The Clear Skies Above Paranal

If you ever wondered why telescopes are perched atop the highest mountains, with the clearest skies, just check out this picture. That’s the night sky above the European Southern Observatory’s Very Large Telescope, located atop Paranal, a 2,600 metre (8,500 foot) mountain in Chile’s Atacama Desert. The photograph was taken by ESO astronomer Yuri Beletsky.

Here’s the cool thing. It’s a single image. The camera was tracking the stars, which is why they look so crisp, while the telescope domes look a little blurry.

The most striking part of the image is, of course, the wide band of stars in the Milky Way. It spans across 100 degrees of the sky. There are two brighter objects in the image as well. The larger, brighter object is Jupiter. You can make out that it has a planetary disk in the photograph. The other is the star Alpha Centauri (one of the closest stars to the Sun).

The beam stretching into the sky is part of the telescope’s adaptive optics system. It creates an artificial star in the sky above the observatory, which a sophisticated computer can use to calculate the amount of atmospheric distortion above the telescope. The telescope’s mirror is then distorted in real time to counteract the effects of the Earth’s atmosphere. It’s like having a space telescope without needing to actually head out into space.

Great picture Yuri!

Here are some past articles about adaptive optics system:

Original Source:ESO news Release