August 19, 2010

Neptune To Enter Opposition On Friday

Neptune will be in line with the Earth and the sun--a condition known as opposition--on August 20, bringing the planet a step closer to completing its first full orbit since being discovered.

The bluish-green planet was officially discovered on September 23, 1846, though it had been observed before then. In fact, according to, Galileo Galilei first observed Neptune in 1612, though at the time he believed it was a star.

In the 1840s, in response to a longstanding theory that a nearby planet was having a gravitational effect on Uranus' movement, Englishman John Couch Adams and Frenchman Urbain Le Verrier calculated where the mystery planet would be located.

It was a German astronomer who first actually located the new world by using a telescope to look at the predicted location calculated by Adams and Le Verrier. A debate ensued over who should get credit for actually finding the planet that would become Neptune, and in the end, all three scientists were listed as co-discovers of what was at the time and is once again the farthest planet from the sun (30 AU).

According to NASA, it will complete its first orbit in 2011.

Last month, a study that appeared in the journal Astronomy & Astrophysics determined that a comet had collided with Neptune roughly two centuries ago, thus causing higher concentrations of carbon monoxide in the upper atmosphere.

"The higher concentration of carbon monoxide in the stratosphere can only be explained by an external origin," Max Planck Institute for Solar System Research (MPS) scientist Paul Hartogh told Denise Chow of on July 26. "Normally, the concentrations of carbon monoxide in troposphere and stratosphere should be the same or decrease with increasing height."

The scientists based their findings off of observations made with the European Space Agency (ESA) developed Herschel infrared space telescope, which is said to be the largest and most powerful infrared telescope of its kind.


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