Giant laser creates an artificial star to clear the sky

It looks like a Stormtrooper’s snapshot of the Death Star’s superlaser in action, but this is actually a photo of a new laser that’s just completed testing at the Very Large Telescope in Chile. The laser shoots 90 kilometres into…

It looks like a Stormtrooper’s snapshot of the Death Star’s superlaser in action, but this is actually a photo of a new laser that’s just completed testing at the Very
Large Telescope in Chile.

The laser shoots 90 kilometres into the atmosphere, where it
interacts with the 10-kilometre-thick layer of sodium atoms left around our
planet by meteoroid impacts. The laser makes the sodium fluoresce, producing a bright
point of light that acts as an artificial star.

Astronomers use this pinpoint as a reference to monitor atmospheric turbulence in the telescope’s line of sight. Deformable
mirrors in the telescope shift in response to these measurements, compensating for the atmosphere’s distortions and creating much
sharper images of the heavenly bodies beyond.

Researchers say that the new laser is more flexible and
reliable than the previous
one, which is being retired after six years of service.

“When we started developing these lasers, everyone said our
goal was nearly impossible – even many of the other experts,” says Domenico
Bonaccini Calia of the European Southern
Observatory (ESO), which runs the telescope.Calia calls the new laser a “breakthrough” and hopes to share the technology “with the wider community”. We hope that doesn’t include moon-sized battle stations.