Paul Sutter

A wild variety of star systems exist in the nearby regions of the Milky Way, and astronomers are eager to know where they might find an "Earth 2.0."

With its frigid temperatures, remoteness from the sun and general dustiness, changing Mars to be more Earth-like is more challenging than it seems (and it already seems pretty tough).

Astrophysicists say our universe might be shaped like a three-dimensional donut, meaning you could point a spaceship in one direction and eventually return to where you started.

Despite numerous attempts, astronomers have not yet confirmed the detection of an exomoon, a moon orbiting a planet around a distant star.

Theories that attempt to resolve the so-called black hole information paradox predict that black holes are much more complicated than general relativity suggests.

Dark matter could be even weirder than anyone thought, say cosmologists who are suggesting this mysterious substance could interact with itself in a higher dimensional universe.

The Dark Energy Survey just released its most comprehensive results. But did they really prove Einstein wrong?

If you'd like to "bake" a universe, you need two essential ingredients and one optional ingredient.

New research shows how a hypothetical form of dark energy might be made inside the sun and could be detected here on Earth. In fact, we may have already seen it.

The supermassive black hole in the center of our galaxy may not be a black hole at all, but rather a fluffy ball of dark matter called darkinos.

Space is big — really big. And if you want to successfully navigate the interstellar depths of our galaxy, you're going to need some sort of reliable system.

Many theories of the early universe predict that the cosmos should be flooded with cracks in space-time, called cosmic strings, but no cosmic strings have been detected yet.

For decades, cosmologists have wondered if the large-scale structure of the universe is a fractal — that is, if it looks the same no matter how large the scale.

Physicists have long been unable to describe what happened just after the Big Bang when a teensy blip ballooned into the universe, a process called inflation. We may know why.

Galaxies are glittering cities, massive metropolises full of stars, dust, gas, black holes, magnetic fields, cosmic rays, dark matter and more.

For years, astronomers thought that the objects responsible for short gamma-ray bursts get kicked out of their home galaxies shortly after they're born. But new observations prove otherwise.

What if one mission could study the gravitational ripples triggered by some of the most violent events in the universe — on the way to observing the least-known planets of our solar system?

Believe it or not, physicists are attempting to understand the universe when it was only a handful of seconds old.

A team of physicists has proposed a clever plan to concoct a quantum theory of gravity: refine an age-old technique, and use it to probe the tiniest scales in the universe.

The hypothetical Planet Nine may not be a planet but rather a small black hole that might be detectable from the theoretical radiation emitted from its edge, so-called Hawking radiation.

Black holes may not be black or holes, a new theory proposes.

New research suggests a way to move heat around "tidally locked" alien planets: ocean currents whipping around the worlds faster than they rotate.

Astrophysicists have a wild idea to explain the bizarre abundance of super-high-energy radiation shooting from the center of our galaxy: gravity portals.

A weird, super-powerful particle that's not truly a particle could have dominated the universe when it was just a second old, releasing a flood of ripples that permeated all of space-time.

It turns out we don't really understand habitable zones.