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/
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)
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? 🔭
October 31, 2025 at 6:14 PM
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? 🔭
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;
6000 exoplanets. 🔭
We’ve found worlds orbiting all sorts of stars, from tiny, slow-burning reds to fast-living blue-whites to middle-of-the-road, prime-of-their-life yellows like our own...
We’ve found worlds orbiting all sorts of stars, from tiny, slow-burning reds to fast-living blue-whites to middle-of-the-road, prime-of-their-life yellows like our own...
September 21, 2025 at 6:43 PM
6000 exoplanets. 🔭
We’ve found worlds orbiting all sorts of stars, from tiny, slow-burning reds to fast-living blue-whites to middle-of-the-road, prime-of-their-life yellows like our own...
We’ve found worlds orbiting all sorts of stars, from tiny, slow-burning reds to fast-living blue-whites to middle-of-the-road, prime-of-their-life yellows like our own...
Just over five hours until Cornell's Alpha CubeSat launches on its way to the International Space Station! Learn more about the satellite, its lightsail, and its holograms at alphacubesat.cornell.edu, and tune into the livestream of the rocket launch there!
September 14, 2025 at 4:27 PM
Just over five hours until Cornell's Alpha CubeSat launches on its way to the International Space Station! Learn more about the satellite, its lightsail, and its holograms at alphacubesat.cornell.edu, and tune into the livestream of the rocket launch there!
Congratulations to project lead/CSI engineer Josh Umanksy-Castro, project advisor/CSI fellow Mason Peck, and to all the Cornell students who poured their heart into this mission!
September 13, 2025 at 7:09 PM
Congratulations to project lead/CSI engineer Josh Umanksy-Castro, project advisor/CSI fellow Mason Peck, and to all the Cornell students who poured their heart into this mission!
The NG-23 ISS commercial resupply mission launch is scheduled for Sunday 9/14 at 6:11pm EST with a backup opportunity on Monday 9/15 at 5:49pm. Alpha will ride to the International Space Station, then patiently wait for its turn to launch off the station and into space in mid-November.
September 13, 2025 at 7:09 PM
The NG-23 ISS commercial resupply mission launch is scheduled for Sunday 9/14 at 6:11pm EST with a backup opportunity on Monday 9/15 at 5:49pm. Alpha will ride to the International Space Station, then patiently wait for its turn to launch off the station and into space in mid-November.
A large group of Cornell students, alumni, family and friends are traveling to Cape Canaveral this weekend to view the launch! We invite you to join us by tuning into the livestream, linked at alphacubesat.cornell.edu.
September 13, 2025 at 7:09 PM
A large group of Cornell students, alumni, family and friends are traveling to Cape Canaveral this weekend to view the launch! We invite you to join us by tuning into the livestream, linked at alphacubesat.cornell.edu.
After 9 years and over 100 students, Cornell's Alpha CubeSat mission is launching to space TOMORROW! This small cube-shaped satellite will test the deployment of the first-ever free-flying light sail in low Earth orbit, a stepping stone towards laser sailing to the stars. 🔭
alphacubesat.cornell.edu
alphacubesat.cornell.edu
September 13, 2025 at 7:09 PM
After 9 years and over 100 students, Cornell's Alpha CubeSat mission is launching to space TOMORROW! This small cube-shaped satellite will test the deployment of the first-ever free-flying light sail in low Earth orbit, a stepping stone towards laser sailing to the stars. 🔭
alphacubesat.cornell.edu
alphacubesat.cornell.edu
For now, CSI researchers will construct better and better models for TRAPPIST-1 e's busy host star, until the day we can fully disentangle little planets from jumpy starlight!
Read more: carlsaganinstitute.cornell.edu/news/there-w...
(Papers also linked in article)!
Read more: carlsaganinstitute.cornell.edu/news/there-w...
(Papers also linked in article)!
September 13, 2025 at 12:04 AM
For now, CSI researchers will construct better and better models for TRAPPIST-1 e's busy host star, until the day we can fully disentangle little planets from jumpy starlight!
Read more: carlsaganinstitute.cornell.edu/news/there-w...
(Papers also linked in article)!
Read more: carlsaganinstitute.cornell.edu/news/there-w...
(Papers also linked in article)!
But even noisy data lets us rule out a few possibilities—models that would cause much larger dips than the ones in the graph. TRAPPIST-1 e is unlikely to have a huge hydrogen atmosphere, nor a huge carbon dioxide atmosphere like Venus, which traps enough heat to melt lead.
September 13, 2025 at 12:04 AM
But even noisy data lets us rule out a few possibilities—models that would cause much larger dips than the ones in the graph. TRAPPIST-1 e is unlikely to have a huge hydrogen atmosphere, nor a huge carbon dioxide atmosphere like Venus, which traps enough heat to melt lead.
TRAPPIST-1 e orbits a small red dwarf star, which tend to have a lot more stellar activity than our own Sun. The activity of the star might be interfering with what we see.
September 13, 2025 at 12:04 AM
TRAPPIST-1 e orbits a small red dwarf star, which tend to have a lot more stellar activity than our own Sun. The activity of the star might be interfering with what we see.
As is typical for tiny planets, noise makes our measurements uncertain, so the white error bars overlap with two models: a possibly Earth-like atmosphere in blue and a bare, airless world in orange. CSI researchers Nikole Lewis, Elijah Mullens, and Ryan Challener say it could go either way.
September 13, 2025 at 12:04 AM
As is typical for tiny planets, noise makes our measurements uncertain, so the white error bars overlap with two models: a possibly Earth-like atmosphere in blue and a bare, airless world in orange. CSI researchers Nikole Lewis, Elijah Mullens, and Ryan Challener say it could go either way.
What do you see in the light from planet TRAPPIST-1 e?
Signs of alien life? Not yet...
Take a look for yourself at real data in the James Webb Space Telescope graph, and read more about it below! 🔭
Signs of alien life? Not yet...
Take a look for yourself at real data in the James Webb Space Telescope graph, and read more about it below! 🔭
September 13, 2025 at 12:04 AM
What do you see in the light from planet TRAPPIST-1 e?
Signs of alien life? Not yet...
Take a look for yourself at real data in the James Webb Space Telescope graph, and read more about it below! 🔭
Signs of alien life? Not yet...
Take a look for yourself at real data in the James Webb Space Telescope graph, and read more about it below! 🔭
Of course, higher levels of oxygen will also make it easier to detect! For this reason, among many others… it’s helpful not to deforest your planet.
(Stay tuned for more CSI research spotlights!)
(Stay tuned for more CSI research spotlights!)
September 7, 2025 at 8:12 PM
Of course, higher levels of oxygen will also make it easier to detect! For this reason, among many others… it’s helpful not to deforest your planet.
(Stay tuned for more CSI research spotlights!)
(Stay tuned for more CSI research spotlights!)
Payne & Kaltenegger don’t explore this final step with the “alien dinosaur” spectra, since their paper is meant to aid future observers who may have a certain planet or telescope in mind. The wavelengths you choose (and the noise levels you curse at) depend on the planet and the telescope.
September 7, 2025 at 8:12 PM
Payne & Kaltenegger don’t explore this final step with the “alien dinosaur” spectra, since their paper is meant to aid future observers who may have a certain planet or telescope in mind. The wavelengths you choose (and the noise levels you curse at) depend on the planet and the telescope.
The second step is to translate the amounts of gases (percentage of oxygen in the lower atmosphere, in the upper atmosphere, etc.) into the actual intensities of light that we’d receive in our telescope. Each gas has its own signal, since different elements emit or absorb different colors of light.
September 7, 2025 at 8:12 PM
The second step is to translate the amounts of gases (percentage of oxygen in the lower atmosphere, in the upper atmosphere, etc.) into the actual intensities of light that we’d receive in our telescope. Each gas has its own signal, since different elements emit or absorb different colors of light.
Here are the in-depth methods (or skip to 🦕 for unanswered questions)!
It takes a few steps to determine the how detectable oxygen is on ”alien dinosaur” planets. First, you need to choose a model for the levels of gases in the atmosphere over time. Billions of years of history are hard to predict!
It takes a few steps to determine the how detectable oxygen is on ”alien dinosaur” planets. First, you need to choose a model for the levels of gases in the atmosphere over time. Billions of years of history are hard to predict!
September 7, 2025 at 8:12 PM
Here are the in-depth methods (or skip to 🦕 for unanswered questions)!
It takes a few steps to determine the how detectable oxygen is on ”alien dinosaur” planets. First, you need to choose a model for the levels of gases in the atmosphere over time. Billions of years of history are hard to predict!
It takes a few steps to determine the how detectable oxygen is on ”alien dinosaur” planets. First, you need to choose a model for the levels of gases in the atmosphere over time. Billions of years of history are hard to predict!