February 2009

Comet Lulin Visible Tonight

Comet Lulin, a beautiful green comet with a double tail is fast approaching Earth. Tonight, and the wee hours of Tuesday morning, right around 1 AM, are you best bets for a view. You'll be able to spot Lulin, with the naked eye, barely, in rural areas without light pollution, but a decent pair of binoculars or a backyard telescope will work just fine for a great view. You'll want to look in the southwestern sky about 40 degrees above the horizon near Saturn, which should be fairly bright and easy to spot. The diagram here has a circled X to show the relative position of Lulin at about ten pm in North America on the Monday night, February 23, tonight.

Cosmic Music

Like many laymen with a passing interest in the epic scales and strange phenomena outside our little planet's atmosphere, there are things out there that I find both fascinating and frightening. Among them are those unusual events that do funny things with the electromagnetic spectrum. Since the invention of the telescope, people have been used to the idea of visually observing the cosmos. More recent inventions also allow us to detect energy emissions in the universe via audible signals as well. Some of them can be downright musical. Here are few to consider: Dawn Chorus If you downloaded from the above link, what you're hearing is known as "Dawn Chorus". It is phenomenon believed to be related to electrons as they pass through Earth's Van Allen Belts. It gets its name from a behavior of common song birds to begin chirping in distinct tones when they are first exposed to sunlight in the morning.

Dark Comets

A couple of UK based astronomers just suggested a rather chilling idea that seems to have found favour with the astronomical community. Bill Napier at Cardiff University and David Asher at the Armagh Observatory have claimed that there could be thousands of dark, dormant comets which we cannot see. With scientific estimates placing the likely number of comets in our solar system at around the 3000 mark, and with only 25 accounted for, the theory seems to be a very real possibility. Various space agencies are engaged in a project to try and monitor potentially threatening comets and asteroids. The group effort is known collectively as Spaceguard and many of the leading figures have agreed there may well be a number of dark comets. Dark comets reflect less light than the bright kind because they have no surface water and absorb sunlight. In fact another scientist, Clark Chapman, from a Research Institute in Colorado has suggested that they could possibly be detected because of the heat they emit.

Orbital Collision Sprays Space Junk Everywhere

For years now, experts have been warning about the danger of collisions with space junk in Earth orbit. There is so much "stuff" rattling around up there, both working and not, that it is almost inevitable that a collision will occur. On Tuesday, the first such major collision happened, between an Iridium communications satellite and a Russian satellite. The collision occurred 490 miles above Siberia, and the resulting bits of broken satellite briefly posed a serious threat to the International Space Station, until it was shifted into a higher orbit. The risk to the ISS is now judged as "very small" by a NASA spokesperson. The American satellite, part of the Iridium Satellite network (used to provide mobile phone service to people who roam outside cell phone networks - for example, to Antarctica), is described as weighing about 1,200 pounds, with a body that was 12 feet long (not counting the various rays and antennas). The Russians have not yet released information about their satellite which was destroyed.

M51 Whirlpool and Friend

This is another of my favorite Hubble images, taken in January of 2005. It's an image of the Whirlpool Galaxy, NGC 1594, better known as M51, and, just to its right, its much smaller companion galaxy, NGC 5195. Sometimes the two galaxies are referred to as M51a and b.Technically, the image to the right is a four-color mosaic, composed of 96 slightly overlapping images taken with four different filters (hence the lovely colors). The Whirlpool galaxy, as its name and image suggests, is a spiral galaxy, like Earth's own Milky Way.

Corot Exo 7b Discovered

A French team of astronomers have recently announced the discovery of a new planet. Spotted by their exo-planet hunter, the Corot Satellite, which was launched back in 2006, the new planet has been dubbed Corot Exo 7b. There have been more than 300 so-called exo-planets discovered in our solar system since 1995 but 7b sticks out because the majority of them are gas giants and it appears to be just 1.75 times the width of Earth and is believed to have a similar mass. Speculators have suggested it may be made of rock or water although it may also be composed of liquid lava. Best not to start booking holidays there just yet since the planet is extremely close to its parent star which would put the temperature on the surface at between 1000 and 1500 degrees Celsius. It also orbits the star once every 20 hours and it is 457 light years away from us. Some experts have suggested that it may have begun life as an ice planet and become a water world as it approached the star and began to heat up. The Corot satellite managed to detect the planet by looking for dimming light as it crossed in front of the star, so they basically saw a small silhouette.