The 5,000 pencil-size robots will fit into 10 wedge-shaped leaves. Here, one of those wedges is completely filled with 500 robots, each of which will be rotatable independently of each other to gather in the light of a well-known group of space objects, including distant galaxies. Credit: DESI Collaboration
A 45-year-old telescope is a high-tech upgrade that will make it possible to search for answers to the most perplexing questions in astronomy, including the existence of dark energy, a hypothetical invisible force that can drive the expansion of the universe.
The Nicholas U. Mayall Telescope in Arizona shut down earlier this week to prepare for the installation of a 9-ton device that the function of 5,000 pencil-size robots focused fiber-optic sensors in distant galaxies.
Every 20 minutes, the rotating robots, the position to be the instrument — the Dark Energy Spectroscopic Instrument (DESI) — for the capture of a new portion of the sky. Ten very powerful instruments called telescopes will then analyze the light of distant objects captured by the sensors, and creating what is described as the largest and most detailed 3D map of the universe to date. [18 Biggest Unsolved mysteries in Physics]
“We started with a conceptual design for the instrument in 2010,” Joseph Silver, a DESI project engineer who works at the University of California, Lawrence Berkeley Laboratory, said in a statement. “It is based on the science that was done on the Baryon Oscillation Spectroscopic Survey (BOSS) instrument. But it is all done by robots instead of manually.”
The BOSS instrument, in the Apache Point Observatory in New Mexico, has 1,000 optical fibers that can detect light signals from the faintest and most distant galaxies. For DESI, the engineers used five times as much fiber. BOSS, have the researchers use of metal plates with carefully drilled holes for the optical fibers in the direction of their goals. For each part of the sky they want the image, the engineers have to make new plates and stick them on the telescope. In the case of DESI, the robots do all the hard work to significantly increase the speed of the scanning, the researchers said.
“There are 5,000 individual robots, and each drives an optical fiber,” Silber told Live Science. “The optical fiber is then routed approximately 50 meters [164 feet] down the telescope to a separate room where this very large and sensitive spectrograph instruments are installed.”
By measuring how the wavelength of the light from distant galaxies (or any object) changes, the researchers will be able to figure out how far apart they are and how fast the galaxies are moving away. When an object is from us, its light shifts towards the red part of the spectrum (longer wavelength), and that is the reason why it is called the redshift.
The scale and complexity of the map will help scientists understand how the dark energy and gravity in the evolution of the universe. Dark energy is the still-unproven force that competes with the severity and the causes of the accelerating expansion of the universe. It is estimated that dark energy makes up 68 percent of the total energy present in the universe.
The sensitivity of the instrument, astronomers can see galaxies so far away that their light travels to the Earth for billions of years. The researchers said that the instrument, by looking at how long it takes for the light to reach it, would allow them to see back to 11 billion years ago. [Our Expanding Universe: Age, History & Other Facts]
“One of the most important ways we learn about the unseen universe by his subtle effects on the clustering of galaxies,” said DESI Collaboration co-spokesman Daniel Eisenstein of Harvard University. “The new cards of the DESI will provide a stunning new level of sensitivity in our study of cosmology.”
During the planned five years of operations, DESI will measure speeds of approximately 30 million galaxies and quasars — extreme black holes surrounded by a disk of a track material, according to Brenna Flaugher, a DESI project scientist who leads the Department of Astrophysics at the Fermi National Accelerator Laboratory.
“Instead of one at a time, we can measure the speeds of 5000 galaxies at a time,” she said.
The instrument, a collaboration between 71 research institutions, to establish about 10 times more data than its predecessor, the BOSS.
“This project is all about generating large amounts of data,” said DESI Director Michael Levi of the Department of Energy, the Lawrence Berkeley National Laboratory (Berkeley Lab), who is leading the project. The researchers use the data in computer simulations of universes.
Silver and his team have already produced 3,000 positioning robots and installed in wedge-shaped leaflets which will be embedded in the instrument focal plane. DESI of the six lenses are currently the definitive treatment of the University College London and will be sent to the USA this spring, so that the installation of the components can begin.
DESI is expected to perform the first measurements in the spring of 2019.
Originally published on Live Science.