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NASA’s Ingenuity Mars Helicopter Team Says Goodbye … for Now
The final downlink shift by the Ingenuity team was a time to reflect on a highly successful mission — and to prepare the first aircraft on another world for its new role.
Engineers working on NASA’s Ingenuity Mars Helicopter assembled for one last time in a control room at the agency’s Jet Propulsion Laboratory in Southern California on Tuesday, April 16, to monitor a transmission from the history-making helicopter. While the mission ended Jan. 25, the rotorcraft has remained in communication with the agency’s Perseverance Mars rover, which serves as a base station for Ingenuity. This transmission, received through the antennas of NASA’s Deep Space Network, marked the final time the mission team would be working together on Ingenuity operations.
Now the helicopter is ready for its final act: to serve as a stationary testbed, collecting data that could benefit future explorers of the Red Planet.
Throughout its mission on the Red Planet, NASA’s Ingenuity Mars Helicopter received thousands of electronic postcards filled with well wishes from all over the world via the mission’s website. In this video, members of the helicopter team read some of those messages. Credit: NASA/JPL-Caltech“With apologies to Dylan Thomas, Ingenuity will not be going gently into that good Martian night,” said Josh Anderson, Ingenuity team lead at JPL. “It is almost unbelievable that after over 1,000 Martian days on the surface, 72 flights, and one rough landing, she still has something to give. And thanks to the dedication of this amazing team, not only did Ingenuity overachieve beyond our wildest dreams, but also it may teach us new lessons in the years to come.”
Originally designed as a short-lived technology demonstration mission that would perform up to five experimental test flights over 30 days, the first aircraft on another world operated from the Martian surface for almost three years, flew more than 14 times farther than the distance expected, and logged more than two hours of total flight time.
Ingenuity’s mission ended after the helicopter experienced a hard landing on its last flight, significantly damaging its rotor blades. Unable to fly, the rotorcraft will remain at “Valinor Hills” while the Perseverance rover drives out of communications range as it continues to explore the western limb of Jezero Crater.
Bytes and CakeThe team enjoyed some “Final Comms” chocolate cake while reviewing the latest data from over 189 million miles (304 million kilometers) away. The telemetry confirmed that a software update previously beamed up to Ingenuity was operating as expected. The new software contains commands that direct the helicopter to continue collecting data well after communications with the rover have ceased.
Engineers working on NASA’s Ingenuity together monitored a transmission from the history-making helicopter in a JPL control room on April 16. They confirmed the operation of a software patch that will allow the helicopter to act as a stationary testbed and collect data that could benefit future Mars explorers.NASA/JPL-CaltechWith the software patch in place, Ingenuity will now wake up daily, activate its flight computers, and test the performance of its solar panel, batteries, and electronic equipment. In addition, the helicopter will take a picture of the surface with its color camera and collect temperature data from sensors placed throughout the rotorcraft. Ingenuity’s engineers and Mars scientists believe such long-term data collection could not only benefit future designers of aircraft and other vehicles for the Red Planet, but also provide a long-term perspective on Martian weather patterns and dust movement.
During this final gathering, the team received a farewell message from Ingenuity featuring the names of people who worked on the mission. Mission controllers at JPL sent the message to Perseverance the day before, which handed it off to Ingenuity so that it could transmit the farewell back to Earth.
Decades of RoomIf a critical electrical component on Ingenuity were to fail in the future, causing data collection to stop, or if the helicopter eventually loses power because of dust accumulation on its solar panel, whatever information Ingenuity has collected will remain stored on board. The team has calculated Ingenuity’s memory could potentially hold about 20 years’ worth of daily data.
“Whenever humanity revisits Valinor Hills — either with a rover, a new aircraft, or future astronauts — Ingenuity will be waiting with her last gift of data, a final testament to the reason we dare mighty things,” said Ingenuity’s project manager, Teddy Tzanetos of JPL. “Thank you, Ingenuity, for inspiring a small group of people to overcome seemingly insurmountable odds at the frontiers of space.”
Tzanetos and other Ingenuity alumni are currently researching how future Mars helicopters — including the Mars Science Helicopter concept — could benefit explorations of the Red Planet and beyond.
More About the MissionThe Ingenuity Mars Helicopter was built by JPL, which also manages the project for NASA Headquarters. It is supported by NASA’s Science Mission Directorate. NASA’s Ames Research Center in California’s Silicon Valley and NASA’s Langley Research Center in Hampton, Virginia, provided significant flight performance analysis and technical assistance during Ingenuity’s development. AeroVironment Inc., Qualcomm, and SolAero also provided design assistance and major vehicle components. Lockheed Space designed and manufactured the Mars Helicopter Delivery System. At NASA Headquarters, Dave Lavery is the program executive for the Ingenuity Mars helicopter.
For more information about Ingenuity:
https://mars.nasa.gov/technology/helicopter
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A Clinical Decision Support System for Earth-independent Medical Operations
Deep space exploration requires a paradigm shift in astronaut medical support toward Earth-independent medical operations. Currently, astronauts rely on real-time communication with ground-based medical providers. However, as the distance from Earth increases, so do communication delays and disruptions. Deep space exploration crews will need to autonomously detect, diagnose, treat, and prevent medical conditions. One potential solution is to augment the long duration exploration crew’s knowledge, skills, and abilities with a digital clinical decision support system, or CDSS. The Exploration Medical Capability (ExMC) element of NASA’s Human Research Program is investigating the feasibility and value of advanced capabilities to promote and enhance EIMO.
Main findings: The ExMC research team has produced a CDSS concept in which medical data would be continuously gathered, through both passive and active monitoring, and delivers real-time guidanance. This helps improve patient outcomes and reduce the workload of health maintenance.
Impact: The assistive technology of ExMC’s envisioned CDSS stands to significantly enhance a crew’s medical capability. Private applications for this approach are currently being considered by commercial space flight programs, a timely example of how ARC Space Biosciences research benefits the entire space sector.
Reference: Russell, B., Burian, B., …, Beard, B., Martin, K., Pletcher, D., … The value of a spaceflight clinical decision support system for earth-independent medical operations. Nature: NPJ Microgravity 9, 46 (2023).
Keep Exploring Discover More Topics From NASA NASA Biological & Physical SciencesBPS administers NASA’s: BPS partners with the research community and a wide range of organizations to accomplish its mission. Grants…
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Space Life Science Highlights
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Preparations for Next Moonwalk Simulations Underway (and Underwater)Spaceflight Atrophy Studied with Machine Learning
Multi-Drug Resistant Bacteria Found on
ISS Mutating to Become Functionally Distinct
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BioNutrients Flight Experiments
When astronauts embark on long space missions, they’ll need to grow their own food because pre-packaged meals from Earth lose their nutritional value over time. The BioNutrients project at Ames Research Center’s Space Biosciences Division has solved this problem by using genetic engineering to create microbially-based food that can produce nutrients and compounds, such as medicines, with minimal resources. The process involves storing dried microbes and food-grade media in small bioreactors, which can be rehydrated and grown years later. The project has already produced carotenoids for antioxidants, follistatin for muscle loss, and yogurt and kefir for a healthy gut biome.
Astronaut mixing the yeast cultures in the Gen-0 bioreactors from the Bionutrients-1 ISS experiment. After a successful first mission, a more compact container was designed as the flat-pack Gen-1 bioreactors.Main Findings: Two different engineered baker’s yeasts were cultured in the BioNutrients-1 (BN-1) Gen-0 bioreactors, producing beta-carotene and zeaxanthin, and their ambient shelf life on the International Space Station (ISS) has now been demonstrated out to 3.9 years. Four additional organism types and products were flown on BioNutrients-2 (BN-2), demonstrating the production of carotenoids, follistatin, yogurt, and kefir products in the Gen-1 bioreactors which have a 91% reduced mass and a flat pack design. The shelf life of yeast-based products is expected to meet 5 years at ambient storage conditions. Analysis of yogurt and kefir is underway.
Impact: BN-1 and BN-2 successes pave the way for further biomanufacturing processes that will ensure the safe consumption of essential nutrients and compounds for long-duration space missions.
Co-Investigators: John Hogan and Frances Donovan
Team: Ball, N., Sharif, S., Downing, S., Gresser, A., Hami, R., Oscar, R., Hindupur, A., Hiromi, K., Kostakis, A., Levri, J., Murikami, M., Settles, A.M., Sims, K., Villanueva, A., Vu, S.
Spaceflight Atrophy Studied with Machine Learning
Background: Even intense exercise by astronauts cannot compensate for muscle atrophy caused by microgravity. Atrophy occurs, in part, by way of an underlying mechanism that regulates calcium uptake. Recent research has shown exposure to spaceflight alters the uptake of calcium in muscles. However, the molecular mechanisms that drive these changes are not well studied.
Researchers at Ames Research Center investigated these mechanisms by applying Machine Learning (ML) to identify patterns in datasets on mice exposed to microgravity. ML methods are particularly effective in identifying patterns in complex biological data and are suited for space biological research where small datasets are often combined to increase statistical power.
In the image above, NASA astronaut Sunita Williams, Expedition 32 flight engineer, exercises on the load-bearing treadmill in the ISS. Resistance training can counteract the negative health effects of microgravity on muscle atrophy, but new Ames Research Center research seeks to understand the physiological mechanisms at play to identify biomarkers that can inform innovative counter measures. The study was a project of NASA’s Space Life Sciences Training Program at Ames Research Center, which provided funding.
Findings: Machine Learning analysis shows molecular drivers to physiological changes in the calcium channel sarcoplasmic/ endoplasmic reticulum (SERCA) pump, leading to muscle changes and muscle loss in spaceflight rodents. ML models were created to identify proteins that could predict an organism’s resilience to microgravity with respect to calcium uptake in muscles. Specific proteins, Acyp1 and Rps7, were found to be the most predictive biomarkers associated with enhanced calcium intake in fast-twitch muscles.
Impact: This study offered a first look at the use of ML on calcium uptake in muscle when exposed to microgravity conditions. This study demonstrated the role of NASA’s open science initiative in accelerating space biology by its reliance on ARC’s Open Science Data Repository (OSDR) and Analysis Working Groups, as well as the involvement of an international research team from the US, Canada, Denmark, and Australia. Notably, the article’s first author was an undergraduate at UC Berkeley, demonstrating the unlimited potential of NASA-Berkeley collaborations in life sciences research with the upcoming Berkeley Space Center at NASA Research Park.
Reference: Li, K., Desai, R., Scott, R., Steele, J.,… Sanders, L., Costes, S. Explainable machine learning identifies multi-omics signatures of muscle response to spaceflight in mice. npj Microgravity 9, 90 (December 2023).
Multi-Drug Resistant Bacteria Found on ISS Mutating to Become Functionally Distinct
In a new scientific paper funded by an Ames Space Biology grant, Principal Investigator Dr. Kasthuri Venkateswaran of NASA’s Jet Propulsion Laboratory strains of the bacterial species Enterobacter bugandensis isolated from the International Space Station (ISS) were studied. Thirteen strains of E. bugandensis, a bacterium notorious for being multi-drug resistant, were isolated from the ISS. Study findings indicate under stress, the ISS isolated strains were mutated and became genetically and functionally distinct compared to their Earth counterparts. The strains were able to viably persist in the ISS over time with a significant abundance. E. bugandensis coexisted with multiple other microorganisms, and in some cases could have helped those organisms survive.
Publication Impact: Closed human-built environments, such as the ISS, are unique areas that provide an extreme environment subject to microgravity, radiation, and elevated carbon dioxide levels. Any microorganisms introduced to these areas must adapt to thrive. By delving into microbial dynamics in extreme environments, this research opens doors to effective preventative measure for astronaut health.
Reference: Sengupta P, Muthamilselvi Sivabalan SK, Singh NK, Raman K, Venkateswaran K.
Genomic, functional, and metabolic enhancements in multidrug-resistant Enterobacter bugandensis facilitating its persistence and succession in the International Space Station. Microbiome. 2024 Mar 23;12:62. ISS results funded by a 2012 Space Biology NNH12ZTT001N grant nos. 19-12829-26 under Task Order NNN13D111T award to K.V., which also funded post-doctoral fellowship for N.K.S. K.R. acknowledges support from the Science and Engineering Board (SERB) MATRICS Grant MTR/2020/000490, IIT Madras, Centre for Integrative Biology and Systems mEdicine (IBSE) and Robert Bosch Center for Data Science and Artificial Intelligence (RBCDSAI).
What's left of the 2024 solar eclipse lives in our hearts
Comet Geyser: Perseverance’s 24th Rock Core
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Comet Geyser: Perseverance’s 24th Rock Core Mastcam-Z image (Sol 1088, zcam05068) of the Comet Geyser core. The partially illuminated core is visible in this image of Perseverance’s coring bit. The diameter of the core is 1.3 cm. NASA/JPL-Caltech/ASUAfter investigating the high-standing bedrock at the Bunsen Peak workspace deep within the Margin Unit, the unique nature and composition of this rock was deemed worthy for collection of Perseverance’s 24th rock core sample, Comet Geyser!
Bunsen Peak is named after a prominent peak in Yellowstone National, Park, Wyoming, USA, and the namesake for Comet Geyser is the silica-sintered cone geyser also in Yellowstone National Park.
Although this rock’s origin remains under investigation and the rover team continues to explore different hypotheses, this core is particularly exciting because it appears to be composed primarily of two minerals: carbonate and silica. Carbonate and silica are both excellent minerals for preserving biosignatures (ancient signs of life). These minerals also have the potential to record the environmental conditions in which they formed, making them important minerals for understanding the habitability of Jezero crater billions of years ago.
The presence of carbonate within the Comet Geyser sample suggests that water, carbon dioxide, and chemical elements derived from rocks or sediments in and around ancient Jezero crater once reacted here to form carbonate. Carbonate minerals from Earth’s rock record are often used to reconstruct ancient climate–including conditions like temperature, precipitation, and aridity–and the history of life. Similarly, silica phases form when water interacts with rocks or sediments. The composition and crystallinity of silica can reveal the extent of the interaction with water, such as the intensity or duration of weathering and the pressure/temperature conditions during formation.
On Earth, biosignatures can be preserved in carbonate and silica for millions of years, or even billions of years in the case of silica. Some of the oldest evidence we have of life on Earth is from rocks that contain fragments of microbial cells that were “permineralized” by silica, a fossilization process that entombs the residues of ancient life and protects them from degradation. Thus, rocks containing these materials are considered among the highest priority samples for investigating whether Jezero crater was once host to microbial life. Perseverance’s 24th core sample at Bunsen Peak represents a significant milestone towards collection of a scientifically diverse set of samples for eventual return to Earth as part of the Mars Sample Return mission.
With rock core #24 now onboard, Perseverance presses forward towards its next strategic objective of investigating a location called Bright Angel, which is a light-toned outcrop exposed in the ancient channel wall of Neretva Vallis. Challenges may arise on this journey, as the terrain ahead is littered with sharp boulders and sand that are proving difficult for the rover’s auto-navigation system. The mission’s rover planners are working hard to manually navigate this tricky terrain. In the meantime, the science team is eagerly anticipating the secrets the rocks of Bright Angel may hold!
Written by Adrian Broz, Postdoctoral Scientist at Purdue University/University of Oregon
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NASA’s Dragonfly Rotorcraft Mission to Saturn’s Moon Titan Confirmed
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NASA’s Dragonfly Rotorcraft Mission to Saturn’s Moon Titan ConfirmedNASA has confirmed its Dragonfly rotorcraft mission to Saturn’s organic-rich moon Titan. The decision allows the mission to progress to completion of final design, followed by the construction and testing of the entire spacecraft and science instruments.
Artist’s concept of Dragonfly soaring over the dunes of Saturn’s moon Titan. NASA/Johns Hopkins APL/Steve Gribben“Dragonfly is a spectacular science mission with broad community interest, and we are excited to take the next steps on this mission,” said Nicky Fox, associate administrator, Science Mission Directorate at NASA Headquarters in Washington. “Exploring Titan will push the boundaries of what we can do with rotorcraft outside of Earth.”
In early 2023, the mission successfully passed all the success criteria of its Preliminary Design Review. At that time, however, the mission was asked to develop an updated budget and schedule to fit into the current funding environment. This updated plan was presented and conditionally approved in November 2023, pending the outcome of the fiscal year 2025 budget process. In the meantime, the mission was authorized to proceed with work on final mission design and fabrication to ensure that the mission stayed on schedule.
With the release of the president’s fiscal year 2025 budget request, Dragonfly is confirmed with a total lifecycle cost of $3.35 billion and a launch date of July 2028. This reflects a cost increase of about two times the proposed cost and a delay of more than two years from when the mission was originally selected in 2019. Following that selection, NASA had to direct the project to replan multiple times due to funding constraints in fiscal years 2020 through 2022. The project incurred additional costs due to the COVID-19 pandemic, supply chain increases, and the results of an in-depth design iteration. To compensate for the delayed arrival at Titan, NASA also provided additional funding for a heavy-lift launch vehicle to shorten the mission’s cruise phase.
The rotorcraft, targeted to arrive at Titan in 2034, will fly to dozens of promising locations on the moon, looking for prebiotic chemical processes common on both Titan and the early Earth before life developed. Dragonfly marks the first time NASA will fly a vehicle for science on another planetary body. The rotorcraft has eight rotors and flies like a large drone.
Dragonfly is being designed and built under the direction of the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, which manages the mission for NASA. Elizabeth Turtle of APL is the principal investigator. The team includes key partners at NASA’s Goddard Space Flight Center in Greenbelt, Maryland; Lockheed Martin Space in Littleton, Colorado; NASA’s Ames Research Center in Silicon Valley, California; NASA’s Langley Research Center in Hampton, Virginia; Penn State University in State College, Pennsylvania; Malin Space Science Systems in San Diego, California; Honeybee Robotics in Pasadena, California; NASA’s Jet Propulsion Laboratory in Southern California; CNES (Centre National d’Etudes Spatiales) in Paris; the German Aerospace Center (DLR) in Cologne, Germany; and JAXA (Japan Aerospace Exploration Agency) in Tokyo. Dragonfly is the fourth mission in NASA’s New Frontiers Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.
Share Details Last Updated Apr 16, 2024 Editor Bill Keeter Related TermsBioNutrients-3 Experiment Completed During Analog Astronaut Mission
From March 4 to 9 at the Hawaiian Space Exploration Analog and Simulation (HI-SEAS) located on Mauna Loa volcano on the Big Island, NASA Ames Scientist Katie Fisher participated as Mission Commander for the 6-day lunar analog. During the mission, she collaborated with the Synthetic Biology BioNutrients team to test continuous passaging and growth methods of BioNutrients-3 kefir cultures.
The mission was a great learning experience for the team of five international analog astronauts. They worked together to overcome connectivity issues and a power outage while still completing experiments, reports, and medical evaluations.
By successfully accomplishing the kefir passaging experiment the team has demonstrated the ability to produce daily fresh cultures of kefir that will provide future astronauts valuable probiotic cultures and nutrients. Overall, the experiment was simple to execute with minimal resources and time. The pH indicator and color board allowed the crew to easily determine when the culture had reached the optimal pH. All 15 experimental bags were shipped back to Ames and are pending analysis of pH, viability, and contamination checks.
Analog Astronauts Katie Fisher and Tuğcağ Dumlupinar of Turkey perform bag hydration and passaging step of kefir cultures. Top right: Pre-incubation. Bottom right: 24 h post-incubation. Pictures courtesy of Katie Fisher.NASA to Host a Pair of Briefings for Starliner Crew Flight
NASA will host two media opportunities on Thursday, April 25, in preparation for the agency’s Boeing Crew Flight Test to the International Space Station. The mission is targeting launch at 10:34 p.m. EDT on Monday, May 6, from Space Launch Complex-41 at Cape Canaveral Space Force Station in Florida.
NASA astronauts Butch Wilmore and Suni Williams will lift off aboard Boeing’s Starliner spacecraft on a United Launch Alliance Atlas V rocket and dock at the orbiting laboratory, where they will stay for about a week.
As part of the agency’s Commercial Crew Program, the mission is the first crewed flight for the Starliner spacecraft. The mission will test the end-to-end capabilities of the Starliner system, including launch, docking, and return to Earth in the western United States. Following a successful crewed flight test, NASA will begin the final process of certifying Starliner and systems for crewed missions to the space station.
The deadline for media accreditation for in-person coverage of this launch has passed. The agency’s media credentialing policy is available online. For questions about media accreditation, please email: ksc-media-accreditat@mail.nasa.gov.
NASA’s coverage is as follows (all times Eastern and subject to change based on real-time operations):
Thursday, April 25
1 p.m.: Crew arrival media event at NASA’s Kennedy Space Center in Florida, with the following participants:
- Janet Petro, director, NASA Kennedy
- Dana Hutcherson, deputy program manager, NASA’s Commercial Crew Program
- NASA astronaut Butch Wilmore
- NASA astronaut Suni Williams
Crew arrival will air live on NASA+, NASA Television, the NASA app, YouTube, and the agency’s website. Learn how to stream NASA TV through a variety of platforms including social media. Questions are limited to in-person media only. Follow Commercial Crew and Kennedy Space Center for the latest arrival updates.
6 p.m.: Flight Test Readiness Review media teleconference (no less than one hour following completion of the readiness review), with the following participants:
- Jim Free, NASA associate administrator
- Ken Bowersox, associate administrator, NASA’s Space Operations Mission Directorate
- Steve Stich, manager, NASA’s Commercial Crew Program
- Dana Weigel, manager, NASA’s International Space Station Program
- Mark Nappi, vice president and program manager, Boeing Commercial Crew Program
Media may participate via phone only. For the dial-in number and passcode, please contact the Kennedy newsroom no later than 4 p.m. on April 25, at: ksc-newsroom@mail.nasa.gov.
NASA’s Commercial Crew Program has delivered on its goal of safe, reliable, and cost-effective transportation to and from the International Space Station from the United States through a partnership with American private industry. This partnership is changing the arc of human spaceflight history by opening access to low-Earth orbit and the International Space Station to more people, more science, and more commercial opportunities. The space station remains the springboard to NASA’s next great leap in space exploration, including future missions to the Moon and, eventually, to Mars.
For NASA’s launch blog and more information about the mission, visit:
https://www.nasa.gov/commercialcrew
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Uranus and Neptune aren't made of what we thought, new study hints
Exotic 'Einstein ring' suggests that mysterious dark matter interacts with itself
The Milky Way’s History is Written in Streams of Stars
The Milky Way is ancient and massive, a collection of hundreds of billions of stars, some dating back to the Universe’s early days. During its long life, it’s grown to these epic proportions through mergers with other, smaller galaxies. These mergers punctuate our galaxy’s history, and its story is written in the streams of stars left behind as evidence after a merger.
And it’s still happening today.
The Milky Way is currently digesting smaller galaxies that have come too close. The Large and Small Magellanic Clouds feel the effects as the Milky Way’s powerful gravity distorts them and siphons a stream of gas and stars from them to our galaxy. A similar thing is happening to the Sagittarius Dwarf Spheroidal Galaxy and globular clusters like Omega Centauri.
There’s a long list of these stellar streams in the Milky Way, though the original galaxies that spawned them are long gone, absorbed by the Milky Way. But the streams still tell the tale of ancient mergers and absorptions. They hold kinematic and chemical clues to the galaxies and clusters they spawned in.
As astronomers get better tools to find and study these streams, they’re realizing the streams could tell them more than just the history of mergers. They’re like strings of pearls, and their shapes and other properties show how gravity has shaped them. But they also reveal something else important: how dark matter has shaped them.
Since dark matter is so mysterious, any chance to learn something about it is a priority. As researchers examine the stellar streams, they’re finding signs of disturbances in them—including missing members—that aren’t explained by the Milky Way’s mass. They suspect that dark matter is the cause.
“If we find a pearl necklace with a few scattered pearls nearby, we can deduce that something may have come along and broken the string.”
Soon, astronomers will have an enormously powerful tool to study these streams and dark matter’s role in disturbing them: the Vera Rubin Observatory (VRO).
Astronomers have different methods of studying dark matter. Weak gravitational lensing is one of them, and it maps dark matter on the large scale of galaxy clusters. But stellar streams are at the opposite end of the scale. By mapping them and their irregularities and disturbances, astronomers can study dark matter at a much smaller scale.
This image shows the core of the Sagittarius Dwarf Spheroidal Galaxy and its stellar streams as it’s absorbed by the Milky Way. Image Credit: David Law/UCLAThe Rubin Observatory will complete its Legacy Survey of Space and Time (LSST) in a ten-year period. Alongside its time-domain astronomy objectives, the LSST will also study dark matter. The LSST Dark Energy Science Collaboration is aimed at dark matter and will use Rubin’s power to advance the study of dark energy and dark matter like nothing before it. “LSST will go much further than any of its predecessors in its ability to measure the growth of structure and will provide a stringent test of theories of modi?ed-gravity,” their website explains.
As we get closer and closer to the observatory’s planned first light in January 2025, the growing excitement is palpable.
“I’m really excited about using stellar streams to learn about dark matter,” said Nora Shipp, a postdoctoral fellow at Carnegie Mellon University and co-convener of the Dark Matter Working Group in the Rubin Observatory/LSST Dark Energy Science Collaboration. “With Rubin Observatory we’ll be able to use stellar streams to figure out how dark matter is distributed in our galaxy from the largest scales down to very small scales.”
Astronomers have ample evidence that a halo of dark matter envelops the Milky Way. Other galaxies are the same. These dark matter halos extend beyond a galaxy’s visible disk and are considered basic units in the Universe’s large-scale structure. These haloes may also contain sub-haloes, clumps of dark matter bound by gravity.
This image shows a simulated Milky Way-size CDM halo. The six circles show sub-haloes enlarged in separate boxes. Sub-haloes are also visible, and the bottom row shows several generations of sub-subhaloes contained within subhalo f. Image Credit: Zavala and Frenk 2019These clumps are what astronomers think are leaving their marks on stellar streams. The dark matter clumps create kinks and gaps in the streams. The VRO has the power to see these irregularities on a small scale and over a ten-year span. “By observing stellar streams, we’ll be able to take indirect measurements of the Milky Way’s dark matter clumps down to masses lower than ever before, giving us really good constraints on the particle properties of dark matter,” said Shipp.
The Lambda Cold Dark Matter (Lambda CDM) model is the standard model of Big Bang Cosmology. One of the Lambda CDM’s key predictions says that many sub-galactic dark matter substructures should exist. Astronomers want to test that prediction by observing these structures’ effect on stellar streams. The VRO will help them do that and will also help them find more of them and build a larger data set.
Stellar streams are difficult to detect. Their kinematics give them away, but sometimes, there are only a few dozen stars in the streams. This obscures them among the Milky Way’s myriad stars. But the VRO will change that.
The VRO will detect streams at much further distances. On the outskirts of the Milky Way, the streams have interacted with less matter, making them strong candidates for studying the effect of dark matter in isolation.
“Stellar streams are like strings of pearls, whose stars trace the path of the system’s orbit and have a shared history,” said Jaclyn Jensen, a PhD candidate at the University of Victoria. Jensen plans to use Rubin/LSST data for her research on the progenitors of stellar streams and their role in forming the Milky Way. “Using properties of these stars, we can determine information about their origins and what kind of interactions the stream may have experienced. If we find a pearl necklace with a few scattered pearls nearby, we can deduce that something may have come along and broken the string.”
The VRO’s powerful digital camera and its system of filters make this possible. Its ultraviolet filter, in particular, will help make more streams visible. Astronomers can distinguish stellar streams from all other stars by examining the blue-ultraviolet light at the end of the visible spectrum. They’ll have thousands upon thousands of images to work with.
Rubin Observatory at twilight in May 2022. Among the observatory’s many endeavours is the study of dark matter. Credit: Rubin Obs/NSF/AURAIn fact, the VRO will unleash a deluge of astronomical data that scientists and institutions have been preparing to handle. AI and machine learning will play a foundational role in managing all that data, which should contribute to finding even more stellar streams.
“Right now it’s a labor-intensive process to pick out potential streams by eye—Rubin’s large volume of data presents an exciting opportunity to think of new, more automated ways to identify streams.”
Astronomers are still finding more stellar streams. Earlier this month, a paper in The Astrophysical Journal presented the discovery of another one. Researchers found it in Gaia’s Data Release 3. It’s likely associated with the merger of the Sequoia dwarf galaxy.
It seems certain that astronomers will keep finding more stellar streams. Their value as tracers of the Milky Way’s history is considerable. But if scientists can use them to understand the distribution of dark matter on a small scale, they’ll get more than they bargained for.
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