Since 1998, when astronomers discovered that a mysterious force known as dark energy is blowing the universe apart, scientists have launched at least a dozen multimillion-dollar projects to figure out what, exactly, dark energy is. These range from the $71-million BigBOSS project to the $900-million Large Synoptic Survey Telescope, which is scheduled to see first light in 2019. But in an era of shrinking research funding, the advantage might go to scientists who can work on a shoestring budget—people such as Basque cosmologist Narciso “Txitxo” Benítez, who says he can scoop every one of those projects for less than $10 million.

 

Benítez is a cosmologist at the Institute of Astrophysics of Andalusia in Spain. During his 20-year career, he has published papers on both the most distant known supernova and the closest one, and he was a core member of the ALHAMBRA survey of galaxies. Now, he is on a mission to define dark energy (like hundreds of other astronomers around the world) and has launched a project called J-PAS to do it.

The first step in that long quest is to determine where dark energy is and where it’s been. Astronomers can do that by measuring the location and redshift of millions of galaxies, thereby mapping the universe’s expansion. As galaxies move away from Earth, the light they emit becomes stretched in the direction of the “red” end of the visible light spectrum. The more distant a star, the farther light emitted by that star has traveled through an expanding universe, and thus the more redshifted it will be. If the galaxies in one part of the sky are accelerating away from us more quickly than those in other places, then that part of the sky contains more dark energy.