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, M13 is now less modestly recognized as the...
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...
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...
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...
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 angle camera did record streaks of...
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...
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...
An Extreme Black Hole Outburst
Astronomers believe they have now found the most powerful example of a black hole outburst yet seen in our Universe. The composite, false-color featured image is of a cluster of galaxies in the constellation of Ophiuchus, the serpent-bearer. The composite...
Wide Field: Fox Fur, Unicorn, and Christmas Tree
What do the following things have in common: a cone, the fur of a fox, and a Christmas tree? Answer: they all occur in the constellation of the unicorn (Monoceros). Pictured as a star forming region and cataloged as NGC...
Milky Way and Zodiacal Light over Chile
What is the band of light connecting the ground to the Milky Way? Zodiacal light — a stream of dust that orbits the Sun in the inner Solar System. It is most easily seen just before sunrise, where it has...