The Messenger spacecraft has sent back some more data about tectonic activity on the planet Mercury. In article titled, The Shrinking Mercury is Active After All, the authors suggest that Mercury is shrinking, due to the cooling of the planet, which causes the appearance of scarps on its surface. As the planet contracts, the surface crust breaks, and small scarps, or fault lines, appear on the surface. The small scarps had to be very young, because due to the constant bombardment of Mercury by meteors, the scarps will not stay there for long. Earth and Mercury are the only 2 tectonically active planets in our Solar System. Also discussed was Elon Musk's ambitious plan to send spacecrafts full of humans to live on Mars by 2030. In an article on gizmodo.com, Maddie Stone argues that Musks' plan was long on hyperbole and promise, but Musk did not explain how it would be done, or who would pay for his ambitous plan. Still, you have to had to Musk: he is an ambitious dude.