Astronomy February 2015

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.

United States
Kalmbach Publishing Co. - Magazines
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2 minutos
abundance of life in the universe

N othing drives astronomy like that oldest of all philosophical questions: Are we alone? The discovery of life elsewhere in the cosmos would certainly mark one of the most incredible moments in human history, a milestone at which we understand we are not unique in the universe. Of course, we know of only one example of life, right here on Earth. In the minds of some, that means the odds of life being an extremely rare thing in the cosmos are high — at least intelligent life, civilizations that could communicate. They point back to an idea that Italian physicist Enrico Fermi raised long ago, in 1950: If the universe contains life, then where is it? Why hasn’t life showed up on our doorstep? But the odds of life in the universe…

2 minutos
fate of the universe

No one knows what the universe will be like at the end. But much of the evidence we know about points toward a “Big Freeze” scenario for the future, a forever expanding cosmos that will become larger, darker, and devoid of activity until it achieves “heat death” with zero activity. Some 100 billion to 1 trillion years from now, the Local Group will merge into a giant single galaxy, and 150 billion years from now the Virgo Cluster will pass beyond our horizon, no longer visible to us. Communication between galaxies will then no longer be possible. In 2 trillion years, galaxies beyond the Local Supercluster (also known as the Virgo Supercluster), the galaxies we see within some 110 million light-years of home, will appear redshifted to the degree that their light…

1 minutos
a monster in hercules

As galaxies go, the Milky Way is big. It measures 120,000 light-years across and holds 200 to 400 billion stars. But Hercules A is huge. This giant elliptical galaxy spans 500,000 light-years, contains roughly 1,000 times more mass than the Milky Way, and sports a central black hole that weighs 2.5 billion Suns. And each of its bullet-shaped radio lobes extends 1 million lightyears. This image combines a visible-light photo taken by the Hubble Space Telescope (red, green, and blue), X-ray data from the Chandra X-ray Observatory showing multimillion-degree gas (purple), and radio observations from the Jansky Very Large Array (blue).…

4 minutos
shadow secrets

Once a decade or so, around Groundhog Day, we explore shadows. The ones cast by woodchucks can be instructive, but let’s “think big” and focus on those cast by celestial bodies. The Moon’s shadow can actually elicit tears of joy. But next month seeing such an inspirational total solar eclipse may be problematical because the lunar shadow only hits the cloudy North Atlantic. The March 20 event unfolds on the vernal equinox, so the shadow encounters Earth’s edge when it reaches the North Pole and will proceed no farther, but instead sweep invisibly out into space. Fully dark umbral shadows are what mostly interest us. Earth’s umbral shadow extends for a million miles and strikes the Moon twice this year, on April 4 and again September 27, with that second total lunar…

1 minutos
from our inbox

California illusion A while back, I read Stephen James O’Meara’s July column on the Fata Morgana in Astronomy. I know it might be a bit after the fact, but I just wanted to let you know of a reoccurring instance of the Fata Morgana that I have witnessed. I often visit Venice Beach in the sunset hours. During the right time and the right season — with the Sun setting over the ocean — the outline of Catalina Island can be seen when looking west on the horizon. However, there are certain times when the edge of the island looks as if it is breaking off and forming its own piece, like a giant pinnacle sticking out of the water. However, we know for a fact that there is no such large…

1 minutos
pulsar challenges theories

Since the 1970s, astrophysicists have been trying to better understand mysterious objects that appear unusually bright in X-rays; for lack of a better term, they labeled them ultraluminous X-ray sources (ULXs). Observations indicated the objects were likely black holes feeding off companion stars, as such objects could be massive enough to release such energy. But while studying the Cigar Galaxy (M82) with NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR), scientists uncovered an unexpected signal from the ULX M82 X-2: pulsing. “That was a big surprise,” says Fiona Harrison, California Institute of Technology scientist and co-author of the ULX study published October 9 in Nature. “For decades, everybody has thought these ultraluminous X-ray sources had to be black holes. But black holes don’t have a way to create this pulsing.” A different remnant…