Last modified: Tuesday, February 27, 2007
Total eclipse of the moon (finally!)
FOR IMMEDIATE RELEASE
Feb. 27, 2007
BLOOMINGTON, Ind. -- The world's first total eclipse of the moon since October 2004 will happen early in the evening on March 3. Totality will begin at 5:44 p.m. EST and end at 6:58 p.m. EST, allowing those in the eastern half of the United States a leisurely view.
The farther east you are, the better the view will be. In most of the Eastern and Central time zones, the full moon will rise in the east already fully eclipsed. Observers in the western part of the Central time zone will see the moon partially eclipsed as it gradually climbs above the horizon. Those farther to the west will see the moon nearly back to normal by the time it rises.
The moon is eclipsed when it passes into Earth's shadow. It can turn various unpredictable colors when that happens, ranging from orange and crimson to brick red. The moon's unusual color during a total lunar eclipse is caused by the light of sunsets and sunrises around Earth's rim being bent into Earth's shadow by the atmosphere (the same way a prism works). This orange light then reflects from the moon's surface the way sunlight normally does, making the moon appear anywhere from dark red to bright orange.
Weather can have darkening effects on the moon's color during an eclipse, and so can atmospheric pollution of various kinds. So an exact prediction of the moon's appearance is not possible.
The entire eclipse will be visible to skywatchers in Europe and Africa, who will have the best seats for this show. See the March issue of Astronomy magazine for details (http://www.astronomy.com/asy/default.aspx?c=a&id=5221).
Venus will dominate the western sky after sunset, a beacon in the west-southwest as the sun disappears. This beautiful "evening star" will be impossible to miss as the sky darkens. The interval between sunset and "Venus-set" will increase from about two and a half hours to three hours during March.
Saturn will be high in the east-southeast at nightfall, well placed for viewing with a telescope. The bright yellow planet will be conspicuous in the dim constellation Cancer the Crab, and its rings will be tilted toward us very favorably for the last time this decade. If you have access to a telescope, take advantage of this fine opportunity to see one of the traditional spectacles of our solar system. Check http://saturn.jpl.nasa.gov/home/index.cfm for the latest news and images from the Cassini spacecraft that is orbiting Saturn.
To the lower right (west) of Saturn will be the familiar bright stars of the constellation Orion the Hunter. The line of three bright stars in Orion's belt always points almost directly to Sirius to the left (east). Sirius is the brightest actual star in the sky of the Northern Hemisphere. In the other direction, the line of Orion's belt points upper right (west) toward the bright orange star Aldebaran. Keep going on the same line past Aldebaran and you'll reach the Pleiades star cluster, a beautiful sight in binoculars.
Jupiter will rise around midnight local time early in March and about two hours earlier by month's end. The best views of Jupiter with a telescope will be when the planet is well up in the southeast before the start of morning twilight. Its pale brilliance will contrast with the bright red-orange star Antares nearby on Jupiter's right (south).
Mercury will be a fine sight for observers in mid-southern latitudes when it reaches its maximum elevation on March 22, but for those in the north it will be close to the eastern horizon, visible only with binoculars shortly before sunrise.
Mars will continue to be low in the east during morning twilight for viewers at mid-northern latitudes during March, difficult to see in a telescope. It will rise little more than an hour before the sun throughout the month.
The sun will cross the celestial equator (an extension of Earth's equator onto the sky) on March 20 at 8:07 p.m. EDT (00:07 Universal Time on March 21) heading north. The March equinox marks the start of spring in the Northern Hemisphere and fall in the Southern Hemisphere. For the next six months in the Northern Hemisphere, the days will be longer than the nights.
Day and night are not precisely the same length at the time of the equinox. That happens on different dates for different latitudes. At higher latitudes in the Northern Hemisphere, the date of equal day and night occurs before the March equinox. In the Southern Hemisphere, this happens after the March equinox. Information about the exact time of the equinox at different places on Earth's surface is provided by the U.S. Naval Observatory at http://aa.usno.navy.mil/faq/docs/equinoxes.html.
The moon will be full on March 3, at third quarter on March 11, new on March 18 and at first quarter on March 25.