Exoplanets

For centuries people have hypothesized about possible planets around other stars than our sun. Now we know there are thousands of them. Several new methods are used to detect and characterize these exoplanets, and they tell us that our solar system is not the norm. Unusual multiplanet systems and strange examples shake our models of how planets form in the first place, and then how they evolve in time. We have recently detected some exoplanets as small as our Earth, but do not know the composition of their atmospheres or if they could have life on them. Future projects may be able to answer these questions.