Neptune's new moon, Hippocamp, could be left behind by a comet crash

We might think that the outer planets of our solar system are solitary vagabonds in a deep, cold space. But as astronomers look closer, it turns out that distant worlds like Neptune are kept in the company by a surrounding tiny moons, including a newly identified Hippocamp.

In 1846, just weeks after the discovery of Neptune, his largest moon, Triton, was also seen for the first time. The global scientist Gerard Kuiper found another, Nereid, in 1949, but it was only Traveling 2In 1989, we really started to look at the neighborhood of Neptune.

The observations made possible by Voyager 2 revealed several small inner moons, which revolve around Neptune and its ring paler than Triton and a handful of small outer moons that would be discovered later.

Now, astronomers have been able to confirm the existence of the seventh and smaller inner moon around Neptune, using images from the Hubble Space Telescope and a particular image processing technique. The little moon, nicknamed Hippocamp after a sea creature of Greek mythology, is only 34 kilometers in diameter and orbiting very near Proteus, the largest and furthest of inner moons.

The details of the discovery appear in a report published Wednesday by the journal Nature. Co-author Mark Showalter of the SETI Institute and his colleagues suggest that an exceptionally large crater on Proteus, named Pharos, might provide clues about nearby Hippocamp training.

"We hypothesize that a significant impact, perhaps the Pharos event itself, would have released Proteus debris into orbit around Neptune," the newspaper reads. "Some of these debris settled in a stable orbit, perhaps 1,000 to 2,000 kilometers (621 to 243 miles) inside Proteus, and were accrued in Hippocamp."

Regardless of the formation of Hippocamp, this discovery brings to 14 the current number of moons around Neptune and further expands the itinerary of places that explorers of many generations will be able to visit in person.