07 January 2015, 04:00 PM ET
Newly announced discoveries by NASA's Kepler space telescope suggest that the first true alien Earth may not elude planet hunters for much longer.
07 January 2015, 11:12 AM ET
A careful study of images taken by the NASA rover Curiosity has revealed intriguing similarities between ancient sedimentary rocks on Mars and structures shaped by microbes on Earth. The findings suggest, but do not prove, that life may have existed ear
06 January 2015, 04:45 PM ET
Eight newfound alien planets appear to orbit in their parent stars' habitable zone — that just-right range of distances that may allow liquid water to exist on a world's surface — and all of them are relatively small, researchers said.
06 January 2015, 02:00 PM ET
NASA's Kepler Space Telescope has discovered its 1,000th alien planet, further cementing the mission's status as a space-science legend. Kepler has found more than half of all known exoplanets to date, and the numbers will keep rolling in.
02 January 2015, 07:00 AM ET
A recent Search for Extraterrestrial Intelligence (SETI) effort studied 86 candidates in the Kepler space observatory's field for radio signals that could potentially indicate the presence of an intelligent civilization.
02 January 2015, 07:00 AM ET
How habitable was Mars in the past, and does it have signs of life? This is part of what Mars 2020, a successor to Curiosity, will examine when it arrives on Mars.
01 January 2015, 12:00 AM ET
See amazing images of the night sky and cosmos in Space.com's gallery of cosmic images posted in December 2014.
31 December 2014, 07:00 AM ET
Researchers suggest that photosynthesis could take place on an alien planet with a bizarre orbit like Mercury's, potentially helping support complex life.
29 December 2014, 07:33 AM ET
Here's a look at the top alien-planet discoveries of 2014, from the first potentially habitable Earth-size world to a staggering haul of 715 newly announced exoplanets.
29 December 2014, 07:31 AM ET
Researchers have trained the Hubble Space Telescope on Europa repeatedly since Europa's geysers were first announced last year, in an attempt to confirm and characterize the plumes. But they've come up empty.
22 December 2014, 07:36 AM ET
In March 2015, NASA's Dawn spacecraft will arrive in orbit around the dwarf planet Ceres, the largest object in the main asteroid belt between Mars and Jupiter. Ceres may be capable of supporting life as we know it, some researchers say.
18 December 2014, 11:32 AM ET
Kepler has spotted its first new alien planet since being hobbled by a malfunction in May 2013. The newly discovered world, called HIP 116454b, is a "super Earth" about 2.5 times larger than our home planet.
17 December 2014, 07:00 AM ET
The discovery is not evidence that life exists, or has ever existed, on Mars, researchers stressed. But it does mark the first time that organics have been confirmed inside Red Planet rocks, and it checks off a chief goal of the rover team.
16 December 2014, 10:58 PM ET
The two-year mission of the one-ton rover is to find out if Mars is, or was, capable of supporting life.
13 December 2014, 12:16 PM ET
From what looks like a freshly baked pie on Mars to a great shot of Dwarf Planet Ceres, don't miss these amazing space images of the week for Dec. 13, 2014.
12 December 2014, 07:14 AM ET
A ground-based telescope in Spain was able to identify a super-Earth orbiting a sunlike star. With the assistance of telescopes on the ground, astronomers could move faster in the search for habitable planets around other stars.
11 December 2014, 02:01 PM ET
The presence of liquid water is just one of many factors that researchers need to take into account when investigating the past or present habitability of Mars or any other cosmic body, researcher Pamela Conrad says.
09 December 2014, 03:05 PM ET
Author Lee Billings discusses the divide among scientists in the hunt for life elsewhere in the universe, and what an alien civilization might tell us about our own future.
08 December 2014, 03:31 PM ET
Curiosity has found evidence that the 96-mile-wide (154 kilometers) Gale Crater, which the rover has been studying since August 2012, hosted a large lake long ago. Runoff into this lake eventually built up Mount Sharp, mission scientists say.
04 December 2014, 05:10 PM ET
The way we define life has consequences for the search for life on other worlds such as Mars, Jupiter's moon Europa and the Saturn satellite Enceladus.
01 December 2014, 12:00 AM ET
See amazing images of the night sky and cosmos in Space.com's gallery of cosmic images posted in November 2014.
29 November 2014, 08:00 AM ET
A robot that can scale the faces of steep cliffs might one day help explore Mars and find signs of life.
27 November 2014, 07:12 AM ET
Titan's "prebiotic" environment consists of molecules that could be a precursor to life.
26 November 2014, 02:01 PM ET
Could life survive a trip on a comet, or the tip of a rocket? New evidence shows that DNA samples remain functional after a trip on the outside of a low-orbit rocket.
23 November 2014, 01:45 PM ET
What was your favorite space news story of the last week?
16 November 2014, 09:50 AM ET
Alien life might flourish on an exotic kind of carbon dioxide, researchers say. This 'supercritical' carbon dioxide, which has features of both liquids and gases, could be key to extraterrestrial organisms much as water is to biology on Earth.
14 November 2014, 06:56 AM ET
Researchers have been testing out "starshade" technology, which could help astronomers find and characterize rocky, Earthlike alien worlds by blocking the overpowering light of their parent stars.
06 November 2014, 07:00 AM ET
NASA astronauts Mike Fincke and Marsha Ivins discussed their off-Earth experiences with "Interstellar" actors Matthew McConaughey, Anne Hathaway and Jessica Chastain during a Google+ Hangout Wednesday.
01 November 2014, 12:00 AM ET
See amazing images of the night sky and cosmos in Space.com's gallery of cosmic images posted in October 2014.
30 October 2014, 10:00 AM ET
Measures taken in the current Ebola outbreak may hold some clues for how to handle Martian samples brought back to Earth from the Red Planet, which could host extraterrestrial microbes.
16 October 2014, 03:06 PM ET
Experts will debate whether or not life is likely to exist on planets orbiting red dwarf stars during a live event tonight. Watch it here at Space.com.
13 October 2014, 12:58 PM ET
Frigid lakes bombarded by UV radiation and boiling, acidic springs are some of the otherworldly Earth environments where scientists plan to hunt for clues to life on Mars.