Wednesday, March 17, 2004

A new world leading to new knowledge


Scientists announced the discovery of a new world this week, a tiny bit of ice and rock far out beyond Pluto.

Sedna, named for an Inuit goddess of arctic creatures, is a place most of us never will see. It is 8 billion miles from Earth, and its orbit sometimes takes it 84 billion miles from the sun. It is visible only with a very powerful telescope. If you were able to stand on its surface, the sun would appear to be so tiny that you could block it out with the head of a pin.

But as far away as it is, Sedna is as exciting a discovery as sailing across the ocean and bumping into a new continent. Astronomers believe it could be a remnant from the earliest days of our solar system. It is an unchanged and untouched piece of our creation from billions of years ago.

The discovery of Sedna, officially designated 2003 VB12, was announced Monday by scientists of the California Institute of Technology's Palomar Observatory. It was first seen as a pinprick of light last November by a telescope at the California observatory that is methodically searching the sky. Once it was determined that the pinprick moved over time, it was tracked and confirmed by other astronomers in Arizona and Chile.

Sedna is the coldest, furthest place from Earth yet discovered in our solar system. The high temperature there is estimated at about 400 degrees Fahrenheit below zero. It was the cold that prompted discoverer Mike Brown and his colleagues to name it Sedna, after the goddess who was said to live in a cave beneath the Arctic Ocean. In legend, Sedna sustains humanity by providing whales, seals and walruses for food.

This Sedna may sustain us with knowledge and future discoveries. Learning more about what it is made up of could provide valuable information about how the solar system formed, Brown said. Its long, elliptical orbit loops it around the sun only about once every 10,500 years. That means the last time it was this close, Earth was going through its last ice age. One of the most intriguing aspects of Sedna is that its existence is a strong indication of other, as yet unseen, bodies in the solar system. Its wildly erratic orbit is believed to be caused by the gravitational pull of a far larger planet orbiting even further out there. It is clear that this voyage of discovery is just beginning.

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