14 DAY TRIAL // A massive-scale study conducted with the NASA Wide-Field Infrared Survey Explorer (WISE) spacecraft has detected no signs of the hypothesized “Planet X,” a hypothesized celestial object that many people believe orbits within our solar system. The probe analyzed hundreds of millions of objects in the night sky, but failed to uncover such a planet.
Among conspiracy theorists, Planet X is also known as Nemesis and Tyche. It is hypothesized to exist somewhere in or beyond the Kuiper Belt, which is itself located beyond the orbit of Pluto. Proponents argue that the object is large, possibly the size of an ice or gas giant, or maybe even larger than Jupiter.
In the new study, astronomers looked at the massive dataset WISE collected during its two full surveys of the night sky. No Saturn-sized object was discovered within 10,000 astronomical units (mean Earth-Sun distances) of our parent star. Additionally, no Jupiter-sized celestial body lies closer than 26,000 AU from the Sun.
For comparison, Earth lies 1 AU from the star, while Pluto is located around 40 AU away. An astronomical unit covers roughly 157 million kilometers (93 million miles). If any gas or ice giant existed towards the outer fringes of the solar system, WISE would have undoubtedly discovered it.
“The outer solar system probably does not contain a large gas giant planet, or a small, companion star,” explains astronomer Kevin Luhman. The expert holds an appointment with the Center for Exoplanets and Habitable Worlds at the Pennsylvania State University (Penn State).
Luhman was also the author of a new paper describing the study, which was published in the latest issue of the esteemed Astrophysical Journal. He explains that WISE did manage to discover a number of new stars and brown dwarfs fairly close to the solar system, but none within it that we did not already know about.
“Neighboring star systems that have been hiding in plain sight just jump out in the WISE data,” says the principal investigator for the observatory, University of California in Los Angeles (UCLA) professor Ned Wright. WISE is currently in sleep mode, having operated between 2010 and mid-2011.
Planet X has until now remained nothing more than an interesting concept. Some conspiracy theorists argued that this object may have been responsible for one or more of Earth's mass extinctions. While this idea was shown to be false even before the new study, the research proves without a doubt that such hypotheses are wrong.
However, scientists will continue to use WISE data to find new stars around the Sun. “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,” Wright concludes.