Age: Maybe nearing its 11 billionth birthday.
Appearance: It’s a planet, so it’s round. And rocky, we know that. Although with the telescopes and imaging technology currently available it’s hard to be utterly precise about these things.
No one’s actually seen it, have they? Not “seen it” as such. But scientists at the Harvard-Smithsonian Center for Astrophysics have just announced that they know it’s there.
How exactly? Because Kepler-10c blocks some of its sun’s light when it moves past it. Nasa’s Kepler space telescope, from which the planet gets its name, is good at noticing these things. It has already found hundreds of other distant planets.
We all have our talents. I can almost bake bread. Good for you. Although Kepler-10c is about 560 lightyears from Earth, and that’s about 3,293 trillion miles, so I think spotting that’s more impressive. It’s also MASSIVE.
Oh yes? How big is it? A little more than twice the width of Earth.
Not bad. Although if I’m honest I was kind of hoping for more than that. Ah, but size isn’t the point here. I said it’s “massive” – about 17 times the mass of Earth. Those scientists reckon the gravity of all that mass has squashed it together, making it very dense indeed – around 7.5g/cc. That’s a bit like being made of solid iron.
Cool! Exactly. The scientists announced its discovery on Tuesday, and have declared a new class of planet for it – the mega-Earth. Until now, no one knew that rocky planets could get so massive. “This is the Godzilla of Earths!” said Professor Dimitar Sasselov. “But unlike the movie monster, Kepler-10c has positive implications for life.”
I love it when scientists do jokes. We all do. Although Sasselov was making another point about 10c’s coolness. It means that there are more rocky planets out there than was thought, which means there are more places where aliens might live. Indeed if 10c has clouds it might even be cool enough to sustain life itself.
So there could be mega-Earthlings! Let’s not go nuts.
Do say: “I want to go there!”
Don’t say: “Even the fastest spacecraft that mankind has ever built would take more than 10,000 years to travel to Kepler-10c so, at best, it could perhaps deliver your corpse.”