At the left is the "Lucky Imaging" system's view of the globular star cluster M13. At the right is the Hubble Space Telescope Advanced Camera for Survey's view of the same cluster. The black band is a gap between sensors (and misses the two bright stars). The clarity and resolution of the "Lucky" image surpasses Hubble's abilities, although Hubble's can consistently take longer exposures and obtain "deeper" images of the universe.
Credit: Craig Mackay/NASA
The Hubble Space Telescope may take photos of the universe's deepest reaches, but some ground telescopes may now get a "Lucky" leg-up on image clarity.
Using the new "Lucky Imaging" system, a team of astronomers claims to have taken pictures of stars twice as sharp as those produced by Hubble.
?These are the sharpest images ever taken either from the ground or from space," said Craig Mackay, an astronomer at the University of Cambridge in England who led the research.
Mackay and his colleagues' findings are presented on the Web site for the Institute of Astronomy at the University of Cambridge.
Earth's fluctuating atmosphere not only causes stars to twinkle, but also blurs the photos of astronomers trying to snap clear images of the cosmos.
Sensitive cameras can beat the blurriness, but they produce grainy "noise" that can make images nearly unusable. On the other hand, space telescopes such as the Hubble avoid the problem by orbiting above Earth's atmosphere altogether, yet they carry billion-dollar price tags.
To create a ground-based system that could beat noise and fit a budget, Mackay and his team used power in numbers. Their new imaging system takes pictures at 20 frames per second, chooses the best of tens of thousands of images, merges them together and eliminates random noise.
?To produce images sharper than Hubble from the ground is a remarkable achievement by anyone?s standards," Mackay said of the system, adding that its estimated cost of about $100,000--less than a hundredth of a percent of the Hubble space telescope's growing price tag--is an even greater achievement.
The astronomers tested the Lucky Imaging system with a 200-inch (5.1-meter) telescope at the Palomar Observatory in San Diego, Calif. The observatory normally produces images 10 times less detailed than Hubble's, but the new camera created images twice as sharp as those of the space telescope.
Mackay explained that the performance boost came from comparing two images of the globular star cluster M13.
"The star cluster image already shows we can exceed Hubble's clarity, but we think we can do much better," Mackay told SPACE.com. The astronomer noted, however, that Hubble has a better ability to take longer exposures and produce "deeper" views of the cosmos.
Mackay thinks the new imaging system's most effective use will be in larger telescopes, where it can be used to expand the search for mysterious dark matter.
?The images space telescopes produce are of extremely high quality, but they are limited to the size of the telescope,? Mackay said. ?Our techniques can do very well when the telescope is bigger than Hubble and has intrinsically better resolution.?
The one catch for Mackay's new system: Clear conditions and plenty of time are required to produce crisp images that exceed Hubble's abilities.
- VOTE: Hubble's Best Images
- NASA's Next Big Telescope Passes Brain Test
- Hubble Hugger Eager to Fix 'Mind-Blowing' Telescope