Courtesy U.S. Naval Observatory
Don’t miss out on the great planetary trio of May 2013. That’s the name for when three planets gather in the same part of the sky, coming less than 5o of one another. This month’s planetary trio – Jupiter, Venus and Mercury – is the first since May 2011 and the last until October 2015. On May 25, the planets are not quite an equal-sided triangle, but they will be soon.
A typical binocular field covers about 5o of sky. If you have binoculars, take them along with you to see Mercury, Venus and Jupiter in a single binocular field. If you don’t have binoculars, view the evening tableau anyway. These beautiful and brilliant planets are visible to the unaided eye.
View larger. | From left to right, Jupiter, Venus and Mercury as seen last night, May 24. EarthSky Facebook friend Duke Marsh captured this photo in Clarksville, Indiana.
All three planets will be about 3o apart as evening dusk falls on May 25, 26 and 27. That’s about the width of your thumb at an arm length. Look for all three worlds to pop out into the deepening dusk around 40 to 60 minutes after sunset. With binoculars, you can spot the close-knit group of planets all the sooner in the glow of sunset.
Venus is the brightest of the threesome, followed by Jupiter and then Mercury. Even though Mercury pales next to Venus and Jupiter, this world is easily as bright as the sky’s brightest stars. Use Venus and Jupiter to guide you to Mercury while the opportunity is at hand!
Be sure to find an unobstructed horizon in the direction of sunset. This planetary trio lurks close to the horizon at evening dusk and follows the sun beneath the horizon around nightfall. If you have binoculars, start your search around 30 minutes after sunset, and if you’re using the eyes alone, start searching about 45 minutes after the sun goes down.
Take advantage of this rare opportunity to witness a planetary trio – the planets Mercury, Venus and Jupiter – over your west-northwest horizon in the darkening twilight.
