A space telescope is a telescope made specifically for use in space to observe things outside of the atmosphere of Earth. Space telescopes are not subject to air distortion, which can blur or distort the images taken by ground-based telescopes, in contrast to ground-based telescopes. As a result, space telescopes are able to take sharper and more in-depth pictures of objects in space. They are especially helpful for studying objects at wavelengths like ultraviolet and X-ray radiation that cannot pass through Earth's atmosphere.

The Hubble Space Telescope, which was launched by NASA in 1990 and is still in use today, is one of the most well-known space telescopes. TheHubble Telescope has captured some of the most iconic images of space, including the famous "Pillars of Creation" in the Eagle Nebula and the "Deep Field" images, which revealed thousands of previously unseen galaxies. The Hubble Telescope has also significantly improved our knowledge of dark matter, the universe's expansion, and galaxy formation.

Other notable space telescopes include the Spitzer Space Telescope, which was launched by NASA in 2003 and has studied the early universe, the formation of stars and planets, as well as the characteristics of asteroids and comets, and the Chandra X-ray Observatory, which was launched by NASA in 1999 and has contributed to our understanding of high-energy phenomena like black holes and supernovae.
Other space observatories, such as the James Webb Space Telescope, which will launch in 2021 and be the largest and most potent space telescope ever built, and the European Space Agency's Gaia mission, which is mapping the positions and motions of over a billion stars in the Milky Way, are also currently in use or in development.