Friday, May 21, 2010

A Real Shooting Star



The Hidden Universe (Episode 13): Mira - A real shooting star!

The star Mira (Omicron Ceti) has kept a stunning secret that scientists have only just discovered in the glow of ultraviolet light.

This is the Hidden Universe of the Spitzer Space Telescope, exploring the mysteries of infrared astronomy with your host Dr. Robert Hurt.

When people say they see a shooting star after noticing a momentary streak of light in the night sky, what they really see are meteors burning up as they enter the Earths atmosphere—nothing to do with stars at all.

However, Mira, the star in this video, really is a shooting star—traveling at supersonic speed and trailing a glowing tail. Go ahead make a wish. You have some time to come up with a good one. The length of the tail and the speed of the star means it has been doing this for at least 30,000 years.

Mira (pronounced my-rah) is also known as Omicron Ceti. Mira is the only normal star known to have a tail. You cant even see Mira very well in the image because it is tiny compared to the tail. Mira is 350 lightyears from Earth. If you could see the star and its tail with your naked eyes, it would be as long as the width of four full Moons! The tail stretches an astonishing 13 light-years. If our Sun had a tail like this, it would reach far beyond the edge of the solar system and extend nearly three times further than Proxima Centauri, the closest star to the Sun. In fact, the 20 nearest stars to the Sun are closer than the length of Miras tail.

http://spitzer.caltech.edu/
http://spaceplace.nasa.gov/en/educato...

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