The Hubble Space Telescope, launched in 1990, has captured iconic images such as the deep field, Crab Nebula, and Eagle Nebula. Because the Hubble orbits the Earth, free from distortion caused by Earth's atmosphere, it can take extremely high-resolution images allowing astronomers to peer deep into space and time.
The W.M. Keck observatory, which has been operating since 1993, sits on top of Mauna Kea, a dormant volcano in Hawaii. Keck's twin telescopes, each about 33 feet in diameter, are the largest optical and infrared telescopes in the world.
The Chandra X-ray Observatory, launched in 1999, is designed to pick up X-rays emitted from extremely hot regions in the universe, such as exploding stars, galaxy clusters, and black holes. Because Earth's atmosphere absorbs most of these X-rays, the Chandra needs to make its observations from space.
The Spitzer Space Telescope, launched in 2003, is designed to study the early universe in infrared light (unlike Hubble, which mostly observes in visible light). Spitzer was the first telescope to see light from a planet outside of our solar system, and has made huge discoveries about comets, stars, exoplanets, and distant galaxies.
The Fermi Gamma-ray telescope, as its name implies, measures gamma rays, one of the most energetic forms of radiation in the universe. These gamma-rays burst out from some of the most violent objects and events in the universe, such as supermassive black holes and exploding stars.
The Kepler Space telescope was built to hunt the universe for planets, with the hopes of finding other Earth-like worlds where alien life might exist. The telescope searches for the faint dimming that occurs when a planet crosses the path of one of those stars. Since the telescope launched in 2009, it has discovered thousands of planets outside of our solar system.
The Atacama Large Millimeter/submillimeter Array is a collection of 66 radio antennas spread across 10 miles, 16,000 feet up in the Chilean Andes. At the time that the telescope began operations in 2012, it was the world's most advanced radio telescope. It was only recently surpassed by the MeerKAT radio telescope, which is currently being built in South Africa.
The MeerKAT radio telescope in South Africa will allow astronomers to probe things like dark matter and the evolution of galaxies. The array, which will consist of 64 radio dishes, will be the largest and most sensitive radio telescope in the southern hemisphere. Although the telescope is still under construction, it has already spotted more than 1,300 new galaxies.