulder likely was present in the pre-TAG image, but much nearer the sampling location, and the forces from the TAG event launched it 40 feet.
To compare the before and after images, the team had to meticulously plan this final flyover.
"Bennu is rough and rocky, so if you look at it from a different angle or capture it at a time when the sun is not directly overhead, that dramatically changes what the surface looks like," said Dathon Golish, a member of the OSIRIS-REx image processing working group, headquartered at UArizona. "These images were deliberately taken close to noon, with the sun shining straight down, when there's not as many shadows."
"These observations were not in the original mission plan, so we were excited to go back and document what we did," Golish said. "The team really pulled together for this one last hurrah."
The spacecraft will remain in Bennu's vicinity until departure on May 10, when the mission will begin its two-year cruise back to Earth. As it approaches Earth, the spacecraft will release the Sample Return Capsule that contains the sample from Bennu. The capsule will then travel through Earth's atmosphere and land under parachutes at the Utah Test and Training Range on Sept. 24, 2023.
Once recovered, the capsule will be transported to the curation facility at the agency's Johnson Space Center in Houston, where the sample will be removed for distribution to laboratories worldwide, enabling scientists to study the formation of the solar system and Earth as a habitable planet.
The OSIRIS-REx mission is the first NASA mission to visit a near-Earth asteroid, survey the surface, and collect a sample to deliver to Earth.
The University of Arizona leads the science team and the mission's science observation planning and data processing. NASA's Goddard Space Flight Center, located in Greenbelt, Maryland, provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. 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.
NASA’s OSIRIS-REx Completes Final Tour of Asteroid Bennu
Mission scientists will compare the final shots of the asteroid Bennu with images taken before the touch-and-go maneuver, which kicked up dust and rocks. Images are expected in about a week and will help scientists understand the asteroid's composition.
By Rani Gran, Goddard Space Flight Center - April 7, 2021
NASA's OSIRIS-REx spacecraft completed its last flyover of Bennu today at about 6 a.m. EDT, or 3 a.m. in Tucson, where the University of Arizona leads the mission. The mission team will have to wait a few more days to find out how the spacecraft changed the surface of Bennu when it grabbed a sample of the asteroid.
The OSIRIS-REx team added this flyby to document surface changes resulting from the touch-and-go, or TAG, sample collection maneuver on Oct. 20. The spacecraft is now slowly drifting away from the asteroid.
"By surveying the distribution of the excavated material around the TAG site, we will learn more about the nature of the surface and subsurface materials along with the mechanical properties of the asteroid," said mission principal investigator and UArizona planetary sciences professor Dante Lauretta. UArizona also leads the science team and the mission's science observation planning and data processing.
During the flyby, OSIRIS-REx imaged Bennu for 5.9 hours, covering more than a full rotation of the asteroid. It flew within 2.1 miles of Bennu's surface – the closest it has been since TAG.
It will take until at least April 13 for the spacecraft to downlink all of the data and new pictures of Bennu's surface recorded during the flyby. It shares the Deep Space Network antennae with other missions, such as Mars Perseverance, and typically gets four to six hours of downlink time per day.
"We collected about 4,000 megabytes of data during the flyby," said Mike Moreau, deputy project manager of OSIRIS-REx at NASA's Goddard Space Flight Center. "Bennu is approximately 185 million miles from Earth right now, which means we can only achieve a downlink data rate of 412 kilobits per second, so it will take several days to download all of the flyby data."
Once the mission team receives the images and other instrument data, it will study how OSIRIS-REx disturbed Bennu's surface. During touchdown, the spacecraft's sampling head sunk 1.6 feet into the asteroid's surface and simultaneously fired a pressurized charge of nitrogen gas. The spacecraft's thrusters kicked up a large amount of surface material during the back-away burn – launching rocks and dust in the process.
OSIRIS-REx, with its pristine and precious asteroid cargo, will remain in Bennu's vicinity until May 10, when it will fire its thrusters and begin its two-year cruise home. The mission will deliver the asteroid sample to Earth on Sept. 24, 2023.
NASA invites the public to watch OSIRIS-REx depart from Bennu on NASA.gov and NASA TV, on May 10 at 4 p.m. EDT.
NASA's Goddard Space Flight Center, located in in Greenbelt, Maryland, provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx (Origins Spectral Interpretation Resource Identification Security - Regolith Explorer). 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.
For more information about this story and OSIRIS-REx visit: NASA - OSIRIS-REx
A Final Look At Bennu Before OSIRIS-REx Heads Home
The OSIRIS-REx mission is on the brink of discovering the extent of the mess it made on asteroid Bennu's surface during last fall's sample collection event.
By Brittany Enos, OSIRIS-REx - April 1, 2021
On April 7, OSIRIS-REx will get one last close-up of asteroid Bennu as the spacecraft performs a final flyover to capture images of the asteroid's surface. While performing the flyover, the spacecraft will observe Bennu from a distance of about 2.3 miles – the closest it has been since the Touch-and-Go, or TAG, sample collection event on Oct. 20.
The University of Arizona-led OSIRIS-REx mission is the first NASA mission to visit a near-Earth asteroid, survey the surface and collect a sample to deliver back to Earth. Analysis of the sample could shed more light on the origins of the solar system and life on Earth.
The OSIRIS-REx team decided to add this final flyover after Bennu's surface was significantly disturbed by the TAG sample collection event. During TAG, the spacecraft's sampling head sunk 1.6 feet into the asteroid's surface and simultaneously fired a pressurized charge of nitrogen gas. The spacecraft's thrusters also mobilized a substantial amount of surface material during the back-away burn. Because Bennu's gravity is so weak, the various forces from the spacecraft had a dramatic effect on the sample site – launching many of the region's rocks and dust in the process. This final flyby of Bennu will provide the mission team an opportunity to learn how the spacecraft's contact with Bennu's surface altered the sample site and the region surrounding it.
"Given the amazing response of the asteroid surface to TAG, I directed the team to design one final observation sequence to document the state of the surface prior to our departure. These data provide scientific value to the returned sample and will allow for a much better understanding of the surface properties," said mission principal investigator and UArizona planetary sciences professor Dante Lauretta. The university leads the science team and the mission's science observation planning and data processing.
The single flyby will mimic one of the observation sequences conducted during the mission's Detailed Survey phase in 2019. The OSIRIS-REx science instruments will observe Bennu for 5.9 hours, more than one full rotation of Bennu. Within this timeframe, the PolyCam imager will obtain high-resolution images of Bennu's northern and southern hemispheres and its equatorial region. The team will then compare these new images with the previous high-resolution imagery of the asteroid obtained in 2019.
Several other science instruments will collect data during the flyover, including the MapCam imager, the OSIRIS-REx Thermal Emission Spectrometer, the OSIRIS-REx Visible and Infrared Spectrometer and the OSIRIS-REx Laser Altimeter. In addition to studying the disturbed surface, exercising these instruments will give the team a chance to assess the current state of each instrument, as dust coated their optics during the sample collection event. Understanding the health of the instruments is also part of NASA's evaluation of possible extended mission opportunities after the sample is delivered to Earth.
After the flyby, it will take one week for the data to be downlinked to Earth. The team will then inspect the images and other data to understand how OSIRIS-REx disturbed Bennu's surface material. At this point, the team will also be able to evaluate the performance of the science instruments.
The spacecraft will remain in asteroid Bennu's vicinity until May 10, when the mission will fire its main rocket engines and enter the Return Cruise phase, beginning the two-year journey back to Earth. As it approaches Earth, the spacecraft will jettison the Sample Return Capsule that contains the rocks and dust collected from Bennu. The capsule will then travel through the Earth's atmosphere and land under parachutes at the Utah Test and Training Range on Sep. 24, 2023.
Once recovered, the capsule will be transported to the curation facility at the agency's Johnson Space Center in Houston, where the sample will be documented and a portion distributed to laboratories worldwide, including at the University of Arizona, to allow scientists to study the formation of our solar system and Earth as a habitable planet.
NASA's Goddard Space Flight Center in Greenbelt, Maryland, provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. 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.
Probing Alien Worlds: NASA's Pandora Mission Builds on UArizona Research
Tools and methods developed at the University of Arizona will help scientists study the atmosphere of exoplanets as part of NASA's Pandora mission concept.
University Communications and NASA's Goddard Space Flight Center - March 24, 2021
In the quest for habitable planets beyond our own, NASA is studying a mission concept called Pandora, which could eventually help decode the atmospheric mysteries of distant worlds in our galaxy. One of four low-cost astrophysics missions selected for further concept development under NASA's new Pioneers program, Pandora would study approximately 20 stars and exoplanets – planets outside of our solar system – to provide precise measurements of exoplanetary atmospheres.
One of the co-investigators on the Pandora mission is Daniel Apai, an associate professor of astronomy and planetary science who heads a major NASA-funded research program called "Alien Earths," dedicated to finding which nearby planets are likely to host habitable worlds. His group has developed powerful tools and methods to create some of the first maps of the atmospheres of exoplanets and brown dwarfs.
"Equipped with the tools and methods we have developed, we will now use data from Pandora to build on advanced data analysis methods," said Apai, who leads Pandora's exoplanets science working group. "This will allow us to push the boundaries of high-precision atmospheric characterization of fascinating new worlds."
The Pandora mission concentrates on studying the atmospheres of stars and their planets by surveying planets as they cross in front of – or transit – their host stars. To accomplish this, Pandora would take advantage of a proven technique called transit spectroscopy, which involves measuring the amount of starlight filtering through a planet's atmosphere, and splitting it into bands of color known as a spectrum. These colors encode information that helps scientists identify gases present in the planet's atmosphere, and can help determine if a planet is rocky with a thin atmosphere like Earth or if it has a thick gas envelope like Neptune.
The Pandora mission would seek to determine atmospheric compositions by observing planets and their host stars simultaneously in visible and infrared light over long periods. Most notably, Pandora would examine how variations in a host star’s light impacts measurements of exoplanet atmospheres. This so-called stellar contamination remains a substantial problem in identifying the atmospheric makeup of planets orbiting stars covered in starspots – the equivalent of the more familiar sunspots – which can cause brightness variations as a star rotates.
Stellar contamination is a sticking point that complicates precise observations of exoplanets, according to Pandora co-investigator Benjamin Rackham, who obtained his doctoral degree in Apai's research group and is now a 51 Pegasi b Postdoctoral Fellow at the Massachusetts Institute of Technology in Cambridge.
"Pandora would help build the necessary tools for disentangling stellar and planetary signals, allowing us to better study the properties of both starspots and exoplanetary atmospheres,” Rackham said.
"Understanding how to disentangle the signals from planetary atmospheres and from those of their host stars is a key step toward studying the atmospheres of potentially habitable worlds," Apai added.
Pandora is a small satellite mission known as a SmallSat, one of three such orbital missions receiving the green light from NASA to move into the next phase of development in the Pioneers program. SmallSats are low-cost spaceflight missions that allow the agency to advance scientific exploration and increase access to space. Pandora would operate in sun-synchronous low-Earth orbit, which always keeps the sun directly behind the satellite. This orbit minimizes light changes on the satellite and allows Pandora to obtain data over extended periods. The mission is focused on trying to understand how stellar activity affects measurements of exoplanet atmospheres, which will lay the groundwork for future exoplanet missions aiming to find planets with Earth-like atmospheres.
Synergy in Space
Joining forces with NASA's larger missions, Pandora would operate concurrently with the James Webb Space Telescope, slated for launch later this year. Webb will provide the ability to study the atmospheres of exoplanets as small as Earth with unprecedented precision, and Pandora would seek to expand the telescope's research and findings by observing the host stars of previously identified planets over longer periods.
Missions such as NASA's Transiting Exoplanet Survey Satellite, Hubble Space Telescope, and the retired Kepler and Spitzer spacecraft have given scientists astonishing glimpses at these distant worlds, and laid a strong foundation in exoplanetary knowledge. These missions, however, have yet to fully address the stellar contamination problem, the magnitude of which is uncertain in previous studies of exoplanetary atmospheres. Pandora seeks to fill these critical gaps in NASA's understanding of planetary atmospheres and increase the capabilities in exoplanet research.
"Pandora is the right mission at the right time because thousands of exoplanets have already been discovered, and we are aware of many that are amenable to atmospheric characterization that orbit small active stars," said Jessie Dotson, an astrophysicist at NASA's Ames Research Center in California's Silicon Valley and the deputy principal investigator for Pandora. "The next frontier is to understand the atmospheres of these planets, and Pandora would play a key role in uncovering how stellar activity impacts our ability to characterize atmospheres. It would be a great complement to Webb's mission."
A Launch Pad for Exploration
NASA's Pioneers program, which consists of SmallSats, payloads attached to the International Space Station, and scientific balloon experiments, fosters innovative space and suborbital experiments for early-to-mid-career researchers through low-cost, small hardware missions. Under this new program, Pandora would operate on a five-year timeline with a budget cap of $20 million.