The changing night sky

1 million years – 1 metre

One million years ago the night sky was entirely different. Simulations do not allow tracing star positions that far.

The Solar System wanders, with respect to the neighbouring stars, about 65 light years in a million years. The night time sky looks completely different from what it is now. The glaciations in northern Europe are more wide-spread and last longer. The large islands of the Mediterranean have small elephants.

Kuva: It is not known what the night sky looked one million years ago.

The changing night sky

Our Solar system rotates around the Milky Way galaxy with a whopping speed, of about 220 km/s. Most of the stars that we can see in the sky also rotate around the galaxy at the same speed. Still, there are small speed differences, of order of some 20 km/s, between our Sun, and separate individual starts in the neighbourhood. We are located on a galactic speedway, where the stars are passing by each other in different directions. Due to the large distances, the relative changes in stars’ positions are still very slow, and therefore the star positions seem to remain unchanged for the duration of a human life. Most of the current stellar constellations could have been recognized as the same ones, already 50 000 years ago. If we could go back in time for a million years, we would see that the constellations would be already totally different. A faint red dwarf star, the Bernard star, has the largest known proper motion. It moves on the sky in relation to the other stars as much as the cross section of the Moon, in 180 years.