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 ...

Ice giant Uranus is in Taurus, floating near the Pleiades star cluster and easy to locate in the early-morning sky.

The Red Planet’s mantle is giving scientists clues to its geological history.

Saturn’s largest moon, Titan, transits with its shadow early this morning, passing over the planet’s northern polar region.

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