Hubble reveals baby galaxies at edge of time
New camera allows space telescope to peer into 'uncharted territory'
Published 06/01/2010 | 05:00
THE Hubble Space Telescope has peered farther back in space and time than ever before to see baby galaxies that may have formed as little as 500 million years after the Big Bang.
Astronomers estimate that three newly identified galaxies, which are small and compact and glow a striking blue, are about 13.2 billion light years away. This means their starlight was emitted about 13.2 billion years ago, when the universe was only 4pc of its present age.
"With the rejuvenated Hubble and its new instruments, we are now entering uncharted territory that is ripe for new discoveries," said Garth Illingworth, of the University of California, Santa Cruz, who led the survey team.
He told the American Astronomical Society conference, in Washington, that the updated Hubble observatory provided an opportunity to "push back the frontiers".
The earliest galaxies detected by Dr Illingworth's team were pinpointed in August last year, following the installation of the telescope's new Wide Field Camera 3 (WFC3).
The instrument was pointed at a section of sky known as the Hubble Ultra Deep Field, first surveyed in visible light, in 2004, to provide one of the telescope's most iconic images -- of a dark sky teeming with more than 10,000 galaxies.
The WFC3 instrument has now repeated the exercise for infrared light. The first analysis of the new 2009 Hubble Ultra Deep Field found objects that were formed about 600 million years after the Big Bang.
Dr Illingworth's team has now found evidence that three galaxies in the image date to about 500 million years after the dawn of the universe.
Marcella Carollo, another member of the research team, said: "They are the very building blocks from which the great galaxies of today, like our own Milky Way, ultimately formed."
Meanwhile, separate research published yesterday reveals that just 10pc of stars in the universe may host solar systems. But that still means hundreds of millions of stars may have solar systems that could harbour life-supporting Earth-like planets.
A four-year search revealed just one similar star system, instead of around eight as expected. That system, discovered in 2006, has two gas giants resembling Jupiter and Saturn.
"While it is true that this initial determination is based on just one solar system and our final number could change a lot, this study shows that we can begin to make this measurement with the experiments we are doing today," said Dr Scott Gaudi, from Ohio State University in the US, who led the study.
Professor Andrew Gould, who works with Dr Gaudi, told the annual meeting of the American Astronomical Society: "With billions of stars out there, even narrowing the odds to 10pc leaves a few hundred million systems that might be like ours." (© The Times, London)