1+ day, 1+ hour ago   (603+ words) The enormous Cygnus Bubble is usually linked to a busy star-forming region. A new study argues that the microquasar Cygnus X-3 may be the more natural source of its highest-energy gamma rays. Cygnus X-3 is a microquasar, a binary system containing a…...

1+ day, 1+ hour ago   (663+ words) The cosmic microwave background is the oldest light we can observe. Here is where it came from, what its tiny patterns reveal, and why it still matters. About 380,000 years after the Big Bang, the expanding universe had cooled enough for…...

3+ day, 20+ hour ago   (1153+ words) The objects are unusually soft in X-rays but bright in extreme ultraviolet light—exactly the combination that makes them difficult to find and potentially important to the history of stars and galaxies. A galaxy can be full of powerful objects…...

4+ day, 1+ hour ago   (418+ words) Imagine finding a Roman coin hundreds of miles from the place where it was made. Who carried it there? A soldier, a merchant, or someone whose journey has left no other trace? One coin leaves those questions open. Put thousands…...

6+ day, 2+ hour ago   (559+ words) In empty space, light travels at exactly 299,792,458 meters per second. That is about 300,000 kilometers per second, or 186,282 miles per second. It is the fastest speed at which matter, energy, or information can travel through the universe. The number is so…...

1+ week, 2+ day ago   (752+ words) A parsec is a distance defined by parallax. Here is how astronomers use the unit to measure the space between stars and galaxies. What is a parsec? It is a unit of distance used by astronomers to describe the space…...

1+ week, 5+ day ago   (461+ words) A telescope is often described as a device that makes distant objects look closer. That is true, but it leaves out the part that matters most to astronomers. The main purpose of a telescope is to collect light—sometimes light…...

1+ week, 5+ day ago   (373+ words) Researchers have completed one of the largest computer simulations of cosmic history yet assembled. Called ASTRID, it follows the growth of galaxies and black holes from the universe’s early days to the present, giving astronomers a virtual laboratory for testing…...

1+ week, 5+ day ago   (447+ words) Two stars once considered promising Dyson sphere candidates have now been removed from the list. Follow-up observations with NASA’s James Webb Space Telescope showed that the infrared glow did not come from enormous artificial structures around the stars. It came…...

2+ week, 3+ day ago   (789+ words) How does a gravity assist send a spacecraft farther into the Solar System? The spacecraft flies close to a moving planet or moon and uses the body’s gravity to bend its path. Seen from the planet, the spacecraft leaves with…...