Astronomy November 2017

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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12 Issues

in this issue

3 min.
making light of galaxies

We live in a world completely saturated by images, 24/7. You wanna see the universe? Just wait a minute and a wash of cosmic images will move down through your social media feed, dozens per day. And that’s great. That we have the tools to share our interests so completely, so nonstop, is pretty neat. But I suggest that you might not want to live in a bubble all the time. Trust me, I’ve been in the astronomy game for a long time, and there’s no alternative to seeing the real thing. Live photons that have traveled for millions of years, only to strike your eye as you peer into a telescope? There’s no substitute for that. Photos are very cool, but there’s nothing like the real deal. This month, Steve O’Meara writes…

2 min.
portrait of a giant

HOT BYTES TRENDING TO THE TOP HOLEY WHEELS A new software algorithm should help reduce wear and tear on the Curiosity rover’s wheels by controlling their speed to adjust traction. GIANT SPOT A sunspot bigger than our planet recently rotated into view of NASA’s Solar Dynamics Observatory. SCIENCE START NASA’s new Neutron star Interior Composition Explorer (NICER) has begun studying pulsars from aboard the International Space Station. When it comes to galaxies, the big ones rule the roost. The largest galaxies we know, called cD galaxies, exist in the hearts of rich galaxy clusters. They have grown substantially over the eons by devouring their neighbors, using gravity to inexorably pull in the nearby smaller galaxies one by one. Thinking of galaxies, it’s easy to start with the Milky Way, our own. We live in a barred…

4 min.
love affair with a saros

The great eclipse is over. Millions are probably hooked. The word saros, which may have previously sounded like a Middle Eastern snack, is now a familiar term. It’s the time period, usually 18 years, 111/3 days, separating a repeat of the same eclipse conditions, such as type, time of year, and duration; each has its own three-digit number. At parties, eclipse fanatics like to name-drop particular saroses. Let me join that chorus to sing a love song for one extraordinary saros that keeps doing amazing things. We’ll begin with the famous totality of May 29, 1919, sometimes called the Einstein or Eddington eclipse. It confirmed general relativity theory. You know the story. Einstein said massive objects can warp space. British physicist Arthur Eddington realized this could be confirmed by observing stars near…

3 min.
astro letters

A family discussion I want to recognize Jeff Hester for his article “A Dunning-Kruger universe” in the June 2017 issue. I am a research scientist and do understand the concepts of proving a scientific theory. Also, my daughter is a psychology major, and I am discussing your article in depth with her. I truly enjoy your interpretation of concepts and the way you look at things around us. It reminds me to not only look but to see, and to be more diligent in my thought process. Thank you, Jeff, for your refreshing viewpoints, and keep up the good work. — Tom Rusek, Aberdeen, MD Inspiring the beginners As a person who enthusiastically watched the heavens through my 50mm refractor in the early ’60s and tried to take pictures, I really appreciated Glenn Chaple’s…

2 min.
our moon’s mantle is wetter than we thought

BUILDING BLOCKS. Researchers at the Murchison Widefield Array successfully detected radio emissions from organic molecules originating in variable stars in our galaxy. For decades, scientists believed the Moon contained little water. But a new study published July 24 in Nature Geoscience indicates that the Moon’s mantle may be relatively water-rich. Ralph Milliken of Brown University and Shuai Li of the University of Hawaii reviewed data from the Moon Mineralogy Mapper on the Indian Space Research Organisation’s Chandrayaan-1 lunar orbiter and found widespread evidence for water just below the crust of the Moon. Water content similar to basalts on Earth has been seen previously in volcanic samples from the Apollo missions. But these samples were small and from isolated areas. “The key question is whether those Apollo samples represent the bulk conditions of the…

1 min.
a tale of two tails

BIG CHANGES. Comets spend most of their time in the outer solar system without their trademark tails. As a comet approaches the inner solar system on its way to perigee (the closest point to the Sun in the comet’s orbit), ices on its surface begin to vaporize, forming a coma of gas around the nucleus. As ultraviolet photons from the Sun hit the gas, they can strip electrons from the atoms, forming ions, which are then pushed directly away from the Sun by its magnetic solar wind. This creates a narrow ion tail. The ion tail always points directly away from the Sun. At the same time, dust particles are swept away from the comet by radiation pressure; they experience a reduced gravitational attraction to the comet, instead orbiting the…