Scientists looking for alien life have sparked excitement after announcing they will scan an object flying past Earth to see if it contains alien technology.
If it does, it would rank among the biggest and most unexpected scientific finds ever. And even if it's not an alien craft, there is something very strange about the object.
We should only have to wait for a few days to find out more about the visitor, known as Oumuamua. Here's how we plan to do it, and why.
Even before suggestions of something more intentional came about, Oumuamua already appeared very strange.