California Wild Winter 2004

The Magazine of the CALIFORNIA ACADEMY OF SCIENCES

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Wandering Stars

Bing F. Quock

January 4: Earth at perihelion, or its nearest point to the Sun, showing that seasons are not caused by Earth’s distance from the Sun, but rather the angle and duration of sunlight.

Peak of the Quadrantid meteor shower, usually one of the year’s better displays. However, the light of a nearly-full Moon may obscure viewing of this year’s 40-meteor-per-hour show. The meteors appear to radiate from the northeast after midnight.

January 7: Full Moon near Saturn. It was historically known to the Sioux as the “Moon of Frost in the Teepee,” to the Cherokee as the “Cold Moon,” and to the Cheyenne as the “Moon of the Strong Cold.”

January 21: New Moon. The first New Moon of the first lunar month of the year marks the start of Chinese New Year. The Chinese calendar is reckoned for the longitude of eastern China, 15 hours ahead of pst. So this year, Chinese New Year officially falls on January 22. Unlike the Muslim and Jewish calendars, which mark dates by the naked-eye sighting of the first visible crescent after New Moon, the Chinese calendar uses the calculated date of the actual New Moon, which is not visible.

February 6: Full Moon rises in Leo at sunset, followed two hours later by Jupiter. It was called the “Little Famine Moon” by the Choctaw, the “Bony Moon” by the Cherokee, and the “Purification Moon” by the Hopi.

February 20: New Moon at 1:18 am. The Moon will be a razor-thin crescent low in the west–but it won't be visible to the unaided eye. The crescent first appears to the naked eye tomorrow evening, marking the beginning of the Muslim year 1425.

March 6: Full Moon. Known as the “Spring Moon” to the Passamaquoddy, the “Little Frog Moon” to the Omaha, and the “Whispering Wind Moon” to the Hopi.

March 19: Spring Equinox (for the Northern Hemisphere) at 10:50 pm pst. It corresponds to 6:50 Universal (or Greenwich) Time March 20, which is when many calendars list the equinox date.

March 20: New Moon at 2:42 pm.

The Planets

Mercury is a morning object in January, emerging briefly from the glow of the rising Sun early in the month—look low in the east just before dawn. It is not visible during February but reappears in the evening sky in mid-March. The Moon passes nearby on the mornings of January 19, February 19, and March 21.

Venus spends much of the first half of the year in the western sky after sunset, dominating the early evening hours. In January, it’s located against the stars of Capricorn, and by mid-month enters Aquarius. On January 15, scan with a good telescope one degree to the right of Venus for a greenish “star” which will be the faint planet Uranus. In March, it seems to be closing in on Mars located just above it. Notice, too, that Venus keeps pace with the Sun as it gradually moves northward along the horizon.

Mars The Red Planet is an evening object all season, slowly moving from its January location due south at sunset to high in the west at sunset by the end of March. From about March 18 to 23, watch it pass the Pleiades star cluster. The Moon comes close on the evening of January 27, closer on February 25, and closer still on March 25.

Jupiter Appropriately enough, the “king of the planets” spends this season against the stars of Leo, the “king of the beasts.” At the beginning of January, it rises in the east just before midnight and a few minutes earlier each night thereafter. At the beginning of February, it rises around 9:00 pm. It reaches opposition by March 4, and rises at sunset. The planet’s cloud belts are visible through a telescope, as are its four largest moons. Our gibbous Moon can be seen nearby on January 11, February 7, and March 5.

Saturn Having reached opposition on December 31, the Ringed Planet is perfectly-placed for viewing. It rises at sunset and is visible all night long as it slowly crosses the sky against the stars of Gemini. A small telescope easily reveals its rings–always a striking and unique sight. The Moon joins Saturn on January 6, February 2, February 29, and March 27 and 28.

	Sunrise	Local Noon	Sunset
January 1	7:25 AM PST	12:13 PM PST	5:01 PM PST
February 1	7:14 AM PST	12:24 PM PST	5:33 PM PST
March 1	6:42 AM PST	12:22 PM PST	6:03 PM PST
April 1	5:55 AM PST	12:14 PM PST	6:32 PM PST

(Times are for San Francisco, CA, and will vary slightly for other locations.)

A Procession of Wanderers

When the ancients observed the heavens, they noticed that certain bright, starlike objects slowly changed their positions against the constellations, approaching and passing one another in a stately, celestial dance. These objects became known as “wandering stars.” The Greeks gave us the modern term for them–planets.

At some time during any given night, you can usually see at least one planet in the sky. But the end of March offers an opportunity to see all five planets visible to the unaided eye at the same time (six, if you count the one you’re standing on). The most difficult is Mercury, the nearest planet to our star, but it occasionally moves far enough out of the Sun’s glare to be glimpsed. If observers look soon after sunset on March 29, they’ll see, in order from the Sun, Mercury, Venus, Mars, Saturn, and Jupiter stretched across the sky. They will remain for roughly a week afterward. Beyond that date, Mercury will be too close to the Sun to be easily seen, although the remaining four planets will still be visible. From March 21 to about April 2, the Moon joins the parade, gradually swinging past each of the planets.

Bing F. Quock is a member of the Morrison Planetarium staff at the California Academy of Sciences. bquock@calacademy.org