Happy Birthday Hubble
By Keir Liddle
Twenty years ago today the Hubble space telescope was launched and, apart from some teething issues with an incorrectly ground mirror (fixed in 1993), it has been astounding us with amazing images of outer space. Hubble’s orbit outside the distortion of Earth’s atmosphere allows it to take extremely sharp images with almost no background light, enabling us to see far further and far clearer than terrestrial telescopes. Hubble’s Ultra Deep Field image, for instance, is the most detailed visible-light image ever produced of the universe’s most distant objects.
The Hubble deep field image is particularly amazing as it actually allows us to look back in time 13 billion years, and it is used to search for galaxies that existed between 400 and 800 million years after the Big Bang. This was achieved by viewing a section of space that had less bright stars in the near field, and is composited from Hubble Space Telescope data accumulated over a period from September 24, 2003 through to January 16, 2004: it is the deepest image of the universe ever taken by humans and contains an estimated 10,000 galaxies.
Many Hubble observations have led to breakthroughs in astrophysics, such as accurately determining the rate of expansion of the universe. The Hubble Key Project (led by Dr. Wendy L. Freedman, Carnegie Observatories) used the Hubble space telescope to establish the most precise optical determination in May 2001 of Hubble’s law. Hubble’s law describes the observation in physical cosmology that the velocity at which various galaxies are receding from the Earth is proportional to their distance from us.
It is the images that Hubble has produced over the years that have brought the wonder and awe of the universe to most people. From the exotic images of galaxies and nebulas, to breath-taking images of our own solar system. Some of these images can be viewed on the Hubble Site here.
Galaxy Zoo Hubble, the latest edition of the Galaxy Zoo crowd sourced science project, uses some of the fantastic and truly awe inspiring images that Hubble has produced, and asks the citizen scientists to classify them; thus increasing our understanding of how galaxies are formed. This works essentially because our brain is better than the most advanced computer at spotting galaxy features- see our podcast on the RAS NAM for an interview with Chris Lintott about the zoo to find out how to get involved.
So, happy birthday Hubble! Long may you continue to wow and amaze us, helping us to understand the vast Universe around this pale blue dot.