Hubble Reveals Infant Galaxies

  / sciencereason   ... The deeper NASAs Hubble Space Telescope looks into space, the farther back in time it looks, because light takes billions of years to cross the observable universe. Hubbles latest image shows 13 billion-year-old infant (and still forming) galaxies.

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The Hubble Space Telescope has captured the earliest image yet of the universe -- just 600 million years after the Big Bang, when the universe was just a toddler.

Scientists released the photo at a meeting of the American Astronomical Society. It's the most complete picture of the early universe so far, showing galaxies with stars that are already hundreds of millions of years old, along with the unmistakable primordial signs of the first cluster of stars.

Hubble can be thought of as a time machine; the deeper it looks into the cosmos, the further back in time it sees. The light emitted from these baby galaxies was produced 13 billion years ago, but since then, the universe has been expanding at an accelerated rate, so it's taken the same light 13 billion years to reach our telescopes. These faint objects are therefore the most ancient and most distant things we have ever seen.

Interestingly, the light from the most distant galaxies in this image is stretched or "red-shifted." As the universe expands, the light is stretched to longer and longer wavelengths. Now this ancient, dim infrared light can only be detected by extremely sensitive instrumentation.

These young galaxies haven't yet formed their familiar spiral or elliptical shapes and are much smaller and quite blue in color. That's mostly because at this stage, they don't contain many heavy metals, said Garth Illingworth, a University of California, Santa Cruz, astronomy professor who was among those releasing the photo.


Until NASA's Hubble telescope was repaired and upgraded last year, the farthest back in time that astronomers could see was about 900 million years after the Big Bang, Illingworth said. Hubble has been key in helping determine the age of the universe at about 13.7 billion years, ending a long scientific debate about a decade ago.

As far back as Hubble can see, it still doesn't see the first galaxies. For that, NASA will have to rely on a new observatory, the $4.5 billion James Webb telescope, which is set to launch in about four years.

The new Hubble picture captures those distant simpler galaxies juxtaposed amid closer, newer and more evolved ones. The result is a cosmic family photo that portrays galaxies at different ages and stages of development over the course of more than 13 billion years.

Tyson, who was not involved in the Hubble image research, said most people only like their own baby pictures, but Hubble's photo is different: "These are the baby pictures for us all, hence the widespread interest."

• http://news.discovery.com/space/hubbl...

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Since 1853, the California Academy of Sciences has been dedicated to exploring, explaining, and protecting the natural world. It is the only place in the world to combine an aquarium, natural history museum, and planetarium all under one living roof.

• http://www.calacademy.org/
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