Good news, everyone! We may have detected our first exomoon outside a solar system. It orbits a gas giant 1800 light years away from us, and it's half the size of Earth—just like the famous Yavin IV from which the Rebel Alliance launched its attack against the Death Star. It's a really weird moon too.
We now have a better picture than ever of what the incredible landscapes of Saturn's moon Titan look like. On the wet north pole of the moon, there are many enormous lakes — and newly-analyzed images from Cassini spacecraft reveal that they're surrounded by dramatic salt flats.
The Moon is ridiculously big relative to the size of Earth, and this was thought to be a cosmic rarity. Now it looks like rocky planets with huge moons are actually extremely common, which might help us find alien life.
Titan's thick atmosphere, sand dunes, and methane lakes make it a world whose geography could be very Earthlike - albeit cold and poisonous. And now astronomers believe this moon of Saturn has seasonal rainstorms and flooding, too. Here's the evidence.
We can determine the atmospheres of exoplanets and the composition of galaxies billions of light-years away...but if you ask astronomers to weigh a star, they're stumped. Now there's an awesomely circuitous way to do it, but we'll need some exomoons.