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Full Moonlight

Copyright: Jeff Dai A photographer in silhouette stands in bright moonlight as the Full Moon rises in this well-planned telephoto image. Of course, the Full Moon is normally the brightest lunar phase. But on November 18/19, the Full Moon’s light will be dimmed during a deep partial lunar eclipse seen across much of planet Earth. […]

NGC 3314: When Galaxies Overlap

Copyright: Why doesn’t the nearby galaxy create a gravitational lensing effect on the background galaxy? It does, but since both galaxies are so nearby, the angular shift is much smaller than the angular sizes of the galaxies themselves. The featured Hubble image of NGC 3314 shows two large spiral galaxies which happen to line up […]

Geminids from Gemini

Copyright: Wang Jin Where are all of these meteors coming from? In terms of direction on the sky, the pointed answer is the constellation of Gemini. That is why the major meteor shower in December is known as the Geminids — because shower meteors all appear to come from a radiant toward Gemini. Three dimensionally, […]

Light Pillar over Volcanic Etna

Copyright: Giancarlo Tinè What happening above that volcano? Something very unusual — a volcanic light pillar. More typically, light pillars are caused by sunlight and so appear as a bright column that extends upward above a rising or setting Sun. Alternatively, other light pillars — some quite colorful — have been recorded above street and […]

How to Identify that Light in the Sky

Copyright: The League of Lost Causes What is that light in the sky? Perhaps one of humanity’s more common questions, an answer may result from a few quick observations. For example — is it moving or blinking? If so, and if you live near a city, the answer is typically an airplane, since planes are […]

Rosetta’s Comet in Gemini

Copyright: CARA Project Returning along its 6.4 year orbit, periodic comet Churyumov-Gerasimenko (67P) is caught in this telescopic frame from November 7. Sweeping past background stars in the constellation Gemini the comet’s dusty tail stretches toward the upper right to Upsilon Geminorum. Also known as Pollux, Beta Geminorum, Gemini’s brightest star, shines just off the […]

Video of a Green Flash

Copyright: Paolo Lazzarotti Many think it is just a myth. Others think it is true but its cause isn’t known. Adventurers pride themselves on having seen it. It’s a green flash from the Sun. The truth is the green flash does exist and its cause is well understood. Just as the setting Sun disappears completely […]

All of These Space Images are Fake Except One

Copyright: Why would you want to fake a universe? For one reason — to better understand our real universe. Many astronomical projects seeking to learn properties of our universe now start with a robotic telescope taking sequential images of the night sky. Next, sophisticated computer algorithms crunch these digital images to find stars and galaxies […]

A Filament Leaps from the Sun

Copyright: Stéphane Poirier Why, sometimes, does part of the Sun’s atmosphere leap into space? The reason lies in changing magnetic fields that thread through the Sun’s surface. Regions of strong surface magnetism, known as active regions, are usually marked by dark sunspots. Active regions can channel charged gas along arching or sweeping magnetic fields — […]

The Galaxy Between Two Friends

Copyright: Martin Lefranc On an August night two friends enjoyed this view after a day’s hike on the Plateau d’Emparis in the French Alps. At 2400 meters altitude the sky was clear. Light from a setting moon illuminates the foreground captured in the simple vertical panorama of images. Along the plane of our Milky Way […]

NGC 147 and NGC 185

Copyright: Dan Bartlett Dwarf galaxies NGC 147 (left) and NGC 185 stand side by side in this sharp telescopic portrait. The two are not-often-imaged satellites of M31, the great spiral Andromeda Galaxy, some 2.5 million light-years away. Their separation on the sky, less than one degree across a pretty field of view, translates to only […]

The Horsehead and Flame Nebulas

Copyright: Wissam Ayoub The Horsehead Nebula is one of the most famous nebulae on the sky. It is visible as the dark indentation to the orange emission nebula at the far right of the featured picture. The horse-head feature is dark because it is really an opaque dust cloud that lies in front of the […]

SN Requiem: A Supernova Seen Three Times So Far

Copyright: We’ve seen this same supernova three times — when will we see it a fourth? When a distant star explodes in a supernova, we’re lucky if we see it even once. In the case of AT 2016jka (“SN Requiem”), because the exploding star happened to be lined up behind the center of a galaxy […]

A Waterfall and the Milky Way

Copyright: Xie Jie The dream was to capture both the waterfall and the Milky Way together. Difficulties included finding a good camera location, artificially illuminating the waterfall and the surrounding valley effectively, capturing the entire scene with numerous foreground and background shots, worrying that fireflies would be too distracting, keeping the camera dry, and avoiding […]

Dark Matter in a Simulated Universe

Copyright: Tom AbelRalf KaehlerKIPACSLACAMNH Is our universe haunted? It might look that way on this dark matter map. The gravity of unseen dark matter is the leading explanation for why galaxies rotate so fast, why galaxies orbit clusters so fast, why gravitational lenses so strongly deflect light, and why visible matter is distributed as it […]