Astronomy

March's vernal equinox heralds spring

By DARYL SCHRADER
© St. Petersburg Times
published March 1, 2003

The vernal equinox will occur on March 20th at 8 p.m. That is when the sun crosses the celestial equator and spring arrives again. The sun will rise directly in the east and set directly in the west. Day and night will be equal in length that day, and the days will grow progressively longer as summer approaches.

At nightfall, Jupiter shines radiantly in the southeast, an easy target for both eye and telescope. Through a telescope, our largest planet is a grand sight with its bands of clouds and four large orbiting moons. The moons' positions are constantly changing during the night. Jupiter is to the lower left of the Beehive Star Cluster, known as M 44. You may be able to get both in the same field of view with binoculars.

Saturn is highest to the south during the early part of the evening this month. Our old friend is not as bright as Jupiter, but more brilliant than any stars, except one. Saturn's rings are magnificent in a telescope as they present themselves at the maximum angle to our line of sight.

Mars is best seen shortly before the first light of dawn in the south-southeast, among the stars of Sagittarius. The red planet will continue to brighten as we move into the summer. Even now it outshines its rival star Antares, which is to its right, among the stars of Scorpius.

Venus is low in the east-southeast before dawn. It is noticeable because of its great brightness. The crescent moon is near it from the 27th to the 29th.

At best Mercury is very low in the east-southeast during the first few days of March.

At the planetariums

SCIENCE CENTER OF PINELLAS COUNTY: The Science Center (7701 22nd Ave. N, St. Petersburg) will present its Spring Festival on March 15 from 10 a.m. to 4 p.m. The festival will feature its 16th century Indian village and Hamlette the pot-bellied pig's 11th birthday fundraiser. There will be exhibits, laser shows and the new planetarium and observatory.

The center continues with the only telescope-making class in the Tampa Bay area on Saturdays from noon to 4 p.m. in the annex building (behind the main building). The St. Petersburg Astronomy Club, the oldest and largest in the Southeast, meets at 8 p.m. on the fourth Friday of each month at the center. Call (727) 384-0027 or visit www.sciencecenterofpinellas.com.

ST. PETERSBURG COLLEGE: The college planetarium at the St. Petersburg campus (Fifth Avenue and 69th Street N) offers free shows at 7 and 8 p.m. every Friday.

If the skies are clear, the telescopes will be set up to view the heavens at night. Don't miss Jupiter and Saturn in our evening sky. Call (727) 341-4320 for more details.

MUSEUM OF SCIENCE AND INDUSTRY (MOSI): The Saunders planetarium at MOSI (4801 E Fowler Ave., Tampa) continues Tampa's Tonight Show, giving a tour of the current night sky. The Challenger Learning Center offers "Journey to Mars" in the year 2076.

The IMAX Dome Theater presents Jane Goodall's Wild Chimpanzees, The Lion King, through the 4th, and Coral Reef Adventure. Call (813) 987-6100 or visit www.mosi.org for more events.

Sky calendar

TODAY: Very low to the east-southeast horizon, Mercury is just to the left of a very thin crescent moon before sunrise.

SUNDAY: New moon.

WEDNESDAY-THURSDAY: Mars is near the Trifid and Lagoon nebulae. You will need a good telescope to see the Trifid or Lagoon.

FRIDAY: Moon is at its greatest distance from Earth (apogee) at 251,893 miles.

MARCH 9: The red star Aldebaran is to the left of the moon at dusk.

MARCH 10: Saturn is to the upper left of the moon at dusk.

MARCH 11: First-quarter moon. Saturn to the lower right of the moon at dusk.

MARCH 12: Neptune less than the moon's width from Venus this morning.

MARCH 14: Jupiter to the right of the moon after sunset in the east-south east. Albert Einstein born in 1879. Zodiacal light may be visible in the west after dusk for the next two weeks.

MARCH 15: Spring Festival at the Science Center of Pinellas County starts at 10 a.m.

MARCH 18: Full moon of March is called the Sap or Crow Moon.

MARCH 19: Moon is closest to the Earth (perigee) at 223,580 miles.

MARCH 20: Vernal equinox occurs at 8 p.m.; spring starts. On this day we have the same number of hours of daylight and darkness. Isaac Newton died in 1727.

MARCH 21: Mercury in superior conjunction -- on the other side of the sun.

MARCH 24: Last-quarter moon.

MARCH 25: Mars to upper left of the moon before sunrise.

MARCH 28: The local astronomy club meets at 8 p.m. at the Science Center of Pinellas County. Uranus (not visible to the naked eye) is very close to Venus in the morning sky. Venus is to the left of the crescent moon just above the east-southeast horizon in the predawn sky.

MARCH 29: Look just before the light of dawn to find Venus to the upper left of the crescent moon. They are low in the east-southeast.

-- Daryl L. Schrader is an astronomy and mathematics professor at St. Petersburg College and teaches astronomy at the University of South Florida.

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