Astronomy Picture Of the Day (APOD)Comet ATLAS and the Mighty Galaxies
Comet ATLAS C/2019 Y4 was discovered by the NASA funded Asteroid Terrestrial-impact Last Alert System, the last comet discovery reported in 2019. Now growing brighter in northern night skies, the comet's pretty greenish...
Morning, Planets, Moon, and Montreal
Dawn's early light came to Montreal, northern planet Earth, on March 18, the day before the vernal equinox. At the end of that nearly equal night the Moon stands above a dense constellation of urban lights in this serene city and skyscape. Of course the Moon's waning crescent faces toward the rising Sun.
M13: The Great Globular Cluster in Hercules
In 1716, English astronomer Edmond Halley noted, "This is but a little Patch, but it shews itself to the naked Eye, when the Sky is serene and the Moon absent." Of course...
Anticrepuscular Rays over Florida
What's happening behind those clouds? Although the scene may appear somehow supernatural, nothing more unusual is occurring than a Sun setting on the other side of the sky. Pictured here are anticrepuscular rays. To understand them, start by picturing common crepuscular rays that are seen any time that sunlight pours though scattered clouds.
M77: Spiral Galaxy with an Active Center
What's happening in the center of nearby spiral galaxy M77? The face-on galaxy lies a mere 47 million light-years away toward the constellation of the Sea Monster (Cetus). At that estimated distance, this gorgeous island universe is about 100 thousand light-years across.
A Moon Dressed Like Saturn
Why does Saturn appear so big? It doesn't -- what is pictured are foreground clouds on Earth crossing in front of the Moon. The Moon shows a slight crescent phase with most of its surface visible by reflected Earthlight known as ashen glow.
The Snows of Churyumov Gerasimenko
You couldn't really be caught in this blizzard while standing by a cliff on Churyumov-Gerasimenko. Orbiting the comet -- frequently abbreviated as 67P or CG -- in June of 2016, the Rosetta spacecraft's narrow...
Moonrise and Mountain Shadow
What phase of the Moon is 3.14 radians from the Sun? The Full Moon, of course. Even though the Moon might look full for several days, the Moon is truly at its full phase when it is 3.14 radians (aka 180 degrees) from the Sun in ecliptic longitude.
Starry Night by Jean Franцois Millet
A dramatic nocturnal landscape from around 1850, this oil painting is the work of French artist Jean-Francois Millet. In the dark and atmospheric night sky are shooting stars, known too as meteors, above a landscape showing a path through the faintly lit countryside that leads toward trees and a cart in silhouette on the horizon.
Falcon 9 Boostback
Short star trails appear in this single 84 second long exposure, taken on March 6 from a rotating planet. The remarkable scene also captures the flight of a Falcon 9 rocket and Dragon cargo spacecraft over Cape Canaveral Air Force Station shortly after launch, on a resupply mission bound for the International Space Station.