astronomy

An innovation as crucial as the invention of the telescope swept astronomy in the late 20th century. New technology enabled astronomers to tune in to all the radiation coming from objects in space - and not simply light. Capturing light tells only part of the story. It is like hearing a single note from a melody: to experience the music fully you need to listen to all the notes from the highest to the lowest. Light forms just one part of a whole range of electromagnetic radiation. Tuning in to invisible waves of energy, such as radio waves and X-rays, reveals a startlingly different picture of the universe.

Stars, galaxies, and other objects in space all give off electromagnetic radiation. Whether it is in the form of light or radio waves, it consists of a stream of vibrating electric and magnetic fields spreading outward. Moving at 300,000 km/s (the speed of light), this radiation may travel thousands or even millions of light-years toward us, but most is then absorbed by Earth's atmosphere. Invisible astronomy has only come of age since scientists have been able to intercept radiation in space.

Astronomical discoveries are continuing to come about, so come check out all the forms of astronomy and see how and what they contribute...

WHAT'S INSIDE

	Infrared
	Check here for info on heat radiation. This type of radiation comes from objects with temperatures up to around 1,000 ^oC. It is absorbed in the lower atmosphere, but some wavelengths can be observed from mountaintops or aircraft.
	Radio
	Find out about the shortest wavelengths here. Radio waves are emitted by many objects - from supernova remnants and active galaxies to the Big Bang itself. A 'window' in Earth's atmosphere allows radio waves with wavelengths less than about 100 meters to reach the surface. Longer waves are reflected back into space by the upper atmosphere.
	Ultraviolet
	Click here to see what the hottest stars emit most of their energy. Luckily, Earth's ozone layer protects us from the worst of the Sun's damaging UV radiation, but obstructs the astronomer's view of the ultraviolet universe.
	X-Ray
	Take a look at radiation that are emitted by hot gas between 1 million and 100 million ^oC in this section. This type of radiation is found between galaxies and near black holes!
	Gamma-Ray
	Come explore the shortest wavelengths, less than 0.01 nanometers, that are also the most energetic forms of radiation. Sources include the enigmatic gamma-ray bursters, which may be distant superpowerful exploding stars.
	Telescopes
	Here is were you'll find observation of the universe through optical radiation. Considered by most the greatest invention of cosmology, this devise studies the universe at the wavelengths between 390 and 700 nanometers. Until recently this narrow band was the only way for astronomers to study the universe.