Turn a telescope towards a seemingly empty section of sky and leave the shutter open. As light millions or even billions of years old pours in, the dark sky gets brighter. Leave the shutter open long enough and you’ll get a picture of thousands upon thousands of galaxies. From 2003 to 2009, this is exactly what the Hubble Telescope did, producing one of astronomy’s most famous images, the “Hubble Ultra Deep Field.”
Today, the Hubble Telescope has done it again, only now with an accumulated exposure time of nine whole years and a new wavelength of light.
The first Hubble Ultra-Deep Field study looked at visible and near-infrared light coming from a small section of space in the southern-hemisphere constellation Fornax. The new study — the Ultraviolet Coverage of the Hubble Ultra Deep Field — compiles images from 841 Hubble orbits looking at the same section (90 minutes each), using the entire spectrum of light available to the telescope, specifically ultraviolet. With the new image, we can see 10,000 individual galaxies over a time that goes all the way back to just after the Big Bang.
Take a long look for yourself:
Looking at ultraviolet light is so important because of how young stars burn. Ultraviolet light often signifies hot young stars being born, and so by looking for them, astronomers can find the galaxies where stars form. This information in turn tells us how galaxies formed, looking at the young stars they acquired.
Hubble’s new image is of nothing less than the evolution of our universe.
Science communicator and outreach consultant for the Hubble team, Scott Lewis created the lovely video below to explain the new image and its significance:
When Hubble’s successor — the James Webb Space Telescope — finally comes online, the new ultraviolet data from the Ultra-Deep Field study will be invaluable in directing and adding to its mission. But for now, Hubble will keep expanding our view of the universe, literally.