A year of wonderful planetary observing will unfold with at least one bright planet being visible in the evening sky on any day during the year. Mars makes a beautiful return to end the year and countless asteroids, meteor showers, comets, and aurorae, along with two total lunar eclipses, portend an excellent observing year.
Two very interesting total lunar eclipses occur this year but occur on opposite sides of the night. As soon as the sun sets on March 3 at 5:53 P.M. EST, the Full Moon will rise already totally eclipsed in the east. It will be fun to see if the Moon will be readily visible in the bright twilight as it is unknown how dark the eclipse will be. As twilight deepens, the Moon will rise higher and its coppery tint should become obvious. Totality ends at 6:58 P.M. and the Moon completely leaves the Earth’s lesser penumbral shadow at 8:12 P.M. If the Sunset Eclipse in March is missed, there is a rare treat of a Sunrise Eclipse on August 28. Partial eclipse begins at 4:51 A.M. with totality beginning at 5:52 A.M. in the brightening twilight. With sunrise at 6:20 A.M., the Moon will probably become lost among the western trees as it sets soon afterwards. If these lunar eclipses end up being too challenging, there is another on February 20, 2008 that will be visible in its entirety before midnight high in the frigid winter sky. There are no solar eclipses this year; the next one will be a very slight partial, about 5%, during sunset on May 20, 2012.
Venus dominates the 2007 evening sky through August. Saturn will join it by February, with Jupiter following by June. Mercury will also appear briefly in the evening from late January through mid-February and again from mid-May through early June. Saturn will leave Venus and Jupiter behind in July; Venus departs in August leaving Jupiter to dominate the evenings until Mars rises before midnight by October. By then Jupiter will depart and Mars will be the dominant planet as the holidays approach. Uranus and Neptune are not spectacular, but both will be visible in the evening from August until next January. Here is the breakdown for each planet in the evening sky during 2007:
Mercury: This scorched world is always a challenge to find, but has a good showing in the evening from January 25 to February 17 with its highest point above the horizon on February 7. The best evening apparition of the year occurs from May 20 to June 12 with Mercury at its highest on June 2. It might be possible to spot Mercury as soon as May 17 when a thin crescent Moon is close to its upper right. Mercury grows steadily larger from 6 to 10 arcseconds across as it approaches Earth; its magnitude will hover around 0. It will go through phases like a tiny, coppery version of the Moon from nearly full to a thin crescent.
Venus: This inferno world has a beautiful evening apparition lasting from New Year’s Day until early August. It will be a dazzling, silvery star shining from magnitude -3.9 to -4.5, and grow steadily higher and larger from nearly full to half phase by early June. It will then become lower and continue to grow larger as it becomes a thin crescent before leaving the evening sky by early August. It will grow from around 10 arcseconds during the beginning of the year to nearly a full arcminute across by August before shrinking again in the morning sky.
Mars: This rusty world has a good apparition later this year when it reaches opposition on December 24 in Gemini and will be up all night. It will be at its brightest at magnitude -1.7 and largest at 15.9 arcseconds across. It will actually be closest to Earth on December 18 when it will be 54.6 million miles away. Mars will be nowhere as large as it was during the oppositions of 2001, 2003, and 2005, but will be high up and promises steady, sharp viewing into early 2008.
Asteroids: This is the perfect year to observe the first four asteroids ever discovered along with another regularly bright asteroid, Amphitrite, since all five reach opposition this year. Juno is at opposition on April 9 in Virgo at magnitude +9.7. Vesta is at opposition on May 30 in Ophiuchus at magnitude +5.4. Pallas is at opposition on September 2 in Pegasus at magnitude +8.8. Ceres is at opposition on November 9 in Cetus at magnitude +7.2. Amphitrite is at opposition on November 17 in Aries at magnitude +8.8.
Jupiter: This stormy world is at its best during the pleasant warm months of the year as it reaches opposition on June 5 in Ophiuchus not far from Antares in Scorpius. It will be 45.8 arcseconds across and shine at magnitude -2.6. Jupiter will be very low this year making seeing finer details a bit more difficult through the turbulent lower atmosphere near the horizon. It will become lost in the evening twilight by November as it fades to magnitude -1.8 and shrinks to 32 arcseconds across.
Saturn: This ringed world presents a beautiful portrait the first half of the year in the evening sky, but the rings are now closing. Opposition is February 10 in Leo when it will be 20.3 arcseconds across and shine at magnitude 0.0. Saturn will slowly fade to magnitude +0.6 and shrink to 17 arcseconds across by July when it will become lost in the evening twilight. Saturn will rise in the northeast before midnight by Christmas to start another spectacular viewing season in 2008.
Uranus: This tilted world reaches opposition on September 9 in Aquarius. It will be 3.7 arcseconds across and shine at magnitude +5.7 not far to the right of the bright star Phi Aquarii.
Neptune: This windy world reaches opposition on August 13 in Capricornus. It will be 2.4 arcseconds across and shine at magnitude +7.8 forming the upper tip of an imaginary triangle with the stars Gamma and Iota Capricorni. A finder chart for Uranus and Neptune will appear in the July issue of Telescopic Topics. Both planets will rise before midnight by August and gradually fade into the evening twilight by January 2008.
Pluto: This frigid world is difficult to find this year as it remains hidden among the countless stars of the Milky Way. It is at opposition on June 19 in Sagittarius and will be a faint spark of light at 0.1 arcseconds across and magnitude +13.9. Pluto will cross the Small Sagittarius Star Cloud, M24, in 2009 and emerge from the other side of the Milky Way in 2015 in the Teaspoon asterism in Sagittarius, the same year the New Horizons spacecraft flies past it.