How To Find An Exoplanet

An exoplanet is a planet that orbits a star other than our Sun.  Even the largest exoplanets are invisible to our mightiest telescopes.  So how do we find them?  Watch and find out:


I’ve known about the solar transit trick for finding exoplanets for some time, but the ability to identify atmospheres had always left me a little perplexed.  After watching the video, I was like,well, duh.  That doesn’t make it any less amazing, though.  Think about it, we have the ability to not only find exoplanets but get a fairly good idea as to what the composition of the exoplanet’s atmosphere and physical makeup are.  And all of it by simply measuring the change in light patterns as the exoplanet traverses its star.

It turns out that exoplanets are much more abundant than ever thought.  It was thought that the norm would be a star without a planetary system, but we’ve discovered the exact opposite.  We’ve found gas giants orbiting their star closer than Mercury orbits our Sun.  We’ve found planets that are almost all water with a solid ice core and a vast ocean and a steam atmosphere.  We’ve even found a few exoplanets that are tantalizing Earth-like.  In fact, around 20% of stars are now thought to contain Earth-sized planets in the Goldilocks zone of its star where it may support life.  That doesn’t mean they’re all habitable, but it’s an enticing promise that there could be a habitable planet circling a star fairly close by.

Of course, there’s a big fat asterisk on the Goldilocks planets.  A lot of this data is extrapolation from what we’ve found so far.  Exoplanets that orbit quickly close to their star are much easier to detect than exoplanets the size of Earth as far away from their star as the Goldilocks zone.  From what I understand, we’ve only found a few actual exoplanets from direct (or I guess indirect) observation.  Regardless, we’re still in the infancy of exoplanetary exploration and detection methods are bound to get better if we can devote more time and resources to this exciting field.