Scientists may have finally found the universe’s missing matter - hidden in invisible hydrogen gas far beyond galaxies.

Using data from space telescopes and other instruments, astronomers, cosmologists, and astrophysicists are able to deduce and ...

The Hubble Space Telescope launched on April 24, 1990, aboard the Space Shuttle Discovery (STS-31), and deployed into Earth ...

A never-before-seen image of the cosmic microwave background, combining data from the Atacama Cosmology Telescope (ACT) and ...

A new analysis of the sky has finally confirmed where the missing half of the Universe's visible matter has been hiding.

Astronomers have confirmed a wandering black hole, about seven times the mass of the Sun, 5,000 light-years from Earth.

Astronomers have long struggled with a troubling puzzle: a significant portion of normal matter in the universe appeared to ...

In the grand puzzle of the cosmos, one question continues to defy easy answers: how fast is the universe expanding?

Mysterious dark matter makes up 85 percent of matter in the universe, and of the remaining 15 percent, scientists couldn’t ...

Astronomers tallying up all the normal matter—stars, galaxies and gas—in the universe today have come up embarrassingly short ...

The halo is more extended that astronomers originally thought, and contains enough hydrogen gas to resolve the problem of the ...