Have astronomers found a Super Earth in our own solar system?

The long-abandoned possibility that a “Planet X” at the edge of the solar system is causing abnormalities in the orbits of Neptune and Uranus has once again resurfaced thanks to two new controversial studies.

In these papers, which have been uploaded here and here on the pre-publication research sharing website arXiv, researchers from Sweden and Mexico claim they were able to detect a Super Earth orbiting the Sun at six times the distance of Pluto, according to Ars Technica.

This object, which the team detected using the Atacama Large Millimeter/submillimeter Array (ALMA) telescope in Chile, is believed to be either an extreme trans-Neptunian object (a minor planet orbiting the Sun at a greater average distance than Neptune),a Super-Earth, or a very cool brown dwarf star located in the extreme outer reaches of the solar system.

The authors report that this new “blackbody point source” appears to be moving in conjunction with the Alpha Centauri star system, which is located approximately 4.3 light years from Earth, but it is not likely to be part of that star system, as an object so far away would likely have been luminous enough to have been spotted previously.

Astronomers are skeptical about the new claims

Other scientists are reacting with skepticism to the papers’ claims, neither of which have underdone peer review as of yet. Experts quickly noted that observations conducted using the NASA Wide-field Infrared Survey Explorer have eliminated the possibility of a Saturn-size planet to a distance of 10,000 AU and a Jupiter-sized planet out to 26,000 AU.

California Institute of Technology astronomer Mike Brown, who according to Scientific American helped discover several TNOs partially responsible for Pluto’s demotion to a dwarf planet, said via Twitter, “Fun fact: if it is true that ALMA accidentally discovered a massive outer solar system object in its tiny, tiny, tiny, field of view, that would suggest that there are something like 200,000 Earth-sized planets in the outer solar system. Which, um, no.”

“Even better,” he added later, “I just realized that this many Earth-sized planets existing would destabilize the entire solar system and we would all die.” Even so, Brown admits that “the idea that there might be large planets lurking in the outer solar system is perfectly plausible.”

Similarly, in a public Facebook group dedicated to discussing exoplanets, Stanford University’s Bruce Macintosh said it would be an “astonishing coincidence” if the first two trans-Neptunian objects discovered by ALMA were located next to bright stars. The most likely explanation, the professor said, is that these objects are actually residual artifacts, illusions appearing in the data due to unusual quirks in the telescope array’s complex calibration system.


Image credit: NASA