We measure the extremely long distances between things in space by light years. A light year is the distance that light travels in one Earth year. Light travels at about 300,000 kilometres per second.

This year, the Buck Moon follows Earth's aphelion, the point in its orbit farthest from the Sun, by just a few days, ...

Baryon acoustic oscillations (BAOs) – the “sound of the Big Bang” – support the idea of a local void. Gabriela Secara, ...

Astronomers using the Green Bank Telescope spotted surprisingly cold, dense hydrogen clouds embedded inside the Milky Way’s ...

Astronomers have studied the globular cluster 47 Tucanae extensively, but still have many questions. It may have an ...

Cosmic radiation occasionally contains enormous amounts of energy, but we don’t know why or where this radiation comes from.

The Helix Galaxy, located 42 million light years away, is an unusual object as it is both a polar ring and a lenticular ...

Chandra X-ray Observatory and X-ray Polarimetry Explorer (IXPE) imagery of the Milky Way's core and supermassive black hole ...

Scientists believe the Milky Way contains up to 400 billion stars and at least as many planets. The largest galaxy known, IC 1101, has more than 100 trillion stars. Step outside on a clear night and ...

The image of supermassive black hole Sagittarius A * was created using data from the Event Horizon Telescope Collaboration.

A new quantum recipe for black holes could be the first step toward a theory of "quantum gravity", the "holy grail" of ...

A new composite image of the Andromeda Galaxy is offering an unprecedented view of our closest spiral galactic neighbor.