- Direct imaging.
Uses infrared light to reveal a planets properties once its star reflects its light off of a planet. A starâ€™s wavelength is about 1 billion times brighter than a planets, which is why it is soo difficult using this method because the planet and star must be aligned correctly to see the visible wavelengths. By using infrared wavelengths and capturing images, we can see the atmosphere. (Only a few hundred exoplanets have been detected with this method so far)
Light (in the background source) is bent by gravitational field to create a distorted effect on the planetary surface. The image is then taken and showed as light curves to show different wavelengths. It uses multiple images in milliseconds to collect a collection of images of bent light wavelengths since a traditional telescope would be too slow and small to detect an image of an exoplanet. This is the best method for detecting exoplanets at great distances from Earth. The only drawbacks is that the image generated event is shown only once so any unique activity would not repeat itself.
(When an observing planet passes its star, the dimming of its light is reflected and revealed.)
When an exoplanet pass and gets in front of a star, it shows its dimming of brightness. The dimming is seen in a light curve. The atmosphere of an exoplanet is revealed from the light (brightness) of its orbital properties such as star temperature, atmospheric composition to determine habitability. This in turn will tell researchers and scientists about the exoplanets temperature and whether or not it can harbor life.
- Radial velocity.
This method is detected when a star moves in an elliptical or small circle pattern in which a starâ€™s gravitational tug is detected with its color-shifting properties. The star moving towards an exoplanet moves slightly-revealing its properties. The stars color spectrum changes slightly towards bluer or redder wavelengths (shorter and longer wavelengths). ITs drawback is that it cannot determine a mass of a planet accurately and can be a low-mass star.
Most known exoplanets have been discovered using the transit method. As you can see from this picture, the green color represents Transit method. The rest are in different colors. Transits within our solar system can be observed from Earth when Venus or Mercury travel between us and the Sun.