A group of European astronomers and engineers are planning to cast a new heavyweight into the observation ring, an optical telescope bigger than a football field.

The European Southern Observatory (ESO), a consortium of 10 countries with a pair of observatories in the Atacama Desert in Chile, are in the concept stage of designing a ground-based telescope 10 times larger than anything in use today. The ESO telescope is just one of a number of extremely large skywatching instruments under development by countries around the world, but outstrips them all in proportion.

"As of today, we have a baseline concept relying almost entirely on proven technologies," said OWL project engineer Phillipe Dierickx in an e-mail interview. "We've also started to look for an OWL's nest, and the search goes worldwide."

Like its avian counterpart, the OWL telescope promises to have stunning night vision. At its heart is a system known as adaptive optics, which allows astronomers to correct for the blurring effect of the atmosphere during observations. The current Goliath of optical telescopes, the 33-foot (10-meter) twins at W.M. Keck Observatory at Mauna Kea, Hawaii, uses them, as do the ESO's own Very Large Telescope (VLT) in northern Chile and many others around the world.

"The key point is compensation for atmospheric turbulence," Dierickx said. "If you can't do it, then it doesn't make sense to go beyond today's largest telescope diameters."

OWL planners hope contruct the 100-meter telescope by joining together a number of smaller, easier to manufacture mirrors. The process is similar to how the Keck telescopes were built. The segments should join together to form a deformable mirror capable of resolving objects taking up just a milli-arcsecond of sky. An arcsecond is a sky measurement used by astronomers to determine sizes of objects in space. There are 60 arseconds in an arcminute, 60 arcminutes in a degree. The full moon is about half a degree, or 30 arcminutes wide.

"This instrument is going to be able to see objects that are fainter and more distant than we can see today," said Marc Postman, an astronomer with the Space Telescope Science Institute that runs the Hubble Space Telescope. "And at certain wavelengths, the 100-meter telescope will have a resolution 20 times better than the Next Generation Space Telescope (NGST)."

Postman told SPACE.com that OWL will work well as a complementary tool to the NGST, NASA's planned successor to the Hubble Space Telescope, which will observe objects at infrared wavelengths while OWL studies at optical and the near-infrared.

Astronomers hope that the constructions of ever-larger telescopes will open a new view into the structure of the universe. OWL and a number of smaller efforts also underway are expected to peer back to the oldest galaxies, perhaps even the first galaxies to form out of the void of space.

"These is something that we just can't do today," said astronomer and Keck Telescope designer Jerry Nelson during a telephone interview. "10 meters is just not enough telescope to see them."

Nelson is working on the California Extremely Large Telescope (CELT), a 30-meter ground-based optical telescope also in the concept design stage. But many scientists in Canada and the United States are looking into the idea of 20-meter instruments, a 25-meter telescope in under development in Russia and Swedish researchers are thinking of building one with a 50-meter aperture.

In addition to finding the first galaxies that formed, OWL scientists hope their telescope could find elusive supernovae and be able to determine the chemical makeup of extrasolar planets in the hunt for other potentially life-sustaining biospheres. Nelson and other astronomers, however, said instruments like Owl are often the most useful for purposes that have not yet been thought of, a notion that project scientists seemed to echo.

"There is undoubtedly a lot of unsuspected science waiting for us," Dierickx said.

The leap to 100-meter telescope is a big one in the instrument's evolution. Historically, optical telescopes have increased in size by a factor of two. Before Keck held the title for world's largest, Postman said, the mantle rested on 5-meter telescopes like the Palomar Observatory in California's San Diego County. Prior to that, the 2.5-meter instrument atop Mount Wilson near Pasadena, California was telescope king.

But OWL is at least 10 times bigger than any of those, leading some astronomers to believe an interim step is needed. Nelson believes smaller steps like CELT are valuable.

"At the 100-meter level, you're starting to get into that area where you start to worry about the survival of the telescope," he said. "In astronomy we usually only worry about strains to telescopes, but we don't really worry about thinks breaking…well unless you drop something."

But OWL, astronomers have to be sure they will not break the instrument simply by moving it to look at another place in the sky. The effects of gravity, too, because of the sheer size of OWL are worrisome because they can cause the telescope's mirror to sag and deform, thus lowering its effectiveness.

"We can build instruments the size of OWL, we've done it," Nelson said, referring to steerable 100-meter radio astronomy antennae in Germany and West Virginia. "It's certainly possible."

While Dierickx conceded that there are a number of challenges to constructed a telescope the size of OWL, he feels they can be met. It is even possible that OWL might be assembled on a kind of "lego" approach, with researchers building the telescope up over time.

"Assuming we find a site which would not require lengthy infrastructure, it would be technically possible to grow the telescope from 45-meters in 2012 to 70-meters in 2013, and 100-meters by 2014," Dierickx said.

The biggest challenge however, that of cost, remains to be seen. OWL is expected to cost just over $1 billion, or about one billion Euro.

"We think an international partnership is likely to come up when the final proposal is put together," Dierickx said. "The main factor is money."