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Possible tenth planet to add to astronomy course content

After the discovery of Sedna, a large object beyond the orbit of Pluto, scientists are wondering whether it can be classified as the Solar System’s tenth planet.

At Syracuse University, Carl Rosenzweig, an astronomy professor of the course AST 101, ‘Our Corner of the Universe,’ already addresses Pluto’s classification, and he said that this discovery will help to back up his arguments in class.

‘We discuss the role of Pluto, and this will reinforce the argument,’ Rosenzweig said. ‘What this will mean most importantly to the average person is to realize that Pluto itself is not a planet.’

The discussion of this new object will be added into the course, Rosenzweig said.

Not all of the astronomy courses at SU will be affected by this discovery. AST 101, ‘Our Corner of the Universe,’ mainly focuses around the solar system and the planets that make it up. The other astronomy course, AST 104, ‘Stars, Galaxies, and the Universe,’ discusses more about star formation and objects deeper in the universe.



Mark Trodden, who teaches an astronomy class, said that this discovery would not have much effect on what he teaches.

Rosenzweig, along with Dr. Michael Brown, the discoverer of Sedna and a professor at the California Institute of Technology, both said that as more discoveries like Sedna’s are made, it will become more and more confusing to decide what can be called a planet.

Instead of a planet, Brown said that he thinks that Sedna, discovered on Nov. 14, 2003 is just a very large body that is part of what is called the Oort cloud, Brown said in a press conference Monday afternoon. The cloud begins well beyond the orbit of Pluto and extends up to half the distance to the next closest star. Scientists believe that it contains comets but are not sure what else is there.

This would be the first object actually discovered while it was in the Oort cloud.

First hypothesized in 1950, little is known about the Oort cloud, and this discovery is helping to educate scientists about what it might be.

‘We would have never expected to find something in the Oort cloud as close as the object we have found here,’ Brown said. ‘We think this discovery shows us that indeed the Oort cloud extends much further and is much more massive than we would have ever thought before.’

Brown and his colleagues are proposing that they name the object Sedna, in honor of the Inuit goddess of the sea from who all sea creatures are derived.

‘Sedna lives at the bottom of the Artic Ocean in a very cold location, and we thought it was appropriate for an object that is this cold and this far away to be named after this Inuit creation goddess,’ Brown said.

Whatever Sedna is determined to be, anything that is discovered helps to further scientists’ understanding of the universe.

‘The more we can learn about objects that are so far away from the sun, the more we are learning about the nature of our solar system,’ Rosenzweig said.

Thus far, Brown said, Sedna is thought to be red in color, and very shiny, both of which were a surprise. It has been determined that the body is between 800 and 1,100 miles in diameter. The Hubble Space Telescope will also help to determine if Sedna has a satellite.

The object cannot be seen, even with very advanced amateur telescopes, however it is currently in the west-southwest sky between the Orion constellation and Venus.

Currently the object is 8 billion miles away from the sun, which is almost three times the current distance of Pluto. It only gets farther. In its 10,000 year orbit, it travels up to 84 billion miles away from the sun.

‘There is absolutely nothing else like it known in the solar system,’ Brown said.





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