The Newest Moon of Neptune: Something We’ve Seen Before?

Nature & Tech |

Every now and then, we get a crazy story from the worlds leading astronomers. What’s going on in our own world is hard enough to understand, so information from outside of this planet can seem quite confusing.

However, we often love to hear about things like the discovery of a new planet, or the moon of a planet. One recent finding was that of the Hippocamp moon that was discovered in 2013. This moon, though, was first thought to be a new moon. Now, scientists believe it might actually be a chip-off from a larger moon, known as Proteus.

This was likely caused by a ‘cosmic explosion’ (sounds cool, right?) many years ago.

It was a puzzling discovery in 2013, and in 2019 it’s still confusing the prominent people looking into it. Speaking about this was SETI Institute expert Mark Showalter, who said: “The first thing we realized was that you wouldn’t expect to find such a tiny moon right next to Neptune’s biggest inner moon,

“In the distant past, given the slow migration outward of the larger moon, Proteus was once where Hippocamp is now.”

That’s quite an interesting view. With the orbit of the two moons being around 7,500 miles apart, they are breaking a lot of conventions that we know about space. Normally, it would be expected that Proteus would have swallowed up the smaller moon – that has not happened.

The major deciding point that builds the chipping theory, though, comes from as far back as a photo taken in 1989. Then, the Voyager 2 found a large impact crater on Proteus.

This is, as far as we know, the first evidence that points to this kind of thing being possible in the first place. It’s quite the finding. Alongside Showalter was Imke de Pater of UC Berkeley and Jack Lissauer of NASA’s Ames Research Centre.

Speaking about this finding, Lissauer said: “Based on estimates of comet populations, we know that other moons in the outer solar system have been hit by comets, smashed apart, and re-accreted multiple times. This pair of satellites provides a dramatic illustration that moons are sometimes broken apart by comets.”

Hippocamp itself is actually the product of many years of violent change in space. It was created by the mass tear-up of what took place when the Triton moon was ‘captured’ by Neptune from the Kuiper Belt. This should have been powerful enough to cause major damage to the entire moon system around Neptune.

De Peter summed it up well when he said: “This discovery is yet another example of the violent collisional history and continuous evolution of our solar system,”

For space fans and people who love to see changes take place in real-time, this is a very exciting and satisfying discovery. Quite what it means, we’re yet to find out: we just know that this further shows how unpredictable the worlds beyond our own are.