1. Since April 24, 1990, Hubble has circled the globe at an altitude of 340 miles.
2. It is about the size of a bus, with a telescopic mirror that is 8 feet in diameter.
3. Hubble has found planets outside our solar system located billions of miles from Earth.
4. One of the biggest discoveries made by Hubble is that the universe is expanding at an ever-increasing rate due to “dark energy,” a kind of repulsive gravity.
TAG: Astronomers using Hubble data have published more than 12,800 scientific papers, making it one of the most productive scientific instruments ever built.