Astronomy December 2021

The world's best-selling astronomy magazine offers you the most exciting, visually stunning, and timely coverage of the heavens above. Each monthly issue includes expert science reporting, vivid color photography, complete sky coverage, spot-on observing tips, informative telescope reviews, and much more! All this in a user-friendly style that's perfect for astronomers at any level.

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Kalmbach Publishing Co. - Magazines
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12 Edições

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2 minutos
close look at the planets

Follow the Dave’s Universe blog: Follow Dave Eicher on Twitter: @deicherstar Often we look deep into space for the latest findings beyond our home turf. But this is also a golden age of discovery and understanding of the solar system. In this issue, we pause to consider the magnificent vault of knowledge scientists have gained in recent times. Associate Editor Jake Parks summarizes this storehouse of research in his “Cosmic tour of the planets” (page 16). Of course, life would never have existed on Earth without the Sun, our local nuclear reactor, located a mere 93 million miles away. The Sun formed in an open cluster about 4.6 billion years ago. What we know of the formation of our solar system — gravity pulling the material into a disk that rotates,…

2 minutos
astro letters

We welcome your comments at Astronomy Letters, P.O. Box 1612, Waukesha, WI 53187; or email to Please include your name, city, state, and country. Letters may be edited for space and clarity. A new light on Apollo I’ve been enjoying your 50th anniversary article series on the Apollo lunar landings these last several years. Many of the historical details and photographs are new to me, and the two essays in the July issue on Apollo 15 did not disappoint. The photo of the crescent Earth rising above the Moon’s limb, which I had never seen before, was mesmerizing. Thank you for sharing it with us! — Justin Soutar, Goshen, VA Farewell, Arecibo Your article in the August issue on the Arecibo Observatory was excellent! I usually like the hard science articles, but this…

1 minutos
martian string of craters

Unlike Earth, the surface of Mars is rife with large, obvious impact craters. Estimates point to at least a quarter of a million such craters on the Red Planet. And with no plate tectonics, imperfections on Mars stick around for a lot longer than they do here on Earth. This orderly collection of craters sits in Mars’ Lunae Planum, known for its rough terrain. Large lava deposits fill the region, likely spewed from the nearby Tharsis Montes volcanic region. The youngest volcanoes located there were last active as recently as a few million years ago. Some research even suggests the area may just be dormant for now and could erupt again in the future. The triplet of craters in this picture, taken by the Colour and Stereo Surface Imaging System camera…

1 minutos
hot bytes

STANDING CLEAR Research suggests that red dwarfs’ most hazardous flares erupt mostly from their poles. This would mean the flares miss exoplanets that orbit in the stars’ equatorial planes, improving those planets’ prospects for hosting life. HER WATCH HAS ENDED The preeminent comet-and asteroid-hunter Carolyn Shoemaker died Aug. 13 at age 92. Among her finds was Comet D/1993 F2 (Shoemaker-Levy 9), which famously smashed into Jupiter in 1994. STUCK IN PLACE An uncrewed demonstration flight of Boeing’s Starliner spacecraft was postponed after some of the craft’s propellant valves became stuck Aug. 3. The capsule was pulled from the launch pad Aug. 13 for further investigation.…

3 minutos
sodium may make asteroid phaethon fizzle

The Geminid meteor shower is best known for the reliable show it puts on during the winter holiday season. But the event is also unique because it stems not from a comet but from an asteroid: 3200 Phaethon. Phaethon’s true nature has puzzled astronomers for more than 10 years, ever since they discovered that it brightens dramatically and expels dust when it nears the Sun. That kind of behavior is usually reserved for comets. When a comet’s path brings it through the inner solar system, the Sun warms and vaporizes the ices on its surface, creating a bright tail extending up to millions of miles behind it. Escaping vapor can also dislodge some of the comet’s dust and rock, which is usually the debris that fuels meteor showers. But asteroids like Phaethon…

1 minutos
seeing echoes of light

A black hole recently gobbled up material from its companion star in the binary system V404 Cygni, located 7,800 light-years from Earth. As the black hole’s meal swirled around it in 2015, the matter heated up and emitted a powerful burst of X-ray light. Like the sound waves of a yodeler echoing through the Swiss Alps, the light waves from the black hole’s outburst are now echoing through the cosmos. This composite image, centered on V404 Cygni, spans some 80 light-years and reveals these so-called light echoes. Each concentric ring is formed as X-rays from the initial burst scatter off clouds of cosmic dust, redirecting the light toward us. The larger the ring, the closer the dust cloud that created it is to Earth. X-ray observations (blue) for this composite…