NASA WISE Spacecraft Unable to Find 'Planet X'

The hypothetical ninth planet argument might be finally put to rest after NASA's Wide-Field Infrared Survey Explorer (WISE) scanned the outer reaches of the solar system and returned no information about another planet's existence.

Previously believed to be four times the size of Earth located beyond Pluto, Planet X was too distant to be spotted by Earth-based telescopes. Its "existence" was based on the gravitational pull of small icy bodies in orbit around Neptune. Scientists thought this hypothetical "Planet X" caused the gravitational pull.

The data provided by WISE and published in the Astrophysical Journal showed no evidence of the hypothetical gas giant. The WISE spacecraft mission, launched in 2009, was equipped with infrared instruments believed to possess the ability to provide information about the dim planet. The instruments, however, made other discoveries while possibly debunking the existence of a ninth planet in our solar system.

The explorer scanned the edge of the solar system in 2010 and 2011 in two separate studies. In the first, WISE imaged nearly 750 million stars, asteroids, and galaxies, including 762 never-before-seen objects. The data showed no evidence of a Jupiter-sized body or planet 26,000 Astronomical Units (AU = 93 million miles) from the sun.

In the second study, NASA reported the discovery of 3.525 new stars and brown dwarfs; brown dwarfs are objects that are larger than planets, but too small to sustain fusion in their core, which make them dimmer and difficult to observe. But still, no evidence of the large planetary body.

Despite the lack of evidence to find "Planet X", NASA researchers are still pleased with WISE's progress.

"We're finding objects that were totally overlooked before," said Davy Kirkpatrick of NASA's Infrared and Processing Analysis Center at the California Institute of Technology, in this Space.com article.

WISE has been able to detect information that telescopes and other technology have previously overlooked. To read more about the WISE mission, visit this Space.com article as well as this Live Science article.