Last modified: Friday, May 1, 2009
STAR TRAK
Six planets and a meteor shower make good viewing in May
FOR IMMEDIATE RELEASE
May 1, 2009
As evening twilight fades, look high in the south to find Saturn in the constellation Leo the Lion. The bright yellow planet will be escorted by Leo's brightest star, Regulus, to the right (west).
Saturn's rings are slightly tilted toward us, but after this month they will begin closing toward edgewise. When Galileo first turned his telescope on the night sky, he saw that Saturn had a different shape from the other planets -- an odd oval appearance -- but the optics of his time were not good enough for him to see the cause. He described Saturn as having "handles." Several decades later, the Dutch astronomer Christiaan Huygens used a better telescope to determine that the planet was actually a sphere with a ring around it.
As Saturn sinks low in the west, Jupiter will rise in the east around 3 a.m. local time at the beginning of May and two hours earlier by month's end. The huge planet will dominate its part of the sky, far outshining the stars of the constellation Capricornus the Goat. The best view with a telescope will be in the hour or so before dawn, after Jupiter climbs higher in the southeast.
On May 25, a telescope or binoculars will show the much dimmer planet Neptune about a half degree north of Jupiter.
Venus and Mars will be low above the eastern horizon at dawn all month, rising within 20 minutes of each other. Venus will be more than a hundred times brighter than Mars, outshining everything in the sky except the sun and moon. You may need binoculars to see the pale orange speck of Mars a few degrees to the left.
Meteor shower
This month, Earth will encounter a stream of dust left behind in space by Comet Halley, causing the Eta Aquarid meteor shower that will peak before dawn on May 6. The shower will be active for a few days before and after the peak as well. The meteors will appear to come from a point called the radiant in the constellation Aquarius, which will rise in the east about two hours before the start of morning twilight. The higher this point is above the horizon, the more meteors will be visible. The moon will be full on May 9, so meteor-watching around that time may be spoiled by bright moonlight. In the Northern Hemisphere, the Eta Aquarid radiant will be low in the east-southeast at 4 a.m. local time after the moon has set. The radiant will be three times higher in the Southern Hemisphere, and observers may see anywhere from 30 to 70 meteors per hour.
Space junk
Orbiting space junk can pose a serious risk to manned shuttle launches, satellites, the International Space Station and the Hubble Space Telescope.
"The threat posed by orbital debris to the reliable operation of space systems will continue to grow unless the sources of space debris are brought under control," said Nicholas Johnson, NASA chief orbital debris scientist.
In the past 30 years, the amount of space traffic has quadrupled as more satellites and other devices orbit Earth. A collision between two satellites in February increased space debris even more. The U.S. Space Surveillance Network is actively tracking more than 19,000 objects at least four inches in size, and there are 300,000 objects about a half-inch in size or larger circling Earth.
Moon phases
The moon will be at first quarter on May 1, full on May 9, at third quarter on May 17, new on May 24 and at first quarter again on May 30.
