An amateur astronomer named Gennady Borisov of Crimea (so I’m calling him Ukrainian), just discovered what is likely (but not yet certainly) the second known visitor to our Solar System from outside of it. The first one, as you might recall, was ‘Oumuamua.
Here is the first animation of our new visitor:
The object is now called C/2019 Q4 (Borisov). If it’s confirmed to be interstellar (from outside the Solar System), then the “C” in its name (for “comet”) will change to “2I”, for “second interstellar” object.
Here’s its position relative to us today:
The Earth is behind the Sun right now, so Borisov is visible through strong telescopes only for a short time before dawn. But in the picture above, Earth is moving into the frame (while Borisov is moving downward), so the Sun will slide aside for us over the next few weeks and there’ll be better viewing. Borisov is in Cancer through September, then moves into Leo for October.
You can run an orbital simulation right in your browser just by clicking HERE. It’s pretty fun because you can play with lots of different viewpoints. You’ll see that it will get pretty close to Mars, so much so that if you lived there, you might even be able to see it with the naked eye.
You may remember that ‘Oumuamua caused a big but brief splash in 2017. It had an odd elongated shape and seemed to use its thinness to get accelerated by solar radiation. Some knowledgeable people even suggested it was a spaceship of some sort (it wasn’t).
But Borisov is different from ‘Oumuamua in some important ways:
- It’s about 10 km across, so at least 1,000 times as massive as ‘Oumuamua
- It’s a comet and not some sort of asteroid; it has a tail and a coma
- We have a much longer time (through 2021) to view it and learn about it
How did Borisov discover this object? With a barrel of a telescope he built himself:
Where did Borisov’s object come from? The current trajectory says from the direction of the lovely W-shaped constellation Cassiopeia:
We’ll certainly learn more about the origin of Borisov in the days and weeks to come, but we’ll learn a lot more over the next year.
There could be some great observations ahead!