When you think of a planet, you probably think of one of the planets in our own solar system, like Earth, Jupiter, or Mars. Most of the exoplanets we’ve discovered have been like those in our solar ...

The universe is full of wonders, but some worlds are downright deadly. From searing heat to violent storms, these planets make Earth look like a paradise. Many of them challenge everything we know ...

Calculating the total mass of the universe is not simple, because most of the mass is invisible. In a pie chart of the contents of the universe, only 5 percent is normal matter, atoms that make up all ...

About 4.6 billion years ago, a celestial cloud collapsed, paving the way for our solar system to form. Then, a nebula with strong gravitational pull took shape, kick-starting the birth of the sun. But ...

Astronomers have discovered that "super-Earth" planets may exist on wider orbits than previously thought — and this implies these rocky, or "terrestrial," worlds are far more common than was suspected ...

A monster galaxy from the early universe shows that the cosmos was rich with oxygen when it was only less than 3% of its present age, astronomers have found. The discovery raises questions about how ...