Hello! According to NASA, we have found 3706 exoplanets so far. 928 of these exoplanets are believed to be terrestrial planets which means that they have a solid, rocky surface. Most of the exoplanets have been identified using the transit method, which looks for measurable dimming in the light from a star when a planet passes directly between the star and the observer. The transit method can also give us information about the composition of an exoplanet's atmosphere or its temperature. When an exoplanet passes in front of its star, some of the starlight passes through its atmosphere. Scientists analyze the colors of this light in order to get clues about the composition of the planet's atmosphere and can determine things like if there is methane or water vapor present.