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Wednesday 4 January 2012

The 2012 Quadrantid meteor shower Live feed from NASA



The new year is kicking off with some cosmic fireworks: The 2012 Quadrantid meteor shower will peak in the predawn hours this Wednesday.
The Quadrantids are mostly visible from the Northern Hemisphere, where the sky show happens in the dead of winter. Observers in the Southern Hemisphere generally see very little, if any, of this shower.
The Quadrantid shower is considered one of the best meteor showers of the year, with average rates of one shooting star a minute visible from dark locations.
Even from the suburbs, observers can expect to see "as many as 40 Quadrantids per hour on the morning of January 4 and, if you are fortunate, that rate could even be higher," said Jim Todd, planetarium manager at the Oregon Museum of Science and Industry.
According to Todd, the "best views will be from North America in the early morning, when the waxing gibbous moon will set by around 3 a.m., leaving a few hours of unobstructed viewing before dawn."
When these sand grain-size particles enter Earth's atmosphere, they burn up and superheat the air around them, creating the characteristic streaks of light.
Astronomers can trace the debris clouds of many meteor showers back to the comets that created them. But for years after the Quadrantids were discovered in the 1800s, scientists couldn't find a source.

Meteors Named for "Lost" Constellation
As with most other meteor showers, the Quadrantid shower gets its name from the constellation from which the meteors appear to radiate, Quadrans Muralis.
However, you won't find this particular pattern of stars in modern sky maps: Overcrowded star charts necessitated the removal of the 19th-century constellation in 1922. Astronomers instead decided to have its stars absorbed by the neighboring constellation Boötes, the Herdsman.
It's likely, Todd said, that astronomers at the time decided to maintain the name of the Quadrantid meteor shower to avoid any confusion with the already established Bootid meteor shower, which peaks in late June.
In addition, the parent object for the Quadrantids remains somewhat of a mystery.
Most annual meteor showers occur when Earth slams into large clouds of particles left behind by passing comets. As the bodies get close to the sun, the heat vaporizes their ices, releasing trapped debris.
When these sand grain-size particles enter Earth's atmosphere, they burn up and superheat the air around them, creating the characteristic streaks of light.
Astronomers can trace the debris clouds of many meteor showers back to the comets that created them. But for years after the Quadrantids were discovered in the 1800s, scientists couldn't find a source.