Skywatch Line for Friday, June 7, through Sunday, June 9, written by Sam Salem

This is Dudley Observatory’s Skywatch Line for Friday, June 7, through Sunday, June 9, written by Sam Salem.

On Friday, Sun rises at 5:17am and sets at 8:32pm; Moon rises at 5:44am and sets at 10:20pm.

The waxing crescent Moon returns to the evening sky, crossing the upright Gemini twins as they set for the season. On Friday evening, the low, thin crescent Moon is only 1½ days old. On Friday and Saturday evenings, the waxing crescent Moon will shine near Pollux and Castor, the twin stars of the constellation of Gemini. Pollux is a bit brighter and shines with a golden light, while Castor is a white star. On both evenings, the unlit portion of the Moon will exhibit the lovely glow of earthshine, which is reflected light from Earth. They’ll rise before sunset, travel across the sky’s dome and set before midnight. On Saturday, the crescent Moon forms a roughly right triangle with Pollux and Castor over it.

Mars and Saturn are in nice view just as dawn begins. The highest and easiest is Saturn, in the southeast. Saturn has a modest magnitude of 1.2, but there’s nothing else that bright anywhere near it. Its background is dim constellation of Aquarius. Look for Mars far lower left of Saturn, by three or four fists at arm’s length. Mars is also dim, at magnitude 1.1. But nothing else around it is as bright. Mars lies in dim constellation of Pisces.

The Big Dipper now hangs down by its handle high in the northwest after dark. The middle star of its handle is Mizar, with tiny little Alcor right next to it. Look for Alcor on the Mizar’s side toward Vega, which is now the brightest star in the east.

At nightfall on June evenings, look in a general southward direction for Spica, the brightest star in the constellation Virgo the Maiden. Use Spica to guide you to three faint constellations: Corvus the Crow, Crater the Cup, and Hydra the Water Snake. 

Use the Big Dipper to find Spica. Find the Big Dipper, then follow the curve in the Big Dipper’s handle to the star Arcturus in the constellation Boötes. Extend the curve in the handle into the southern sky to meet Spica. Now, use Spica to find the constellation Corvus. Look for a little squarish figure farther to the south than Spica. This square star pattern is the constellation Corvus the Crow. Use a start chart to help locate the three constellations.

Bernard Flood Burke was born on June 7, 1928. The American astronomer co-discovered that the giant planet Jupiter emits radio waves. In 1955, Burke and Kenneth Franklin, astronomers at the Carnegie Institution in Washington, were scanning the sky for radio waves from galaxies. By chance, they found a radio signal that resembled short bursts of static, similar to interference by lightning on home radios. After weeks of study, finding the signals were periodic, four minutes earlier each day, they pin-pointed Jupiter as the source. This was the first time radio sounds from a planet in our solar system been detected. Later study showed the radio waves were circularly polarized because of a magnetic field.