How can you detect exo planets?

Answer 1

With our current technology, it is very hard to spot one directly.

There are however two methods today which are commonly used to find exoplanets.

1) Gravitational "tug": Basically, when a planet moves around it's parent star, the gravitational force of the planet pulls the star slightly. Similar to our moon tugging on Earth and causing the tides.

The problem is tat a small planet can't make a big, noticeable tug, only big gas giants do.

2) Light dimming: when a planet moves in front of our view of a star it blocks some of the light, therefore making the star at that time, dimmer, so we know something must be around the star to do that.

Once again it is only good for gas giants because smaller planets don't block as much light.

But with the advancement of the technology of astronomy we should soon see more exoplanets. Possibly with life (but don't get your hopes up)!

Answer 2

Well, there is a technique called the 'Wobble' Technique. Theoretically, when a planet is rotating around a star, the star is slightly 'wobbled' around due to the gravitational force of the exoplanet. Scientists search for 'wobbling' stars and find exoplanets in this way. Another technique is the good old light factor. When a planet passes in front of its host star, the light we receive from that specific star slightly diminishes because of the eclipse created by the planet. Of course, gas giants are being found more frequently than rocky planets due to their size, they are easier to find with either of the techniques.

Answer 3

By noticing how stars being orbited wobble in space. Planets also exert gravitional pull on the suns they're orbiting and since stars are luminous objects they can be seen whereas planets can't.

Another method is to detect differences in luminousity when a planet partially eclipses their star. A small dark spot moving across a star would indicate that something is crossing it, and blocking some of the light.