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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 is an example of early autotrophs.
Click on image for full size
Image courtesy of Corel Photography

Early Life

Over a very long time, gradual changes in the earliest cells gave rise to new life forms. These new cells were very different from the earlier heterotrophs because they were able to get their energy from a new source -- the Sun.

Organisms that are able to make their own food (in the form of sugars) by using the energy of the Sun are called autotrophs, meaning "self-feeders". Photosynthesis is the name of the process by which these autotrophs use energy from the sun and eat.

Because the autotrophic bacteria were able to feed themselves by using the energy of the Sun, they were no longer dependent on the same limited food supply as their ancestors and were able to flourish. Over millions of years of evolution, photosynthetic bacteria eventually gave rise to modern day plants.

The appearance of organisms capable of performing photosynthesis was very significant -- if it weren't for the photosynthetic activity of these early bacteria, Earth's atmosphere would still be without oxygen and the appearance of oxygen-dependent animals, including humans, would never have occurred!

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The Spring 2010 issue of The Earth Scientist, focuses on the ocean, including articles on polar research, coral reefs, ocean acidification, and climate. Includes a gorgeous full color poster!

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Traveling Nitrogen Classroom Activity Kit

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Photosynthesis

Photosynthesis is the name of the process by which autotrophs (self-feeders) convert water, carbon dioxide, and solar energy into sugars and oxygen. It is a complex chemical process by which plants and...more

The First Living Cells

The first beings were probably much like coacervates. As a group, these bacteria are called heterotrophic anaerobes (ann-air-robes). Because there was virtually no oxygen in the atmosphere at this time,...more

Kingdom Plantae

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The Archean

The Archean is the name of the age which began with the forming Earth. This period of Earth's history lasted a long time, 2.8 billion years! That is more than half the expected age of the Earth! And no...more

Iron Ore Deposits

Eventually, photosynthesis by the earliest forms of plant life (a form of life capable of feeding itself instead of feeding off of others) began to produce significant amounts of oxygen. One important...more

Extreme Environments

Extreme environments are places where "normal" life finds it hard to survive. That doesn't mean that there isn't any life in extreme environments. Certain creatures can live and grow in extreme environments....more

Extremophiles

Some environments are not good homes for most "normal" kinds of life. Places like that are called extreme environments. That doesn't mean that there isn't any life in extreme environments. Certain creatures...more

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The Winter 2010 issue of The Earth Scientist includes a variety of educational resources, ranging from astronomy to glaciers. Check out the other publications and classroom materials in our online store.

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