Continued congratulations to the Alpha CubeSat team of students led by CSI fellow Dr. Josh Umansky-Castro!
15.02.2026 02:33
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Continued congratulations to the Alpha CubeSat team of students led by CSI fellow Dr. Josh Umansky-Castro!
If you’re wondering why the images from Alpha are so grainy: Alpha’s optical deployment sensor is positioned at the bottom of its light sail compartment, and was only included to verify that the light sail had fully left the compartment and deployed. These clear views certainly prove that!
Four CubeSats (bottom left is Alpha!) deploying from the International Space Station. Image credit: Voyager Technologies
Alpha deploying from the International Space Station, with a party hat added to celebrate its recent milestone of 1000 orbits around Earth! Image credits: Voyager Technologies, Gillis Lowry
From low Earth orbit, our planet still looms large below the little CubeSat, so perhaps it’s more accurate to say that Alpha is the "pale purple dot" here.
See below for its size compared to the International Space Station, where it first deployed into space (party hat added for 1000 orbits)!
A tiny image of the Pacific Ocean by Alpha CubeSat!
A tiny image of Central America (El Salvador, Honduras, and Nicaragua?) by Alpha CubeSat!
Happy Pale Blue Dot Day and Valentine’s Day! 💙 We’re sending our love to Alpha CubeSat for completing 1000 orbits and beaming down its own pale blue images of Earth! 🔭
Detecting exoplanets through radio bursts: planet-star interactions unveiled in new technique! (An attempt at a retro vibe on top of cool artwork of a star's magnetic field arcing through its planet).
A new research paper including CSI fellow Jake Turner investigates magnetic interactions between stars and their planets—using distant auroras to detect and survey other worlds! 🔭
Read more: as.cornell.edu/news/novel-w...
Image credit: Danielle Futselaar/Artsource.nl
Image 2 artist impression: Pablo Carlos Budassi (Celestialobjects)
Jupiter image credit: NASA / JPL-Caltech / SwRI / MSSS / Gerald Eichstaedt / Sean Doran
Such tiny creatures wouldn’t be proof of the sinkers, hunters, and floaters ecosystem that Sagan & Salpeter imagined, but who knows how many different creatures may float in alien skies? ☁️ ☁️ ☁️
Read more about Dr. Lígia Fonseca Coelho’s paper here: news.cornell.edu/stories/2025...
The team found that a very high amount of floating microbes would significantly alter the light we’d observe, making the microbes possible to detect with upcoming space telescopes.
CSI fellow Lígia Fonseca Coelho and her team measured the reflected light from Earth’s rare cloudy microbes, which often involve colorful pigments to help protect themselves from extreme temperatures and the Sun’s ultraviolet light.
When Sagan & Salpeter imagined an ecosystem in Jupiter’s clouds, little was known about the microbes afloat in our own.
Clouds are normally a hindrance in the search for life—they block views of the surface. But if organisms exist in clouds, might signs of life on overcast planets be detectable?
CSI fellow Lígia Fonseca Coelho and her team measured the reflected light from Earth’s rare cloudy microbes, which often involve colorful pigments to help protect themselves from extreme temperatures and the Sun’s ultraviolet light.
Snowman at the Fuertes Observatory. ☃️
Alpha’s mission sends the first holographic images to space, tests tiny ChipSat technology, demonstrates one of the smallest—and first free-flying—light sail designs, and proves that low-cost light sailing is a possible path for a variety of future missions.
Ad astra, Alpha Cubesat ✨
Alpha CubeSat team members (including CSI fellow Dr. Josh Umansky-Castro on the left) constructing the spacecraft!
Regardless of its short lifespan, Alpha CubeSat has demonstrated the tenacity of hundreds of undergraduate students, equipped with a toolkit of nothing more than hobbyist electronics and their drive to help build the future of spaceflight.
The final ChipSat design, four of which are currently affixed to the light sail in space!
Drag is expected to pull the light sail out of orbit quicker than the CubeSat, so this may explain the silence. The sail was only projected to live for a few days, and the ChipSats are much smaller/harder to pick up than the CubeSat—so it's an incredible feat that we heard from them at all!
The CubeSat is currently alive and transmitting. You can see the data update every few hours here: alphacubesat.cornell.edu/dashboard.html. There's also a link to the light sail's ChipSat signals (although he team hasn't heard from the light sail's ChipSats recently).
The first signal from the ChipSats on Alpha CubeSat's light sail!
Just as suddenly as it fell silent, the spacecraft spoke again! Alpha heard the command and deployed the light sail successfully, and the tiny radio transmitters on the light sail (contained in four credit card-sized computers called “ChipSats”) began to send their own separate signals down, too.
Alpha was silent for over 24 hours. After some movie-worthy moments of suspense, the team decided to send the “light sail deploy” command, hoping the spacecraft could still hear them.
This video from the International Space Station on December 2nd shows four CubeSats (small cube-shaped spacecraft), one of which is Alpha, holding its light sail inside. Tumbling through space at thousands of miles per hour, Alpha sent radio signals soon after launch… then fell silent.
Artistic rendition of Alpha CubeSat deploying its light sail!
The light sail's estimated location above the coast of Africa on December 4th, 2025!
CONGRATULATIONS to CSI fellow Dr. Josh Umansky-Castro and the whole Alpha CubeSat team: they've successfully deployed the first-ever light sail to “free fly” in space (disconnect from its spacecraft)!
Read the story of its first few days in space below!
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Happy 91st birthday, Carl Sagan.
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Stay tuned for posts this week that honor both his research legacy and his quest to make a more scientifically literate world…
If alien life fluoresces at the same wavelengths we’re familiar with—and if clouds don’t block too much of our view—then with upcoming telescopes like the Habitable Worlds Observatory, it may be challenging, but possible, to find glow-in-the-dark signs of life on small, rocky exoplanets!
Alien life may also need protection around cooler stars, whose ultraviolet flares can sometimes strike planets. Life around many types of stars could glow in the dark... if it exists for our telescopes to find. (Artwork of an astronaut peering down at a glowing planet beneath a red star). Illustration by Wendy Kenigsberg/Matt Fondeur/Cornell University
In a follow-up paper, the authors also found that biofluorescence could be useful around cooler red dwarf stars that have ultraviolet “flares"—high-energy bursts that life would need to protect itself from.
Paper 1: academic.oup.com/mnras/articl...
Follow-up: academic.oup.com/mnras/articl...
Pictured at the top is a table with differing values for the increased life we'd receive, depending on how much of the planet these lifeforms cover. If alien life fluoresces at the same wavelengths we're familiar with—and if it covers enough of the planet—then by observing in these wavelengths, it may be possible to see glow-in-the-dark life.
O’Malley-James & Kaltenegger found that if a planet around a bluer F-type star was covered in 70% ocean and 30% lifeforms such as strongly biofluorescent coral on Earth, then we could receive roughly 10% more light at the wavelengths that these organisms emit (see table below for more scenarios)
Around stars with higher rates of dangerous ultraviolet light, alien life might fluoresce to protect itself, perhaps even more strongly than our best examples on Earth (similar to the ones pictured here—certain coral species).
On alien planets orbiting bluer stars, where more “sunscreen” is needed, biofluorescence might make up a larger fraction of the light we’d receive in our telescopes. CSI researchers O’Malley-James & Kaltenegger examined biofluorescent life on Earth to determine what glowing colors of light we’d see.
Many plants on Earth glow via biofluorescence, as mapped here—absorbing high-energy light, then "glowing" at a lower energy. However, planets reflect green light much more than they glow from biofluorescence. (The map shows high biofluorescence in forested regions on Earth).
You may be wondering—how bright is this “biofluorescence” anyway? Earth is covered in plants, and many of them emit a small amount of fluorescent light. However, this is just a fraction of a percent of all the green light we see reflected. (More info in Sagan’s Galileo study: tinyurl.com/yc2xtr43)
The Sun’s ultraviolet light can damage our skin over time, leading to harmful mutations. On planets around slightly hotter “F-type” stars, which emit more blue and ultraviolet light than the Sun, it’s even more crucial to protect yourself. Alien life might use biofluorescence as natural “sunscreen!”
“Biofluorescence” works the same way as glow-in-the-dark stickers or shirts: some organisms on Earth have pigments that absorb high-energy (mostly ultraviolet) light, then slowly re-emit less energetic light, causing a long-lasting glow.
Happy Halloween! ✨ 👻 🎃 Jack-o’-lanterns aren’t the only signs of life that glow in the dark. Some organisms on Earth do, too. Would a distant planet full of glow-in-the-dark aliens be detectable to our telescopes? 🔭
Someday soon, we may be able to say that out of 70 habitable zone planets, out of 6000 found, out of hundreds of billions that surely exist in the Milky Way… there is one more corner of the universe that knows itself.
