Carl Sagan Institute
@carlsaganinstitute.bsky.social
Interdisciplinary research team at Cornell University, following Carl Sagan's legacy by building the tools to find life in the Universe.
https://carlsaganinstitute.cornell.edu/
https://carlsaganinstitute.cornell.edu/
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 ✨
Ad astra, Alpha Cubesat ✨
December 5, 2025 at 6:55 PM
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 ✨
Ad astra, Alpha Cubesat ✨
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.
December 5, 2025 at 6:55 PM
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.
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!
December 5, 2025 at 6:55 PM
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).
December 5, 2025 at 6:55 PM
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).
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.
December 5, 2025 at 6:55 PM
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.
December 5, 2025 at 6:55 PM
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.
December 5, 2025 at 6:55 PM
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.
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!
October 31, 2025 at 6:14 PM
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!
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...
Paper 1: academic.oup.com/mnras/articl...
Follow-up: academic.oup.com/mnras/articl...
October 31, 2025 at 6:14 PM
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...
Paper 1: academic.oup.com/mnras/articl...
Follow-up: academic.oup.com/mnras/articl...
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)
October 31, 2025 at 6:14 PM
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)
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.
October 31, 2025 at 6:14 PM
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.
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)
October 31, 2025 at 6:14 PM
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!”
October 31, 2025 at 6:14 PM
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.
October 31, 2025 at 6:14 PM
“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.
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.
September 21, 2025 at 6:43 PM
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.
Recent papers from Carl Sagan Institute researchers and exoplanet scientists worldwide (such as studies of TRAPPIST-1 e!) have brought us one step closer to detecting an atmosphere around an Earth-like, potentially habitable world.
September 21, 2025 at 6:43 PM
Recent papers from Carl Sagan Institute researchers and exoplanet scientists worldwide (such as studies of TRAPPIST-1 e!) have brought us one step closer to detecting an atmosphere around an Earth-like, potentially habitable world.
The star will have to treat its planet kindly, lest it strip away the planet’s atmosphere, or heat the planet so intensely it becomes a “lava world.” Even if the planet avoids these extremes and organisms manage to thrive, the world those organisms call home may look quite different from ours.
September 21, 2025 at 6:43 PM
The star will have to treat its planet kindly, lest it strip away the planet’s atmosphere, or heat the planet so intensely it becomes a “lava world.” Even if the planet avoids these extremes and organisms manage to thrive, the world those organisms call home may look quite different from ours.
Some of these planets—the more sedate, less extreme ones—have a chance at hosting life. They’ll need to be not too far, not too close, but just the right distance from their host star: in the “Goldilocks” or “habitable” zone where liquid water could exist on a planet's surface.
September 21, 2025 at 6:43 PM
Some of these planets—the more sedate, less extreme ones—have a chance at hosting life. They’ll need to be not too far, not too close, but just the right distance from their host star: in the “Goldilocks” or “habitable” zone where liquid water could exist on a planet's surface.
There is a planet that takes 49 minutes to orbit its pulsar, in a pirouette too tight to ever allow for life; there are red-hot planets where gems may fall from clouds of metal and deep blue dots where glass may rain sideways.
September 21, 2025 at 6:43 PM
There is a planet that takes 49 minutes to orbit its pulsar, in a pirouette too tight to ever allow for life; there are red-hot planets where gems may fall from clouds of metal and deep blue dots where glass may rain sideways.
There are exoplanets that see two Suns in their skies, even three Suns; there are “rogue planets,” likely ejected from the disks of young stars, that shoot through an endless night; there is a planet that takes one million years to orbit its star;
September 21, 2025 at 6:43 PM
There are exoplanets that see two Suns in their skies, even three Suns; there are “rogue planets,” likely ejected from the disks of young stars, that shoot through an endless night; there is a planet that takes one million years to orbit its star;