2+ day, 17+ 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, 23+ 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, 1+ 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, 3+ 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, 4+ 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, 4+ 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, 4+ day ago   (711+ words) They use a chain of methods rather than one universal measuring tape. Radar can reach planets. Parallax works for nearby stars. Farther out, astronomers compare known brightnesses, stellar pulsations and the stretching of light. Each step is checked against the…...