We’re getting good at discovering planetary systems beyond our own. NASA’s Kepler spacecraft was launched to discovered planets in other star systems. Since 2009 it’s found over 1000 confirmed exoplanets, meaning we’re finally getting an idea of what other planetary systems are like. If exoplanets are too large to impress you, we’ve even found some candidate exomoons.
You might expect we know everything about the planets and moons in our own solar system if we’re already investigating habitable worlds elsewhere in the galaxy, but much remains unknown in our neck of the woods. For example, astronomers think there’s a giant ninth planet out there but we don’t know for certain. There’s clearly still a lot to learn about the tiny dot of space we call home.
This week NASA announced the discovery of a new moon orbiting the dwarf planet Makemake. The moon, named MK 2, was discovered after analysing observations made by the Hubble space telescope last year. In many ways it’s amazing that we can see it at all as MK 2 is pretty much black and only 100 miles in diameter.
The dwarf planet Makemake is an interesting place itself and the discovery of MK 2 will help astronomers figure out more about the planet. Makemake was discovered in 2005 by Michael Brown and named for the creator of humanity from the Rapa Nui mythology of Easter Island. Makemake is the 2nd brightest planet beyond Neptune, falling short to Pluto. It seems to be a world very similar to Pluto and is likely covered in frozen methane. We’ll be able to learn a lot more about Makemake now that we know it has a moon. For example, moons making calculating the mass of planets much easier.
It’s a testament to just how big the universe is and how difficult astronomy is that we’re still figuring out what’s in our astronomical backyard.
Main image © NASA, ESA, and A. Parker (Southwest Research Institute)