Neptune’s (almost) full circle, sorry, ellipse..

According to Space.com, Neptune will be in opposition today. Big wow, I hear people say but tonight the planet will be returning close to the spot where it was discovered in 1846, marking its first complete trip around the sun since its discovery. It won’t actually complete its first orbit since being discovered yet until next year though

The planet Uranus was discovered more or less by accident in 1781 by Sir William Herschel, in the course of his search for deep sky objects. As time went by, Uranus' position wasn't quite what astronomer's predicted, and mathematical astronomers began to suspect that there was another planet out there whose gravity was influencing Uranus' motion.

In the mid-1840s an Englishman named John Couch Adams and a Frenchman named Urbain Le Verrier independently calculated where this new planet would have to be located to have the observed effect on Uranus, German astronomer Johann Galle actually looked at the predicted location and discovered the tiny blue-green disk of the planet that eventually came to be known as Neptune. The date was Sept. 23, 1846.

Well there you have it..... At least it gives me a less than gratuitous reason for putting up a pic of the planet!

There’s diamonds in them thar planets

Are you are a budding imperial overlord and have just taken purchase of your own Space Shuttle? Is threatening to level New York just too passé? Well it may need a few extra engines and a big oxygen tank but there may be treasure a plenty out in the outer solar system.
According to a new study published by Nature there may be diamond oceans filled with solid diamond icebergs, could be floating on Neptune and Uranus.

The research is based on the first detailed measurements of the melting point of diamond. It found diamond behaves like water during freezing and melting, with solid forms floating atop liquid forms.

"Diamond is a relatively common material on Earth, but its melting point has never been measured," says Dr Jon Eggert of the Lawrence Livermore National Laboratory in California. "You can't just raise the temperature and have it melt; you have to also go to high pressures, which makes it very difficult to measure the temperature."

The scientists liquefied the diamond at pressures 40 million times greater than what a person feels when standing at sea level on Earth. From there they slowly reduced the temperature and pressure.

When the pressure dropped to about 11 million times the atmospheric pressure at sea level on Earth and the temperature dropped to about 50,000 degrees solid chunks of diamond began to appear. The pressure kept dropping, but the temperature of the diamond remained the same, with more and more chunks of diamond forming. But the diamond did something unexpected.
The chunks of diamond didn't sink. They floated. he diamond was behaving like water.

An ocean of diamond could help explain the orientation of the planet's magnetic field as well, says Eggert. Roughly speaking, the Earth's magnetic poles match up with the geographic poles. The magnetic and geographic poles on Uranus and Neptune do not match up; in fact, they can be up to 60 degrees off of the north-south axis. A swirling ocean of liquid diamond could be responsible for the discrepancy.

I have no idea if this is a load of hooey but the idea of diamond icebergs... well it could go a long way to funding the intergalactic empire of your dreams!

Did Galileo beat Le Verrier to the discovery of Neptune?

Science Daily reports that a Melbourne physicist has put forward a theory that Galileo knew he had discovered a new planet in 1613, 234 years before its official discovery date.
Professor David Jamieson, Head of the School of Physics, is investigating the Galileo’s notebooks and believes that he discovered a new planet that we now know as Neptune.

Galileo was observing the moons of Jupiter in the years 1612 and 1613 and recorded his observations in his notebooks. Over several nights he also recorded the position of a nearby star which does not appear in any modern star catalogue.

"It has been known for several decades that this unknown star was actually the planet Neptune. Computer simulations show the precision of his observations revealing that Neptune would have looked just like a faint star almost exactly where Galileo observed it," Professor Jamieson says.
But a planet is different to a star because planets orbit the Sun and move through the sky relative to the stars. It is remarkable that on the night of January 28 in 1613 Galileo noted that the "star" we now know is the planet Neptune appeared to have moved relative to an actual nearby star."

There is also a mysterious unlabeled black dot in his earlier observations of January 6, 1613, which is in the right position to be Neptune. "I believe this dot could reveal he went back in his notes to record where he saw Neptune earlier when it was even closer to Jupiter but had not previously attracted his attention because of its unremarkable star-like appearance."

If the mysterious black dot on January 6 was actually recorded on January 28, Professor Jamieson proposes this would prove that Galileo believed he may have discovered a new planet.

"Galileo may indeed have formed the hypothesis that he had seen a new planet which had moved right across the field of view during his observations of Jupiter over the month of January 1613," Professor Jamieson says."If this is correct Galileo observed Neptune 234 years before its official discovery."

But there could be an even more interesting possibility still buried in Galileo's notes and letters."Galileo was in the habit of sending a scrambled sentence, an anagram, to his colleagues to establish his priority for the sensational discoveries he made with his new telescope. He did this when he discovered the phases of Venus and the rings of Saturn. So perhaps somewhere he wrote an as-yet undecoded anagram that reveals he knew he discovered a new planet," Professor Jamieson speculates.

Well there you have it.

Source: University of Melbourne (2009, July 9). Galileo's Notebooks May Reveal Secrets Of New Planet. ScienceDaily. Retrieved July 12, 2009, from http://www.sciencedaily.com¬ /releases/2009/07/090709095427.htm