Credit: NASA – Hubble Space Telescope has captured the tiny moon Phobos during its orbital trek around Mars

Space telescopes or space observatories are spacecrafts that gather information about outer space using different frequency ranges such as gamma ray, x-ray, ultraviolet, visible, infrared, microwave and radio.

Hubble is a large telescope in space taking pictures of planets, stars and galaxies since 1990. Hubble orbits high above Earth and its atmosphere which makes it better than telescopes on Earth. It uses a digital camera to take pictures of space and uses radio waves to send them back to Earth. Check out the pictures taken by Hubble here.

Chandra telescope uses X-rays to study the universe since its launch in 1999. Chandra orbits high above Earth and its atmosphere and can detect X-ray emission from extremely hot areas of the Universe such as exploded stars, clusters of galaxies, and matter around black holes. Check out the images of the Chandra X-ray Observatory here.

Credit: NASA – Hubble Space Telescope

Credit: NASA – Artist’s concept of the Chandra X-Ray Observatory

Below are some of Hubble’s great achievements (source: National Geographic):

• Hubble’s images have helped estimate the age of the universe, which the expansion rate of pulsating stars suggests is some 13 billion to 14 billion years.
• Hubble has also captured images of many ancient galaxies, in all stages of evolution, and so lets scientists see back into the past days of a young and developing universe.
• The telescope was also instrumental in the discovery of dark energy, a little-known but ubiquitous force that works against gravity and contributes to the ongoing expansion of the universe.
• Hubble also measures the atmospheres of planets outside our own solar system, exploring their compositions and building data that could someday aid the search for extraterrestrial life.

Below are some of Chandra’s facts (source: Chandra website):

• Chandra flies 200 times higher than Hubble – more than 1/3 of the way to the moon!
• Chandra can observe X-rays from clouds of gas so vast that it takes light five million years to go from one side to the other!
• During maneuvers from one target to the next, Chandra slews more slowly than the minute hand on a clock.
• At 45 feet long, Chandra is the largest satellite the shuttle has ever launched.
• Chandra’s resolving power is equivalent to the ability to read a stop sign at a distance of twelve miles.
• The electrical power required to operate the Chandra spacecraft and instruments is 2 kilowatts, about the same power as a hair dryer.
• The light from some of the quasars observed by Chandra will have been traveling through space for ten billion years.
• STS-93, the space mission that deployed Chandra, was the first NASA shuttle mission commanded by a woman “Commander Eileen Collins”
• Chandra can observe X-rays from particles up to the last second before they fall into a black hole.