Even after using its Wide-Field Infrared Survey Explorer (WISE), NASA has yet again failed to find evidence to support the existence of Planet X.

Planet X is a theoretical planet that is thought to exist somewhere beyond the orbit of Neptune. The existent of the planet was first theorized by Percival Lowell in the early 20th century due to the apparent discrepancies in the orbits of gas giants in the solar system. While a lot of effort has been put into finding Planet X over the last one hundred years, no planet fitting the requirements for Planet X has been found. Planet X has been called a number of names over the years including "Tyche" and "Nemesis."

Using data gathered by WISE, NASA scientists were unable to discern any celestial bodies larger than Jupiter at a distance of 26,000 astronomical units (au). An astronomical unit is equivalent to around 93 million miles, which is also the distance from Earth to the sun. Moreover, the scientists were also unable to find any celestial bodies larger than Saturn up until a distance of 10,000 au.

"The outer solar system probably does not contain a large gas giant planet, or a small, companion star," said Kevin Luhman, an astronomer from the Center for Exoplanets and Habitable Worlds. 

While the WISE data did not reveal any information about the possible location of Planet X, further analysis of the data has revealed thousands of other celestial bodies in the neighboring areas relatively near our solar system. Many of these newly discovered objects include stars as well as brown dwarfs.

"Neighboring star systems that have been hiding in plain sight just jump out in the WISE data," said Ned Wright, an astronomy professor from the University of California.

NASA's WISE space telescope was launched in December of 2009 and it has been gathering infrared data from space from 2010 to 2011. In just two surveys, the space telescope was able to take photos of almost 750 million celestial objects including galaxies, stars and even asteroids.

With the two WISE searchers, NASA scientists were able to compile a lot of data about our solar neighborhood. While one sweep alone would have missed a lot of celestial objects, the second sweep was able to capture many objects that were not seen in the first sweep.

"We think there are even more stars out there left to find with WISE. We don't know our own sun's backyard as well as you might think," said Wright.