These are exciting times for all the stargazers out there. Recently scientists spotted a planet in the exact spot where the planet Vulcan from Star Trek is supposed to be located. And now they have spotted an exomoon which is so large that it is challenging our previous notions about how moons are formed.
All this has been made possible by the Hubble Space Telescope. The existence of the Neptune-sized moon is still to be confirmed, and if it is, scientists have to return to the drawing board and come up with new theories about how these planetary satellites come into existence.
David Kipping and Alex Teachey, astronomers at the University of Columbia, were monitoring Kepler 1625, a star located some 8,000 light years away. Scientists were already aware that the star was orbited by a planet similar in size to our own solar system’s Jupiter. The planet orbited around the planet every 287 days. While they were observing the planet, they noticed a second dimming of starlight emitting from Kepler 1625. This dip is thought to be caused by the exomoon. Scientists observed this before, but only recently has there been enough data to confirm this claim. The scientists aptly named the moon Kepler 1625b i. But Neptmoon sounds much more interesting.
All of this occurred during a routine observation of the Kepler star which was scheduled for the period between the 28th and 29th of October in 2017. Hubble was able to spot a secondary dip in starlight during that period. Scientists also noted that the planet started its normal transit 80 minutes earlier. This usually means that the planet was tugged on gravitationally by some other object.
But all of this is still to be confirmed. Scientists have to wait until May of 2019 for the planet to perform its next transit. Hopes are high, and scientists are excited about the prospect of the first ever exomoon, but a lot of research still has to be done before any celebrations are in place.
The main reason for caution is the way in which this exomoon was seemingly formed. So far scientists know of three ways a moon can form. One is if it is knocked out of a planet due to a large impact, the second is if it has coalesced from rock and gas that is orbiting the planet, and finally, from being captured by the planets gravitational pull. The size of the Neptmoon is confusing and offers little in the way of clarifying how something so large came to be.