Astronomy June 2019

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

2 min.
the expanding cosmos

The famous Hubble constant has been a source of heated controversy since its earliest days in the 1920s. The number that defines the expansion rate of the universe, the Hubble constant (or H0) is estimated primarily by measuring redshifts: changes in a galaxy’s spectrum attributed to the fast motion of the galaxy away from an observer. Spectral lines are shifted toward the red end of the spectrum by a small amount, giving away a galaxy’s distance. This may all sound complex, but it’s not the end of the story. For decades, astronomers have argued about the value of the Hubble constant and faced off in different camps, depending on the technique used to find the magic number. The classic battle raged from the 1960s through the 1980s and saw teams led…

2 min.
astro letters

No Bull “Specters of past constellations” in your February issue is a fine article on failed constellations, but it missed Poniatowski’s Bull. It was created in honor of Stanislaw Poniatowski, king of Poland from 1764 to 1795. This starry tribute goes unrecognized today, but it grips you nonetheless. When I showed the Bull to my survey class in astronomy last semester, it looked back at us through its eye, double star 70 Ophiuchi. At a mere 17 light-years away, Poniatowski lives on! And a wide-field scope makes this bull’s-eye a showpiece. — Michael Farney, Mitchell, SD Alien commentary Kiona N. Smith wrote compellingly in February’s “How to build aliens in the lab” about the attempts to create non-carbon-based life, like what might exist on Titan. The beauty of this comes from the scientists’…

1 min.
quantum gravity

HOT BYTES TRENDING TO THE TOP PUZZLE PIECE Neptune’s newly discovered smallest moon, Hippocamp, may be a piece broken off from the larger moon Proteus. TALK IT OUT A Northwestern University model will use data from isolation experiments to predict and avoid crew communications problems on missions to Mars. DUSTY DISCOVERY While searching data for brown dwarfs, citizen scientist Melina Thévenot discovered the first white dwarf surrounded by multiple dusty rings. ESA/HUBBLE, NASA, L. CALÇADA…

1 min.
glowing galaxies

This vivid image shows the slow merger of the two galaxies that make up the Whirlpool Galaxy (M51). They both sit 23 million light-years from Earth. The photo combines optical imagery (appearing in blue) from the Sloan Digital Sky Survey with X-ray data (shown in green) from NASA’s NuSTAR mission. Much to astronomers’ surprise, the supermassive black holes in the centers of these two galaxies are not shining as intensely in X-rays as expected. Researchers think this may be due to a brief dip in brightness as the black holes “flicker” over time. Odder still, the X-ray emission from these behemoths is matched by an object millions of times less massive: a single, incredibly dense neutron star about 12 miles (20 kilometers) across and two times the mass of the Sun. This…

3 min.
mars lander digs in, then grinds to a halt

NASA’s Mars InSight lander touched down in November and immediately got to work studying Mars’ deep interior, including what it’s made of and how the planet’s layers move. InSight spent months studying the area around its landing site, practicing its movements and scouting the best locations to place instruments. Then, in late February, it started digging — and promptly got stuck. ABRUPT STOP InSight’s Heat Flow and Physical Properties Package (HP3) instrument includes a “mole” — a self-hammering spike — designed to burrow up to 16 feet (5 meters) underground. But the mole made it only about a foot (0.3 m) deep before stopping. In March, HP3 principal investigator Tilman Spohn told Astronomy the team’s best guess was that the mole hit a rock or a gravel layer shortly after beginning to…

1 min.
summer storms on uranus and neptune

CLOUDY SKIES. Astronomers use the Hubble Space Telescope to check on our outer solar system neighbors annually. These images, taken in September and November 2018, show weather on the ice giants. At right, a dark storm spanning about 6,800 miles (11,000 kilometers) rages on Neptune. It is the fourth such tempest Hubble has imaged on the planet since 1993. To the right of the dark vortex are white companion clouds, which form as methane gas is thrust upward by the storm’s vortex and freezes into clouds. On the left is Uranus, with a large, white cloud over its north polar cap. Researchers believe the cloud is a result of the planet’s unique rotation and tilt, which expose the north pole to uninterrupted sunlight during the long summer season. Astronomers aren’t sure…