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  • Kansas Legislator Proposes Bill to Outlaw Sustainability Education
    A bill has been introduced in the Kansas legislature this week that would prohibit the promotion of ...Read more

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    Kansas Legislator Proposes Bill to Outlaw Sustainability Education

    A bill has been introduced in the Kansas legislature this week that would prohibit the promotion of sustainability. Here is a link to the one-page bill: http://www.kslegislature.org/li/b2013_14/measures/documents/hb2366_00_0000.pdf. See report on Bloomberg News.
  • Earth's Center Is 1,000 Degrees Hotter Than Previously Thought, Synchrotron X-Ray Experiment Shows
    Scientists have determined the temperature near the Earth’s center to be 6000 degrees Celsius, 1000 ...Read more

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    Earth's Center Is 1,000 Degrees Hotter Than Previously Thought, Synchrotron X-Ray Experiment Shows

    Scientists have determined the temperature near the Earth’s center to be 6000 degrees Celsius, 1000 degrees hotter than in a previous experiment run 20 years ago. These measurements confirm geophysical models that the temperature difference between the solid core and the mantle above, must be at least 1500 degrees to explain why the Earth has a magnetic field. For more information about this study, see the press release from the European Synchrotron Radiation Facility.
  • Ocean Volcanic Rocks Contain Samples of Recycled Crust
    Scientists have long believed that lava erupted from certain oceanic volcanoes contains materials fr...Read more

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    Ocean Volcanic Rocks Contain Samples of Recycled Crust

    Scientists have long believed that lava erupted from certain oceanic volcanoes contains materials from the early Earth’s crust. But decisive evidence for this phenomenon has proven elusive. New research from a team including Carnegie’s Erik Hauri demonstrates that oceanic volcanic rocks contain samples of recycled crust dating back to the Archean era 2.5 billion years ago. Their work is published in Nature. Oceanic crust sinks into the Earth’s mantle at so-called subduction zones, where two plates come together. Much of what happens to the crust during this journey is unknown. Model-dependent studies for how long subducted material can exist in the mantle are uncertain and evidence of very old crust returning to Earth’s surface via upwellings of magma has not been found until now. For more information about these results, see the press release from the Carnegie Institution.
This picture shows the shape and size of the orbit of Comet Wild 2. The comet's orbit is aqua. You can also see the orbits of Jupiter, Mars, and Earth.
Click on image for full size
NASA/JPL

Comet Wild 2

Comet Wild 2 is named after the scientist who discovered it. Paul Wild is an astronomer from Switzerland who discovered the comet in January 1978. Wild 2 is pronounced "Vilt 2".

The comet orbits the Sun once every 6.39 years, which is a pretty short time for a comet. Some comets take more than 100 years to go around the Sun one time! The comet's orbit is not a circle. Its orbit is shaped more like an oval, which astronomers call an ellipse. When the comet is at one end of the ellipse it is as close to the Sun as it gets. When it is at the other end, it is far from the Sun. The orbit of Wild 2 brings it a bit closer to the Sun than the planet Mars. The orbit also swings the comet out beyond the orbit of Jupiter.

When we see a comet from Earth, we actually see the dust and gas the comet gives off. The dust and gas form a fuzzy head called the "coma" and tails that are thousands of kilometers (miles) long. The solid part of a comet is called the nucleus, and is in the middle of the coma. The nucleus of Wild 2 is only about five km (three miles) across.

A spacecraft named Stardust flew by Comet Wild 2 in January 2004. I took some very nice pictures of the nucleus and gathered some dust samples. It will bring the dust back to Earth so scientists can study it.

Last modified January 11, 2006 by Randy Russell.

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As the ices of the comet nucleus evaporate, they expand rapidly into a large cloud around the central part of the comet. This cloud, called the coma, is the atmosphere of the comet and can extend for millions...more

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Comet Wild 2

Comet Wild 2 is named after the scientist who discovered it. Paul Wild is an astronomer from Switzerland who discovered the comet in January 1978. Wild 2 is pronounced "Vilt 2". The comet orbits the Sun...more

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