By Kerry Bennett
Office of the Vice President for Research


The Carnegie Institution for Science recently announced the discovery of 12 new moons of Jupiter, bringing the total number of moons orbiting the solar system’s largest planet to 79—a finding that has garnered international media coverage, including NBC News, The Washington Post, BBC, the New York Times, CNN and NPR.

The discovery team, led by Carnegie astronomer Scott Sheppard, found the new moons in its ongoing search for the so-called Planet X—a giant ice planet that orbits the sun far beyond Pluto.

Northern Arizona University astronomer Chad Trujillo is a long-time collaborator on the discovery team. In 2014, Trujillo was co-discoverer with Sheppard of the extreme dwarf planet 2012 VP113, results that were published in the journal Nature—and that led the team to propose the existence of an unknown giant planet in the outer solar system. Since then, Trujillo has spent most of his time on the hunt for Planet X, although he occasionally contributes to related findings that result from the ongoing search.

In a statement released by Carnegie, Sheppard said, “Jupiter just happened to be in the sky near the search fields where we were looking for extremely distant solar system objects, so we were serendipitously able to look for new moons around Jupiter while at the same time looking for planets at the fringes of our solar system.”

“The Jupiter moon search was all Scott Sheppard’s idea,” Trujillo said. “It was a great way to use a portion of our survey time when our regular Planet X search fields weren’t available. He coordinated the effort to track the moons as well.”

Trujillo examined images of a few of the moons taken at the 4.3-meter Discovery Channel Telescope, which is owned and operated by Lowell Observatory in Flagstaff.

“It’s really exciting to be part of a team where we are not only looking for an undiscovered planet in our solar system, but at the same time we are able to search for exciting things like new Jupiter moons,” Trujillo said. “It takes a lot of people to make discoveries like this, not only the scientists and observers, but also all of the engineers and observatory staff that help make the telescopes work so well.”