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Our home planet, the third from the Sun in the solar system. The Earth orbits the Sun at an average distance of 93 million miles (149 million km/1 astronomical unit) and has a mass of 6x10^24 kg. It is made of solid, rocky materials such as iron, nickel, and silicon, and it has an atmosphere composed mainly of nitrogen and oxygen with traces of argon, carbon dioxide, and other compounds. Liquid water covers 71 percent of the planet’s surface. Earth has one moon.


Earth’s Moon February 19, 2016


Earth February 10, 2016

Radio Programs

Far From the Sun Changing the distance to the Sun July 3, 2019

Pointing North Keeping us pointed in the right direction April 5, 2019

Supernova vs. Megalodon Supernova versus Megalodon February 15, 2019

Losing Weight A “global” weight-loss plan October 18, 2018

Moon and Companions Planets that pump up Earth’s orbit September 12, 2018

Steady On Changes in Earth’s magnetic field September 4, 2018

Round Earth Rounding off planet Earth September 3, 2018

Visiting Astronomers Where to see pioneering astronomers July 22, 2018

Catching Dust Catching dust in the stratosphere June 19, 2018

The Twins A goodly supply of twins January 26, 2018

Extremophiles Life in the most unlikely of places November 24, 2017

Far from the Sun Circling far from the Sun July 3, 2017

On the Move Racing across the universe June 10, 2017

Hydrothermal Vents A starting point in the search for life February 17, 2017

Moon and Planets Earth and the Moon move around January 3, 2017

Winter Solstice Winter and the laws of planetary motion December 20, 2016

Heating Up Heating up the young Earth September 23, 2016

New Helium A common but hard-to-find element September 10, 2016

Iron Rain Showering Earth with iron raindrops August 17, 2015

Noctilucent Clouds Electric-blue clouds in the twilight July 26, 2015

Leap Second Stretching out the month of June June 29, 2015

Second Generation A second generation of planets June 7, 2015

Oceans Gained Filling up Earth’s oceans June 4, 2015

Meteorites II Measuring the age of the solar system April 17, 2015

Twin Monsters Giving life to a classic story April 4, 2015

Close to the Sun Snuggling close to the Sun January 2, 2015

Featured Images

Grand Prismatic Spring, Yellowstone National Park

Extreme Life November 24, 2017

Combined X-ray and optical image of a supernova remnant

Zone of Death August 31, 2017

Cassini view of Earth, Moon, and Saturn's rings

Looking Back April 24, 2017

Artist's concept of Earth's distant future

Bright Future April 29, 2015

Supercomputer simulations of Earth's magnetic field

Twist and Flip April 8, 2013

Earth and Moon from International Space Station

Blue Moon? March 21, 2011

Sky view from space shuttle Discovery, February 2011

Nice View March 2, 2011

Earth is in the middle of the Sun's habitable zone

In the Zone January 18, 2011

Just Hanging Around January 11, 2010