Dark Energy instrument snaps its first shot of the sky

The first images from a revolutionary new telescope have been snapped this week. The Dark Energy Spectroscopic Instrument (DESI) is designed to hunt for clues about a mysterious force that permeates the universe, by building a comprehensive 3D map of the sky. On April 1 DESI achieved "first light" with a mesmerizing image of the Whirlpool Galaxy.

Taken on the first night of observations with the new telescope, this image captured the red light of the galaxy using an r-band filter. But as eye-catching as it is, it won't hold a candle to what DESI will be capable of when it's fully up and running later this year.

The instrument is still in the process of being installed on the Mayall Telescope in Arizona and this first batch of images was snapped during an early trial run designed to test out the six large lenses that were recently assembled on the telescope. These expand the viewing window by about 16 times.

The meat of DESI is still to come. Eventually, the light that streams through those lenses will be captured by an array of 5,000 robotic positioners, which can independently move their own fiber optic cables with a precision down to 5 microns. That light will then be funneled into a series of 10 spectrographs, which split it into different colors to reveal new details about the cosmological targets.

Using this method, DESI will analyze the spectra of more than 30 million galaxies and quasars, which can tell scientists a lot about how far away an object is and how fast it's moving. That in turn can help us understand dark energy, the strange force that fills the universe and appears to be causing its expansion to accelerate.

This first testing phase of the lenses and the equipment required to position them will last about six weeks. After that, the focal plane, which houses the positioners, will be installed ahead of DESI's first official data run later in the year.

The team discusses DESI in the video below.

Source: Berkeley Lab