Current Events

  • 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

    x

    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

    x

    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

    x

    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 is a drawing of how a comet behaves as it passes by the sun.
Click on image for full size
JPL

The Perihelion Passage of a Comet

Comets are disturbed from their orbits in the Oort Cloud and begin a passage into the solar system, spinning and tumbling as they come. The trajectory which they acquire can be hyperbolic, parabolic, or elliptic in shape. Only if a comet acquires an elliptic trajectory will it make repeated passes to the sun, as does Halley's comet every 76 years.

As the comet comes closer to the sun, near the region of space occupied by Mars it becomes warm enough for the comet to begin to evaporate. When evaporation begins, the coma and tail form.

This picture shows that, once the tails forms, it always points away from the sun. That means that the tail will point in different directions at different places in the comet's orbit.

Shop Windows to the Universe Science Store!

Learn about Earth and space science, and have fun while doing it! The games section of our online store includes a climate change card game and the Traveling Nitrogen game!

Windows to the Universe Community

News

Opportunities

You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

The Comet Coma

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

It's Time Again for the Leonids!

There have been predictions that this year's Leonid meteor shower could turn out to be one of the most spectacular sky events of the 21st century. The peak of this meteor shower should occur in the early...more

Comet Wild 2

Comet Wild 2 is a short-period comet that orbits the Sun once every 6.39 years. A Swiss astronomer named Paul Wild discovered it on January 6, 1978. Wild 2 is pronounced "Vilt 2". The comet comes about...more

Trans-Neptunian Objects (TNO)

There are many icy and rocky planetoids on the outer edge of our Solar System. As a group, all bodies that orbit, on average, further from the Sun than the 8th planet Neptune are called Trans-Neptunian...more

Orionid Meteor Shower

The Orionid meteor shower is one of several major meteor showers that occur on roughly the same date each year. The Orionids typically "peak" (are at their greatest level of activity) around October 21st....more

Leonid Meteor Shower

The Leonid meteor shower is one of several major meteor showers that occur on roughly the same date each year. The Leonids typically "peak" (are at their greatest level of activity) in mid to late November....more

Geminid Meteor Shower

The Geminid meteor shower is one of several major meteor showers that occur on roughly the same date each year. The Geminids typically "peak" (are at their greatest level of activity) in mid December....more

Shop Windows to the Universe

Please help support Windows to the Universe, and our activities to help Earth and space science teachers, with a tax-exempt donation today!

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF