Three orbiting X-ray space telescopes have detected an increased rate of X-ray flares from the usually quiet giant black hole at the center of our Milky Way galaxy after new long-term monitoring.

Earlier this year, astronomers discovered what appeared to be a pair of supermassive black holes circling toward a collision so powerful it would send a burst of gravitational waves surging through the fabric of space-time itself. Astronomers at Colu ...

The news yesterday of NASA's confirmation of the existence of a vast global ocean on Enceladus casts a spotlight on Saturn's icy moon as the most potentially habitable spot beyond Earth in the Solar System for life as we know...

Scientists may be closer to solving the mystery of how Mars changed from a world with surface water billions of years ago to the arid Red Planet of today.

Cygnus, is a constellation that is full of interest, and which contains a wide variety of fascinating objects. It is so far north that it is on view from England for much of the year, and anyone who owns a telescope or a pair of binoculars can have e ...

Scientists have discovered an ancient lakebed on Mars that dates to the time period when the Red Planet dried up.

We only have one example of a planet with life: Earth. But within the next generation, it should become possible to detect signs of life on planets orbiting distant stars. If we find alien life, new questions will arise.

An ambitious project aims to image the close environs of a black hole for the first time.

Go on at tour of the ISS and learn everything you wanted to know about daily life in space--bathroom stuff included.

Astronomers using Hubble found that Markarian 231, the nearest galaxy that hosts a quasar, is powered by two central black holes furiously whirling about each other.

Jim Green, NASA’s head of planetary science, announced that the space agency is considering sending a spacecraft to Uranus and/or Neptune, as well as their ocean moons.

Last week, the nothing-short-of-phenomenal Cassini spacecraft made its last close pass of Saturn’s icy moon Dione. Yes, last. After more than a decade orbiting Saturn, the Cassini mission’s days are numbered. It will end late in 2017, after deservedl ...

Through extremely high precision measurements of a pulsar orbiting a white dwarf star, astronomers have found that the gravitational constant, which dictates the force of gravity, is "reassuringly constant" throughout the universe.

In a complicated mystery of double star systems, merging galaxies, and twin black holes, astronomers are explaining a series of unusual supernovae found beyond the typical confines of their galaxies.

A team of astronomers led by Caltech has discovered a giant swirling disk of gas 10 billion light-years away--a galaxy-in-the-making that is actively being fed cool primordial gas tracing back to the Big Bang.

A graphical guide to four giant experiments spread across the world.

Jumping Neptune solves Kuiper belt mystery

For the first time, astronomers have successfully confirmed the existence of an exoplanet found via microlensing. The planet is Uranus's mass and orbits an orange dwarf star.

NASA has selected three finalists for a new Explorer-class astrophysics satellite mission scheduled to launch by the end of 2020, and two of the proposals aim to fulfill similar goals to an X-ray telescope shelved after cost overruns in 2012

The 46th anniversary of the first human lunar landing passed largely without notice in the national media last week. It’s hard to understand how such an epochal event, the fulfillment of a dream born in the first stirrings of human consciousness and ...