Astronomers Skeptical about "Planet X" Claims
Two controversial new studies suggest the discovery of large objects at the outer reaches of the solar system
Extraterrestrial Life324 articles archived since 1845
Ceres Is Cloudy, with a Chance of Cryovolcanoes
New findings reveal a crater’s vaporous hazes, and hint at the dwarf planet’s possible origin in the outer solar system
A Tale of 2 Habitable Planets
New study explores how life on one exoplanet could spread to its neighbor
Graphic: A World of Exoplanet Discoveries
What we know about alien worlds—and what’s coming next
![Oh the Places We Won't Go: Humans Will Settle Mars, and Nowhere Else [Excerpt]](https://static.scientificamerican.com/sciam/cache/file/1931F154-D6DE-4B1D-B8EE96CCB52948E9_agenda.jpg?w=275&h=154&fit=crop)
Oh the Places We Won't Go: Humans Will Settle Mars, and Nowhere Else [Excerpt]
Planetary Society co-founder Louis Friedman argues the Red Planet will be humanity’s final destination, but our robots could reach the stars
Human Missions to Mars Will Look Completely Different from The Martian
The blockbuster film’s futuristic vision of interplanetary exploration could soon be out of date
How Our View of Mars Has Changed from Lush Oasis to Arid Desert
Once thought of as a lush alien world teeming with life and later dismissed as an arid, desolate orb, the Red Planet’s salty, liquid water just might aid in the search for extraterrestrial life
Water Flows on Mars Today, NASA Announces
The Mars Reconnaissance Orbiter found evidence that flowing water causes suspicious dark streaks on the Red Planet
Searching for Life in Martian Water Will Be Very, Very Tricky
The risk of microbial contamination could prevent humans and even robots from visiting the most promising parts of the Red Planet
Alien Transit Systems May Be a Giveaway in the Search for ET
A Harvard professor devises a scheme to detect extraterrestrials by tracking how they might commute from one world to the next
Astronomers Glimpse a Young Jupiter, 51 Eridani b
The newfound planet is 96 light years away, but it's the closest twin to Jupiter astronomers have ever directly seen
Life's Building-Block Chemicals Found on Comet by Lander
Instruments on the Rosetta spacecraft’s Philae lander discovered nitrogen and amino acids, key ingredients for life, on comet 67P Churyumov-Gerasimenko
Search for Alien Life Ignites Battle over Giant Telescope
Private funding for the Arecibo Observatory—the largest single-dish radio telescope in the world—may be a poison pill
Kepler Mission Discovers a Near-Twin of Earth Orbiting Sunlike Star
The planet, Kepler 452 b, is likely rocky and orbits in its star’s habitable zone where liquid water can exist
Search for Extraterrestrial Intelligence Nets Historic Cash Infusion
With a $100-million donation, billionaire Yuri Milner plans to revolutionize the astronomical quest to find alien life
Alien Intelligence Search Gets Major New Push
Entrepreneur and former physicist Yuri Milner talks about the just-announced $100-million Breakthrough Listen Project to search for extraterrestrial technological civilizations
Stephen Hawking and Yuri Milner Announce $100M Initiative to Seek ET
Milner, a tech start-up entrepreneur and philanthropist, is partnering with scientists around the world to search for life among the stars
New Horizons Delivers First Close-Up Glimpse of Pluto and Charon
High-resolution images of the icy worlds reveal towering mountains, yawning canyons and perhaps hints of a subsurface ocean
Making Space for Everyone: A Q&A with BoldlyGo's Jon Morse
NASA’s former director of astrophysics plans to revolutionize space science with agile, privately funded missions
Exotic Glass Could Help Unravel Mysteries of Mars
Brown University researchers have detected glass deposits on Mars that might contain evidence of past conditions and, possibly, life