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The Earth: Top 10 Questions

April 2014

Thanks to Dr. Virginia Gillerman, Geologist, Idaho Geological Survey; and Dr. Jeffrey Johnson, Assistant Research Professor of Geophysics, Boise State University for their answers.

1: What are tectonic plates?

Tectonic plates are the rigid layers of rock that float on a hot and more fluid, semi-liquid rock underneath. They are constantly in motion and when one of them dives under the other, they can form mountain ranges and volcanoes. Tectonic plates are moving constantly, about the same rate a fingernail grows; but we cannot feel them. (From Billy at Anser Charter School in Boise)

2: How big is the Earth?

The Earth has a radius of 6,371 kilometers, or about 4,000 miles on average. It is similar to the distance from Idaho to New York and back. Also, the Earth has a radius that is bigger at the equator than at the poles. So it's really a sphere that is slightly squashed. (From Jameson at Riverside Elementary School in Boise)

3: Will Earth's continents ever meet again?

Over the last billion years, the Earth's continents have moved together and then been driven apart several times. Because of this, super continents have formed and over time those will break apart again. Like billiard balls, they hit each other and bounce off. It's like a slow-motion collision. Currently, India and Asia are coming together at a rate of a few inches a year. This is causing a continuing uplift seen in the growth of the Himalayan Mountains. (From Addison at Anser Charter School in Boise)

4: How was the Earth formed?

The Earth was formed about 4.6 billion years ago. It accumulated from interstellar gases and debris that grew into what we live on today. (From Aris at Cynthia Mann Elementary School in Boise)

5: How did gravity ever get to Earth?

Gravity is a force that exists any time you have mass. The larger the mass, the larger the gravitational force. Earth's mass is very, very large so we notice gravity, and this is why we don't float off into space. If we were to go to a larger planet, the gravitational force would be greater and we would weigh more. (From Allie at Spring Valley Elementary School in Durham, North Carolina)

6: What purpose do the layers of the atmosphere serve?

The atmosphere is critical for human life. It provides oxygen for us to breathe. It provides carbon dioxide, which plants breathe and use for photosynthesis. It also provides an ozone layer that helps to protect us from the sun's harmful radiation. We would not be here without the atmosphere. In addition, weather occurs in the different layers of the atmosphere. (From Kellan at Anser Charter School in Boise)

7: How does Earth's atmosphere compare to other planets'?

Earth's atmosphere is the best atmosphere that we know of for sustaining life. Other planets also have atmospheres, but many of them have much, much, thinner atmospheres than ours and none of them have oxygen, which is necessary for life as we know it. Venus is a planet that has a thick atmosphere, which is comprised of a lot of carbon dioxide. As far as we know, that is not a gas that is good for most types of life forms. (From Zoe at Anser Charter School in Boise)

8: Is it possible to live on another planet?

It would not be possible for humans to live on any of the other planets in our solar system because the planets do not have the right amount of oxygen in the atmosphere. Also, some of the planets are way, way too hot, and some are way, way too cold to support human life. (From Kyle at Dalton Gardens Elementary School in Dalton)

9: How does the atmosphere keep in oxygen?

Thi atmosphere has a very important role in keeping in the oxygen. Some of that is due to carbon dioxide and other gases in the atmosphere. Gravity, ultimately, keeps the atmosphere next to the Earth. However, we are losing oxygen due to travel outside of our atmosphere as well as oxygen that is absorbed by rocks. So it's a balance between oxygen being produced by plants and that which is lost. (From Indy at Anser Charter School in Boise)

10: How does a volcano shoot out lava?

Volcanic gases drive explosions and those gases can be steam, carbon dioxide and sulfur dioxide. Pressurized gases blow material out of a volcanic vent with more energy and more power than what is imaginable. (From Chloe at Hillcrest Elementary School in Boise)


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