For decades before Pluto, Eris, and other distant objects in our solar system were discovered, astronomers had posited that there must be another planet beyond Neptune that would make observed orbital calculations for Neptune and Uranus add up. This planet was dubbed "Planet X" and was searched for extensively during the late 19th century. The search was largely abandoned when better measurements were obtained and the icy dwarf planets beyond Neptune were discovered.
NASA today confirmed that astronomers have seen no evidence of a hidden Planet X in new data from its Wide-Field Infrared Survey Explorer (WISE) sky survey. The survey extensively observed the sky above Earth in infrared light but found no evidence of such an object. More specifically, new research published in the Astrophysical Journal confirms that no objects larger than Saturn exists within 10,000au of Earth and no objects larger than Jupiter have been found within 26,000au of Earth.
This doesn't mean that the entire survey was a waste of time, though. Researchers have been using the WISE data to uncover thousands of new nearby celestial objects that had, until now, been overlooked. So far 3,525 new stars and brown dwarfs have been pinpointed using recent WISE data, all of them within 500 light years of our sun. A binary system of two brown dwarfs has been discovered to be just 6.5 light-years from our solar system. Also, a star only 20 light-years away was located in the constellation Norma.
"Neighboring star systems that have been hiding in plain sight just jump out in the WISE data," said Ned Wright, principal investigator for the WISE survey and an astronomer at UCLA.
Astronomers were able to discover the new nearby objects by comparing the new WISE data to a previous WISE survey. The shift in position that objects show between the data can reveal just how close they are to the Earth.
Image via DSS/NASA/JPL-Caltech