So first post in a month or so from me due to traveling, but luckily Kári has done a nice job in the meantime. This will also be the reason why I am writing about some pretty old news once i a while, but hey, nobody said this is a news site, right?

Well enough with the excuses. One thing that caught my eye from the last month of scientific news is this press release about how the extinction of the dinosaurs might have been indirectly caused by the our movement in the Galaxy. You see we are actually not just making our way around the Galaxy every 220 million years in the normal circular way, but we are also bouncing up and down through the galactic plane every 36 million years. With the increased density in the galactic plane, the Solar System is subject to more gravitational disturbances when passing through it, and comets and asteroids from the outer parts of the Solar System might be thrown towards new orbits passing through the inner part where Earth goes about it’s day. Of course, Earth is then more likely to be hit, and it just so happens that we were probably passing right through the galactic plane about 65 million years ago when a large comet hit Earth, causing what is called the Cretaceous–Tertiary extinction event that killed off large parts of life on Earth.

So no, passing through the galactic plane didn’t finish off the dinosaurs, but it might have increased the probability of the asteroid collision that did.

On a quick but interesting note in the last part of the piece, the scientists behind the theory also mentions that large collisions like this one might be able to send micro-organisms hurling into space, seeding the Universe with life from Earth… or maybe that is how life on Earth first started? In that case the green aliens might not be so green and alien after all!