Neptune, as you’ve never seen it
A beefed-up telescope promises much-improved images for astronomers. Andrew Masterson reports.
A new optics system fitted to the European Southern Observatory’s Very Large Telescope (VLT) in Chile’s Atacama Desert has gone into operation, producing images as crisp, its operators say, as those produced by NASA’s Hubble Space Telescope.
The new system (dubbed, a little clumsily, GALACSI) uses a method known as laser tomography. The method deploys a number of high-powered lasers, aiming them into the sky to create what could be described as simulated guide-stars.
By measuring these it is possible to calculate to a high degree of accuracy the amount of turbulence and interference present in the Earth’s atmosphere above the telescope. This can then be corrected during the image processing stage, producing pictures with far greater clarity than those obtained by other earth-bound observatories.
A similar system is being built into the Australian National University’s Giant Magellan Telescope (GMT), currently being constructed on the summit of a mountain called Las Campanas, also in Chile. The GMT is expected to be operational by 2020.
The VLT’s first test images using the GALACSI apparatus focussed on Neptune, with a result markedly different to other pictures of the planet.