Real-life Sci-Fi world 11: Kalgash, a planet in permanent daytime (from Asimov’s Nightfall)

Isaac Asimov‘s sci-fi stories are one reason I wanted to become an astronomer (I talked about this in a recent interview). So I’m a little sad to shoot down a classic…. Nightfall is a classic Asimov story (and later, novel). The residents of a planet called Kalgash live in system of six stars that leaves … More Real-life Sci-Fi world 11: Kalgash, a planet in permanent daytime (from Asimov’s Nightfall)

Exo-moons: Innocent bystanders during gas giant instabilities

Gas giants are the bullies of planetary systems.  They are hundreds of times more massive than small rocky or icy worlds, so when gas giants throw a tantrum, their whole planetary system feels it. Giant planet moons are among the innocent bystanders swept up in the chaos. Giant planets around other stars have different orbits … More Exo-moons: Innocent bystanders during gas giant instabilities

Where did Earth’s (and the asteroid belt’s) water come from?

Imagine a dry Earth. No waterfalls. No oceans. No beer (or people to drink it).  A sad place. Water is pretty important stuff.  In this post we will go deep into how Earth got its water (much deeper than in this post from a while back).  And since it’s connected with how Earth formed, our … More Where did Earth’s (and the asteroid belt’s) water come from?