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Full Moon, Full Mars

Copyright: On January 13 On January 13 a Full Moon and a Full Mars were close, both bright and opposite the Sun in planet Earth’s sky. In fact Mars was occulted, passing behind the Moon, when viewed from some locations in North America and northwest Africa. As seen from Richmond, Virginia, USA, this composite image […]

Supernova Remnant Cassiopeia A

Copyright: Massive stars in our Milky Way Galaxy live spectacular lives. Collapsing from vast cosmic clouds, their nuclear furnaces ignite and create heavy elements in their cores. After only a few million years for the most massive stars, the enriched material is blasted back into interstellar space where star formation can begin anew. The expanding […]

M83: The Southern Pinwheel

Copyright: Beautiful and bright spiral galaxy M83 lies a some twelve million light-years away, near the southeastern tip of the very long constellation Hydra. Prominent spiral arms traced by dark dust lanes and blue star clusters lend this galaxy its popular name, The Southern Pinwheel. Still, reddish star forming regions that dot this cosmic pinwheel’s […]

Wolf Moon Engulfs Mars

Copyright: Imran Sultan Does the Moon ever engulf Mars? Yes, but only in the sense that it moves in front, which happens on rare occasions. This happened just yesterday, though, as seen from some locations in North America and western Africa. This occultation was notable not only because the Moon was a fully lit Wolf […]

North Star: Polaris and Surrounding Dust

Copyright: Davide Coverta Why is Polaris called the North Star? First, Polaris is the nearest bright star toward the north spin axis of the Earth. Therefore, as the Earth turns, stars appear to revolve around Polaris, but Polaris itself always stays in the same northerly direction — making it the North Star. Since no bright […]

Comet ATLAS Before Sunrise

Copyright: Petr Horalek / Institute of Physics in Opava Comet ATLAS is really bright now, but also really close to the Sun. Outside the glow of the Sun, Comet C/2024 G3 (ATLAS) would be one of the more remarkable comet sights of recent years, reflecting about as much sunlight to Earth as Comet Tsuchinshan-ATLAS did […]

Mimas: Small Moon with a Big Crater

Copyright: Whatever hit Mimas nearly destroyed it. What remains is one of the largest impact craters on one of Saturn’s smallest round moons. Analysis indicates that a slightly larger impact would have destroyed Mimas entirely. The huge crater, named Herschel after the 1789 discoverer of Mimas, Sir William Herschel, spans about 130 kilometers and is […]

An Evening Sky Full of Planets

Copyright: Dario Giannobile Only Mercury is missing from a Solar System parade of planets in this early evening skyscape. Rising nearly opposite the Sun, bright Mars is at the far left. The other naked-eye planets Jupiter, Saturn, and Venus, can also be spotted, with the the position of too-faint Uranus and Neptune marked near the […]

Young Stars, Dark Nebulae

Copyright: Long Xin An unassuming region in the constellation Taurus holds these dark and dusty nebulae. Scattered through the scene, stars in multiple star systems are forming within their natal Taurus molecular cloud complex some 450 light-years away. Millions of years young and still going through stellar adolescence, the stars are variable in brightness and […]

Peculiar Galaxies of Arp 273

Copyright: Dave Doctor The colorful, spiky stars are in the foreground of this image taken with a small telescope on planet Earth. They lie well within our own Milky Way Galaxy. But the two eye-catching galaxies in the frame lie far beyond the Milky Way, at a distance of over 300 million light-years. The galaxies’ […]

Supernova Remnants Big and Small

Copyright: Stéphane Vetter (Nuits sacrées) What happens after a star explodes? A huge fireball of hot gas shoots out in all directions. When this gas slams into the existing interstellar medium, it heats up so much it glows. Two different supernova remnants (SNRs) are visible in the featured image, taken at the Oukaïmeden Observatory in […]

A New Year’s Aurora and SAR Arc

Copyright: Alessandra Masi It was a new year, and the sky was doubly red. The new year meant that the Earth had returned to its usual place in its orbit on January 1, a place a few days before its closest approach to the Sun. The first of the two red skyglows, on the left, […]

Colliding Spiral Galaxies from Webb and Hubble

Copyright: Billions of years from now, only one of these two galaxies will remain. Until then, spiral galaxies NGC 2207 and IC 2163 will slowly pull each other apart, creating tides of matter, sheets of shocked gas, lanes of dark dust, bursts of star formation, and streams of cast-away stars. The featured image in scientifically […]

Rocket Launch as Seen from the International Space Station

Copyright: Have you ever seen a rocket launch — from space? A close inspection of the featured time-lapse video will reveal a rocket rising to Earth orbit as seen from the International Space Station (ISS). The Russian Soyuz-FG rocket was launched in November 2018 from the Baikonur Cosmodrome in Kazakhstan, carrying a Progress MS-10 (also […]

Welcome to Perihelion

Copyright: Barden Ridge Observatory rth’s orbit around the Sun is not a circle, it’s an ellipse. The point along its elliptical orbit where our fair planet is closest to the Sun is called perihelion. This year perihelion is today, January 4, at 13:28 UTC, with the Earth about 147 million kilometers from the Sun. For […]