Direct imaging is not commonly used to detect exoplanets because it is very difficult to directly observe exoplanets due to their small size and distance from Earth.

Gas giants, such as Jupiter and Saturn, are the most common type of exoplanet that has been discovered so far.

GJ 1132b, discovered in 2015, is the smallest exoplanet that has been discovered so far, with a mass only about 1.6 times that of Earth.

Finding exoplanets that are similar to Earth is not a challenge in exoplanet research, as many Earth-like exoplanets have been discovered.

Kepler-452b, discovered in 2015, was the first Earth-sized exoplanet that was discovered in the habitable zone of its host star.

Rogue planets, which are exoplanets that are not gravitationally bound to any star, have not been conclusively discovered yet.

The James Webb Space Telescope, launched in 2018, is a powerful space telescope that is expected to revolutionize our understanding of exoplanets.

Direct imaging is not used to characterize the atmospheres of exoplanets because it is very difficult to directly observe exoplanets due to their small size and distance from Earth.

J1407b, discovered in 2012, was the first exoplanet that was discovered to have a ring system.

The presence of clouds in the atmosphere is not a potential sign of life on an exoplanet, as clouds can be formed by non-biological processes.

GJ 1214b, discovered in 2009, was the first exoplanet that was discovered to have a subsurface ocean.

The lack of interest in searching for life on exoplanets is not a potential challenge in the search for life on exoplanets, as there is a great deal of interest in this topic.

Kepler-1625b I, discovered in 2018, was the first exoplanet that was discovered to have a moon.

Learning more about the history of the universe is not a potential benefit of studying exoplanets, as exoplanets are not directly related to the history of the universe.

WASP-17b, discovered in 2009, was the first exoplanet that was discovered to have a retrograde orbit.