POST-ECLIPSE UPDATE: Others from the Western US and other parts of the world were treated to a marvelous eclipse. See a growing gallery of images at SpaceWeather.com.
On the morning of Saturday, December 10, 2011 there will be a total lunar eclipse. While much of North America will be in a position to see this natural wonder, those of us east of the Mississippi are pretty much completely out of luck! Timing is everything in this case.
Those who have seen total lunar eclipses know that they are wonderful astronomical experiences. They occur when the Moon passes through the shadow Earth casts out into space, away from the Sun. The colors of Earth’s sunrises and sunsets act as filters giving the darkened Moon hues ranging from copper tones to deep red. Lunar eclipses are safe to view (never any brighter than the full Moon), don’t require telescopes or special optics to enjoy, and are visible over a wide area.
Total lunar eclipses can only happen when the Moon is in its Full phase –on the opposite side of Earth from the Sun– which often results in local observers seeing only part of the event. Locally we might see the beginning or end of an eclipse, or be totally out of luck because the Moon has set and the Sun has risen. On rare occasions at a given locale, the entire eclipse cycle, covering a period of several hours, can be seen; those eclipses take place in the mid-night hours rather than just before Sun- or Moonrise.
For those of us in Northeastern Ohio, the December 10 eclipse will barely have begun when the Moon sets just as the Sun rises. The thin shade of Earth’s outer shadow or penumbra will only just have begun to cover our Moon as it sets slowly in the west. Those on the West Coast will be able to enjoy more of the show, being a few hours behind our time.
In today’s world of Internet-connected telescopes and Web broadcasts there will be opportunities for remote eclipse watching. Learn more and possibly watch a “webcast” at the following URLs:
The CAA will host their last program and star party of the year for the Medina Park District Saturday, Nov. 12, starting at 8 PM at the Letha House building.
Club president William Murmann will give a presentation about the European Southern Observatory at 8 PM, followed by a public star gazing program if sky conditions permit.
If the skies are clear, observers will see the 17-day waning Moon offering great edge-of-terminator views of some large craters on the eastern limb including floor-fractured Petavius.
Io should be crossing Jupiter around 9:30 that moon casting its shadow on Jupiter’s cloud tops — a good target for larger scopes. All of the Galilean Moons will be visible. The Pleiades and Hyades star clusters will be up, and Orion will be rising in the east.
Club members are asked to please bring their telescopes and join in the star party.
Tuesday, Nov. 8 at about 6:28 PM, a space rock a little over 1,300 feet in diameter will pass within about 202,000 miles of Earth. It will not hit our home planet nor will it have any other effect on us; it’s just passin’ through. Designated 2005 YU55, it is a potentially hazardous asteroid because of its size and near-Earth orbit. It was discovered on December 28, 2005 by Robert S. McMillan at Steward Observatory, Kitt Peak, Ariz.
The main reason the flyby is known to the public is that this large asteroid will be closer to us than is our own Moon and that’s a neat science headline. When good-sized asteroids come close to Earth, news of the event has different effects in different quarters.
Amongst astronomers asteroid fly-bys offer an excellent opportunity to study small “worlds” usually too far away to see clearly with telescopes. NASA and other agencies are already scanning the space rock with high-powered radar systems in an effort to learn more about the object. The data can be used to learn something about the texture and composition of the object and a bit about its history. The asteroid’s orbit will also be highly refined through tracking by observers from around the world allowing improved prediction of its future movements.
Amongst conspiracy and doomsday fanatics, the close passage is another opportunity to spread FUD (Fear, Uncertainty, and Doubt) through pseudoscience and false prophesy. The Web is abuzz with gloom, doom, and gobs of misinformation already. What will they be saying Wednesday morning after 2005 YU55 has floated clean by Earth and left us unscathed? Those folks do have rich imaginations.
Here are some facts about our visitor from space and asteroids in general:
The word asteroid literally means “star-like object.”
Asteroids come in sizes ranging from small stones to a body about 3,300 feet in diameter: Ceres, the largest known object of that type.
The last time a space rock as large as 2005 YU55 came as close to Earth was in 1976, although astronomers did not know about the flyby at the time. The next known approach of an asteroid this size will be in 2028.
Asteroid 2005 YU55 will pass through the constellations Aquila and Pegasus glowing like an 11th magnitude star (very dim) when closest, not visible to the unaided eye. You’d need a good-sized telescope and clear dark skies to see the tiny star-like object.
This asteroid orbits the Sun, roughly as close as Venus to as far away as Mars. Along the way it crosses Earth’s orbital path, one factor that makes it potentially hazardous.
Large asteroids pass closer to Earth than the Moon about every five years; smaller ones pass close more frequently and often enter Earth’s atmosphere.
Asteroids nearly the size of a house collide with Earth about once a year with no harmful effects to us — they ordinarily explode in the upper atmosphere and the fragments burn up.
Though a good-sized ball of rock, 2005 YU55 does not have enough mass to have any gravitational effect on Earth.
Asteroid close-encounters do not cause earthquakes, high tides, or any other geological or weather events.
Asteroids are cataloged, their orbits calculated, and the objects tracked regularly both for scientific study and planetary protection ends. Those data are publicly available and often incorporated into home astronomy software.
The approach of asteroids cannot be kept secret. They are “out there” and potentially visible to all who care to look. Any truly dangerous situation would quickly be confirmed by scientific authorities from around the world.
Asteroids are but one small part of our fascinating solar system. Enjoy the real adventure and wonder of our corner of the universe that is yours through astronomy!