Observing Calendar

Since the most impressive telescopic object is the Moon, and since the Moon figured prominently in Galileo’s work, the ideal time to hold monthly sidewalk-astronomy events is on Friday and/or Saturday evenings near first-quarter Moon, which occurs on the following dates in 2009: Sun., Jan. 4; Mon., Feb. 2; Wed., Mar. 4; Thu., Apr. 2; Fri., May 1; Sun., May 31; Mon., June 29; Tue., July 28; Thu., Aug. 27; Sat., Sept. 26; Mon., Oct. 26; Tue., Nov. 24; Thu., Dec. 24.

Mercury’s best evening apparition for the U.S. is on Sun. evening, Apr. 26, when the planet sits just below the thin waxing crescent Moon (making it easy to find).

Venus is at greatest elongation in the evening sky in mid-Jan. 2009. The main attraction of Venus is its full cycle of phases, which showed Galileo that it orbits the Sun, not the Earth.
Unfortunately, Mars doesn’t reach opposition till Jan. 29, 2010, and it’ll then be only 14 arcsec in diameter, so it’s not a very good evening target in 2009. Still, Mars will be in the news during IYA 2009, thanks to ongoing exploration by current mis-sions and the launch of Mars Science Laboratory in the fall.

Jupiter and its Galilean satellites come to opposition on Friday-Saturday, August 14-15. Note that Neptune reaches opposition on Aug. 17, and that the two planets are just 3° apart that week. This offers a wonderful opportunity to tell people how Gali-leo missed the chance to discover Neptune when, in Dec. 1612 and Jan. 1613, he ob-served it near Jupiter and mistook it for a star. Most people, of course, have never seen Neptune (let alone Jupiter) in a telescope. Here’s a chance to see two planets at once! Bonus: Jupiter and Neptune will be less than 1° apart and will fit together in a low-power eyepiece on three occasions in 2009: late May (morning sky), early July (late evening, early morning sky), and late Dec. (evening sky).

Saturn’s opposition is Mar. 8, but note that Saturn’s rings are nearly edge-on, with a ring-plane crossing on Sept. 4, when the planet is only 11° from the Sun. Sat-urn won’t look as “telegenic” as usual, but this does offer a chance to talk about how the changing aspect of the rings made it impossible for Galileo to figure out what was going on there.
The year’s best meteor showers in 2009 are the Leonids in mid-November and the Geminids in mid-December (unfortunately the Perseids in mid-August, when the nights are warmer, will be drowned out by moonlight).

The total solar eclipse on July 22 is the longest of the 21st century, lasting 6m 39s at greatest eclipse in the Pacific Ocean. The centerline goes right through Shang-hai, China, where totality lasts 5m 56s. Thousands of astronomy enthusiasts will travel to China or the Pacific to see this eclipse, but millions (billions?) more can watch online during the Mother of All Webcasts.

The Moon will just nick the northern edge of Earth’s umbral shadow on the last night of the year, Sun., Dec. 31. This partial lunar eclipse isn’t visible in most of the Western Hemisphere, but we include it here as icing on the cake of IYA 2009 for observers in the East.