Exoplanets are planets that exist outside our solar system. Most of what we've discovered orbit distant stars while others roam freely in the vastness depths of space.
Currently NASA has registered over 6,000 exoplanets and is continuously discovering new ones.
The search for exoplanets derives its importance from understanding how planetary systems form, by studying these physical processes, we can determine whether there are systems similar to our own or whether ours is completely atypical compared to others.
Brightness of a star is measured over time, periodic fluctuations in that brightness indicate an object covers part of the starlight.
Light bends its path with the gravitational pull of a planet, this causes a shift in the star's position which can be measured to infer the planet's mass and period.
A direct picture of the planet taken directly by a telescope.
Stars strong gravitational pull can bend and magnify the light of a background star acting as a lens. If a planet orbits the background star, it causes a pertubation that can be measured.
The regular light pulses from certain stars can be slightly disturbed when a planet orbits around them, revealing its presence.