Sky-watchers this week get a chance to go eye to eye with a cosmic scorpion and witness a magnificent meeting of three neighboring worlds in the evening skies. (Take a solar system quiz.)
Red Antares Rising. By nightfall starting Monday, May 20, look for bright orange star Antares rising into the southeastern sky. Representing the eye of the summertime constellation Scorpius, the scorpion, Antares is a super red giant star 600 light-years from Earth and is the 16th brightest star in the entire sky. It’s also a whopping 900 times the diameter of our sun—so big that if Antares were to replace our sun at the center of our solar system, its outer atmosphere would almost reach out to Jupiter’s orbit.
Moon and Spica. Look towards the south on Tuesday, May 21, for waxing gibbous moon parked to the right of Virgo constellation’s brightest star. Located some 263 light-years from Earth, brilliant blue-white Spica is the fifth brightest star in the entire heavens and is a blue giant that is about 14 times the mass of our own sun. (Video: Moon 101.)
Saturn Pairs with Moon. By Wednesday night , May 22, the moon will have jumped to the lower right of Saturn. While the ringed planet does not look too different from Spica, this is an illusion, since Saturn is many orders of magnitude closer—a gas giant planet only 1.34 billion kilometers from Earth.
Planetary Trio Meeting. Beginning at dusk on Friday, May 24, the main sky show of the month begins! Look toward the low western sky a half hour after sunset for the planetary trio of Jupiter, Venus, and Mercury forming a cosmic trio. The three worlds will be within 5 degrees of each other—equal to the width of three middle fingers held at arm’s length—for the next five days. Mercury and Venus will be at their tightest—and most striking—separation this evening, at less than 1.5 degrees, or three lunar disks, apart. (See a picture of a 2012 Venus-Jupiter conjunction.)
Moon Joins Antares. Having trouble hunting down the eye of the celestial arachnoid? A couple hours after sunset tonight, May 25, the waning gibbous moon rises in the southeast to the far left of Antares. There’s is an extremely shallow lunar eclipse at 12:10 am ET—but will unfortunately remain undetectable as only 4 percent of the moon’s disk just skims by the outer shadow cone of Earth.
Tight Planet Triangle. Don’t miss this cosmic gathering in the evening sky! With a clear line of sight low to the western horizon on Sunday, May 26, Venus, Jupiter, and Mercury reach their tightest huddle in the sky, forming a nearly equilateral triangle. All three worlds are within 2 degrees of each other—making for a pretty photo op and amazing views with binoculars and low power backyard telescopes. (Learn more about the universe.)
Tell us—what amazing sky phenomena have you seen lately?