Laser meets lightning

On Thursday 18 August, the sky above the Allgäu Public Observatory in southwestern Bavaria was an amazing sight, with the night lit up by two very different phenomena: one an example of advanced technology, and the other of nature’s dramatic power.

As ESO tested the new Wendelstein laser guide star unit by shooting a powerful laser beam into the atmosphere, one of the region’s intense summer thunderstorms was approaching — a very visual demonstration of why ESO’s telescopes are in Chile, and not in Germany. Heavy grey clouds threw down bolts of lightning as Martin Kornmesser, visual artist for the ESO outreach department, took time-lapse photographs of the test for ESOcast 34. With purely coincidental timing this photograph was snapped just as lightning flashed, resulting in a breathtaking image that looks like a scene from a science fiction movie. Although the storm was still far from the observatory, the lightning appears to clash with the laser beam in the sky.

Laser guide stars are artificial stars created 90 kilometres up in the Earth’s atmosphere using a laser beam. Measurements of this artificial star can be used to correct for the blurring effect of the atmosphere in astronomical observations — a technique known as adaptive optics. The Wendelstein laser guide star unit is a new design, combining the laser with the small telescope used to launch it in a single modular unit, which can then be placed onto larger telescopes.

The laser in this photograph is a powerful one, with a 20-watt beam, but the power in a bolt of lightning peaks at a trillion (one million million) watts, albeit for just a fraction of a second! Shortly after this picture was taken the storm reached the observatory, forcing operations to close for the night. While we may have the ability to harness advanced technology for devices such as laser guide stars, we are still subject to the forces of nature, not least among them the weather!

Links

 

    Credit:

    ESO/M. Kornmesser

    About the Image

    Id:potw1136a
    Type:Photographic
    Release date:5 September 2011, 10:15
    Size:4134 x 2567 px

    About the Object

    Name:Allgäu Public Observatory
    Type:Unspecified : Sky Phenomenon : Light Phenomenon : Lightning
    Unspecified : Technology : Observatory
    Category:Premises

    Mounted Image

    Image Formats

    Large JPEG
    2.1 MB
    Screensize JPEG
    111.4 KB

    Zoomable


    Wallpapers

    1024x768
    183.9 KB
    1280x1024
    299.1 KB
    1600x1200
    425.7 KB
    1920x1200
    489.8 KB
    2048x1536
    693.0 KB