Nacreous Clouds over SwedenVivid and lustrous, wafting iridescent waves of color wash across this skyscape from northern Sweden. Known as nacreous clouds or mother-of-pearl clouds, they are rare. But their unforgettable appearance was captured in this snapshot on January 12 with the Sun just below the local horizon. A type of polar stratospheric…Read More

The Variable Nebula NGC 2261The interstellar cloud of dust and gas captured in this sharp telescopic snapshot is seen to change its appearance noticeably over periods as short as a few weeks. Discovered over 200 years ago and cataloged as NGC 2261, bright star R Monocerotis lies at the tip of the fan-shaped nebula. About one light-year across and…Read More

Hydrogen Clouds of M33Gorgeous spiral galaxy Messier 33 seems to have more than its fair share of glowing hydrogen gas. A prominent member of the local group of galaxies, M33 is also known as the Triangulum Galaxy and lies a mere 3 million light-years away. The galaxy’s central 60,000 light-years or so are shown in this sharp galaxy portrait. The…Read More

Dust Shells around WR 140 from WebbWhat are those strange rings? Rich in dust, the rings are likely 3D shells — but how they were created remains a topic of research. Where they were created is well known: in a binary star system that lies about 6,000 light years away toward the constellation of the Swan (Cygnus) — a system dominated by the…Read More

Comet G3 ATLAS over UruguayComets can be huge. When far from the Sun, a comet’s size usually refers to its hard nucleus of ice and rock, which typically spans a few kilometers — smaller than even a small moon. When nearing the Sun, however, this nucleus can eject dust and gas and leave a thin tail that can spread to an enormous length — even…Read More