New data involving millions of galaxies and luminous galactic cores is providing fresh evidence that the enigmatic and invisible cosmic force called dark energy - responsible for the universe's accelerated expansion - has weakened over time rather than remaining constant,

The Dark Energy Spectroscopic Instrument (DESI) is studying dark energy and the accelerated expansion of the universe.

Dark energy, the mysterious force thought to be driving the ever-faster expansion of the universe, appears to be changing over time, according to new observations released Wednesday.