Diamonds, the saying goes, are a girl's best friend and Jupiter and Saturn just might be filled to the brim with them, scientists say.
Chunks of diamonds may be floating in hydrogen and helium fluid deep in the atmospheres of Saturn and Jupiter. What's more, at even lower depths, the extreme pressure and temperature can melt the precious gem, literally making it rain liquid diamond, researchers said.
Alien planets could also play host to diamonds. An exoplanet 40 light-years from the solar system is made largely out of diamond, astronomers have said. Scientists think the planet (named 55 Cancri e) is more carbon-rich than Earth, an ideal environment for diamond formation.
There's a "blue marble" alien planet just 63 light-years from Earth, but the world is anything but friendly to life. Researchers say the blue color in the atmosphere likely comes from a rain of molten glass.
This super-hot glass rain is just one consequence of the close proximity between the gas giant alien planet HD189733b and its sun. which causes daytime temperatures to soar as high as 1,700 degrees Fahrenheit, scientists said.
Astronomers have snapped a photo of a pink alien world that's the smallest yet exoplanet found around a star like our sun.
The alien planet GJ 504b is a colder and bluer world than astronomers had anticipated and it likely has a dark magenta hue, infrared data from the Subaru Telescope in Hawaii revealed.
Glowing a dark magenta, the newly discovered exoplanet GJ 504b weighs in with about four times Jupiter's mass, making it the lowest-mass planet ever directly imaged around a star like the sun.
A newly discovered gaseous planet has been directly photographed orbiting a star about 300 light-years from Earth -- equivalent to 3.7 billion round trip flights to the moon.
Imaging alien planets is difficult, and this world may be the least massive planet directly observed outside of the solar system, scientists say.
Einstein's special relativity has proven more useful than ever, as scientists have now used it to discover an alien planet around another star.
The planet, officially known as Kepler-76b, is 25 percent larger than Jupiter and weighs about twice as much, putting it in a class known as "hot Jupiters." The world orbits a star located about 2,000 light-years from Earth in the constellation Cygnus.
Astronomers have captured what may be the first-ever direct photograph of an alien planet in the process of forming around a nearby star.
The picture, which captured a giant alien planet as it is coming together, was snapped by the European Southern Observatory's Very Large Telescope in Chile. It shows a faint blob embedded in a thick disk of gas and dust around the young star HD 100546. The object appears to be a baby gas giant planet, similar to Jupiter, forming from the disk's material, scientists say.
Astronomers have discovered a giant asteroid belt circling the bright star Vega, a find that may ultimately reveal an entire solar system of planets, scientists say.
Vega is one of the brightest stars in the night sky and located about 25 light-years from Earth. It gained fame as the fictional source of an alien signal in the science fiction novel “Contact” by famed astronomer Carl Sagan, which was adapted into a film starring Jodie Foster.
A possible alien planet discovered by NASA's Kepler space telescope is the most Earth-like world yet detected beyond our solar system, scientists say.
With a radius that is just 1.5 times that of Earth, the potential planet is what a so-called "super-Earth," meaning it is just slightly larger than the Earth. The candidate planet orbits a star similar to the sun at a distance that falls within the "habitable zone" — the region where liquid water could exist on the planet's surface. Scientists say the planet, if confirmed, could be a prime candidate to host alien life.
The unbalanced orbit of a so-called "zombie planet" in a dusty star system has astronomers struggling to explain the exoplanet's behavior.
Observations of the planet Fomalhaut b by the Hubble Space Telescope revealed the oddball orbit, which has wild extremes between its closest and farthest points from the parent star and appears to cross through a vast minefield of dusty debris.
"We are shocked. This is not what we expected," said study leader Paul Kalas, an astronomer with the University of California at Berkeley and the SETI Institute in Mountain View, Calif.
Newborn stars often have clouds of leftover gas and dust around them that condense into rings called protoplanetary disks. Eventually, under the pull of gravity, the material in these disks may clump together to form orbiting planets.
A team of astronomers captured detailed images of the disk around young star SAO 206462, about 460 light-years away in the constellation Lupus. For their observations, they used the HiCIAO camera on Japan's Subaru Telescope in Hawaii, which is designed to block out harsh central starlight that would normally make it difficult to detect fainter nearby objects, such as a disk around a star.
For more, check out our list of the wildest alien planets of 2012.
Pink planets and diamond rain? Take a look at the 10 strangest alien worlds in outer space.