Feed aggregator
Hera asteroid mission’s Mars flyby
On Wednesday 12 March 2025 ESA’s Hera spacecraft for planetary defence performs a flyby of Mars. The gravity of the red planet shifts the spacecraft’s trajectory towards its final destination of the Didymos binary asteroid system, shortening its trip by months and saving substantial fuel.
Watch the livestream release of images from Hera’s flyby by the mission’s science team on Thursday 13 March, starting at 11:50 CET!
Hera comes to around 5000 km from the surface of Mars during its flyby. It will also image Deimos, the smaller of Mars’s two moons, from a minimum 1000 km away (while venturing as close as 300 km). Hera will also image Mars’s larger moon Phobos as it begins to move away from Mars.
Launched on 7 October 2024, Hera on its way to visit the first asteroid to have had its orbit altered by human action. By gathering close-up data about the Dimorphos asteroid, which was impacted by NASA’s DART spacecraft in 2022, Hera will help turn asteroid deflection into a well understood and potentially repeatable technique.
Hera will reach the Didymos asteroid and its Dimorphos moonlet in December 2026. By gathering crucial missing data during its close-up crash scene investigation, Hera will turn the kinetic impact method of asteroid deflection into a well understood technique that could potentially be used for real when needed.
Did you know this mission has its own AI? You can pose questions to our Hera Space Companion!
'Amazing' spinning needle proof unlocks a whole new world of maths
'Amazing' spinning needle proof unlocks a whole new world of maths
NASA’s Webb Peers Deeper into Mysterious Flame Nebula
- Webb
- News
- Overview
- Science
- Observatory
- Multimedia
- Team
- More
The Flame Nebula, located about 1,400 light-years away from Earth, is a hotbed of star formation less than 1 million years old. Within the Flame Nebula, there are objects so small that their cores will never be able to fuse hydrogen like full-fledged stars—brown dwarfs.
Brown dwarfs, often called “failed stars,” over time become very dim and much cooler than stars. These factors make observing brown dwarfs with most telescopes difficult, if not impossible, even at cosmically short distances from the Sun. When they are very young, however, they are still relatively warmer and brighter and therefore easier to observe despite the obscuring, dense dust and gas that comprises the Flame Nebula in this case.
NASA’s James Webb Space Telescope can pierce this dense, dusty region and see the faint infrared glow from young brown dwarfs. A team of astronomers used this capability to explore the lowest mass limit of brown dwarfs within the Flame Nebula. The result, they found, were free-floating objects roughly two to three times the mass of Jupiter, although they were sensitive down to 0.5 times the mass of Jupiter.
“The goal of this project was to explore the fundamental low-mass limit of the star and brown dwarf formation process. With Webb, we’re able to probe the faintest and lowest mass objects,” said lead study author Matthew De Furio of the University of Texas at Austin.
Image A: Flame Nebula: Hubble and Webb Observations This collage of images from the Flame Nebula shows a near-infrared light view from NASA’s Hubble Space Telescope on the left, while the two insets at the right show the near-infrared view taken by NASA’s James Webb Space Telescope. Much of the dark, dense gas and dust, as well as the surrounding white clouds within the Hubble image, have been cleared in the Webb images, giving us a view into a more translucent cloud pierced by the infrared-producing objects within that are young stars and brown dwarfs. Astronomers used Webb to take a census of the lowest-mass objects within this star-forming region.
The Hubble image on the left represents light at wavelengths of 1.05 microns (filter F105W) as blue, 1.3 microns (F130N) as green, and 1.39 microns (F129M) as red. The two Webb images on the right represent light at wavelengths of 1.15 microns and 1.4 microns (filters F115W and F140M) as blue, 1.82 microns (F182M) as green, 3.6 microns (F360M) as orange, and 4.3 microns (F430M) as red.NASA, ESA, CSA, M. Meyer (University of Michigan), A. Pagan (STScI) Smaller Fragments
The low-mass limit the team sought is set by a process called fragmentation. In this process large molecular clouds, from which both stars and brown dwarfs are born, break apart into smaller and smaller units, or fragments.
Fragmentation is highly dependent on several factors with the balance between temperature, thermal pressure, and gravity being among the most important. More specifically, as fragments contract under the force of gravity, their cores heat up. If a core is massive enough, it will begin to fuse hydrogen. The outward pressure created by that fusion counteracts gravity, stopping collapse and stabilizing the object (then known as a star). However, fragments whose cores are not compact and hot enough to burn hydrogen continue to contract as long as they radiate away their internal heat.
“The cooling of these clouds is important because if you have enough internal energy, it will fight that gravity,” says Michael Meyer of the University of Michigan. “If the clouds cool efficiently, they collapse and break apart.”
Fragmentation stops when a fragment becomes opaque enough to reabsorb its own radiation, thereby stopping the cooling and preventing further collapse. Theories placed the lower limit of these fragments anywhere between one and ten Jupiter masses. This study significantly shrinks that range as Webb’s census counted up fragments of different masses within the nebula.
“As found in many previous studies, as you go to lower masses, you actually get more objects up to about ten times the mass of Jupiter. In our study with the James Webb Space Telescope, we are sensitive down to 0.5 times the mass of Jupiter, and we are finding significantly fewer and fewer things as you go below ten times the mass of Jupiter,” De Furio explained. “We find fewer five-Jupiter-mass objects than ten-Jupiter-mass objects, and we find way fewer three-Jupiter-mass objects than five-Jupiter-mass objects. We don’t really find any objects below two or three Jupiter masses, and we expect to see them if they are there, so we are hypothesizing that this could be the limit itself.”
Meyer added, “Webb, for the first time, has been able to probe up to and beyond that limit. If that limit is real, there really shouldn’t be any one-Jupiter-mass objects free-floating out in our Milky Way galaxy, unless they were formed as planets and then ejected out of a planetary system.”
Image B: Low Mass Objects within the Flame Nebula in Infrared Light This near-infrared image of a portion of the Flame Nebula from NASA’s James Webb Space Telescope highlights three low-mass objects, seen in the insets to the right. These objects, which are much colder than protostars, require the sensitivity of Webb’s instruments to detect them. These objects were studied as part of an effort to explore the lowest mass limit of brown dwarfs within the Flame Nebula.
The Webb images represent light at wavelengths of 1.15 microns and 1.4 microns (filters F115W and F140M) as blue, 1.82 microns (F182M) as green, 3.6 microns (F360M) as orange, and 4.3 microns (F430M) as red.NASA, ESA, CSA, STScI, M. Meyer (University of Michigan) Building on Hubble’s Legacy
Brown dwarfs, given the difficulty of finding them, have a wealth of information to provide, particularly in star formation and planetary research given their similarities to both stars and planets. NASA’s Hubble Space Telescope has been on the hunt for these brown dwarfs for decades.
Even though Hubble can’t observe the brown dwarfs in the Flame Nebula to as low a mass as Webb can, it was crucial in identifying candidates for further study. This study is an example of how Webb took the baton—decades of Hubble data from the Orion Molecular Cloud Complex—and enabled in-depth research.
“It’s really difficult to do this work, looking at brown dwarfs down to even ten Jupiter masses, from the ground, especially in regions like this. And having existing Hubble data over the last 30 years or so allowed us to know that this is a really useful star-forming region to target. We needed to have Webb to be able to study this particular science topic,” said De Furio.
“It’s a quantum leap in our capabilities between understanding what was going on from Hubble. Webb is really opening an entirely new realm of possibilities, understanding these objects,” explained astronomer Massimo Robberto of the Space Telescope Science Institute.
This team is continuing to study the Flame Nebula, using Webb’s spectroscopic tools to further characterize the different objects within its dusty cocoon.
“There’s a big overlap between the things that could be planets and the things that are very, very low mass brown dwarfs,” Meyer stated. “And that’s our job in the next five years: to figure out which is which and why.”
These results are accepted for publication in The Astrophysical Journal Letters.
Image C (Animated): Flame Nebula (Hubble and Webb Comparison) This animated image alternates between a Hubble Space Telescope and a James Webb Space Telescope observation of the Flame Nebula, a nearby star-forming nebula less than 1 million years old. In this comparison, three low-mass objects are highlighted. In Hubble’s observation, the low-mass objects are hidden by the region’s dense dust and gas. However, the objects are brought out in the Webb observation due to Webb’s sensitivity to faint infrared light.NASA, ESA, CSA, Alyssa Pagan (STScI)
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 CSA (Canadian Space Agency).
DownloadsClick any image to open a larger version.
View/Download all image products at all resolutions for this article from the Space Telescope Science Institute.
Media ContactsLaura Betz – laura.e.betz@nasa.gov
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Matthew Brown – mabrown@stsci.edu
Space Telescope Science Institute, Baltimore, Md.
Christine Pulliam – cpulliam@stsci.edu
Space Telescope Science Institute, Baltimore, Md.
Learn more about brown dwarf discoveries
Related For Kids En Español Keep Exploring Related Topics James Webb Space TelescopeWebb is the premier observatory of the next decade, serving thousands of astronomers worldwide. It studies every phase in the…
Universe
Universe Stories
Stars Stories
Share Details Last Updated Mar 10, 2025 EditorMarty McCoyContactLaura Betzlaura.e.betz@nasa.gov Related TermsWatch live: Images from Hera’s Mars flyby
Join us live for a star-studded event this Thursday, as scientists working on ESA’s Hera mission for planetary defence release the mission’s first scientific observations beyond the Earth-Moon system, following its imminent flyby of Mars.
New recipe for gravity could unite Einstein's general relativity with quantum physics — and probe the dark universe
Microsoft under fire for claiming it has a new quantum computer
Microsoft under fire for claiming it has a new quantum computer
Moon Mascot: NASA Artemis II ZGI Design Challenge
Will you design the zero gravity indicator (ZGI) that accompanies the Artemis II mission around the Moon? If your design is one of the most compelling and resonates with the global community and the Artemis II astronauts, your design might fly into space aboard the Orion spacecraft and you could win US$1225. Zero gravity indicators are small items carried aboard spacecraft that provide a visual indicator for when a spacecraft has reached the weightlessness of microgravity. A plush Snoopy doll was the ZGI for the Artemis I mission. For that uncrewed mission, Snoopy floated around, tethered inside the vehicle to indicate when the Orion spacecraft had reached space. For this Challenge, we’re asking creatives from all over the world to design a new ZGI to be fabricated by NASA’s Thermal Blanket Lab and launched into space aboard the Artemis II mission.
Award: $23,275 in total prizes
Open Date: March 7, 2025
Close Date: May 27, 2025
For more information, visit: https://www.freelancer.com/contest/Moon-Mascot-NASA-Artemis-II-ZGI-Design-Challenge-2527909/details
Our Narrow View of Masculinity Is Hurting Boys
Masculinity isn’t “toxic” by itself, but the strain boys feel from society and parents to meet unrealistic expectations is
Earth May Soon Get Early Solar Flare Warnings
Flickering loops in the sun’s corona may appear before dangerous solar activity
Measles Misinformation Sparks Concern, Supreme Court Limits EPA Power, and Scientists Create Woolly Mice
In this week's news roundup, we dig into measles misinformation, ozone recovery and new findings on using nasal cartilage to treat knee injuries.
Station Science Top News: March 7, 2025
Challenges to measuring space-induced brain changes
CSA (Canadian Space Agency) astronaut David Saint-Jacques undergoes an MRI for Wayfinding. CSA
Researchers found that an upward shift in the brain during spaceflight makes it hard to distinguish different types of tissue, causing errors in determining changes in brain volume. Previous studies have interpreted these changes as evidence of adaptation to space. This finding suggests that unique methods are needed to analyze astronaut brain structure.
Wayfinding, a CSA (Canadian Space Agency) investigation, looked at how the brain adapts to space and readapts after return to normal gravity using a variety of assessments, including neuroimaging. The researchers propose that previous data could be reanalyzed based on the errors identified by this paper.
Catching micrometeoroids
JAXA’s (Japan Aerospace Exploration Agency) Tanpopo panels were mounted on the Exposed Experiment Handrail Attachment Mechanism (ExHAM) at top center of this image. JAXA/Takuya Onishi
An impact track made by a micrometeoroid on a panel outside the International Space Station contained iron and orthopyroxene crystals. This finding, along with previous studies, suggests that micrometeoroids containing these elements are abundant in low Earth orbit and more measurements are needed to determine their origins and potential for carrying life.
At least 90% of meteoroids at one astronomical unit or AU (93 million miles or the distance between Earth and the Sun) do not reach Earth’s surface, so investigating those in low Earth orbit is key to understanding their nature. The JAXA (Japan Aerospace Exploration Agency) Tanpopo experiment placed blocks of a special gel outside the station to capture solid microparticles to test the theory that they could transport life among celestial bodies. Most meteoroids at one AU may have originated from Jupiter family comets.
This week's 'blood moon' eclipse mirrors one Christopher Columbus used to scare indigenous people in 1504
ESA’s pioneering Biomass satellite arrives at launch site
Marking another step towards new insights into Earth’s forests and their role in the carbon cycle, ESA’s groundbreaking Biomass satellite has arrived at Europe's Spaceport in French Guiana, to be prepared for liftoff on a Vega-C rocket at the end of April.
James Gentile: Shaping the Artemis Generation, One Simulation at a Time
James Gentile always wanted to fly. As he prepared for an appointment to the U.S. Air Force Academy to become a pilot, life threw him an unexpected curve: a diagnosis of Type 1 diabetes. His appointment was rescinded.
With his dream grounded, Gentile had two choices—give up or chart a new course. He chose the latter, pivoting to aerospace engineering. If he could not be a pilot, he would design the flight simulations that trained those who could.
Official portrait of James Gentile. NASA/Robert Markowitz
As a human space vehicle simulation architect at NASA’s Johnson Space Center in Houston, Gentile leads the Integrated Simulation team, which supports the Crew Compartment Office within the Simulation and Graphics Branch. He oversees high-fidelity graphical simulations that support both engineering analysis and flight crew training for the Artemis campaign.
His team provides critical insight into human landing system vendor designs, ensuring compliance with NASA’s standards. They also develop human-in-the-loop simulations to familiarize teams with the challenges of returning humans to the lunar surface, optimizing design and safety for future space missions.
“I take great pride in what I have helped to build, knowing that some of the simulations I developed have influenced decisions for the Artemis campaign,” Gentile said.
One of the projects he is most proud of is the Human Landing System CrewCo Lander Simulation, which helps engineers and astronauts tackle the complexities of lunar descent, ascent, and rendezvous. He worked his way up from a developer to managing and leading the project, transforming a basic lunar lander simulation into a critical tool for the Artemis campaign.
What began as a simple model in 2020 is now a key training asset used in multiple facilities at Johnson. The simulation evaluates guidance systems and provides hands-on piloting experience for lunar landers.
James Gentile in the Simulation Exploration and Analysis Lab during a visit with Apollo 16 Lunar Module Pilot Charlie Duke. From left to right: Katie Tooher, Charlie Duke, Steve Carothers, Mark Updegrove, and James Gentile. NASA/James Blair
Before joining Johnson as a contractor in 2018, Gentile worked in the aviation industry developing flight simulations for pilot training. Transitioning to the space sector was challenging at first, particularly working alongside seasoned professionals who had been part of the space program for years.
“I believe my experience in the private sector has benefited my career,” he said. “I’ve been able to bring a different perspective and approach to problem-solving that has helped me advance at Johnson.”
Gentile attributes his success to never being afraid to speak up and ask questions. “You don’t always have to be the smartest person in the room to make an impact,” he said. “I’ve been able to show my value through my work and by continuously teaching myself new skills.”
As he helps train the Artemis Generation, Gentile hopes to pass on his passion for aerospace and simulation development, inspiring others to persevere through obstacles and embrace unexpected opportunities.
“The most important lessons I’ve learned in my career are to build and maintain relationships with your coworkers and not to be afraid to step out of your comfort zone,” he said.
James Gentile with his son at NASA’s Johnson Space Center during the 2024 Bring Youth to Work Day.
His journey did not go as planned, but in the end, it led him exactly where he was meant to be—helping humanity take its next giant leap.
“I’ve learned that the path to your goals may not always be clear-cut, but you should never give up on your dreams,” Gentile said.