What's Up In the Sky Sept 2010
Post date: Aug 14, 2010 7:01:57 PM
On the night of August 19-20 the planet Neptune was at opposition to the Sun. That means you could draw a straight line from the Sun through Earth and on out to Neptune. It also means that Neptune came up at sunset and set at dawn, just like the full Moon. Neptune cannot be seen without using a telescope and is not always easy to find with one. It was the first planet to be found using math to predict it existed and that prediction became the center of an international incident.
In 1782 William Herschel discovered a new planet. Overnight Herschel had doubled the size of the known Solar System. The new planet, the seventh, had been named Uranus and now in 1846 it had nearly completed its first orbit since its discovery, however, something was wrong. Uranus's orbit had been calculated in 1821 by Alexis Bouvard and up until now it had followed the predicted path, but something caused Uranus to speed up and then slow down. It was felt among astronomers that the cause was still another large planet further out. According to Newtonian physics as Uranus drew near the slower moving body it would speed up, then slow down again after passing it. Two men, independently, set out to find it. In France Urbain Le Verrier, one of the finest astronomers in the world, could not get an observatory in his own country to search for the new planet. His help came from a young graduate, Dr. Galle, a subordinate at the Berlin Observatory which was ran by Professor Encke. To use a telescope to do research for Le Verrier, Galle had to get permission from Professor Encke, to do so without it would cost him his job. Galle was smart. He waited to ask for permission until Encke was in a rush to go home for his birthday celebration. After all, what his assistant did on that night didn't bother him at all. That night Galle and an assistant found the new planet with little difficulty near where Le Verrier said it would be. Now Galle had the pleasure of knocking on Professor Encke's door and at the height of the evenings celebration say, "We have just found Le Verrier's planet!"
It is said that Le Verrier's handwritten calculations covered 10,000 sheets of paper. Yet John Couch Adams who was more or less working in secret in Cambridge, England, on the same problem couldn't have used much less. To get someone to search for him Adams sent his calculations to the Astronomer Royal in Greenwich, Sir George Airy. In an odd coincidence Airy was in Berlin when Galle found the eighth planet. He apparently had never got to Adams' papers or had asked for some clarification that Adams never sent. Airy, after seeing Le Verrier's calculations, gave the go ahead to James Challis, the head of the Cambridge Observatory, to look for the new planet, which he found within a degree of Le Verriers's calculations and twelve degrees from Adams. So now Adams, upset with Airy, claimed he had discovered the new planet ten months before Galle. The scientific community of both France and England both wanted credit for the discovery. Sir George Airy was now despised in his own country. Eventually an international consensus was given that both Le Verrier and Adams deserved credit for the discovery. The new planet was given the name Neptune after the Greek God of the deep.
BUT WAIT! In 1998 historians rediscovered the "Neptune papers". These documents, which included Adams work, had been stolen from the Royal Observatory, Greenwich. After reviewing the papers it was decided that Adams didn't seem sure of his calculations and didn't deserve any credit at all.
Neptune's orbit around the Sun takes 165 years. On July 11, 2011, Neptune will complete its first full orbit since its discovery.
" cosomologist are often in error but never in doubt". Lev Landau, physicist.
Sept 01 Last quarter Moon.
The bright star Spica will have Venus on its left and Mars on its right in almost a line in the west at sunset.
4-5 Venus and Mars are now to the right of Spica.
08 New Moon
10 Look for Mars, Venus, Spica and the crescent Moon in thw western sky at dusk.
13 The bright star Antares is to the left of the crescent Moon.
15 First quarter Moon.
17-19 Jupiter and Uranus 0.8 deg apart in the constellation Pisces. The following nights, 20-21, they are at their closest approach to Earth.
Jupiter is at opposition on the 21ST.
23 Full Moon.
27 Look for the Pleiades to rise just after the waning Moon.
30 Last quarter Moon.