Hubble spots mother lode of 250 ancient tiny galaxies
Hubble spots mother lode of 250 ancient tiny galaxies
Scientists are getting a peek into the early days after the big bang thanks to Hubble's discovery of a large collection of dwarf galaxies.
The Hubble Space Telescope has been in operation since 1990 and it still can amaze scientists and space fans alike. A team of astronomers has used the Hubble to make a fascinating discovery that links back to the early days of our universe: a collection of over 250 dwarf galaxies.
Researchers date the galaxies to an estimated "only 600-900 million years after the big bang." That sounds like a long time to us, but it's a pittance on the scale of the universe's life span. NASA notes that it took over 12 billion years for the light from the galaxies to reach the Hubble.
The galaxies aren't just interesting for their age, but also for how faint they are. "The faintest galaxies detected in these Hubble observations are fainter than any other yet uncovered in the deepest Hubble observations," says Johan Richard, an astronomer who worked on the project.
Scientists are using the Hubble data to peek into the early stages of the universe. Let's go way, way back in time to when the universe was chock-full of thick hydrogen gas. All that gas once blocked the travel of ultraviolet light in the universe. This fog began to clear, creating what scientists call the epoch of reionization. When it cleared, ultraviolet light was able to cover great distances. NASA refers to this as the universe becoming "transparent to ultraviolet light."
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