Very Large Telescope's new optics achieve super sharp images of Neptune

July 18 (UPI) -- The Very Large Telescope has achieved first light using its new optics technique called laser tomography. Astronomers with the European Southern Observatory used the new technology to image Neptune in an unprecedented detail.

The new adaptive optics mode accounts and corrects for the turbulence in different layers of Earth's atmosphere. With the new corrective technology, VLT's Unit Telescope 4 will be able to produce images comparable in sharpness to those of the Hubble Space Telescope.

"It will enable astronomers to study in unprecedented detail fascinating objects such as supermassive black holes at the centres of distant galaxies, jets from young stars, globular clusters, supernovae, planets and their satellites in the solar system and much more," ESO announced in a news release.

Atmospheric turbulence is the reason stars twinkle. It's a problem all ground-based telescopes must work to overcome.

To help UT4 compensate for atmospheric blur, scientists outfitted the mirror with four powerful lasers. The lasers shoot intense beams of orange light into the sky, exciting sodium atoms in the upper layers of the atmosphere. These glittering atoms work as laser guide stars.

The light bounced back from the laser guide stars can be measured to determine the atmospheric turbulence. As the turbulence is measured in realtime, UT4's secondary mirror can react, altering its shape to correct for the atmospheric distortion.

The latest laser tomography mode is just one of several astronomical adaptive optics systems that have been installed over the years to improve the accuracy of VLT's many instruments.