Astronomers use many methods to determine this number, including gravitational lensing, the universe’s expansion rate, and more.

Asteroid 2 Pallas, at 10th magnitude, exhibited a stationary position at 7:00 A.M. EDT within the constellation Aquila. Pallas's location was approximately 6.5° southeast of Altair, Aquila's brightest ...

Cepheid variable stars exhibit regular pulsations whose period directly correlates with their intrinsic brightness (absolute luminosity). The Leavitt law establishes this relationship between ...

Saturn reached opposition at 2 A.M. EDT, exhibiting high visibility throughout the night and presenting optimal viewing conditions for its rings and moons. Saturn's apparent magnitude was 0.6 in ...

As of March 2025, Saturn possesses 274 confirmed moons, the highest number among planets in the solar system. Early discoveries, beginning with Titan in 1655, were limited to five moons by the late ...

On September 20th, beginning around 12:30 A.M. EDT, Titan, a moon of Saturn, will transit across the planet's disk, accompanied by its shadow. The transit will be visible telescopically, with Titan's ...

Current space debris tracking technology is limited to objects larger than 10 centimeters, leaving a significant population of smaller, untrackable debris posing a collision risk to future space ...

Neptune reached opposition at 9:00 A.M. EDT, rendering it visible throughout the night. Neptune, at magnitude 7.7, is not visible to the unaided eye but can be located 2.7° northeast of Saturn using ...

Data from NASA's Dawn mission, analyzed via thermal and chemical models, suggests Ceres possessed a long-lasting internal heat source driven by radioactive element decay. This heat source, reaching ...

The autumnal equinox occurs at 2:19 P.M. EDT, marking the beginning of astronomical autumn in the Northern Hemisphere and spring in the Southern Hemisphere, with equal sunlight distribution across ...

NGC 457, also known as the Owl Cluster, is readily observable with binoculars or telescopes in the evening sky. Located approximately 2.1° southwest of Delta Cassiopeiae, it is easily identified near ...

SpaceX's Starship Flight 9, though achieving orbit, failed due to a damaged pressurization system diffuser on the main fuel tank, leading to a chain of events including payload door failure and loss ...