Mars, Venus visit the Beehive

With all the grand celestial giants to observe through this spring/summer transition, it's important that skywatchers don't overlook the small, glittering jewels sojourning June's night skies and the space between them.

Mars, about 30 degrees above the western horizon around 8 p.m. early in the month, continues to beat a hasty retreat from last December's opposition at a rate of ½ degree per day. Although unimpressive in telescopes as a featureless dot, the campfire-red ember sparks at magnitude 1.6, making it one of the ten brightest evening-hour objects.

From June 1-3, use binoculars to see the Red Planet traverse the northern tier of the Beehive Cluster (M44) in Constellation Cancer, the crustacean, shining 76 times brighter than the brightest bee star. Use the bees as reference points to watch Mars move along its orbital path in real time, about 1.5 degrees per hour.

The Beehive Cluster is a beautiful open star cluster with a mix of about 1000 multicolored gravitationally bound stars, the brightest of which are blue-white giants around magnitude 6. One of the closest clusters at 610 light years away, the brightest stars at magnitude 3.7 are visible with the naked eye under moderate seeing conditions.

Venus has been dominant in the west since the beginning of the year. On June 3, the “supercritical” carbon dioxide cloud-shrouded orb reaches 45 degrees east of the sun (eastern quadrature), so it's putting in its highest and longest nightly apparitions for the year. Watch it to start appearing lower each subsequent nightfall and setting ever-earlier before abandoning the evening skies altogether in mid-august.

On June 12, the goddess of love makes her own pass through M44. As a striking inverse to the Mars/beehive episode, Venus's transit is most spectacular in telescopes, binoculars being an acceptable second choice. Aphrodite shines at magnitude — 4.5, more than 20,000 times brighter than the brightest blue bee. Venus is so bright that its glare will wash out the Beehive's stars if you try to observe the event unaided.

About an hour of the first days of summer June 21-23, you'll see Mars, Venus and the moon form compelling triangles of various configurations. No optical aid necessary. June's night skies offer plenty of both spring and summer constellations, but one is particularly notable for its nautical applications, legends and great void. Constellation Boötes, the ox-driver or herdsman, culminates 9 p.m. June 15 at zenith (directly overhead). Its alpha star Arcturus, the fourth brightest star in the night sky, starts the month fewer than 10 degrees from zenith.

Although the asterism itself is composed of 15 main and 59 associated stars, there's otherwise a whole lot of nothing here. The span that Boötes occupies faces away from the Milky Way into the great beyond, so it is lacking in nebula and star clusters. There are two spiral galaxies here, NGC 5248 and NGC 5676, and many dim ones of magnitude 13 or fainter. However, even these thin out near the border of a spherical swath of space called the Boötes void, an unimaginably vast emptiness with a diameter 330,000,000 light years across. This “Great Nothing,” known as a supervoid, is one of the largest in

NASA, ESA, J. LEE (CALIFORNIA INSTITUTE OF TECHNOLOGY),AND A. FILIPPENKO (UNIVERSITY OF CALIFORNIA - BERKELEY — NASA CATHOLIC UNIVERSITY OF AMERICA NGC 5248, or Caldwell 45, is a spiral galaxy located in Constellation Boötes, and it is notable for the ring structure around its nucleus. These nuclear rings are characterized by “hot spots” of starburst activity. Starburst regions are sites where stars form at a much higher rate than usual. At a distance of 59million light-years, the starburst regions in Caldwell 45are some of the nearest to Earth and are less visually obstructed than many others.