This new NASA Hubble Space Telescope image features a member of the galaxy group Arp 295.
NASA/ESA/J. Dalcanton (University of Washington)/R. Windhorst (Arizona State University)/Processing: Gladys Kober (NASA/Catholic University of America)
One of the galaxies from a galactic group known as Arp 295 is visible in this new NASA Hubble Space Telescope image, along with part of the faint 250,000-light-year-long bridge of stars and gas that stretches between two of the galaxies. The galaxies have passed close enough together that their mutual gravity created this cosmic streamer.
When galaxies pass close enough to gravitationally disrupt each other’s shape, they are known as interacting galaxies. This type of interaction happens over billions of years and repeated close passages can result in the merger of the two galaxies. Galactic mergers are thought to be common, and even our own Milky Way is expected to merge with the massive, neighboring Andromeda galaxy in about 4 billion years.
Arp 295 is made up of three spiral galaxies designated Arp 295a, Arp 295b, and Arp 295c. Arp 295a is the edge-on galaxy seen in the center of the image, and Arp 295c is the smaller and bluer face-on spiral to its right. Arp 295b is off the top left of this image and not visible here. Together, they are the largest of a loose grouping of galaxies located about 270 million light-years in the direction of the constellation Aquarius.
NASA Autonomous Flight Software Successfully Used in Air Taxi Stand-Ins
4 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
NASA pilots along with Sikorsky safety pilots flying Sikorsky’s Black Hawk Optionally Piloted Vehicle, left, and SARA S-76B over Long Island Sound Thursday, Oct. 26, 2023. These flights will allow NASA researchers to test and evaluate multiple Advanced Air Mobility autonomous flight software products designed by NASA.
NASA/Steve Freeman
In late October, two research helicopters from the manufacturer Sikorsky, a Lockheed Martin company, made a dozen test flights over Long Island Sound, Connecticut taking care to avoid other aircraft in the area around them. Except the ordinary-looking helicopters were flying autonomously – guided by NASA-designed software – and those other aircraft were virtual, part of a simulation to test pilotless flight systems. This was the first time two autonomous aircraft were flying at one another using NASA designed collision avoidance software.
The test flights were part of a collaboration by NASA, Sikorsky, and DARPA (Defense Advanced Research Projects Agency). Researchers were able to collect data that will advance completely autonomous flight —systems that can operate an aircraft without a pilot from takeoff to touchdown. The work was part of NASA’s efforts to design and evaluate technologies that could eventually lead to air taxis and other new, automated air transportation options.
For the tests, the team used two experimental helicopters adapted for autonomous systems, known as the SARA (Sikorsky Autonomy Research Aircraft) a modified S-76B and the larger OPV (Optionally Piloted Vehicle) Black Hawk. Researchers loaded five NASA-designed software systems into the helicopters, which worked with the automated flight system already integrated by Sikorsky and DARPA.
“These flight tests using Sikorsky’s SARA and OPV helicopters show how we can stack technologies together to increase automation over time in a maintainable and scalable way,” says Adam Yingling, NASA project lead. “These efforts demonstrate that we can safely integrate operations to fly the aircraft using several technologies in one navigation tablet.”
A NASA and a Sikorsky safety pilot onboard each helicopter supervised the flight tests. Sikorsky’s flight autonomy system, in combination with NASA software, running on tablets the agency designed, allowed the helicopters to fly autonomously along multiple planned routes. The tablets also enabled the safety pilots to monitor flight path options the software selected whenever course corrections needed to occur.
The safety pilots observed how the helicopters responded to software-initiated commands, and NASA researchers evaluated how the different software systems worked together to control each aircraft.
The tests also assessed how human pilots interacted with the autonomous systems. During the flights, the NASA research pilots were outfitted with specially designed glasses to understand how long they interacted with the navigation tablets and how they physiologically responded to information the tablets provided. Researchers will employ this user experience data to assist in future visual and interactive designs for the software and tablets.
The team flew 12 successful flights covering 70 different flight test maneuvers and generating more than 30 flight hours for each aircraft. The NASA collaboration with Sikorsky and DARPA offered a foundation for furthering testing of the automation technology.
Virtual flight data is shown from the Dallas-Fort Worth urban area overlaid onto the actual flight test area over the Long Island Sound, near Bridgeport, Connecticut allowing pilots to fly in a mixed reality airspace while testing autonomous software systems.
NASA/Stewart Nelson
Mixed-Reality Airspace
The tests demonstrated the software’s capabilities in a mixed-reality setting. As the SARA and OPV helicopters flew over Long Island Sound, multiple virtual aircraft were added into the same airspace.
“For this test, we are using a model of future Advanced Air Mobility airspace with more than 150 virtual aircraft and their flight plans integrated with the flight path management software and the Sikorsky mission manager technology to fly the two helicopters in a mixed-reality mode,” said Mark Ballin, principal investigator for flight path management system development.
The NASA-designed software, which commanded both the SARA and OPV helicopters simultaneously, allowed research pilots and engineers to run planned interactions with the virtual aircrafts’ flight plans. The multiple software systems aboard the helicopters worked together, making adjustments to avoid the virtual aircraft and each other. That meant changing altitude, speed, and direction to avoid virtual “collisions” or maintain orbital patterns for landing. This NASA, Sikorsky, and DARPA collaboration will help usher in a new era of autonomy in aviation that could save lives, aircraft, and resources. NASA uses these tests to support the integration of automated systems research that will inform the Federal Aviation Administration with data on flight procedures to help introduce Advanced Air Mobility systems into the national airspace.
NASA’s Hubble Finds Water Vapor in Small Exoplanet’s Atmosphere
5 min read
NASA’s Hubble Finds Water Vapor in Small Exoplanet’s Atmosphere
This is an artist’s concept of the exoplanet GJ 9827d, the smallest exoplanet where water vapor has been detected in the atmosphere. The planet could be an example of potential planets with water-rich atmospheres elsewhere in our galaxy. With only about twice Earth’s diameter, the planet orbits the red dwarf star GJ 9827. Two inner planets in the system are on the left. The background stars are plotted as they would be seen to the unaided eye looking back toward our Sun. The Sun is too faint to be seen. The blue star at upper right is Regulus; the yellow star at center bottom is Denebola; and the blue star at bottom right is Spica. The constellation Leo is on the left, and Virgo is on the right. Both constellations are distorted from our Earth-bound view from 97 light-years away.
Astronomers using NASA’s Hubble Space Telescope observed the smallest exoplanet where water vapor has been detected in the atmosphere. At only approximately twice Earth’s diameter, the planet GJ 9827d could be an example of potential planets with water-rich atmospheres elsewhere in our galaxy.
“This would be the first time that we can directly show through an atmospheric detection, that these planets with water-rich atmospheres can actually exist around other stars,” said team member Björn Benneke of the Trottier Institute for Research on Exoplanets at Université de Montréal. “This is an important step toward determining the prevalence and diversity of atmospheres on rocky planets.”
“Water on a planet this small is a landmark discovery,” added co-principal investigator Laura Kreidberg of Max Planck Institute for Astronomy in Heidelberg, Germany. “It pushes closer than ever to characterizing truly Earth-like worlds.”
However, it remains too early to tell whether Hubble spectroscopically measured a small amount of water vapor in a puffy hydrogen-rich atmosphere, or if the planet’s atmosphere is mostly made of water, left behind after a primeval hydrogen/helium atmosphere evaporated under stellar radiation.
“Until now, we had not been able to directly detect the atmosphere of such a small planet. And we’re slowly getting in this regime now,” added Benneke. “At some point, as we study smaller planets, there must be a transition where there’s no more hydrogen on these small worlds, and they have atmospheres more like Venus (which is dominated by carbon dioxide).”
Astronomers using NASA’s Hubble Space Telescope have observed water vapor in the atmosphere of the smallest exoplanet ever detected. Located 97 light-years away, planet GJ 9827d is approximately twice the size of Earth. Credit: NASA’s Goddard Space Flight Center/Lead Producer: Paul Morris
Because the planet is as hot as Venus, at 800 degrees Fahrenheit, it definitely would be an inhospitable, steamy world if the atmosphere were predominantly water vapor.
At present the team is left with two possibilities. One scenario is that the planet is still clinging to a hydrogen-rich atmosphere laced with water, making it a mini-Neptune. Alternatively, it could be a warmer version of Jupiter’s moon Europa, which has twice as much water as Earth beneath its crust.” The planet GJ 9827d could be half water, half rock. And there would be a lot of water vapor on top of some smaller rocky body,” said Benneke.
If the planet has a residual water-rich atmosphere, then it must have formed farther away from its host star, where the temperature is cold and water is available in the form of ice, than its present location. In this scenario, the planet would have then migrated closer to the star and received more radiation. The hydrogen was heated and escaped, or is still in the process of escaping the planet’s weak gravity. The alternative theory is that the planet formed close to the hot star, with a trace of water in its atmosphere.
The Hubble program observed the planet during 11 transits – events in which the planet crossed in front of its star – that were spaced out over three years. During transits, starlight is filtered through the planet’s atmosphere and has the spectral fingerprint of water molecules. If there are clouds on the planet, they are low enough in the atmosphere so that they don’t completely hide Hubble’s view of the atmosphere, and Hubble is able to probe water vapor above the clouds.
“Observing water is a gateway to finding other things,” said Thomas Greene, astrophysicist at NASA’s Ames Research Center in California’s Silicon Valley. “This Hubble discovery opens the door to future study of these types of planets by NASA’s James Webb Space Telescope. JWST can see much more with additional infrared observations, including carbon-bearing molecules like carbon monoxide, carbon dioxide, and methane. Once we get a total inventory of a planet’s elements, we can compare those to the star it orbits and understand how it was formed.”
GJ 9827d was discovered by NASA’s Kepler Space Telescope in 2017. It completes an orbit around a red dwarf star every 6.2 days. The star, GJ 9827, lies 97 light-years from Earth in the constellation Pisces.
The Hubble Space Telescope is a project of international cooperation between NASA and ESA. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble and Webb science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington, D.C.
NASA Collaborating on European-led Gravitational Wave Observatory in Space
4 min read
NASA Collaborating on European-led Gravitational Wave Observatory in Space
The LISA (Laser Interferometer Space Antenna) mission, led by ESA (European Space Agency) with NASA contributions, will detect gravitational waves in space using three spacecraft, separated by more than a million miles, flying in a triangular formation. Lasers fired between the satellites, shown in this artist’s concept, will measure how gravitational waves alter their relative distances.
AEI/MM/Exozet
The first space-based observatory designed to detect gravitational waves has passed a major review and will proceed to the construction of flight hardware. On Jan. 25, ESA (European Space Agency), announced the formal adoption of LISA, the Laser Interferometer Space Antenna, to its mission lineup, with launch slated for the mid-2030s. ESA leads the mission, with NASA serving as a collaborative partner.
“In 2015, the ground-based LIGO observatory cracked open the window into gravitational waves, disturbances that sweep across space-time, the fabric of our universe,” said Mark Clampin, director of the Astrophysics Division at NASA Headquarters in Washington. “LISA will give us a panoramic view, allowing us to observe a broad range of sources both within our galaxy and far, far beyond it. We’re proud to be part of this international effort to open new avenues to explore the secrets of the universe.”
The LISA mission will enable observations of gravitational waves produced by merging supermassive black holes, seen here in a computer simulation. Most big galaxies contain central black holes weighing millions of times the mass of our Sun. When these galaxies collide, eventually their black holes do too. Download high-resolution video from NASA’s Scientific Visualization Studio. Credit: NASA’s Goddard Space Flight Center/Scott Noble; simulation data, d’Ascoli et al. 2018
NASA will provide several key components of LISA’s instrument suite along with science and engineering support. NASA contributions include lasers, telescopes, and devices to reduce disturbances from electromagnetic charges. LISA will use this equipment as it measures precise distance changes, caused by gravitational waves, over millions of miles in space. ESA will provide the spacecraft and oversee the international team during the development and operation of the mission.
Gravitational waves were predicted by Albert Einstein’sgeneral theory of relativity more than a century ago. They are produced by accelerating masses, such as a pair of orbiting black holes. Because these waves remove orbital energy, the distance between the objects gradually shrinks over millions of years, and they ultimately merge.
These ripples in the fabric of space went undetected until 2015, when LIGO, the Laser Interferometer Gravitational-Wave Observatory, funded by the U.S. National Science Foundation, measured gravitational waves from the merger of two black holes. This discovery furthered a new field of science called “multimessenger astronomy” in which gravitational waves could be used in conjunction with the other cosmic “messengers” – light and particles – to observe the universe in new ways.
Along with other ground-based facilities, LIGO has since observed dozens more black hole mergers, as well as mergers of neutron stars and neutron star-black hole systems. So far, the black holes detected through gravitational waves have been relatively small, with masses of tens to perhaps a hundred times that of our Sun. But scientists think that mergers of much more massive black holes were common when the universe was young, and only a space-based observatory could be sensitive to gravitational waves from them.
“LISA is designed to sense low-frequency gravitational waves that instruments on Earth cannot detect,” said Ira Thorpe, the NASA study scientist for the mission at the agency’s Goddard Space Flight Center in Greenbelt, Maryland. “These sources encompass tens of thousands of small binary systems in our own galaxy, as well as massive black holes merging as galaxies collided in the early universe.”
Gravitational waves from a simulated population of compact binary systems in our galaxy were used to construct this synthetic map of the entire sky. Such systems contain white dwarfs, neutron stars, or black holes in tight orbits. Maps like this using real data will be possible once the LISA mission becomes active in the next decade. The center of our Milky Way galaxy lies at the center of this all-sky view, with the galactic plane extending across the middle. Brighter spots indicate sources with stronger gravitational signals and lighter colors indicate those with higher frequencies. Larger colored patches show sources whose positions are less well known.
NASA’s Goddard Space Flight Center
LISA will consist of three spacecraft flying in a vast triangular formation that follows Earth in its orbit around the Sun. Each arm of the triangle stretches 1.6 million miles (2.5 million kilometers). The spacecraft will track internal test masses affected only by gravity. At the same time, they’ll continuously fire lasers to measure their separations to within a span smaller than the size of a helium atom. Gravitational waves from sources throughout the universe will produce oscillations in the lengths of the triangle’s arms, and LISA will capture these changes.
The underlying measurement technology was successfully demonstrated in space with ESA’s LISA Pathfinder mission, which operated between 2015 and 2017 and also included NASA participation. The spacecraft demonstrated the exquisite control and precise laser measurements needed for LISA.
Shrinking Moon Causing Moonquakes and Faults Near Lunar South Pole
4 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater)
As NASA continues to make progress toward sending astronauts to the lunar South Pole region with its Artemis campaign, data from a NASA-funded study is helping scientists better understand this strategic part of the Moon. The study presents evidence that moonquakes and faults generated as the Moon’s interior gradually cools and shrinks are also found near and within some of the areas the agency identified as candidate landing regions for Artemis III, the first Artemis mission planned to have a crewed lunar landing.
The epicenter of one of the strongest moonquakes recorded by the Apollo Passive Seismic Experiment was located in the lunar south polar region. However, the exact location of the epicenter could not be accurately determined. A cloud of possible locations (magenta dots and light blue polygon) of the strong shallow moonquake using a relocation algorithm specifically adapted for very sparse seismic networks are distributed near the pole. Blue boxes show locations of proposed Artemis III landing regions. Lobate thrust fault scarps are shown by small red lines. The cloud of epicenter locations encompasses a number of lobate scarps and many of the Artemis III landing regions.
NASA/LROC/ASU/Smithsonian Institution
“Our modeling suggests that shallow moonquakes capable of producing strong ground shaking in the south polar region are possible from slip events on existing faults or the formation of new thrust faults,” said Tom Watters of the Smithsonian Institution, Washington, lead author of a paper on the research published January 25 in the Planetary Science Journal. “The global distribution of young thrust faults, their potential to be active, and the potential to form new thrust faults from ongoing global contraction should be considered when planning the location and stability of permanent outposts on the Moon.”
Lunar Reconnaissance Orbiter Camera (LROC), Narrow Angle Camera (NAC) mosaic of the Wiechert cluster of lobate scarps (left pointing arrows) near the lunar south pole. A thrust fault scarp cut across an approximately 1-kilometer (0.6-mile) diameter degraded crater (right pointing arrow).
The lobate scarps are formed when the lunar crust is pushed together as the Moon contracts. This causes the near-surface materials to break forming a thrust fault. The thrust fault carries crustal materials up and sometimes over adjacent crustal materials. Slip events on existing faults or the formation of new thrust faults trigger shallow moonquakes that can cause strong seismic shaking tens of miles (many tens of kilometers) away from the scarp.
Arizona State University/Smithsonian
The formation of the faults is accompanied by seismic activity in the form of shallow-depth moonquakes. Such shallow moonquakes were recorded by the Apollo Passive Seismic Network, a series of seismometers deployed by the Apollo astronauts. The strongest recorded shallow moonquake had an epicenter in the south-polar region. One young thrust-fault scarp, located within the de Gerlache Rim 2, an Artemis III candidate landing region, is modeled in the study and shows that the formation of this fault scarp could have been associated with a moonquake of the recorded magnitude.
The team also modeled the stability of surface slopes in the lunar south polar region and found that some areas are susceptible to regolith landslides from even light seismic shaking, including areas in some permanently shadowed regions. These areas are of interest due to the resources that might be found there, such as ice.
Image shows predicted areas of surface slope instability in the south polar region. Models are for a one-meter-thick (about 3.3-foot) regolith landslide. Blue dots are areas with the least unstable slopes, green dots are moderately unstable slopes, and red dots are most unstable slopes. Image centered on Shackleton crater and the lunar south pole. Locations of proposed Artemis III landing regions are shown by the blue boxes. The model predicts large portions of the interior walls of Shackleton crater are suspectable to landslides (inset) as well as portions of interior crater walls in the Nobile Rim 1 landing region.
NASA/LROC/ASU/Smithsonian Institution
“To better understand the seismic hazard posed to future human activities on the Moon, we need new seismic data, not just at the South Pole, but globally,” said Renee Weber, a co-author of the paper at NASA’s Marshall Space Flight Center, Huntsville, Alabama. “Missions like the upcoming Farside Seismic Suite will expand upon measurements made during Apollo and add to our knowledge of global seismicity.”
“LRO is committed to acquiring data of the lunar surface to aid scientists in understanding important features such as thrust faults,” said LRO Deputy Project Scientist Maria Banks of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, a co-author of the paper. “This study is a good demonstration of one of the many ways in which LRO data is being used to assist planning for our return to the Moon.”
This research was funded by NASA’s LRO mission, launched on June 18, 2009. LRO is managed by NASA Goddard for the Science Mission Directorate at NASA Headquarters in Washington. With Artemis missions, NASA is exploring the Moon for scientific discovery, technology advancement, and to learn how to live and work on another world as we prepare for human missions to Mars. We will collaborate with commercial and international partners and establish the first long-term presence on the Moon. NASA will land the first woman and first person of color on the Moon, using innovative technologies to explore more of the lunar surface than ever before.
