If you are at all interested in astronomy, chances are you've already heard that the Hubble Space Telescope is celebrating its 25th anniversary this week. What some people may not know is that Hubble is one of four siblings, so to speak. Back in the 1980s, NASA commissioned the "Great Observatories," each designed and built to study different wavelengths of light.
The Electromagnetic Spectrum. NASA's Great Observatories (Compton, Chandra, Hubble and Spitzer) and the electromagnetic thermometer scale. (Credit: NASA/CXC/M.Weiss)
The four Great Observatories, in order of their launches that took place between 1990 and 2003, are Hubble, the Compton Gamma Ray Observatory, the Chandra X-ray Observatory, and the Spitzer Space Telescope.
A photo of the Hubble Space Telescope, doing its job in space. Credit: NASA
NASA's Hubble Space Telescope was launched on April 24, 1990. Hubble has four main scientific instruments that allow it to observe not only in visible light but also near ultraviolet and near infrared. Hubble helped determine how old our Universe is, what quasars are, and also helped discover "dark energy."
Read the full article at the Huffington Post