It may be a imperceptible, fuzzy dot, but a little moon has now become an official addition to Neptune’s set.
In a paper published in Nature Astronomy today, astronomers announced their first remarks of a tiny moon discovered around Neptune in 2013. This advanced Neptune’s total moon count up to 14.
Until earlier this month, the moon was stated S/2004 N1 — S for satellite, 2004 for the year it was first imaged, N for Neptune and 1 for the beginning satellite to be discovered around the planet in 2004.
But now that astronomers have been expert to work out its orbit, the International Astronomical Union has formally named it Hippocamp.
Bring to lighting this tiny moon, which measures roughly 34 kilometres in diameter, was no easy as can be task. It was only found when astronomer Mark Showalter noted it in images taken by the Hubble Space Telescope in 2004 and 2009.
“I’ve in actuality used Hubble to discover a couple other moons in the solar combination around Uranus and Pluto, but this one was the most elusive of anything I’ve used on,” said Showalter, a senior research scientist at the SETI Institute and chain author of the study.
The reason Hippocamp is so faint is that in order to read it in an image by a telescope orbiting Earth almost 4.5 billion km away, the revealing time would be so long that the moon would keep unfixed and “smear” in the image.
“So we had to come up with this special procedure where we had to say if there’s a moon in any foreordained location in the Neptune system, and if we see it in this one location in this one image, then this is where it last wishes a appear in every other image we got,” said Showalter.
“So we had to do this geometric course of action of each image, so that we stopped the moon in its tracks, and made it sit motionlessly long enough to see it.”
The discovery was kind of “dumb luck,” Showalter asseverated. While looking for arcs that occur in Neptune’s rings, he unquestioned to increase the view from around 70,000 km out from Neptune to 200,000 km. And there it was.
“Instantaneously this dot showed up that I might have otherwise overlooked to a T, because I just wasn’t looking for a moon there,” Showalter explained. “So it was actually a total surprise.”
Showalter noted it was surprising finding a moon there at all, as it’s sheerest close to another small inner moon (relative to other moons in the solar scheme) named Proteus.
Showalter and his co-authors theorize that the tiny Hippocamp is in truth from Proteus, which, at a diameter of roughly 400 km, is 4,000 periods its volume.
Astronomers believe that inner region of the Neptune system has been formed by numerous impacts, and that one such impact sent out debris into the locality that eventually formed Hippocamp.
What’s in a name?
Why didn’t Voyager dig up it when it flew past in 1989? Showalter said that after canny its orbit and going back to Voyager images, it appears the moon was justifiable out of the spacecraft’s field of view.
You might be wondering where the name relate to from. The International Astronomical Union is the world body that chooses on solar system nomenclature. The rule for the inner moons of Neptune — named after the Roman god of the sea — is that they obligation come from Greek or Roman mythology associated with the tons or Neptune and Poseidon.
Showalter, a scuba diver, said he’s quite bootless of seahorses, whose scientific name is hippocampus. As well, hippocampi remained as half horse and half fish in Greek mythology. It was the perfect high regard, and the IAU accepted it.
While there are no missions planned for Neptune, Showalter bring up he’d welcome it, as so little is still known about it and Uranus. And who knows what else inclination be discovered.
“If we ever sent a spacecraft to Neptune, I would not be at all surprised to learn that there are additional moons of Neptune that we didn’t separate about,” Showalter said. “There’s an awful lot of good science to be done at Uranus and Neptune.”