Universe Today
If Life Exists in Venus' Atmosphere, It Could Have Come From Earth
A new study presented at the 2026 LPSC suggests that if life does exist in Venus' clouds, there's a chance it came from Earth.
Astrobiology
The search for life in the universe
Recent Articles
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Exomoons Could Be Habitable for Billions of Years, Provided they have Hydrogen Atmospheres
Liquid water is considered essential for life. Surprisingly, however, stable conditions that are conducive to life could exist far from any sun. A research team from the Excellence Cluster ORIGINS at LMU and the Max Planck Institute for Extraterrestrial Physics (MPE) has shown that moons around free-floating planets can keep their water oceans liquid for up to 4.3 billion years by virtue of dense hydrogen atmospheres and tidal heating—that is to say, for almost as long as Earth has existed and sufficient time for complex life to develop.
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How Will Martian Gravity Affect Skeletal Muscle?
Marie Mortreux, an assistant professor in the University of Rhode Island’s College of Health Sciences, is part of an international team of researchers studying how the Mars’s gravity would affect astronauts’ skeletal muscle.
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Why Conventional SETI Needs A Major Refocus
After decades of searching for alien signals in narrow radio and microwave bandwidths, a new paper suggests that we take a wholly different approach. The idea is to broaden the search to a much wider range of the electromagnetic spectrum.
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New Study Complicates the Search for Alien Oxygen
Oxygen has been the most important gas in our search for life among the cosmos thus far. On Earth, we have it in abundance because it is produced by biological synthesis. But that might not be the case on other planets, so even if we do find a very clear high oxygen signal in the atmosphere of an exoplanet, it might not be a clear indication that life exists there. A new paper, available in pre-print on arXiv, from Margaret Turcotte Seavey and a team of researchers from institutions like the NASA Goddard Space Flight Center and Johns Hopkins University, adds some additional context to what else might be going on in those atmospheres. In particular, they note that if there’s even a little bit of water vapor, it can make a big difference in whether a lifeless rock looks like a living, thriving world.
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Are Rogue Exomoons the Newest Frontier in the Search for Habitability?
There may be as many rogue planets or free-floating planets in the Milky Way as there are stars. If there are billions of these worlds, some of them have likely held onto their moons. New research reveals a pathway to habitability for these rogue exomoons.
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Life, But Not As We Know It
For sixty years, the search for life beyond Earth has been built on the single assumption that alien life will look enough like us to recognise. A radical new idea called Assembly Theory is challenging that assumption. A team from the Arizona State University has proposed applying it to the atmospheres of distant exoplanets, not to look for specific gases, but to measure how much complexity a planetary atmosphere contains, and whether blind chemistry alone could plausibly have produced it. If it works, it could transform the way humanity searches for life among the stars, and redefine what we are even searching for.
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"Ionic Liquids" Could Redefine the Habitable Zone
“Follow the water” has been a guiding mantra of astrobiology, and even space exploration more generally for decades. If you want to find life, it makes sense to look for the universal solvent that almost all types of life on Earth use. But what if life doesn’t actually need water to live or even evolve? A recent paper, available in pre-print on arXiv by researchers at MIT, including Dr. Sara Seager, and the University of Cardiff, proposes an alternative to water as the basis for life - ionic liquids (ILs) and deep eutectic solvents (DES). These liquids could allow life to exist in environments we had once thought were far too hot, too cold, or too barren to support life, and could dramatically change our search for it throughout the cosmos.
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New Study Says There's a Way to Make Dyson Bubbles and Stellar Engines Stable
While megastructures are clearly speculative, new research shows that they can (in theory) be built in a way that ensures long-term stability. These findings can provide insight into the properties of potential technosignatures in search for extraterrestrial intelligence studies.
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AI Could Make Alien Contact More Likely for SETI's 'Project Hail Mary'
A new movie called "Project Hail Mary" tells the story of an unlikely astronaut who teams up with an alien to deal with a common cosmic threat. In the latest Fiction Science podcast, SETI astronomer Seth Shostak provides a status report on the real-world quest for alien contact.
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Astronauts Use Bacteria and Fungi to Harvest Metals in Space
If humankind is to explore deep space, one small passenger should not be left behind: microbes. In fact, it would be impossible to leave them behind, since they live on and in our bodies, surfaces and food. Learning how they react to space conditions is critical, but they could also be invaluable fellows in our endeavor to explore space.
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Introducing the 'Interplanetary Habitable Zone'
Anyone familiar with the search for alien life will have heard of the “Goldilocks Zone” around a star. This is defined as the orbital band where the temperature is just right for liquid water to pool on a rocky planet’s surface - a good approximation for what we thought of as the early conditions for life on Earth. But what happens if that life doesn’t stay on an Earth analog? If they, like we, start to move towards their neighboring planets, the idea of a habitable zone becomes much more complicated. A new paper from Dr. Caleb Scharf of the NASA Ames Research Center, and one of the agency’s premier astrobiologists, tries to account for this possibility by introducing the framework of an Interplanetary Habitable Zone (IHZ).
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Red Dwarf Stars Might Starve Alien Plants of the "Quality" Light They Need to Breathe
Red dwarfs make up the vast majority of stars in the galaxy. Such ubiquity means they host the majority of rocky exoplanets we’ve found so far - which in turn makes them interesting for astrobiological surveys. However, there’s a catch - astrobiologists aren’t sure the light from these stars can actually support oxygen-producing life. A new paper, available in pre-print on arXiv, by Giovanni Covone and Amedeo Balbi, suggests that they might not - when it comes to stellar light, quality is just as important as quantity. And according to their calculations, Earth-like biospheres are incredibly difficult to sustain around red dwarfs.
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Some Extremophiles Could Survive an Asteroid Impact on Mars, and the Dangerous Journey to Earth
Panspermia is the idea that life was spread from world to world somehow. New research shows that one type of Earthly extremophile can survive the extremely high pressure from asteroid impacts on Mars, be blasted into space, and maybe even survive the journey to Earth.
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The Coldest "Stars" in the Galaxy Might Actually Be Alien Megastructures
Ever since physicist Freeman Dyson first proposed the concept in 1960, the “Dyson sphere” has been the holy grail of techno-signature hunters. A highly advanced civilization could build a “sphere” (or, in our more modern understanding, a “swarm” of smaller components) around their host star to harvest its entire energy output. We know, in theory at least, that such a swarm could exist - but what would it actually look like if we were able to observe one? A new paper available in pre-print on arXiv, and soon to be published in Universe from Amirnezam Amiri of the University of Arkansas digs into that question - and in the process discloses the types of stars that are the most likely to find them around.
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How Long Do Civilisations Last?
In 1950, the physicist Enrico Fermi sat down to lunch with colleagues and asked a question that has haunted astronomers ever since. If the universe is so vast, so old, and so full of stars, where is everybody? A new study has turned that question around and come up with an answer that is quietly unsettling. If intelligent life is common in the Galaxy, the mathematics suggests it cannot last very long.
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The Toughest Animals in the Universe Just Got a New Job
They are the toughest animals on Earth and possibly the key to surviving on Mars. Tardigrades, the microscopic creatures nicknamed 'water bears', have survived the vacuum of space, the crushing pressure of the deep ocean and temperatures that would kill virtually anything else. Now a new study has put them to work as unlikely pioneers, testing whether the hostile soil of Mars could ever support life and the results are full of surprises.
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Would Earth Still Be Habitable Without Us?
Scientists have built a working model of Earth without any life on it and what they found might change how we search for aliens. By simulating 4.5 billion years of our planet's evolution minus every bacterium, plant, and creature that ever existed, they've created a new tool for spotting genuinely habitable worlds among the thousands of rocky planets soon to be studied by the next generation of space telescopes.
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Europa and Other Jovian Moons May Have Formed With Their Own Supply of Life's Building Blocks
Complex Organic Molecules (COMs) are important building blocks for life. They can form in space and be delivered to planets. But new research shows some of them can form in circumplanetary disks where moons form, boosting the prospects for life in Europa's ocean.
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Are There Aliens Broadcasting from Hycean World K2-18b? Astronomers Just Listened In
If you’ve been following exoplanet research over the last couple of years, you’ve definitely heard of K2-18b. Located 124 light years away in the constellation Leo, it’s attracted a lot of attention as it sits squarely in its red dwarf host star’s habitable zone, and measurements of the James Webb Space Telescope show its atmosphere is rich in carbon dioxide and methane. It’s one of the prime candidates for a “Hycean” world - one where a thick hydrogen-rich atmosphere covers a global liquid water ocean. It is such an intriguing target for Search for Extraterrestrial Intelligence (SETI) researchers that they turned two of the most powerful radio telescopes in the world to watch K2-18b’s system. A recent paper, available in pre-print on arXiv, shows that there is likely no artificial narrow-band radio signals that are equivalent to our technology level coming from the planet, despite millions of potential hits.