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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.
This image shows different objects that rotate. Rotational period is the time it takes for that object to rotate just once.

Rotational Period

Rotational period is the term describing the length of time necessary for a space object to make one complete rotation. This time varies from planet to planet, and on Earth it is 1 day.

This length of time is not always constant, and in fact the Earth’s rotational period is slowing (by 0.002 seconds every hundred years). This is because of the Moon’s influence on our rotation.

One planet that has already slowed down a lot is Venus. Scientists think this is because a long time ago something big hit Venus and slowed down its rotation. Now, Venus spins so slowly that it revolves around the Sun faster than it spins on its own axis. That means that a Venus day is longer than a Venus year!

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Our online store includes fun classroom activities for you and your students. Issues of NESTA's quarterly journal, The Earth Scientist are also full of classroom activities on different topics in Earth and space science!

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Traveling Nitrogen Classroom Activity Kit

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

AU

AU stands for Astronomical Units. It is a useful way to measure the distances in interplanetary space. It is the distance between the Earth and the Sun, which is about 93 million miles. For reference,...more

The Spiral of the IMF

The solar wind is formed as the Sun's top layer blows off into space, carrying magnetic fields still attached to the Sun. Gusts form in the solar wind associated with violent events on the Sun. Particles...more

Spiral Path of Material

For a planet to be affected by a blob of material being ejected by the sun, the planet must be in the path of the blob, as shown in this picture. The Earth and its magnetosphere are shown in the bottom...more

The SAR Arc

The aurora we are most familiar with is the polar aurora. This is what people are talking about when they say the northern or southern lights. But there are other less-known aurora, such as SAR arcs....more

The Effect of Aurora on the Atmosphere

This figure shows the effect of the aurora on the atmosphere. When FAC's enter the atmosphere and create the aurora, they heat the atmosphere suddenly and abruptly. This creates an impulse which travels...more

The forming Aurora

This picture shows the flowing of particles into and out of the auroral zone, as Field-Aligned currents (FAC's) take at short-cut through the atmosphere. Some of the particles entering the auroral zone...more

The Expanding Auroral Oval

This figure shows a series of images of the auroral oval as it expands over the course of about an hour in response to a geomagnetic storm. This is an animation of the auroral oval expanding....more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA