Hunt for Hypothetical Planet Turns Up New Moons of Jupiter

Jun 29, 2017

A national team of astronomers looking for the hypothetical ‘Planet Nine’ chanced upon two new moons of Jupiter. KNAU’s Melissa Sevigny reports.

Jupiter and its moon Io
Credit NASA/JPL/University of Arizona


The team used telescopes in Flagstaff, Hawaii and Chile to find and track the new moons. The finding brings the number of Jupiter’s moons up to sixty-nine.

Chad Trujillo of Northern Arizona University is part of the research team. He says, "These are small moons, like a mile across, so they’re not giant moons, and they’re also irregular, so, they can be faint, and their orbits are not necessarily that well known."

Trujillo thinks the moons could be fragments of a shattered asteroid. The team also rediscovered five moons of Jupiter that have been “lost” for more than a decade.

In addition, they’ve found a comet and a couple of asteroids with rare-comet like tails.

‘Planet Nine’ itself remains elusive. Trujillo and a colleague first proposed its existence in 2014. It’s thought to be a giant ice planet orbiting far beyond Neptune.