Orbiter.ch Space News: 2020-02-16

samedi 22 février 2020

NASA Wants Your Help Designing a Venus Rover Concept

NASA logo.

Feb. 22, 2020

NASA's Jet Propulsion Laboratory in Pasadena, California, under a grant from the NASA Innovative Advanced Concepts program, is running a public challenge to develop an obstacle avoidance sensor for a possible future Venus rover. The "Exploring Hell: Avoiding Obstacles on a Clockwork Rover" challenge is seeking the public's designs for a sensor that could be incorporated into the design concept.

Venus is an extreme world. With a surface temperature in excess of 840 degrees Fahrenheit and a surface pressure 90 times that of Earth, Venus can turn lead into a puddle and crush a nuclear-powered submarine with ease. While many missions have visited our sister planet, only about a dozen have made contact with the surface of Venus before quickly succumbing to the oppressive heat and pressure.

Image above: An illustration of a concept for a possible wind-powered Venus rover. Image Credits: NASA/JPL-Caltech.

The last spacecraft to touch the planet's surface, the Soviet Vega 2, landed in 1985. Now, engineers and scientists at JPL are studying mission designs that can survive the hellish landscape.

"Earth and Venus are basically sibling planets, but Venus took a turn at one point and became inhospitable to life as we know it," said Jonathan Sauder, a senior mechatronics engineer at JPL and principal investigator for the Automaton Rover for Extreme Environments (AREE) concept. "By getting on the ground and exploring Venus, we can understand what caused Earth and Venus to diverge on wildly different paths and can explore a foreign world right in our own backyard."

Exploring and studying different geologic units across the surface of Venus could help us understand the planet's evolution, and could contribute to a better understanding of Earth's climate.

Powered by wind, AREE is intended to spend months, not minutes, exploring the Venus landscape. AREE could collect valuable, long-term longitudinal scientific data. As the rover explores the planet, it must also detect obstacles in its path, such as rocks, crevices and steep terrain. And NASA is crowdsourcing help for that sensor design. The challenge's winning sensor will be incorporated into the rover concept and could potentially one day be the mechanism by which a rover detects and navigates around obstructions.

The difficulty of this challenge is in designing a sensor that does not rely on electronic systems. Current state-of-the-art electronics fail at just over 250 degrees Fahrenheit and would easily succumb to the extreme Venus environment. That is why NASA is turning to the global community of innovators and inventors for a solution.

"This is an exciting opportunity for the public to design a component that could one day end up on another celestial body," said Ryon Stewart, challenge coordinator for the NASA Tournament Lab at the agency's Johnson Space Center in Houston. "NASA recognizes that good ideas can come from anywhere and that prize competitions are a great way to engage the public's interest and ingenuity and make space exploration possible for everyone."

Participants will have an opportunity to win a first-place prize of $15,000. Second place wins $10,000; and third place, $5,000. JPL is working with the NASA Tournament Lab to execute the challenge on the heroX crowdsourcing platform. Submissions will be accepted through May 29, 2020.

"When faced with navigating one of the most challenging terrestrial environments in the solar system, we need to think outside the box," Sauder said. "That is why we need the creativity of makers and garage inventors to help solve this challenge."

For more information about the challenge and how to enter, visit:

https://www.herox.com/VenusRover

AREE is an early-stage research study funded by the NASA Innovative Advanced Concepts (NIAC) program within the agency's Space Technology Mission Directorate (STMD). NIAC is a visionary and far-reaching aerospace program, one that has the potential to create breakthrough technologies for possible future space missions; however, such early-stage technology developments may never become actual NASA missions.

NASA Tournament Lab is part of NASA's Prizes and Challenges program within STMD. The program supports the use of public competitions and crowdsourcing as tools to advance NASA R&D and other mission needs.

Learn more about opportunities to participate in your space program:

http://www.nasa.gov/solve

Space Technology Mission Directorate (STMD): https://www.nasa.gov/directorates/spacetech/home/index.html

heroX crowdsourcing platform: https://www.herox.com/

NASA Tournament Lab: https://www.nasa.gov/offices/COECI/index.html

NASA Innovative Advanced Concepts: https://www.nasa.gov/directorates/spacetech/niac/index.html

AREE: https://www.nasa.gov/feature/automaton-rover-for-extreme-environments-aree

Image (mentioned), Text, Credits: NASA/Randal Jackson/Clare A. Skelly/JPL/Matthew Segal.

Greetings, Orbiter.ch

vendredi 21 février 2020

NASA's Mars InSight Lander to Push on Top of the 'Mole'

NASA - InSight Mission patch.

Feb. 21, 2020

After nearly a year of trying to dig into the Martian surface, the heat probe belonging to NASA's InSight lander is about to get a push. The mission team plans to command the scoop on InSight's robotic arm to press down on the "mole," the mini pile driver designed to hammer itself as much as 16 feet (5 meters) down. They hope that pushing down on the mole's top, also called the back cap, will keep it from backing out of its hole on Mars, as it did twice in recent months after nearly burying itself.

Animation above: NASA InSight recently moved its robotic arm closer to its digging device, called the "mole," in preparation to push on its top, or back cap. Animation Credits: NASA/JPL-Caltech.

Part of an instrument called the Heat Flow and Physical Properties Package, or HP3, the mole is a 16-inch-long (40-centimeter-long) spike equipped with an internal hammering mechanism. While burrowing into the soil, it is designed to drag with it a ribbonlike tether that extends from the spacecraft. Temperature sensors are embedded along the tether to measure heat coming deep from within the planet's interior to reveal important scientific details about the formation of Mars and all rocky planets, including Earth. HP3 was provided to NASA by the German Aerospace Center, or DLR.

The team has avoided pushing on the back cap until now to avoid any potential damage to the tether.

Image above: This test using an engineering model of the InSight lander here on Earth shows how the spacecraft on Mars will use its robotic arm to press on a digging device, called the "mole." Image Credits: NASA/JPL-Caltech.

The mole found itself stuck on Feb. 28, 2019, the first day of hammering. The InSight team has since determined that the soil here is different than what has been encountered on other parts of Mars. InSight landed in an area with an unusually thick duricrust, or a layer of cemented soil. Rather than being loose and sandlike, as expected, the dirt granules stick together.

The mole needs friction from soil in order to travel downward; without it, recoil from its self-hammering action causes it to simply bounce in place. Ironically, loose soil, not duricrust, provides that friction as it falls around the mole.

This past summer, the InSight team started using the robotic arm's scoop to press on the side of the mole, a technique called "pinning" that added just enough friction to help it dig without coming in contact with the fragile science tether connected to the mole's back cap.

While pinning helped, the mole popped back out of the Martian soil on two occasions, possibly from soil building up from beneath. With few alternatives left, the team has decided to try helping the mole dig by carefully pressing on its back cap while attempting to avoid the tether.

Mars InSight lander & logo. Animation Credits: NASA/JPL

It might take several tries to perfect the back-cap push, just as pinning did. Throughout late February and early March, InSight's arm will be maneuvered into position so that the team can test what happens as the mole briefly hammers.

Meanwhile, the team is also considering using the scoop to move more soil into the hole that has formed around the mole. This could add more pressure and friction, allowing it to finally dig down. Whether they pursue this route depends on how deep the mole is able to travel after the back-cap push.

About InSight:

JPL manages InSight for NASA's Science Mission Directorate. InSight is part of NASA's Discovery Program, managed by the agency's Marshall Space Flight Center in Huntsville, Alabama. Lockheed Martin Space in Denver built the InSight spacecraft, including its cruise stage and lander, and supports spacecraft operations for the mission.

A number of European partners, including France's Centre National d'Études Spatiales (CNES) and the German Aerospace Center (DLR), are supporting the InSight mission. CNES provided the Seismic Experiment for Interior Structure (SEIS) instrument to NASA, with the principal investigator at IPGP (Institut de Physique du Globe de Paris). Significant contributions for SEIS came from IPGP; the Max Planck Institute for Solar System Research (MPS) in Germany; the Swiss Federal Institute of Technology (ETH Zurich) in Switzerland; Imperial College London and Oxford University in the United Kingdom; and JPL. DLR provided the Heat Flow and Physical Properties Package (HP3) instrument, with significant contributions from the Space Research Center (CBK) of the Polish Academy of Sciences and Astronika in Poland. Spain's Centro de Astrobiología (CAB) supplied the temperature and wind sensors.

Related articles:

Mars InSight's Mole Has Partially Backed Out of Its Hole
https://orbiterchspacenews.blogspot.com/2019/10/mars-insights-mole-has-partially-backed.html

Mars InSight's 'Mole' Is Moving Again
https://orbiterchspacenews.blogspot.com/2019/10/mars-insights-mole-is-moving-again.html

NASA's Push to Save the Mars InSight Lander's Heat Probe
https://orbiterchspacenews.blogspot.com/2019/10/nasas-push-to-save-mars-insight-landers.html

For more about InSight, read here:

https://mars.nasa.gov/insight/

https://www.nasa.gov/insight/

Seismic Experiment for Interior Structure (SEIS): https://mars.nasa.gov/insight/mission/instruments/seis/

Image (mentioned), Animations (mentioned), Text, Credits: NASA/Tony Greicius/Alana Johnson/JPL/Andrew Good.

Greetings, Orbiter.ch

Space Station Science Highlights: Week of February 17, 2020

ISS - Expedition 62 Mission patch.

Feb. 21, 2020

The three members of Expedition 62 currently aboard the International Space Station conducted scientific research the week of Feb. 17 that included studies of neutron radiation, bone loss and phage therapy. New scientific experiments and facilities and supplies arrived early on Tuesday, Feb. 18, on the Northrop Grumman 13th commercial resupply services mission. The Cygnus spacecraft remains at the space station until May. NASA’s CubeSat Launch Initiative deployed nine small satellites, including AzTechSat-1, developed by the Universidad Popular Autonoma del Estado de Puebla (UPAEP) in Mexico that will use the Globalstar satellite constellation for satellite phone and low-speed data communications.

Image above: New scientific experiments and supplies arrived at the space station early on Tuesday, Feb. 18, on Northrop Grumman’s Cygnus cargo craft, shown here attached to the Unity module shortly after being captured with the Canadarm2 robotic arm. Cygnus remains docked at the space station for three months. Image Credit: NASA.

Now in its 20th year of continuous human presence, the space station provides a platform for long-duration research in microgravity and for learning to live and work in space. Experience gained on the orbiting lab supports Artemis, NASA’s program to go forward to the Moon and on to Mars.

Here are details on some of the microgravity investigations currently taking place:

Nowhere to hide for neutrons

Image above: One of the bubble detectors for the Radi-N2 investigation, which characterizes the neutron environment aboard the space station in order to help define the risk posed to the health of crew members and support development of measures to protect them on future long spaceflights. Image Credit: NASA.

The crew deployed detectors for the Radi-N2 investigation near Cupola windows. This Canadian Space Agency investigation uses bubble detectors to better characterize the neutron environment on the space station, which could help define the risk this radiation source poses to crew members and provide data necessary to develop advanced protective measures for future spaceflight. Neutrons make up a significant fraction of the biologically effective radiation exposure in low-Earth orbit. The bubble detectors monitor neutrons and ignore all other radiation.

A close look at osteoblasts

Image above: Osteoblast and osteoclast cells fixed and stained for the OsteoOmics investigation, which examines bone-forming cells to determine the molecular mechanisms behind bone loss experienced by people in space. Image Credits: Bruce Hammer, University of Minnesota.

Humans experience bone loss in microgravity as well as from disease or prolonged bed rest on Earth. OsteoOmics investigates the molecular and metabolic changes that occur in osteoblasts, cells in the body that form bone, in real and simulated microgravity. A better understanding of these changes could help researchers understand the mechanisms of bone loss in space and on Earth and lead to better prevention and treatment.

During the week, crew members conducted set-up and operations for the investigation.

Fighting viruses with phages

Bacteriophages, viruses that invade and destroy bacteria, have potential for fighting infectious diseases. With resistance to antibiotics increasing, phage therapy offers a possible alternative. In addition, phages can eliminate harmful bacteria without causing large-scale damage to the body’s beneficial bacterial population or microbiome. Scientists also can evolve phages in the laboratory to remain potent even if resistant bacteria develop.

Phage Evolution examines the effects of microgravity and radiation exposure on phage and host interactions, including phage specificity for a host and host resistance to specific phages. A better understanding of the effects of microgravity and cosmic radiation on bacteriophages and hosts could result in significant developments for phage technology, ultimately helping protect the health of astronauts on future missions. Crew members performed set-up activities in the Space Automated Bioproduct Lab (SABL) and the Minus Eighty-Degree Laboratory Freezer for ISS (MELFI) for the investigation.

Other investigations on which the crew performed work:

- ISS HAM gives students an opportunity to talk directly with crew members via ham radio when the space station passes over their schools. This interaction engages and educates students, teachers, parents and other members of the community in science, technology, engineering and math.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=337

- Zero-G Oven examines heat transfer properties and the process of baking food in microgravity. On future long-duration missions, fresh-baked food could have psychological and physiological benefits for crew members.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7993

- Food Acceptability examines the effect of repetitive consumption of the food currently available during spaceflight. “Menu fatigue” resulting from a limited choice of foods over time may contribute to the loss of body mass often experienced by crew members, potentially affecting astronaut health, especially as mission length increases.
https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7562

Space to Ground: Liftoff from Virginia: 02/21/2020

jeudi 20 février 2020

ROSCOSMOS - Soyuz-2.1a launches new Meridian-M satellite

ROSCOSMOS logo.

Feb 20, 2020

Soyuz-2.1a carrying Meridian-M launch

A Soyuz-2.1a launch vehicle launched a new Meridian-M communications satellite from the Plesetsk Cosmodrome, Russia, on 20 February 2020, at 08:24 UTC (11:24 local time). According to official sources, the satellite was placed into the desired orbit.

Soyuz-2.1a launches new Meridian-M satellite

A Russian government Soyuz rocket with a Fregat upper stage will launch a Meridian M communications satellite for the Russian Ministry of Defense.

Meridian-M satellite

The Soyuz rocket will fly in the Soyuz-2.1a configuration. Delayed from Jan. 24.

For more information about ROSCOSMOS, visit: http://en.federalspace.ru/

Images, Video, Text, Credits: ROSCOSMOS/SciNews/Günter Space Page/Orbiter.ch Aerospace/Roland Berga.

Best regards, Orbiter.ch

CASC - Long March-2D launches four satellites

CASC - China Aerospace Science and Technology Corporation logo.

Feb 20, 2020

Long March-2D rocket carrying four satellites launch

A Long March-2D rocket launched four new technology test satellites (JSW-C, D, E, F) from the Xichang Satellite Launch Center, Sichuan Province, southwest China, on 19 February 2020, at 21:07 UTC (20 February, at 05:07 local time). According to official sources, the satellites entered their planned orbits and will be mainly used for new Earth-observation technology tests.

Long March-2D launches four satellites

Two satellites were developed by the Shanghai Academy of Spaceflight Technology, the other two satellites were respectively developed by the Harbin Institute of Technology and the DFH Satellite Co., Ltd.

ÑuSat 7 & ÑuSat 8 satellites

A Chinese Long March 2D launches a small satellite for the Jilin 1 Earth observation constellation owned by Chang Guang Satellite Technology Co. Ltd. The Long March 2D will also launch the ÑuSat 7 and ÑuSat 8 Earth observation microsatellites for Satellogic, a company based on Argentina.

For more information about China Aerospace Science and Technology Corporation (CASC): http://english.spacechina.com/n16421/index.html

Images, Text, Video, Credits: CASC/China Central Television (CCTV)/SciNews/Satellogic/Orbiter.ch Aerospace/Roland Berga.

Greetings, Orbiter.ch

Bone Research and Pilot Studies as Crew Trains for Emergencies

ISS - Expedition 62 Mission patch.

February 20, 2020

New bone research kicked off on the International Space Station today to improve human health on and off the Earth. The Expedition 62 crew also practiced an emergency simulation with ground controllers.

Living in space causes bone loss and scientists are studying ways to offset the negative effects to ensure long-term mission success. Results from the new OsteoOmics-02 study aboard the orbiting lab also have implications bone diseases on Earth.

Image above: Astronauts Andrew Morgan and Jessica Meir were conducting space biology research inside the Japanese Kibo lab module’s Life Sciences Glovebox in November 2019. Image Credit: NASA.

NASA astronauts Jessica Meir and Andrew Morgan spent Thursday morning setting up the bone experiment hardware for operations in the Life Sciences Glovebox. Doctors will be observing the mechanisms of rapid bone loss in microgravity and extend that knowledge to learn more about osteoporosis on Earth.

The duo then joined Commander Oleg Skripochka of Roscosmos in the afternoon and practiced their emergency response training. The three crewmates coordinated their communication, roles and responsibilities with mission controllers in Houston and Moscow. In the unlikely event of a fire, chemical leak or pressure leak, the crew would need to locate safety gear, close module hatches and possibly evacuate the station aboard a Soyuz crew ship.

International Space Station (ISS). Animation Credit: NASA

Before the training session, Skripochka spent the morning on an experiment exploring how long-term spaceflight impacts the professionalism of a crewmember. Results will help Russian scientists understand how a cosmonaut will react to different phases of a mission such as docking to another spacecraft or landing on another planet.

Related links:

Expedition 62: https://www.nasa.gov/mission_pages/station/expeditions/expedition62/index.html

OsteoOmics-02: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=1149

Life Sciences Glovebox: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=7676

Professionalism of a crewmember: https://www.energia.ru/en/iss/researches/human/24.html

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Image (mentioned), Animation (mentioned), Text, Credits: NASA/Mark Garcia.

Best regards, Orbiter.ch

Beyond the Brim, Sombrero Galaxy’s Halo Suggests Turbulent Past

NASA - Hubble Space Telescope patch.

Feb. 20, 2020

Surprising new data from NASA's Hubble Space Telescope suggests the smooth, settled "brim" of the Sombrero galaxy's disk may be concealing a turbulent past. Hubble's sharpness and sensitivity resolves tens of thousands of individual stars in the Sombrero's vast, extended halo, the region beyond a galaxy's central portion, typically made of older stars. These latest observations of the Sombrero are turning conventional theory on its head, showing only a tiny fraction of older, metal-poor stars in the halo, plus an unexpected abundance of metal-rich stars typically found only in a galaxy's disk, and the central bulge. Past major galaxy mergers are a possible explanation, though the stately Sombrero shows none of the messy evidence of a recent merger of massive galaxies.

"The Sombrero has always been a bit of a weird galaxy, which is what makes it so interesting," said Paul Goudfrooij of the Space Telescope Science Institute (STScI), Baltimore, Maryland. "Hubble's metallicity measurements (i.e., the abundance of heavy elements in the stars) are another indication that the Sombrero has a lot to teach us about galaxy assembly and evolution."

"Hubble's observations of the Sombrero's halo are turning our generally accepted understanding of galaxy makeup and metallicity on its head," added co-investigator Roger Cohen of STScI.

Long a favorite of astronomers and amateur sky watchers alike for its bright beauty and curious structure, the Sombrero galaxy (M104) now has a new chapter in its strange story — an extended halo of metal-rich stars with barely a sign of the expected metal-poor stars that have been observed in the halos of other galaxies. Researchers, puzzling over the data from Hubble, turned to sophisticated computer models to suggest explanations for the perplexing inversion of conventional galactic theory. Those results suggest the equally surprising possibility of major mergers in the galaxy's past, though the Sombrero's majestic structure bears no evidence of recent disruption. The unusual findings and possible explanations are published in the Astrophysical Journal.

Image above: On the left is an image of the Sombrero galaxy (M104) that includes a portion of the much fainter halo far outside its bright disk and bulge. Hubble photographed two regions in the halo (one of which is shown by the white box). The images on the right zoom in to show the level of detail Hubble captured. The orange box, a small subset of Hubble's view, contains myriad halo stars. The stellar population increases in density closer to the galaxy's disk (bottom blue box). Each frame contains a bright globular cluster of stars, of which there are many in the galaxy's halo. The Sombrero's halo contained more metal-rich stars than expected, but even stranger was the near-absence of old, metal-poor stars typically found in the halos of massive galaxies. Many of the globular clusters, however, contain metal-poor stars. A possible explanation for the Sombrero's perplexing features is that it is the product of the merger of massive galaxies billions of years ago, even though the smooth appearance of the galaxy's disk and halo show no signs of such a huge disruption. Image Credits: NASA/Digitized Sky Survey/P. Goudfrooij (STScI)/The Hubble Heritage Team (STScI/AURA).

"The absence of metal-poor stars was a big surprise," said Goudfrooij, "and the abundance of metal-rich stars only added to the mystery."

In a galaxy's halo astronomers expect to find earlier generations of stars with less heavy elements, called metals, as compared to the crowded stellar cities in the main disk of a galaxy. Elements are created through the stellar "lifecycle" process, and the longer a galaxy has had stars going through this cycle, the more element-rich the gas and the higher-metallicity the stars that form from that gas. These younger, high-metallicity stars are typically found in the main disk of the galaxy where the stellar population is denser — or so goes the conventional wisdom.

Complicating the facts is the presence of many old, metal-poor globular clusters of stars. These older, metal-poor stars are expected to eventually move out of their clusters and become part of the general stellar halo, but that process seems to have been inefficient in the Sombrero galaxy. The team compared their results with recent computer simulations to see what could be the origin of such unexpected metallicity measurements in the galaxy's halo.

The results also defied expectations, indicating that the unperturbed Sombrero had undergone major accretion, or merger, events billions of years ago. Unlike our Milky Way galaxy, which is thought to have swallowed up many small satellite galaxies in so-called "minor" accretions over billions of years, a major accretion is the merger of two or more similarly massive galaxies that are rich in later-generation, higher-metallicity stars.

The satellite galaxies only contained low-metallicity stars that were largely hydrogen and helium from the big bang. Heavier elements had to be cooked up in stellar interiors through nucleosynthesis and incorporated into later-generation stars. This process was rather ineffective in dwarf galaxies such as those around our Milky Way, and more effective in larger, more evolved galaxies.

The results for the Sombrero are surprising because its smooth disk shows no signs of disruption. By comparison, numerous interacting galaxies, like the iconic Antennae galaxies, get their name from the distorted appearance of their spiral arms due to the tidal forces of their interaction. Mergers of similarly massive galaxies typically coalesce into large, smooth elliptical galaxies with extended halos — a process that takes billions of years. But the Sombrero has never quite fit the traditional definition of either a spiral or an elliptical galaxy. It is somewhere in between — a hybrid.

For this particular project, the team chose the Sombrero mainly for its unique morphology. They wanted to find out how such "hybrid" galaxies might have formed and assembled over time. Follow-up studies for halo metallicity distributions will be done with several galaxies at distances similar to that of the Sombrero.

Hubble Space Telescope (HST)

The research team looks forward to future observatories continuing the investigation into the Sombrero's unexpected properties. The Wide Field Infrared Survey Telescope (WFIRST), with a field of view 100 times that of Hubble, will be capable of capturing a continuous image of the galaxy's halo while picking up more stars in infrared light. The James Webb Space Telescope will also be valuable for its Hubble-like resolution and deeper infrared sensitivity.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

Related link:

Astrophysical Journal: http://apj.aas.org/

For more information about Hubble, visit:

http://hubblesite.org/

http://www.nasa.gov/hubble

http://www.spacetelescope.org/

Image (mentioned), Animation (ESA/NASA), Text, Credits: NASA/Rob Garner/Goddard Space Flight Center/Claire Andreoli/Rob Gutro/Space Telescope Science Institute/Leah Ramsay/Ray Villard/Roger Cohen/Paul Goudfrooij.

Best regards, Orbiter.ch

A Cosmic Jekyll and Hyde

NASA - Chandra X-ray Observatory patch.

Feb. 20, 2020

A double star system has been flipping between two alter egos, according to observations with NASA’s Chandra X-ray Observatory and the National Science Foundation’s Karl F. Jansky Very Large Array (VLA). Using nearly a decade and a half worth of Chandra data, researchers noticed that a stellar duo behaved like one type of object before switching its identity, and then returning to its original state after a few years. This is a rare example of a star system changing its behavior in this way.

Astronomers found this volatile double, or binary, system in a dense collection of stars, the globular cluster Terzan 5, which is located about 20,000 light years from Earth in the Milky Way galaxy. This stellar duo, known as Terzan 5 CX1, has a neutron star (the extremely dense remnant left behind by a supernova explosion) in close orbit around a star similar to the Sun, but with less mass.

In this new image of Terzan 5 (right), low, medium and high-energy X-rays detected by Chandra are colored red, green and blue respectively. On the left, an image from the Hubble Space Telescope shows the same field of view in optical light. Terzan 5 CX1 is labeled as CX1 in the Chandra image.

In binary systems like Terzan 5 CX1, the heavier neutron star pulls material from the lower-mass companion into a surrounding disk. Astronomers can detect these so-called accretion disks by their bright X-ray light, and refer to these objects as “low-mass X-ray binaries.”

Spinning material in the disk falls onto the surface of the neutron star, increasing its rotation rate. The neutron star can spin faster and faster until the roughly 10-mile-wide sphere, packed with more mass than the Sun, is rotating hundreds of times per second. Eventually, the transfer of matter slows down and the remaining material is swept away by the whirling magnetic field of the neutron star, which becomes a millisecond pulsar. Astronomers detect pulses of radio waves from these millisecond pulsars as the neutron star's beam of radio emission sweeps over the Earth during each rotation.

While scientists expect the complete evolution of a low-mass X-ray binary into a millisecond pulsar should happen over several billion years, there is a period of time when the system can switch rapidly between these two states. Chandra observations of Terzan 5 CX1 show that it was acting like a low-mass X-ray binary in 2003, because it was brighter in X-rays than any of the dozens of other sources in the globular cluster. This was a sign that the neutron star was likely accumulating matter.

In Chandra data taken from 2009 to 2014, Terzan 5 CX1 had become about ten times fainter in X-rays. Astronomers also detected it as a radio source with the VLA in 2012 and 2014. The amount of radio and X-ray emission and the corresponding spectra (the amount of emission at different wavelengths) agree with expectations for a millisecond pulsar. Although the radio data used did not allow a search for millisecond pulses, these results imply that Terzan 5 CX1 underwent a transformation into behaving like a millisecond pulsar and was blowing material outwards. By the time Chandra had observed Terzan 5 CX1 again in 2016, it had become brighter in X-rays and changed back to acting like a low-mass X-ray binary again.

To confirm this pattern of “Jekyll and Hyde” behavior, astronomers need to detect radio pulses while Terzan 5 CX1 is faint in X-rays. More radio and X-ray observations are planned to search for this behavior, along with sensitive searches for pulses in existing data. Only three confirmed examples of these identity-changing systems are known, with the first discovered in 2013 using Chandra and several other X-ray and radio telescopes.

The study of the “Jekyll and Hyde” binary was led by Arash Bahramian of the International Center for Radio Astronomy Research (ICRAR), Australia and was published in the September 1st, 2018 issue of The Astrophysical Journal. A preprint is available here.

Two other recent studies have used Chandra observations of Terzan 5 to study how neutron stars in two different low-mass X-ray binaries recover after having had large amounts of material dumped on their surface by a companion star. Such studies are important for understanding the structure of a neutron star’s outer layer, known as its crust.

In one of these studies, of the low-mass X-ray binary Swift J174805.3–244637 (T5 X-3 for short), material dumped onto the neutron star during an X-ray outburst detected by Chandra in 2012 heated up the star's crust. The crust of the neutron star then cooled down, taking about a hundred days to fall back to the temperature seen before the outburst. The rate of cooling agrees with a computer model for such a process.

Chandra X-ray Observatory. Animation Credits: NASA/CXC

In a separate Chandra study of a different low-mass X-ray binary in Terzan 5, IGR J17480–2446 (T5 X-2 for short) the neutron star was still cooling when its temperature was taken five and a half years after it was known to have an outburst. These results show this neutron star’s crust ability to transfer, or conduct, heat may be lower than what astronomers have found in other cooling neutron stars in low-mass X-ray binaries. This difference in the ability to conduct heat may be related to T5 X-2 having a higher magnetic field compared to other cooling neutron stars, or being much younger than T5 X-3.

Both T5 X-3 and T5 X-2 are labeled in the image.

The work on the rapidly cooling neutron star, led by Nathalie Degenaar of the University of Amsterdam in the Netherlands, was published in the June 2015 issue of the Monthly Notices of the Royal Astronomical Society and a preprint is available here. The study of the slowly cooling neutron star, led by Laura Ootes, then of the University of Amsterdam, was published in the July 2019 issue of the Monthly Notices of the Royal Astronomical Society and a preprint is available here: https://arxiv.org/abs/1805.00610

NASA's Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory's Chandra X-ray Center controls science and flight operations from Cambridge and Burlington, Massachusetts.

Read more from NASA's Chandra X-ray Observatory: https://chandra.harvard.edu/photo/2020/terzan5/

For more Chandra images, multimedia and related materials, visit: http://www.nasa.gov/chandra

Animation (mentioned), Images, Text, Credits: NASA/Jennifer Harbaugh/Chandra X-ray Center/Megan Watzke/Marshall Space Flight Center/Molly Porter.

Greetings, Orbiter.ch

Improving Shoes, Showers, 3D Printing: Research Launching to the Space Station

SpaceX - Dragon CRS-20 Mission patch.

Feb. 20, 2020

A variety of science investigations, along with supplies and equipment, launch to the International Space Station on the 20th SpaceX commercial resupply services mission. The Dragon cargo spacecraft is scheduled to leave Earth March 2 from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida. Its cargo includes research on particle foam manufacturing, water droplet formation, the human intestine and other cutting-edge investigations.

Image above: Airbus workers unpack the Bartolomeo platform at NASA’s Kennedy Space Center in Florida in preparation for its launch to the International Space Station. The platform, manufactured by Airbus Defence and Space, hosts multiple external payloads in low-Earth orbit. Image Credit: NASA.

The space station, now in its 20th year of continuous human presence, provides opportunities for research by government agencies, private industry, and academic and research institutions. Such research supports Artemis, NASA’s missions to the Moon and Mars, and leads to new technologies, medical treatments and products that improve life on Earth.

High-tech shoes from space

Particle foam molding is a manufacturing process that blows thousands of pellets into a mold where they fuse together. The shoe company Adidas uses this process to make performance midsoles, the layer between the sole of a shoe and the insole under your foot, for its products. The BOOST Orbital Operations on Spheroid Tesellation (Adidas BOOST) investigation looks at how multiple types of pellets behave in this molding process. Using one type of pellet creates a foam with the same properties throughout the sole component. Using multiple pellet types can allow engineers to change mechanical properties and optimize shoe performance and comfort. Removing gravity from the process enables a closer look at pellet motion and location during the process.

Results of this investigation could demonstrate the benefits of microgravity research for manufacturing methods, contributing to increased commercial use of the space station. New processes for particle foam molding could benefit a variety of other industries, including packaging and cushioning materials.

New facility outside the space station

The Bartolomeo facility, created by ESA (European Space Agency) and Airbus, attaches to the exterior of the European Columbus Module. Designed to provide new scientific opportunities on the outside of the space station for commercial and institutional users, the facility offers unobstructed views both toward Earth and into space. Experiments hosted in Bartolomeo receive comprehensive mission services, including technical support in preparing the payload, launch and installation, operations and data transfer and optional return to Earth. Potential applications include Earth observation, robotics, material science and astrophysics.

Airbus is collaborating with the United Nations Office of Outer Space Affairs to offer UN Member States the opportunity to fly a payload on Bartolomeo. Developing countries are particularly encouraged to participate, and the mission is devoted to addressing the UN’s Sustainable Development Goals. Bartolomeo is named for the younger brother of Christopher Columbus.

Conserving water in the shower

Droplet Formation Studies in Microgravity (Droplet Formation Study) evaluates water droplet formation and water flow of Delta Faucet’s H2Okinetic showerhead technology. Reduced flow rates in shower devices conserve water, but also can reduce their effectiveness. That can cause people to take longer showers, undermining the goal of using less water. Gravity’s full effects on the formation of water droplets are unknown, and research in microgravity could help improve the technology, creating better performance and improved user experience while conserving water and energy.

Insight gained from this investigation also has potential applications in various uses of fluids on spacecraft, from human consumption of liquids to waste management and use of fluids for cooling and as propellants.

Studying the human intestine on a chip

Organ-Chips as a Platform for Studying Effects of Space on Human Enteric Physiology (Gut on Chip) examines the effect of microgravity and other space-related stress factors on biotechnology company Emulate’s human innervated Intestine-Chip (hiIC). This Organ-Chip device enables the study of organ physiology and diseases in a laboratory setting. It allows for automated maintenance, including imaging, sampling, and storage on orbit and data downlink for molecular analysis on Earth.

Image above: Human intestine cells forming microvilli inside Emulate’s Intestine-Chip. Image Credit: Emulate.

A better understanding of how microgravity and other potential space travel stressors affect intestine immune cells and susceptibility to infection could help protect astronaut health on future long-term missions. It also could help identify the mechanisms that underlie development of intestinal diseases and possible targets for therapies to treat them on Earth.

Toward better 3D printing

Self-assembly and self-replication of materials and devices could enable 3D printing of replacement parts and repair facilities on future long-duration space voyages. Better design and assembly of structures in microgravity also could benefit a variety of fields on Earth, from medicine to electronics.

The Nonequilibrium Processing of Particle Suspensions with Thermal and Electrical Field Gradients (ACE-T-Ellipsoids) experiment designs and assembles complex three-dimensional colloids – small particles suspended within a fluid – and controls density and behavior of the particles with temperature. Called self-assembled colloidal structures, these are vital to the design of advanced optical materials, but control of particle density and behavior is especially important for their use in 3D printing. Microgravity provides insight into the relationships among particle shape, crystal symmetry, density and other characteristics.

Functional structures based on colloids could lead to new devices for chemical energy, communication, and photonics.

Growing human heart cells

Generation of Cardiomyocytes From Human Induced Pluripotent Stem Cell-derived Cardiac Progenitors Expanded in Microgravity (MVP Cell-03) examines whether microgravity increases the production of heart cells from human-induced pluripotent stem cells (hiPSCs). HiPSCs are adult cells genetically reprogrammed back into an embryonic-like pluripotent state, which means they can give rise to several different types of cells. This makes them capable of providing an unlimited source of human cells for research or therapeutic purposes. For MVP Cell-03, scientists induce the stem cells to generate heart precursor cells, then culture those cells on the space station for analysis and comparison with cultures grown on Earth.

Image above: The Multi-use Variable-g Platform (MVP) used for the MVP Cell-03 experiment, shown with the MVP door removed and two carousels inside. Image Credit: Techshot Inc.

These heart cells or cardiomyocytes (CMs) could help treat cardiac abnormalities caused by spaceflight. In addition, scientists could use them to replenish cells damaged or lost due to cardiac disease on Earth and for cell therapy, disease modeling and drug development. Human cardiac tissues damaged by disease cannot repair themselves, and loss of CMs contributes to eventual heart failure and death.

Related links:

Adidas BOOST: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=8210

Bartolomeo: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=7799

UN Sustainable Development Goals: https://sustainabledevelopment.un.org/?menu=1300

Droplet Formation Study: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7541

Gut on Chip: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=8078

Organ-Chip: https://www.nasa.gov/tissue-chips

ACE-T-Ellipsoids: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=8166

MVP Cell-03: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7725

ISS National Lab: https://www.issnationallab.org/

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Text, Credits: NASA/Michael Johnson/JSC/International Space Station Program Science Office/Melissa Gaskill.

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XMM-Newton reveals giant flare from a tiny star

ESA - XMM-Newton Mission patch.

Feb. 20, 2020

A star of about eight percent the Sun’s mass has been caught emitting an enormous ‘super flare’ of X-rays – a dramatic high-energy eruption that poses a fundamental problem for astronomers, who did not think it possible on stars that small.

The culprit, known by its catalogue number J0331-27, is a kind of star called an L dwarf. This is a star with so little mass that it is only just above the boundary of actually being a star. If it had any less mass, it would not possess the internal conditions necessary to generate its own energy.

Astronomers spotted the enormous X-ray flare in data recorded on 5 July 2008 by the European Photon Imaging Camera (EPIC) onboard ESA’s XMM-Newton X-ray observatory. In a matter of minutes, the tiny star released more than ten times more energy of even the most intense flares suffered by the Sun.

Solar eruption larger than Earth

Image above: A giant flare suffered by our own Sun, captured on 27 July 1999 by the ESA/NASA Solar and Heliospheric Observatory (SOHO).

Flares are released when the magnetic field in a star’s atmosphere becomes unstable and collapses into a simpler configuration. In the process, it releases a large proportion of the energy that has been stored in it.

This explosive release of energy creates a sudden brightening – the flare – and this is where the new observations present their biggest puzzle.

“This is the most interesting scientific part of the discovery, because we did not expect L-dwarf stars to store enough energy in their magnetic fields to give rise to such outbursts,” says Beate Stelzer, Institut für Astronomie und Astrophysik Tübingen, Germany, and INAF – Osservatorio Astronomico di Palermo, Italy, who was part of the study team.

Energy can only be placed in a star’s magnetic field by charged particles, which are also known as ionised material and created in high-temperature environments. As an L dwarf, however, J0331-27 has a low surface temperature for a star – just 2100K compared to the roughly 6000K on the Sun. Astronomers did not think such a low temperature would be capable of generating enough charged particles to feed so much energy into the magnetic field. So the conundrum is: how a super flare is even possible on such a star.

“That’s a good question,” says Beate. “We just don’t know – nobody knows.”

Giant flare from a tiny star

The super flare was discovered in the XMM-Newton data archive as part of a large research project led by Andrea De Luca of INAF – Istituto di Astrofisica Spaziale e Fisica Cosmica in Milan, Italy. The project studied the temporal variability of around 400 000 sources detected by XMM-Newton over 13 years

Andrea and collaborators were particularly looking for peculiar phenomena and in J0331-27 they certainly got that. A number of similar stars had been seen to emit super flares in the optical part of the spectrum, but this is the first unambiguous detection of such an eruption at X-ray wavelengths.

The wavelength is significant because it signals which part of the atmosphere the super flare is coming from: optical light comes from deeper in the star’s atmosphere, near its visible surface, whereas X-rays come from higher up in the atmosphere.

Understanding the similarities and differences between this new – and so far unique – super flare on the L dwarf and previously observed flares, detected at all wavelengths on stars of higher mass is now a priority for the team. But to do that, they need to find more examples.

“There is still much to be discovered in the XMM-Newton archive,” says Andrea. “In a sense, I think this is only the tip of the iceberg.”

XMM-Newton

One clue they do have is that there is only one flare from J0331-27 in the data, despite XMM-Newton having observed the star for a total of 3.5 million seconds – about 40 days. This is peculiar because other flaring stars tend to suffer from numerous smaller flares too.

“The data seem to imply that it takes an L dwarf longer to build up the energy, and then there is one sudden big release,” says Beate.

Stars that flare more frequently release less energy each time, while this L dwarf seems to release energy very rarely but then in a really big event. Why this might be the case is still an open question that needs further investigation.

“The discovery of this L dwarf super flare is a great example of research based on the XMM-Newton archive, demonstrating the mission's enormous scientific potential,” says Norbert Schartel, XMM-Newton project scientist for ESA. “I look forward to the next surprise.”

Notes for Editors:

“EXTraS discovery of an X-ray superflare from an L dwarf” by A. De Luca et al. 2020 is published in Astronomy & Astrophysics: https://doi.org/10.1051/0004-6361/201937163%20

The discovery was made as a result of the Exploring the X-ray Transient and variable Sky (EXTraS) project, a EU/FP7 project devoted to a systematic variability study of the X-ray sources in the XMM-Newton public archive.

ESA XMM-Newton: https://www.esa.int/Science_Exploration/Space_Science/XMM-Newton_overview

Images, Text, Credits: ESA/C. Carreau/SOHO (ESA & NASA)/ESA/Norbert Schartel/INAF/Andrea De Luca/Institut für Astronomie und Astrophysik Tübingen/Beate Stelzer.

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mercredi 19 février 2020

The CubeSat Launch Initiative Celebrates its 100th CubeSat Mission Deployment

NASA logo.

Feb. 19, 2020

CubeSat's in space. Image Credit: NASA

Today the Hyper-Angular Rainbow Polarimeter (HARP) CubeSat made history by becoming the 100th CubeSat Launch Initiative (CSLI) selected mission deployed into space. This mission marks nearly 12 years of the CSLI providing CubeSat developers rideshare opportunities to space via Educational Launch of Nanosatellites (ELaNa) missions.

“This 100th mission is extremely noteworthy because it highlights just how special and valuable CSLI is. Not only does the initiative provide real-life, hands-on experience to the next generation of space exploration professionals, it also adds tremendous value and moves NASA’s mission forward in meaningful ways,” said Jim Norman, director, Launch Services at NASA Headquarters in Washington. "I want to thank all the university students, faculty and staff, industry partners and NASA centers who have participated in this program for their contributions.”

Lucky 100—Hyper-Angular Rainbow Polarimeter (HARP)

HARP is a 3U CubeSat designed to measure the microphysical properties of atmospheric aerosols, cloud water and ice particles. It is a precursor for a new generation of imaging polarimeters to be used for the detailed measurements of aerosol and cloud properties in larger missions. The wide field-of-view imager splits three spatially identical images into three independent polarizer and detector arrays. This technique achieves simultaneous imagery of the three polarization states and is the key innovation to achieve a high polarimetric accuracy with no moving parts. The mission is expected to spend nearly a year in orbit with three months dedicated to technology demonstrations and an extended science data period of an additional seven months.

Image above: An artistic rendering of HARP’s wide field of view of aerosols below. Image Credits: NASA/SDL/UMBC.

Funded by NASA’s Earth Science Technology Office, HARP launched Nov. 2, 2019, as part of the ELaNa 25 mission on Northrup Grumman’s 12th Commercial Resupply Services mission to the International Space Station.

About CSLI

NASA’s CSLI provides access to space for small satellites and CubeSats, developed by accredited educational institutions, non-profit organizations, Federal agencies, and NASA Centers. CSLI provides CubeSat developers a low-cost pathway for conducting scientific investigations and technology demonstrations in space, and NASA a mechanism for low-cost technology development and scientific research to help bridge strategic knowledge gaps and accelerate qualified technology. Sponsored by the Human Exploration Operations Mission Directorate’s Launch Services Program and Advanced Exploration Systems Division, CSLI is an integrated cross-agency collaborative effort that streamlines and prioritizes rideshare and deployment opportunities.

Animation above: CSLI provides CubeSat developers a low-cost pathway for conducting scientific investigations and technology demonstrations in space and NASA a mechanism for low-cost technology development and scientific research to help bridge strategic knowledge gaps and accelerate qualified technology. Animation Credit: NASA.

CubeSats are built in standard units of approximately 10 cm x 10 cm x 10 cm, or in configurations of one, 1.5, two, three, four, five, six and 12 units. These small satellites play a valuable role in the agency’s exploration, technology, educational, and science investigations, including planetary exploration, Earth observation, and fundamental Earth and space science. They are a cornerstone in the development of cutting-edge NASA technologies like laser communications, satellite-to-satellite communications, and autonomous movement. Each proposed investigation must demonstrate a benefit to NASA by addressing aspects of science, exploration, technology development, education, or operations consistent with NASA’s strategic goals.

The History of CSLI

"The first CSLI activity was announced in 2010. CSLI program founders Jason Crusan, Anne Sweet, Carol Galica, Diane Detroye, and Garrett Skrobot built in processes for establishing the criteria for opportunity announcements, developed CubeSat design specifications and created a process for vetting the hundreds of proposals received during each announcement cycle," said Scott Higginbotham, NASA Launch Services Program ELaNa Mission Lead. "The team not only established a selection system, they also created resources to assist in the success of CubeSat developers."

The first CSLI mission, ELaNa-1—consisting of three CubeSats, Explorer-1 (Montana State University), HERMES (University of Colorado) and KYSat-1 (University of Kentucky)—launched from Vandenberg Air Force Base, California on March 4, 2011. The mission was a success as it provided participating university students hands-on, space flight hardware development and launch vehicle integration experience. All three organizations went on to launch other successful missions that also flew on ELaNa flights.

Small Satellite launched from SlingShot on ISS. Animation Credit: NASA

Since that first mission, 176 CubeSat missions from 39 states, the District of Columbia and Puerto Rico have been selected, 101 missions (as of today) have been deployed into their own free-flying orbit, and over 97 unique organizations and 75 universities have participated in this initiative. Currently, there are 39 missions manifested and awaiting a launch opportunity.

CSLI is in its 11th annual selection cycle. Final CubeSat mission selections will be announced in February of this year.

Related articles:

What is AzTechSat-1?
https://www.nasa.gov/ames/aztechsat-1

Mexican Students Launch a Small Satellite to the International Space Station
https://www.nasa.gov/mission_pages/station/research/news/aztech-first-mexican-student-satellite

To learn more about CSLI visit:

https://www.nasa.gov/directorates/heo/home/CubeSats_initiative

To learn more about upcoming ELaNa launches visit:

https://www.nasa.gov/content/upcoming-elana-cubesat-launches

ELaNa-1: http://www.nasa.gov/sites/default/files/files/ELaNa_I_Glory_CubeSat_Factsheet_2011_Final.pdf

CubeSats: http://www.nasa.gov/cubesats/

Small Satellite Missions: http://www.nasa.gov/mission_pages/smallsats

SlingShot: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7847

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Animations (mentioned), Text, Credits: NASA/Denise Hill.

Greetings, Orbiter.ch

Findings From NASA's Juno Update Jupiter Water Mystery

NASA - JUNO Mission logo.

February 19, 2020

The mission publishes its first stream of data on the amount of water in Jupiter's atmosphere - the first findings on the gas giant's water since the agency's 1995 Galileo mission.

Image above: The JunoCam imager aboard NASA's Juno spacecraft captured this image of Jupiter's southern equatorial region on Sept. 1, 2017. The image is oriented so Jupiter's poles (not visible) run left-to-right of frame. Image Credits: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill.

NASA's Juno mission has provided its first science results on the amount of water in Jupiter's atmosphere. Published recently in the journal Nature Astronomy, the Juno results estimate that at the equator, water makes up about 0.25% of the molecules in Jupiter's atmosphere - almost three times that of the Sun. These are also the first findings on the gas giant's abundance of water since the agency's 1995 Galileo mission suggested Jupiter might be extremely dry compared to the Sun (the comparison is based not on liquid water but on the presence of its components, oxygen and hydrogen, present in the Sun).

An accurate estimate of the total amount of water in Jupiter's atmosphere has been on the wish lists of planetary scientists for decades: The figure in the gas giant represents a critical missing piece to the puzzle of our solar system's formation. Jupiter was likely the first planet to form, and it contains most of the gas and dust that wasn't incorporated into the Sun.

The leading theories about its formation rest on the amount of water the planet soaked up.Water abundance also has important implications for the gas giant's meteorology (how wind currents flow on Jupiter) and internal structure. While lightning - a phenomenon typically fueled by moisture - detected on Jupiter by Voyager and other spacecraft implied the presence of water, an accurate estimate of the amount of water deep within Jupiter's atmosphere remained elusive.

Image above: Thick white clouds are present in this JunoCam image of Jupiter's equatorial zone. At microwave frequencies, these clouds are transparent, allowing Juno's Microwave Radiometer to measure water deep into Jupiter's atmosphere. The image was acquired during Juno's flyby on Dec. 16, 2017. Image Credits: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill.

Before the Galileo probe stopped transmitting 57 minutes into its Jovian descent in December 1995, it radioed out spectrometer measurements of the amount of water in the gas giant's atmosphere down to a depth of about 75 miles (120 kilometers), where the atmospheric pressure reached about 320 pounds per square inch (22 bar). The scientists working on the data were dismayed to find ten times less water than expected.

Even more surprising: The amount of water the Galileo probe measured appeared to be still increasing at the greatest depth measured, far below where theories suggest the atmosphere should be well mixed. In a well-mixed atmosphere, the water content is constant across the region and more likely to represent a global average; in other words, it's more likely to be representative of water planetwide. When combined with an infrared map obtained at the same time by a ground-based telescope, the results suggested the probe mission may have just been unlucky, sampling an unusually dry and warm meteorological spot on Jupiter.

"Just when we think we have things figured out, Jupiter reminds us how much we still have to learn," said Scott Bolton, Juno principal investigator at the Southwest Research Institute in San Antonio. "Juno's surprise discovery that the atmosphere was not well mixed even well below the cloud tops is a puzzle that we are still trying to figure out. No one would have guessed that water might be so variable across the planet."

Measuring Water From Above

A rotating, solar-powered spacecraft, Juno launched in 2011. Because of the Galileo probe experience, the mission seeks to obtain water abundance readings across large regions of the immense planet. A new kind of instrument for deep space planetary exploration, Juno's Microwave Radiometer (MWR) observes Jupiter from above using six antennas that measure atmospheric temperature at multiple depths simultaneously. The Microwave Radiometer takes advantage of the fact that water absorbs certain wavelengths of microwave radiation, the same trick used by microwave ovens to quickly heat food. The measured temperatures are used to constrain the amount of water and ammonia in the deep atmosphere, as both molecules absorb microwave radiation.

Juno spacecraft orbiting Jupiter

The Juno science team used data collected during Juno's first eight science flybys of Jupiter to generate the findings. They initially concentrated on the equatorial region because the atmosphere there appears more well-mixed, even at depth, than in other regions. From its orbital perch, the radiometer was able to collect data from a far greater depth into Jupiter's atmosphere than the Galileo probe - 93 miles (150 kilometers), where the pressure reaches about 480 psi (33 bar).

"We found the water in the equator to be greater than what the Galileo probe measured," said Cheng Li, a Juno scientist at the University of California, Berkeley. "Because the equatorial region is very unique at Jupiter, we need to compare these results with how much water is in other regions."

Northward Bound

Juno's 53-day orbit is slowly moving northward, as intended, bringing more of Jupiter's northern hemisphere into sharper focus with each flyby. The science team is eager to see how atmospheric water content varies by latitude and region, as well as what the cyclone-rich poles can tell them about the gas giant's global water abundance.

Juno's 24th science flyby of Jupiter occurred on Feb 17. The next science flyby takes place on April 10, 2020.

"Every science flyby is an event of discovery," said Bolton. "With Jupiter there is always something new. Juno has taught us an important lesson: We need to get up close and personal to a planet to test our theories."

NASA's Jet Propulsion Laboratory in Pasadena, California, manages the Juno mission for the principal investigator, Scott Bolton, of the Southwest Research Institute in San Antonio. Juno is part of NASA's New Frontiers Program, which is managed at NASA's Marshall Space Flight Center in Huntsville, Alabama, for NASA's Science Mission Directorate. The Italian Space Agency contributed the Jovian Infrared Auroral Mapper and the Ka-Band translator system. Lockheed Martin Space in Denver built and operates the spacecraft.

More information about Juno is available at:

https://www.nasa.gov/juno

https://www.missionjuno.swri.edu

More information on Jupiter is at: https://www.nasa.gov/jupiter

The public can follow the mission on Facebook and Twitter at:

https://www.facebook.com/NASAJuno

https://www.twitter.com/NASAJuno

Images (mentioned), Animation, Text, Credits: NASA/Grey Hautaluoma/Joshua Handal/JPL/DC Agle/Southwest Research Institute/Deb Schmid.

Greetings, Orbiter.ch