NASA celebrated the 20th anniversary of the Hubble Space Telescope Saturday.
Since its launch into space on April 24, 1990, the telescope has been instrumental in improving human understanding of the vast space around us.
This is largely thanks to the fact that it has relatively unhindered views of space, compared to land-based telescopes that are at the mercy of Earth's atmospheric conditions.
The telescope has long been plagued by problems, but repairs have improved the quality of images it can capture, with detailed images of the surface of Mars captured in 1997.
Hubble, named for groundbreaking astronomer Edwin Hubble, has captured some of the most dazzling images of the heavens ever seen.
Hubble already has changed astronomers' understanding of how the universe formed and is evolving. It found ancient galaxies that formed well before scientists believed it was possible for them to exist, setting the age of the universe at about 13.7 billion years.
It also provided evidence of an anti-gravity force known as "dark energy" that is inflating all of space at a faster and faster rate.
"It's changed a lot of thinking and it's changed a lot of what I learned 30 years ago in grad school," said Ed Weiler, NASA associate administrator for the Science Mission Directorate, who was chief scientist for the Hubble program when it launched.
NASA, the European Space Agency (ESA), and the Baltimore-based Space Telescope Science Institute (STScI) have released new pictures from the telescope this week, to celebrate Hubble's anniversary
