Eyes to the Sky: Mercury follows setting sun
On Sunday, Mercury reaches its greatest eastern elongation at 3 a.m. The planet is furthest from the sun in its orbit and sets later than anytime during its current appearance in the evening sky.
As the closest planet to the sun of the eight in our solar system, it is often invisible to Earthly sky observers, hidden in the sun's light. Aptly named after the mythical Roman herald, or messenger of the gods, Mercury alternates between morning and evening apparitions, visible ahead of the rising sun or, as now, seen following the setting sun. Although it is losing brightness, the little planet is wonderful to behold during a twilight hour in the west-northwest for the rest of the month.
Sunset today will be at 8:16 p.m.; twilight begins at 8:50 p.m.. Mercury sets at 10:13. Sundown will be a minute later everyday this week while Mercury sets a minute or two earlier each day. To locate the little planet, look for Jupiter, the brightest star-like object in the western sky and the largest planet in our solar system. As the sky darkens, gaze to the right of the king of the gods to spot bright, yellowish Capella, the fourth brightest star in northern skies. Mercury, the smallest planet in our solar system, will be down and to the left of Capella, almost equidistant from Jupiter and Capella. The three points of light form a triangle in the colorful, twilight sky.
Mercury will be easiest to identify at the end of the week. A young moon, the second waxing (increasing in size) crescent of the month, appears to the planet's left Friday as twilight deepens. Moonset will be at 9:56 p.m. and Mercury sets 10 minutes later.
Make another delightful date with the crescent moon on Saturday night when it appears below brilliant Jupiter and a distance to the left and above Mercury. Moonset will be at 10:38 p.m., Saturday, with Jupiter not far behind.
To contact Judy Isacoff go to: www.naturesturn.org
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