X-ray: NASA/CXC/SAO; Optical: NASA/ESA/STScl; IR: NASA/ESA/CSA/STScl/Milisavljevic et al., NASA/JPL/CalTech; Image Processing: NASA/CXC/SAO/J. Schmidt and K. Arcand
For the first time, astronomers have combined data from NASA’s Chandra X-ray Observatory and James Webb Space Telescope to study the well-known supernova remnant Cassiopeia A (Cas A). This work has helped explain an unusual structure in the debris from the destroyed star called the “Green Monster,” because of its resemblance to the wall in the left field of Fenway Park.
By combining the Webb data with X-rays from Chandra, researchers have concluded that the Green Monster was created by a blast wave from the exploded star slamming into material surrounding it. Detailed analysis found that filaments in the outer part of Cas A, from the blast wave, closely matched the X-ray properties of the Green Monster, including less iron and silicon than in the supernova debris. This interpretation is apparent from the color Chandra image, which shows that the colors inside the Green Monster’s outline best match with the colors of the blast wave rather than the debris with iron and silicon.
NASA Shares Progress Toward Early Artemis Moon Missions with Crew
Artemis II crew members (from left) CSA (Canadian Space Agency) astronaut Jeremy Hansen, and NASA astronauts Christina Koch, Victor Glover, and Reid Wiseman walk out of Astronaut Crew Quarters inside the Neil Armstrong Operations and Checkout Building to the Artemis crew transportation vehicles prior to traveling to Launch Pad 39B as part of an integrated ground systems test at Kennedy Space Center in Florida on Wednesday, Sept. 20, to test the crew timeline for launch day.
NASA
NASA announced Tuesday updates to its Artemis campaign that will establish the foundation for long-term scientific exploration at the Moon, land the first woman and first person of color on the lunar surface, and prepare for human expeditions to Mars for the benefit of all. To safely carry out these missions, agency leaders are adjusting the schedules for Artemis II and Artemis III to allow teams to work through challenges associated with first-time developments, operations, and integration.
NASA will now target September 2025 for Artemis II, the first crewed Artemis mission around the Moon, and September 2026 for Artemis III, which is planned to land the first astronauts near the lunar South Pole. Artemis IV, the first mission to the Gateway lunar space station, remains on track for 2028.
“We are returning to the Moon in a way we never have before, and the safety of our astronauts is NASA’s top priority as we prepare for future Artemis missions,” said NASA Administrator Bill Nelson. “We’ve learned a lot since Artemis I, and the success of these early missions relies on our commercial and international partnerships to further our reach and understanding of humanity’s place in our solar system. Artemis represents what we can accomplish as a nation – and as a global coalition. When we set our sights on what is hard, together, we can achieve what is great.”
Ensuring crew safety is the primary driver for the Artemis II schedule changes. As the first Artemis flight test with crew aboard the Orion spacecraft, the mission will test critical environmental control and life support systems required to support astronauts. NASA’s testing to qualify components to keep the crew safe and ensure mission success has uncovered issues that require additional time to resolve. Teams are troubleshooting a battery issue and addressing challenges with a circuitry component responsible for air ventilation and temperature control.
NASA’s investigation into unexpected loss of char layer pieces from the spacecraft’s heat shield during Artemis I is expected to conclude this spring. Teams have taken a methodical approach to understand the issue, including extensive sampling of the heat shield, testing, and review of data from sensors and imagery.
The new timeline for Artemis III aligns with the updated schedule for Artemis II, ensures the agency can incorporate lessons learned from Artemis II into the next mission, and acknowledges development challenges experienced by NASA’s industry partners. As each crewed Artemis mission increases complexity and adds flight tests for new systems, the adjusted schedule will give the providers developing new capabilities – SpaceX for the human landing system and Axiom Space for the next-generation spacesuits – additional time for testing and any refinements ahead of the mission.
“We are letting the hardware talk to us so that crew safety drives our decision-making. We will use the Artemis II flight test, and each flight that follows, to reduce risk for future Moon missions,” said Catherine Koerner, associate administrator, Exploration Systems Development Mission Directorate at NASA Headquarters in Washington. “We are resolving challenges associated with first-time capabilities and operations, and we are closer than ever to establishing sustained exploration of Earth’s nearest neighbor under Artemis.”
In addition to the schedule updates for Artemis II and III, NASA is reviewing the schedule for launching the first integrated elements of Gateway, previously planned for October 2025, to provide additional development time and better align that launch with the Artemis IV mission in 2028.
NASA also shared that it has asked both Artemis human landing system providers – SpaceX and Blue Origin – to begin applying knowledge gained in developing their systems as part of their existing contracts toward future variations to potentially deliver large cargo on later missions.
“Artemis is a long-term exploration campaign to conduct science at the Moon with astronauts and prepare for future human missions to Mars. That means we must get it right as we develop and fly our foundational systems so that we can safely carry out these missions,” said Amit Kshatriya, deputy associate administrator of Exploration Systems Development, and manager of NASA’s Moon to Mars Program Office at headquarters. “Crew safety is and will remain our number one priority.”
NASA leaders emphasized the importance of all partners delivering on time so the agency can maximize the flight objectives with available hardware on a given mission. NASA regularly assesses progress and timelines and as a part of integrated programmatic planning to ensure the agency and its partners can successfully accomplish its Moon to Mars exploration goals.
With Artemis, NASA will explore more of the Moon than ever before, learn how to live and work away from home, and prepare for future human exploration of the Red Planet. NASA’s SLS (Space Launch System) rocket, exploration ground systems, and Orion spacecraft, along with the human landing system, next-generation spacesuits, Gateway lunar space station, and future rovers are NASA’s foundation for deep space exploration.
NASA’s Webb Finds Signs of Possible Aurorae on Isolated Brown Dwarf
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NASA’s Webb Finds Signs of Possible Aurorae on Isolated Brown Dwarf
Artist’s concept portrays the brown dwarf W1935.
Credits: NASA, ESA, CSA, and L. Hustak (STScI)
Infrared emission from methane suggests atmospheric heating by auroral processes.
Astronomers using NASA’s James Webb Space Telescope have found a brown dwarf (an object more massive than Jupiter but smaller than a star) with infrared emission from methane, likely due to energy in its upper atmosphere. This is an unexpected discovery because the brown dwarf, W1935, is cold and lacks a host star; therefore, there is no obvious source for the upper atmosphere energy. The team speculates that the methane emission may be due to processes generating aurorae.
These findings are being presented at the 243rd meeting of the American Astronomical Society in New Orleans.
To help explain the mystery of the infrared emission from methane, the team turned to our solar system. Methane in emission is a common feature in gas giants like Jupiter and Saturn. The upper-atmosphere heating that powers this emission is linked to aurorae.
Image: Artist Concept Brown Dwarf W1935
This artist concept portrays the brown dwarf W1935, which is located 47 light-years from Earth. Astronomers using NASA’s James Webb Space Telescope found infrared emission from methane coming from W1935. This is an unexpected discovery because the brown dwarf is cold and lacks a host star; therefore, there is no obvious source of energy to heat its upper atmosphere and make the methane glow. The team speculates that the methane emission may be due to processes generating aurorae, shown here in red.
NASA, ESA, CSA, and L. Hustak (STScI)
On Earth, aurorae are created when energetic particles blown into space from the Sun are captured by Earth’s magnetic field. They cascade down into our atmosphere along magnetic field lines near Earth’s poles, colliding with gas molecules and creating eerie, dancing curtains of light. Jupiter and Saturn have similar auroral processes that involve interacting with the solar wind, but they also get auroral contributions from nearby active moons like Io (for Jupiter) and Enceladus (for Saturn).
For isolated brown dwarfs like W1935, the absence of a stellar wind to contribute to the auroral process and explain the extra energy in the upper atmosphere required for the methane emission is a mystery. The team surmises that either unaccounted internal processes like the atmospheric phenomena of Jupiter and Saturn, or external interactions with either interstellar plasma or a nearby active moon, may help account for the emission.
A Detective Story
The aurorae’s discovery played out like a detective story. A team led by Jackie Faherty, an astronomer at the American Museum of Natural History in New York, was awarded time with the Webb telescope to investigate 12 cold brown dwarfs. Among those were W1935 – an object that was discovered by citizen scientist Dan Caselden, who worked with the Backyard Worlds zooniverse project – and W2220, an object that was discovered using NASA’s Wide Field Infrared Survey Explorer. Webb revealed in exquisite detail that W1935 and W2220 appeared to be near clones of each other in composition. They also shared similar brightness, temperatures, and spectral features of water, ammonia, carbon monoxide, and carbon dioxide. The striking exception was that W1935 showed emission from methane, as opposed to the anticipated absorption feature that was observed toward W2220. This was seen at a distinct infrared wavelength to which Webb is uniquely sensitive.
“We expected to see methane because methane is all over these brown dwarfs. But instead of absorbing light, we saw just the opposite: The methane was glowing. My first thought was, what the heck? Why is methane emission coming out of this object?” said Faherty.
The team used computer models to infer what might be behind the emission. The modeling work showed that W2220 had an expected distribution of energy throughout the atmosphere, getting cooler with increasing altitude. W1935, on the other hand, had a surprising result. The best model favored a temperature inversion, where the atmosphere got warmer with increasing altitude. “This temperature inversion is really puzzling,” said Ben Burningham, a co-author from the University of Hertfordshire in England and lead modeler on the work. “We have seen this kind of phenomenon in planets with a nearby star that can heat the stratosphere, but seeing it in an object with no obvious external heat source is wild.”
Image: Spectra W1935 vs W2220
Astronomers used NASA’s James Webb Space Telescope to study 12 cold brown dwarfs. Two of them – W1935 and W2220 – appeared to be near twins of each other in composition, brightness, and temperature. However, W1935 showed emission from methane, as opposed to the anticipated absorption feature that was observed toward W2220. The team speculates that the methane emission may be due to processes generating aurorae.
NASA, ESA, CSA, and L. Hustak (STScI)
Clues from our Solar System
For clues, the team looked in our own backyard, to the planets of our solar system. The gas giant planets can serve as proxies for what is seen going on more than 40 light-years away in the atmosphere of W1935.
The team realized that temperature inversions are prominent in planets like Jupiter and Saturn. There is still ongoing work to understand the causes of their stratospheric heating, but leading theories for the solar system involve external heating by aurorae and internal energy transport from deeper in the atmosphere (with the former a leading explanation).
Brown Dwarf Aurora Candidates in Context
This is not the first time an aurora has been used to explain a brown dwarf observation. Astronomers have detected radio emission coming from several warmer brown dwarfs and invoked aurorae as the most likely explanation. Searches were conducted with ground-based telescopes like the Keck Observatory for infrared signatures from these radio-emitting brown dwarfs to further characterize the phenomenon, but were inconclusive.
W1935 is the first auroral candidate outside the solar system with the signature of methane emission. It’s also the coldest auroral candidate outside our solar system, with an effective temperature of about 400 degrees Fahrenheit (200 degrees Celsius), about 600 degrees Fahrenheit warmer than Jupiter.
In our solar system the solar wind is a primary contributor to auroral processes, with active moons like Io and Enceladus playing a role for planets like Jupiter and Saturn, respectively. W1935 lacks a companion star entirely, so a stellar wind cannot contribute to the phenomenon. It is yet to be seen whether an active moon might play a role in the methane emission on W1935.
“With W1935, we now have a spectacular extension of a solar system phenomenon without any stellar irradiation to help in the explanation.” Faherty noted. “With Webb, we can really ‘open the hood’ on the chemistry and unpack how similar or different the auroral process may be beyond our solar system,” she added.
The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.
Want to help discover a new world?
Want to help discover a new world? Join the Backyard Worlds: Planet 9 citizen science project and search the realm beyond Neptune for new brown dwarfs and planets. Or try NASA’s new Burst Chaser citizen science project, which launched Jan. 9.
Be a Burst Chaser and Witness the Most Powerful Explosions in the Universe!
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Be a Burst Chaser and Witness the Most Powerful Explosions in the Universe!
The Burst Chaser Project was launched today at the American Astronomical Society meeting in New Orleans, Louisiana.
Credit: NASA Goddard Space Flight Center/Zooniverse
Yes, the universe IS talking to you! Gamma-ray bursts, massive explosions visible from everywhere in the observable universe, are telling us something about how stars end their lives and how massive black holes form. Now astronomers are asking you join the Burst Chaser project to read the signals from these bursts and decode what the universe is saying.
NASA’s Neil Gehrels SWIFT observatory regularly detects pulses of gamma rays, a very energetic form of light, coming from billions of light years away. At Burst Chaser, you’ll examine plots that show how much gamma ray energy arrived at this space telescope as a function of time and classify their shapes—the pulse shapes.
Gamma-ray bursts are known to be mostly connected to supernovae or the mergers of neutron stars and black holes, but exactly how these events produce pulses with such a variety of characteristics remains a mystery. “We need your help to classify these pulses for more clues of what they really are!” said Professor Amy Lien from the University of Tampa, the project’s Principal Investigator.
Besides professional astronomers like Lien, the project’s science team includes three undergraduate students from the University of Tampa: Katherine Kurilov, Carter Murawski, and Sebastian Reisch. Several NASA volunteers also helped design the project: Sovan Acharya, Eduardo Antonini, Sumit Banerjee, Marco Zaccaria Di Fraia, Jonathan Holden, Vikrant Kurmude, Hugo Durantini Luca, Orleo Marinaro, John Yablonsky, and U.S. military veteran, Danny Roylance, interviewed here. The project platform is hosted by Zooniverse, a NASA Partner.
NASA, NOAA to Announce 2023 Global Temperatures, Climate Conditions
This map depicts global temperature anomalies for meteorological summer in 2023 (June, July, and August). It shows how much warmer or cooler different regions of Earth were compared to the baseline average from 1951 to 1980.
Climate researchers from NASA and NOAA (National Oceanic and Atmospheric Administration) will release their annual assessments of global temperatures and discuss the major climate trends of 2023 during a media briefing at 11 a.m. EST Friday, Jan. 12.
NASA will stream audio of the briefing on the agency’s YouTube.
Participants will include:
Kate Calvin, chief scientist and senior climate advisor, NASA Headquarters
Gavin Schmidt, director, NASA’s Goddard Institute for Space Studies
Sarah Kapnick, chief scientist, NOAA
Russ Vose, chief, analysis and synthesis branch, NOAA’s National Centers for Environmental Information
Members of the media can access the briefing using the online registration.
NASA and NOAA are two keepers of the world’s temperature data and independently produce a record of Earth’s surface temperatures and changes based on historical observations over oceans and land.
For more information about NASA’s Earth science programs, visit:
