Red giants and icy planets
Wednesday, March 30th, 2005
Once upon a time there was this big red giant - only it wasn’t a normal giant, it was a star blowing itself to pieces.
And it wasn’t once upon a time - it’s happening all around in the universe.
Scientists have known for a while that the sun will change. After a few billion years, it’ll grow really big, into a type of star known as a red giant.
How big would the sun be as a red giant? Well, the edge of the sun would be touching the earth - that’s how massive it would become. Not for a few billion years, though.
Anyway, normally when astronomers are searching for other planets that may have life, they look for places that look like how our solar system is at the moment.
But a group of astrophysicists from the US and Europe say they should also be looking at solar systems that have red giants.
Why? Because if they have any planets on the far outskirts of a red giant, they could have great conditions for developing life.
So when our sun becomes a red giant, it won’t be good for the earth - everything on this planet will be dead.
But other places in our solar system may develop just the right conditions for life because of it.
There are plenty of moons in the solar system with water on them, such as Europa, Callisto, and maybe even Titan - when they start to melt, they may just start to form seas that could support life.
So it’s worth looking for planets around other stars that are not simply just like our own sun. As it is at the moment.