Scholz's Star

There are more stars in the universe than we could ever imagine. However, there is even more nothingness. There's a vast amount of space between the stars - so much of it that a collision between two of them is nigh on impossible. 

This means that there's no danger, either, of the Sun ever being obliterated in a collision. So far, the closest it came to it was when Scholz's Star flew past us 70,000 years ago. In truth, it's a slight exaggeration to describe the event as a near miss, given that the closest that Scholz's Star ever came to the Sun was a not inconsiderable 52,000 astronomical units. In other words, the other star was 52,000 times further away from the Sun than our own 0.8 light years - a more than sufficient clearance, then.

Even though the distance to Scholz's Star comprised less than a fifth of today's distance between the Sun and its closest neighbour, Proxima Centauri, our Stone Age ancestors are unlikely to have taken much notice. Scholz's Star is a tiny red dwarf star less than a tenth of the size of the Sun in the Monoceros ('unicorn') constellation. It's so dim that you can't see it except through a large telescope, and astronomers remained oblivious to its existence until 2013, when Ralf-Dieter Scholz of the Leibniz Institute for Astrophysics in Potsdam noticed that the star displayed as good as no sideways movement in the sky. This normally tells us that an object is travelling directly towards or away from us, and when we investigated its motion more closely we saw that it was moving away from the Sun in a straight line. This meant that it had been even closer to us 70,000 years ago. The star became famous overnight, and was nicknamed 'Scholz's Star' – a clear improvement on its official designation of WISE J072003.20-084651.2.

- Florian Freistetter, A History of the Universe in 100 Stars, London, 2021, p.234-5.