The Night Sky Guide for April 2012
Constellations, deep-sky objects, planets and events, Tonight’s Sky
Highlights of the April Sky Transcript:
In early April, four planets grace the sky at nightfall.
In the west, Jupiter hangs low on the horizon. Around mid-month, the planet disappears into the sunset.
Venus blazes just above Jupiter in the west. Use a telescope to see its crescent phase.
In the south, Mars is already climbing high. It will remain visible into the early morning.
Saturn will shine low in the east in the evening but climb higher during the night. On April 15th, Saturn reaches opposition, meaning it is opposite the Sun in Earth’s sky. It is also closer to Earth than it’ll be the rest of the year, making it
appear slightly bigger and brighter.
Constellations and Deep-Sky Objects
Late in the evening, high in the northern sky lies the Great Bear, Ursa Major.
The constellation of Ursa Major contains the well-known star pattern, the Big Dipper. It resembles a large drinking cup with a handle.
The two stars that make up the front side of the cup are called “pointer stars” because they point toward the star Polaris, also known as the North Star. The Big Dipper overflows with interesting stars and deep-sky objects.
The stars Mizar and Alcor make up a double-star system that can be seenwithout a telescope. In ancient times, when Mizar and Alcor were even closer together, they were used as a test of keen eyesight.
M81 and M82 are a magnificent pair of galaxies, showpieces of the northern night sky. M82 has an irregular shape, bestowed by a collision with its larger neighbor, M81.
Turning to the south, we see Leo, the Lion, heralding the coming of spring. In Greek mythology, Leo is the great beast slain by Hercules.
The star Denebola, which in Arabic means “tail,” represents exactly that. The bright star Regulus is the heart of the Lion.
Leo has several galaxies in his belly. M65, M66, and NGC 3628 make up the “Leo Triplet,” a lovely grouping of galaxies easily seen with a telescope. Close by is another group. M95 and M96 are large spiral galaxies.
Between the Big Dipper and the head of Leo are three pairs of bright stars known to ancient Arab astronomers as “The Three Leaps of the Gazelle.”
The Lyrid meteor shower will be best seen in the early morning hours of April 22nd. Under a dark sky, you can expect to see up to 20 bright meteors per hour.
The night sky is always a celestial showcase. Explore its wonders from your own backyard.
Credits:Produced by the Space Telescope Science Institute, Office of Public Outreach
Starfield images created with Stellarium
Mythological constellation forms from Firmamentum Sobiescianum sive
Uranographia by Johannes Hevelius, courtesy of the United States Naval Observatory
Jupiter image courtesy of Todd Gross
Venus image courtesy of Mario Weigand
Mars image courtesy of Matt Wedel
Saturn image courtesy of John Endreson
M81 and M82 image courtesy of the Digitized Sky Survey, AURA
Leo Triplet image courtesy of REU program/NOAO/AURA/NSF
M95 and M96 image courtesy of the Digitized Sky Survey, AURA
Narrated by Nancy Calo
Music written by Jonn Serrie
Production: Lucy Albert, Greg Bacon, John Bintz, John Godfrey, and Vanessa Thomas