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

Mars and Spica will appear in close proximity (2° separation) in the evening western sky shortly after sunset, setting before 9 PM local daylight time. Observations of Mars and Spica are best ...

A Full Moon occurs when the Earth is between the Sun and the Moon. The Moon's orbit creates different phases, including a Full Moon. Full Moons have traditional names, like the Sturgeon Moon. The 2025 ...

Equuleus, also known as the Foal, is a small and faint constellation located southwest of Pegasus. Unlike many constellations, Equuleus lacks bright stars, nearby stars, prominent meteor showers, or ...

Saturn, at magnitude 0.6 in Pisces, is observable in the southeast at approximately 30° altitude. Titan, Saturn's largest moon, undergoes an occultation behind Saturn, beginning around 11:10 P.M. EDT ...

Today in the history of astronomy, NASA announces evidence of material being consumed by the black hole at the center of our ...

Planetariums around the world are invited to participate in this year’s edition of the IAU’s annual outreach event.

September’s Full Corn Moon is eclipsed for some observers, Titan passes behind Saturn, and Mars moves north of Spica in the ...

President Donald Trump has announced that the U.S. Space Command will relocate from Colorado to Huntsville, Alabama.

On August 8th, the close conjunction of the Moon and Pluto will occur, though Pluto's visibility will be obscured by the Moon's brightness. Observation of the double star Albireo in Cygnus is ...

The Andromeda constellation, encompassing the mythological princess, is notable for its size (19th largest) and moderate brightness (37th brightest), with its brightest star, Alpheratz, officially ...