Flash! Comet Hale-Bopp is not being escorted through the solar system by a hollow alien spacecraft four times the size of the Earth.
That's the bad news.
The good news is that the comet is on course for a spectacular springtime display. It should provide backyard astronomers with a nighttime show at least as good as the naked-eye appearance by Comet Hyakutake in March.
Hale-Bopp is sure to be the highlight of a 1997 astronomy calendar that also promises a near-total eclipse of the moon in March, and a striking lineup of planets in late December.
Comets are notoriously fickle. Comet hunter David Levy has compared them to cats: "They have tails," he said, "and they do precisely what they want."
But most observers say Hale-Bopp is continuing to brighten as it nears the sun. It should make a good appearance in the morning sky in February and early March, and in the evening by mid-March through April. Its closest approach to the Earth is March 23.
It caused quite a stir when it was first discovered in July 1995. Working independently, American amateurs Alan Hale and Thomas Bopp spotted the comet well beyond the orbit of Jupiter. And it already appeared 1,000 times brighter than Halley's Comet did at the same distance.
As it continued to brighten, astronomers began to speculate that Hale-Bopp would become one of the brightest, most spectacular naked-eye comets of the century.
The comet's buzz took an odd turn last month when an amateur astronomer in Houston announced on a radio talk show that he had spotted a strange "Saturn-like-object" alongside the comet that didn't appear on his computerized star charts.
Internet chatter soon twisted the discussion. Cyber-rumor had it that the comet was changing course under the influence of the giant object. The object itself became a gigantic alien spacecraft, four times the size of Earth and the source of radio transmissions.
The Space Telescope Science Institute in Baltimore was soon accused of conspiring to withhold photographs of the spacecraft shot by the Hubble Space Telescope.
Professional astronomers quickly countered that the "alien spacecraft" in the amateur's photo was actually a well-documented star. And space telescope scientists said Hubble has taken -- and published -- photos of the comet. They showed no alien spacecraft, nor have any other photos of the comet snapped by observatories around the world.
Hale-Bopp is believed to be an unusually large comet -- perhaps 25 miles across. By comparison, close-up photos of Halley's Comet in 1987 showed its icy core was only 5 to 10 miles across.
The extraordinary brightness, however, is probably due to vigorous emissions of dust and gas rather than to Hale-Bopp's size. As many as five separate jets have been photographed. Comet fans hope those emissions last until the comet's closest approach to the sun April 1.
Its long, 2,400-year obit around the sun will bring it no closer than 122 million miles from Earth. That's more than 10 times farther away than Comet Hyakutake's closest approach last year.
Photos and information on Comet Hale-Bopp are available on the Internet. Two good places to start are: www.skypub.com/ comets/comets.shtml or http: // newproducts.jpl.nasa.gov/comet/ other.html/
Here are some of the year's other astronomical highlights.
JANUARY: Earth is at perihelion (closest to the sun) at 7 p.m. EST on New Year's Day, just 91.4 million miles. The cold of winter is due to Earth's tilted axis, which keeps the sun low in the sky. Weather permitting on the 4th, you can watch the latest sunrise of the year at 7: 32 a.m. EST. On the 7th, get up before dawn to see the always-impressive sight of a crescent moon near bright Venus in the east.
FEBRUARY: A slow month, except for night owls looking for Comet Hale-Bopp in the hours before dawn. Look to the east. You should also see Jupiter and Venus there Feb. 6. They'll be huddled together barely a half-degree apart.
MARCH: On the 16th, Mars is at opposition -- on the opposite side of the Earth from the sun and therefore high in the sky at midnight. It will be just 61 million miles from Earth on the 20th. It's a relatively close pass and a good time for a look through a telescope.
Comet Hale-Bopp peaks this month. Look just below the W-shaped constellation Cassiopeia, low in the northwest evening sky after 7 p.m.
The Vernal Equinox occurs on the 20th at 8: 55 a.m. EST. On the 23rd, a near-total (92 percent) partial eclipse of the moon begins at 9: 58 p.m. EST.
APRIL: On the 3rd, Jupiter and the moon rise together after 3 a.m. The moon and Mars are paired on the 18th.
MAY: The Eta Aquarid meteor shower should be worth a look after midnight on the 4th. There's no bright moon to dim the show -- about 30 "shooting stars" per hour. On the night of the 16th, look for the moon near Mars.
JUNE: A month of extremes. The earliest sunrise (5: 43 a.m. EDT in Baltimore) occurs on the 14th. Summer arrives with the solstice at 4: 20 a.m. EDT the 21st. It's also the longest day of the year, with 15 hours and 1 minute of daylight at Baltimore's latitude. The latest sunset is on the 27th at 8: 43 p.m. EDT. Enjoy.
JULY. Earth is at aphelion (farthest from the sun) on the 4th. That's 94.5 million miles. It's also the day that NASA's Mars Pathfinder spacecraft and its tricycle-sized rover are due to land on Mars. They began their looping, 310-million-mile voyage in December. You can see Mars in the evening in the western sky; it sets just before midnight.
The moon flirts with Venus in the western sky on the evening of the 6th, and they repeat the evening rendezvous early each month for the rest of the year.
AUGUST: Jupiter is at opposition on the 8th, rising as the sun sets, and setting at sunrise. The moon passes Jupiter on the 17th -- worth seeing. The Perseid meteor shower (100 per hour) is the year's most reliable if the weather is clear. It peaks after midnight on the 12th. The moon will have set.
SEPTEMBER: On the 6th, look for reddish Mars just to the left of the moon in the evening sky. The next night, the moon will have moved above the Red Planet. The bright planet near the moon on the 13th is Jupiter. The full Harvest Moon rises on the 16th. Fall arrives with the autumnal equinox at 7: 56 p.m. EDT on the 22nd. The moon passes just above Saturn shortly before sunrise on the 18th.
OCTOBER: On the 5th, the moon and Venus are joined by Mars in the evening sky. Yellowish Saturn is at opposition on the 9th, the best time for a look. Rising at sunset, it's high in the southern sky by midnight, the only bright "star" in the area. Saturn's rings are a sight you won't forget. Find someone with a telescope and get a look.
The full Hunter's Moon shines on the 15th. Just after sunset on the 25th, Venus should be brilliant, low in the southwest near a much dimmer Mars.
NOVEMBER: The moon, Mars and Venus stand in a triangle in the southwest just after sunset on the 4th. The moon and Saturn are very close on the 11th. In the southern United States, the moon actually occults, or passes in front of the ringed planet. Mercury, Venus, Mars, Jupiter and Saturn line up in the west at sunset on the 28th, a warm-up for their year-end spectacular.
A year-end finale
DECEMBER: The earliest sunset of the year (4: 44 p.m. in Baltimore) occurs Dec. 7. The Geminid meteor shower peaks after midnight on the 14th. No moon will interfere. Winter arrives with the solstice at 3: 07 p.m. the 21st. It's also the shortest day of the year, barely 9 hours 20 minutes of daylight.
Venus shines its brightest on the 11th in the west just after sunset. It is joined by Jupiter and Mars for a brilliant Christmastime display. The light show gets even better New Year's Eve when the slender crescent moon enters the mix. That's bright Jupiter on the upper left, brighter Venus on the lower right, and Mars in the middle.
Invisible without a telescope, but lined up in the same part of the sky from our vantage point, are Mercury, Uranus, Neptune and Pluto. Only Saturn, alone in the southeast, is out of line. It is the last great lineup of planets in this century.
Pub Date: 12/31/96