What’s that Rusty Spot Up There?
Mars has lost its recent luster
The waning moon slips into pre-dawn skies this week, with Friday’s last-quarter moon rising around 1:48am and then about 25 minutes later each day after. Sunday and Monday, that puts the crescent moon to either side of Mars as they rise in the east after 2am.
Mars itself has been on the wane, shining at +1 magnitude low against the horizon and appearing as little more than a rust-colored dot. Over the next several months Mars draws closer to us, nearly tripling in apparent diameter between now and the end of the year, when the red planet will be at opposition juxtaposed from earth with the sun in the middle.
It takes Mars a little more than two of our years to orbit the sun, meaning that roughly every 26 months the red planet, the sun and the earth align in opposition. Even so, don’t expect the fiery red globe of recent years. Unlike our own planet’s orbit around the sun, which is nearly circular, Mars’ orbit is more elliptical.
When Mars is at perihelion from the sun while at opposition with us, as it was the summer of 2003, only 35 million miles separate Earth from the red planet. When at aphelion, however, come the spring of 2012, the distance is 63 million miles.
Elsewhere in our solar system, Mercury is fading fast low in the northwest at dusk and setting before 10pm. Much brighter Venus hovers above the west horizon, outshining any other object until setting around midnight. Saturn appears higher in the sky at sunset but is still no contender to the evening star. But watch over the next couple weeks as Saturn pulls within scant degrees of Venus. Jupiter, the night sky’s stalwart, shines in the southeast at sunset, around 8:30 this week, until a few hours before dawn, near 5:40.
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.