NASA's Great Observatories
Each portion of the
electromagnetic spectrum (X-rays, gamma rays, ultraviolet, visible, infrared
and radio) brings us unique information about the Universe and the objects within
X-rays and gamma rays bring us information about high energy phenomena such
as black holes, supernova remnants, hot gas, and neutron stars. Ultraviolet
light reveals hot stars and quasars, while visible light shows us warmer stars,
planets, nebulae and galaxies. In the infrared we see cool stars, regions of
starbirth, cool dusty regions of space, and the core of our galaxy.
Radiation in the radio region shows us cold molecular clouds and the radiation left
over from the Big Bang.
If we want to better understand the Universe, we need to study it in all
of its light - across the electromagnetic spectrum.
To achieve this goal, NASA created the Great Observatories Program - a series
of four space observatories designed to gather light across the spectrum.
The first Great Observatory to be launched was the famous
Hubble Space Telescope (HST). Launched in 1990, Hubble is a long term
space-based observatory designed to gather visible, ultraviolet, and
light. It is regularly upgraded with improved optics and instruments.
The second Great Observatory, launched in 1991, was the
Compton Gamma-Ray Observatory (CGRO). Designed to observe high energy gamma
rays, this observatory continues to collect information on some of the most
violent processes in the Universe.
Third in the series is the
Chandra X-Ray Observatory(CXO). Launched in 1999, this observatory is
used to study X-rays from objects such as black holes, quasars, and
regions containing high-temperature gases.
Spitzer Space Telescope
is the fourth and final mission in NASA's
Great Observatories Program. Scheduled for launch in 2003, Spitzer will
study the infrared radiation from space.
Spitzer is also part of NASA's
Astronomical Search for Origins Program,
designed to provide information which will help us understand our cosmic roots,
and how galaxies, stars and planets develop and form.
To learn more about the value of observing the Universe across the electromagnetic
spectrum, visit our web site on