SETI Live

New JWST observations suggest that some of Neptune's small inner moons may be remnants of much larger icy worlds destroyed billions of years ago.
Using JWST, researchers studied Neptune's rings and three of its inner moons — Larissa, Galatea, and Proteus — and discovered compositions unlike anything previously seen in the outer solar system. Larissa, Galatea, and the rings contain magnesium-rich clay minerals that form in the presence of liquid water, yet show no evidence of the water ice scientists expected.
Where did those minerals come from?
One possibility points to a dramatic event in Neptune's past: the capture of Triton. Neptune's largest moon likely formed elsewhere before being captured into its unusual retrograde orbit. That gravitational upheaval may have destroyed an earlier system of large icy moons, exposing material from deep within their interiors. Some of the debris could then have reassembled into the small moons and rings we see today.
Join SETI Live host Dr. Moiya McTier and lead author Dr. M. Ryleigh Davis of UC San Diego as they explore what JWST has revealed about Neptune's strange moon system, Triton's potentially destructive arrival, and how the remains of ancient worlds could offer a rare glimpse inside the icy bodies of the outer solar system.
Read more: https://www.caltech.edu/about/news/neptunes-inner-moons-may-be-shattered-remains-of-ancient-icy-worlds 
Read the paper: https://www.science.org/doi/10.1126/sciadv.aeb1437

Astronomers may have found the first convincing evidence of a moon-like object beyond our Solar System — but calling it a "moon" turns out to be surprisingly complicated.
Using the CRIRES+ instrument on ESO's Very Large Telescope, researchers detected evidence of a massive object orbiting a brown dwarf in the young CD-35 2722 system. The newly detected object is at least as massive as Jupiter, while its brown-dwarf companion is more than 30 times Jupiter's mass. That brown dwarf, in turn, orbits a star.
So what exactly have astronomers discovered: a moon, a planet, an exosatellite — or something that shows our familiar astronomical labels aren't quite ready for the diversity of other planetary systems?
Join SETI Institute senior planetary astronomer Dr. Franck Marchis and lead author Kevin Hoy as they explore how astronomers detected this unusual object, why previous exomoon candidates have been so difficult to confirm, and what this strange system could teach us about how planets, moons, and brown dwarfs form.
Press release: https://www.eso.org/public/news/eso2610/ 
Paper: https://www.nature.com/articles/s41586-026-10751-w

Why do some solar eruptions blast into space while others never make it?
SETI Institute heliophysicist Dr. Becca Robinson talks with Dr. Kathy Reeves of the Center for Astrophysics | Harvard & Smithsonian about new research revealing what can stop a solar eruption in its tracks.
Using observations of a failed solar eruption in March 2024, Reeves and her colleagues examined how the Sun's complex magnetic fields can both drive an eruption upward and ultimately prevent it from escaping. Their research shows how magnetic reconnection above an eruption can weaken it, while strong overlying magnetic fields act as a kind of cage, trapping the material before it can develop into a coronal mass ejection.
Understanding why some solar eruptions succeed while others fail could improve our understanding of space weather—and may even help explain why astronomers see powerful flares on other stars but relatively few stellar coronal mass ejections.
What determines whether an eruption escapes? What can this event teach us about the Sun's magnetic environment? And what could it tell us about space weather around other stars and planets?
Press release: https://www.cfa.harvard.edu/news/astronomers-uncover-why-some-solar-eruptions-die 
Paper: https://www.nature.com/articles/s41550-026-02872-z

One of the coldest planetary-mass objects ever directly imaged has been hiding something unusual in its atmosphere: salt clouds.
Known as the "Pink Planet," GJ 504 b is a mysterious world orbiting a Sun-like star about 57 light-years from Earth. At roughly 25 times Jupiter's mass, it lies near the uncertain boundary between giant planets and brown dwarfs. It is also so cold and faint that previous attempts to study its atmosphere from the ground were unsuccessful.
Now, JWST has captured the first direct spectrum of GJ 504 b. The observations revealed an atmosphere containing water vapor, methane, carbon dioxide, ammonia, hydrogen sulfide, and other molecules. When researchers modeled the spectrum, they found that clouds—particularly salt clouds—were essential to explaining what JWST observed.
Join host Dr. Moiya McTier and lead author Dr. Aneesh Baburaj (Northwestern University) to learn how astronomers separated the faint light of GJ 504 b from the glare of its host star, what salt clouds can tell us about cold planetary atmospheres, and why scientists still are not sure whether the Pink Planet formed like a planet or a star.
Read the paper:
https://iopscience.iop.org/article/10.3847/1538-3881/ae6919 
Read the Northwestern University story:
https://news.northwestern.edu/stories/2026/06/famous-pink-planet-harbors-a-salty-surprise

NASA's next great observatory is here.
The Nancy Grace Roman Space Telescope is designed to revolutionize our understanding of the universe, from dark energy to thousands of newly discovered exoplanets. But one of its most exciting instruments is the Coronagraph—a cutting-edge technology that can block the overwhelming glare of distant stars, allowing astronomers to directly observe planets orbiting them.
Joining host Dr. Franck Marchis is Dr. Margaret Turnbull, senior scientist at the SETI Institute and Co-Principal Investigator on Roman's Coronagraph Instrument. She'll explain how this remarkable technology works, what we'll learn from the mission, and why Roman is paving the way toward future telescopes capable of imaging Earth-like worlds.
We'll discuss:
• Why Roman is NASA's newest flagship space observatory
• How a coronagraph "creates an artificial eclipse"
• The challenge of directly imaging exoplanets
• What Roman will reveal about giant planets and planetary systems
• How Roman prepares us to search for potentially habitable worlds
• What excites scientists most as launch approaches
Whether you're fascinated by exoplanets, space telescopes, or the search for life beyond Earth, this episode offers a behind-the-scenes look at one of NASA's most ambitious missions.