The optical lenses for the Dark Energy Spectroscopic Instrument have seen their first light. Fermilab contributed key components to DESI, including the corrector barrel and its support structures, along with vital software that ensures the instrument’s 5,000 robotic positioners are precisely aligned with their celestial targets.

For The New York Times, Feb. 25, 2019: Axions? Phantom energy? Astrophysicists scramble to patch a hole in the universe, rewriting cosmic history in the process. Fermilab scientist Josh Frieman is quoted in this article.

The discovery of gravitational waves, predicted by Einstein in 1916, is now enabling important tests of the theory of general relativity, as well as beginning multimessenger astronomy: the combined observations of astrophysical phenomena using electromagnetic radiation, gravitational waves and neutrinos. Barish will explore plans and prospects for gravitational-wave science.

From Nature Reviews Physics, Jan. 28, 2019: The Dark Energy Survey completed its six-year-mission to map more than 300 million distant galaxies; however, an equally arduous task — analyzing the acquired 50 terabytes of data with a view to understanding the expansion of the universe — is just beginning.

From APS’s Physics, Jan. 29, 2019: On Jan. 9, a handful of researchers with the Dark Energy Survey — one of the most ambitious attempts to probe the dynamics of the universe’s expansion — headed to the control room of Chile’s Blanco Telescope. For one last time, they opened the white telescope’s dome. From their perch overlooking the red Andean Mountains, they set up for a night of observing the southern sky.

Chicago in January may feel like the coldest place in the universe, but it’s colder at the South Pole. Scientists there are looking out into space and observing microwaves that have been traveling at the speed of light for 13.6 billion years. Once they were ultraviolet rays, but as the universe expanded, their wavelengths stretched, and they became blue, then red, then infrared (heat) and now they are microwaves, which you may have in an oven in your kitchen. Radio waves have even longer wavelengths.

The Dark Energy Camera mounted on the 4-meter Blanco telescope at the Cerro Tololo Inter-American Observatory in Chile. The final day of data-taking for the Dark Energy Survey is Jan. 9.

After scanning in depth about a quarter of the southern skies for six years and cataloguing hundreds of millions of distant galaxies, the Dark Energy Survey will finish taking data on Jan. 9. DES scientists recorded data from more than 300 million distant galaxies. More than 400 scientists from over 25 institutions around the world have been involved in the project, hosted by Fermilab. The collaboration has already produced about 200 academic papers, with more to come.