A Billion Miles from Home
With the sun its farthest from earth, we’re not feeling the chill
A waning gibbous moon reaches last quarter phase Saturday as it recedes into pre-dawn skies. Late-nighters or early risers Monday morning will see the moon rising with Mars just below the crescent around 2am. The two appear no more than five degrees apart, half the width of your fist held at arm’s length, and are high in the east with daybreak at 5:50.
Just a couple weeks from solstice, we’ve already lost several minutes of morning daylight. On June 21 the sun rose at 5:42 and by the first of July at 5:46. At evening, too, we’re sliding toward darkness. There, thanks to earth’s elliptical orbit, we’ve lost but a minute since solstice, as the latest sunset fell on June 28.
While the days grow shorter, the sun draws nearer. Not that you’ll notice the difference or feel the chill, but Friday marks earth’s aphelion, its point in orbit farthest from the sun. We are at the peak of our elliptical orbit, 94,528,925 miles from the sun. At the opposite extreme, the sun is a mere 91,419,287 miles away at perhelion in January.
That difference amounts to little if anything here on terra firma. Either way, it still takes eight minutes for the sun’s light to reach us. Nor does the difference account for our changing seasons and temperatures, which are a result of earth’s 231⁄2 degree tilted axis.
In the evening sky, Saturn and Venus cling to the western horizon. As the two planets drift apart, Venus nears blue-white Regulus, appearing just two degrees apart Tuesday and Wednesday. Jupiter reigns in the south from sunset until around 3am, with red Antares just below.
Illustration: © Copyright 1925 M.C. Escher/Cordon Art-Baarn-Holland; Graphics: © Copyright 2007 Pacific Publishers. Reprinted by permission from the Tidelog graphic almanac. Bound copies of the annual Tidelog for Chesapeake Bay are $14.95 ppd. from Pacific Publishers, Box 480, Bolinas, CA 94924. Phone 415-868-2909. Weather affects tides. This information is believed to be reliable but no guarantee of accuracy is made by Bay Weekly or Pacific Publishers. The actual layout of Tidelog differs from that used in Bay Weekly. Tidelog graphics are repositioned to reflect Bay Weekly’s distribution cycle.Tides are based on National Oceanic and Atmospheric Administration and are positioned to coincide with high and low tides of Tidelog.