What is it we are looking for when we probe nearby planetary systems? Certainly the search for life elsewhere compels us to find planets like our own around stars much like the Sun. But surely our goal isn’t restricted to finding duplicate Earths, if indeed they exist. A larger goal would be to find life on planets unlike the Earth — perhaps around stars much different from the Sun — which would give us some idea how common living systems are in the galaxy.
And beyond that? The ultimate goal is simply to find out what is out there. That takes in outcomes as different as widespread microbial life, perhaps leading to more complex forms, and barren worlds in which life never emerged. A galaxy filled with life vs. a galaxy in which life is rare offers us two striking outcomes. We ignore preconceptions to find out which is true.
Flaring Red Stars
Let’s try to put Proxima Centauri’s recent flare, discussed yesterday, in context. Events like this highlight our doubts about the viability of red dwarf systems in developing life. Flares are not uncommon on ultra-cool dwarf stars, meaning nearby planets in any habitable zone (as defined by ...