”Fascinating,” says planetary scientist Doug Hemingway of the University of California, Berkeley. “This is a great reminder that when you build up the capability to study one thing, you never know what else you might discover along the way.”
Scott Sheppard, a student at the Carnegie Institution of Science, and a few of his colleagues have recently discovered 12 new moons orbiting Jupiter.
Last year, Sheppard heard about a planet that is rumored to orbit beyond Pluto. When Sheppard and his team arrived at Chile’s Cerro Tololo Inter-American Observatory, they were looking for the rumored planet, but ended up observing Jupiter. It was March 2017 when Sheppard was investigating Jupiter and noticed some hints of moons orbiting the planet. Sheppard later confirmed the moons in May. Compared to Jupiter’s largest moon, Ganymede, these moons range from one to three miles in diameter. Finding moons orbiting Jupiter is a bit of a task. Because of how bright and massive Jupiter is, its glare can overshadow smaller moons.
When Sheppard found the twelve moons orbiting Jupiter, he noticed that two of the moons are closer to Jupiter than the other nine, and they orbit in the same direction that Jupiter spins. Nine of the 12 moons that Sheppard found are farther away from Jupiter, but they orbit in the opposite direction. Sheppard predicts that these moons came from much larger moons that broke up into smaller pieces after collideding with space debris.
It is a bit surprising that out of the 12 moons Sheppard discovered, only one of them has a publicly proposed name. This moon is named after the Roman goddess of health and hygiene, Valetudo. Compared to the other moons, Valetudo is eccentric because it orbits in the same direction that Jupiter spins. But like the other nine moons, Valetudo is farther away from Jupiter. “It’s like if you’re driving down the highway the wrong way,” said Sheppard, “collisions are bound to happen.”
While Sheppard was observing Jupiter, he also observed Neptune and Uranus and was disappointed when he learned that there were no moons orbiting the two planets. “Uranus is the best one to find moons around,” Sheppard says, “because you get to name things after Shakespearean characters.”
[Source: National Geographic]