Geminid Skies over Crestone

A Geminid Fireball December 2009. (Note that the meteor passes through the lower half of Orion, below the three stars of the belt and near the sword). photograph by Wally Pacholka in the Mojave Desert) .

by Kim Malville

Almanac

December 2: Jupiter will be in opposition to the Sun, rising at sunset, reaching its highest at midnight, and setting at sunrise. This will be one of the closest passages to Earth in Jupiter’s 12-year orbit, and the giant planet will dominate our night skies. Jupiter will be in Taurus, above Aldebaran, the blood-shot eye of the Bull. It will be moving retrograde (to the west) at its fastest rate.

December 9: For those with a good view of the eastern horizon, look about one hour before sunrise and admire Mercury and Venus. Venus will be brilliant and impossible to miss. Mercury will be to its lower left, close to the horizon.

December 13-14: Geminid meteor shower.

The Geminids are a new shower, first observed in 1862. By comparison, the Perseids, which are produced by a comet, have been viewed by Boy Scouts and others before them since 36 CE. The number of Geminids has been increasing year by year, and this year there may be as many as 120 per hour. It’s a particularly good year because the shower occurs near the dark of the moon. The best time for observing will be between 10 pm and dawn. Climb into a sleeping bag or better yet two sleeping bags, and find a comfortable reclining chair. The color of the meteors should be yellow, and they will be coming out of the east from the constellation of Gemini.

December 21: Solstice occurs at 4:12am local time, the beginning of winter in the northern hemisphere and summer in the southern hemisphere. Baktun 14 starts at this time, but no catastrophe is anticipated by astronomers or Mayan scholars. Predictions of impending doom are not found in any of the Mayan accounts when the world passes from Baktun 13 to Baktun 14. The Baktun cycle of time encompasses 144,000 days or 394.26 years. The years just keep cycling:  there is no end in sight for these Baktun cycles. The idea that the end of Baktun 13 heralds the end of the world misrepresents Maya history and culture. In fact, living Mayan communities condemn these predictions as the self-serving promotions of travel agencies and greedy doomsday authors.

December 25: About an hour after sunset look for the moon and Jupiter in close conjunction.

Rubble piles and meteors

Most meteor showers are produced by disintegrating comets. The Geminids, on the other hand, come from an asteroid, often loosely held together clumps of rock, dust, and ice. An example of such a rubble pile is asteroid Itokawa, photographed by a Japanese remote probe. Around 1862 something happened to the Geminid asteroid: it was hit by another asteroid or started spinning and particles were thrown out, some of which will stream into the earth’s atmosphere.

The end of the world, Baktun style

Every year, on the December solstice, the Sun and the Milky Way, as viewed from the surface of the Earth, appear to come into alignment. Precession of the earth’s axis of rotation causes a slight shift in the location of the sun relative to the Milky Way. The sun at December solstice came closest to the center of the galaxy in 1998, and nothing disastrous happened. But doomsdaysayers continue to be hopeful and claim that on 21 December 2012 the gravitation effect of sun combined with that of the massive black hole in center of the galaxy will create havoc on Earth.  Despite the facts that the alignment already happened in 1998, some folks are still hopeful. The supermassive black hole is 27,000 light years away and would have to be more than 6 million times closer to cause any gravitational disruption of the solar system. These dire threats were discussed in a rather strange and unreliable History Channel documentary, Decoding the Past, which John Major Jenkins has described as “45 minutes of unabashed doomsday hype and the worst kind of inane sensationalism”.

The black hole in the center of the galaxy

At the center of our Milky Way Galaxy, 27,000 light-years away, lies the black hole with 4 million times the mass of the Sun. The Milky Way’s black hole, a gentle giant, is mild-mannered compared to the central black holes many some galaxies that contain billions of solar masses and eat up huge numbers of stars. Our black hole consumes an occasional star, an unlucky planet or a comet, but most of the time it goes hungry. From time to time it does produce modest burps of X-rays. An outburst lasting several hours was recently observed in July by the freshly launched NuSTAR satellite. Just like its gravity, the x-rays from the center of the galaxy will have no effect on earth because of the immense distance of the black hole.

The most distant galaxy in our universe

Speaking of great distances, the most distant object yet seen in our universe has just been found with the aid of a naturally occurring cosmic zoom lens. The new record holder is a galaxy that is about 13.3 billion light-years away, far, far away in space and time. The universe itself is only 13.7 billion years old, so this galaxy’s light has been traveling toward us for almost the whole history of space and time. It has been detected with the natural process of gravitational lensing. This lens is a huge cluster of galaxies whose collective gravity warps space. Light follows the curved lines of space and is concentrated, just like a lens concentrates sunlight and can start a fire. The galaxy was formed when the universe was only 420 million years old: not old enough for life to have started on any of its planets. We are going to have to wait another 13.3 billion years before we know what is happening on that galaxy this year. It probably doesn’t exist.