(SCIENCE TREK MUSIC) JOAN CARTAN-HANSEN, HOST: Scientists have several different ways to find an exoplanet.
One is called radial velocity.
Orbiting planets cause a change in the color of the light of a star.
Astronomers call it a wobble.
Another method is called a transit.
When a planet passed between the star and the observer, the light of the star dims a tiny amount.
That change in light indicates a possible exoplanet.
Astronomers can also take pictures of an exoplanet by blocking out the glare of the star it orbits.
That's called direct imaging.
Then there's gravitational microlensing.
Light from a distant star get bent and focused by gravity as an exoplanet passes between that star and Earth.
And finally, astronomers look for very tiny or minuscule movements of stars in relation to other nearby stars.
The orbit of a planet can cause its star to wobble in its orbit.
Exoplanets are very far away and difficult to spot, but scientists are working hard to find them.
For more information about exoplanets, check out the Science Trek website.
You'll find it at ScienceTrek.org.