Earth

Earth, our home planet, is a beautiful blue and white ball when seen from space. The third planet from the Sun, it is the largest of the inner planets. Earth is the only planet known to support life and to have liquid water at the surface. Earth has a substantial atmosphere and magnetic field, both of which are critical for sustaining life on Earth. Earth is the innermost planet in the solar system with a natural satellite – our Moon. Explore our beautiful home planet – unique in our solar system - through the links in this section.

This iconic image of Earth rising above the surface of the <a href="/earth/moons_and_rings.html&edu=high&dev=1…">Moon</a>, was taken on December 24, 1968 by astronauts on the <a href="/space_missions/apollo8.html&edu=high&dev=1…">Apollo 8 mission</a>. Apollo 8 was the first <a href="/space_missions/manned.html&edu=high&dev=1…">manned mission</a> to the Moon, and entered into lunar orbit on Christmas Eve. That evening, the astronauts held a live broadcast from lunar orbit, in which they showed pictures of the Earth and moon as seen from their spacecraft.<p><small><em> Image courtesy of NASA</em></small></p>A new study has found that <a href="/earth/Atmosphere/airpollution_intro.html&edu=high&dev=1…">pollution</a> from <a href="/earth/Atmosphere/particulates.html&edu=high&dev=1…">fine particles</a> in the air - mainly the result of burning coal or <a href="/earth/interior/eruptions.html&edu=high&dev=1…">volcanic eruptions</a> - can shade <a href="/earth/Life/cnidarian.html&edu=high&dev=1…">corals</a> from sunlight and cool the surrounding water resulting in reduced growth rates. Coral growth rates in the Caribbean were affected by volcanic aerosol emissions in the early 20th century and by aerosol emissions caused by humans in the later 20th century. For more information, see the <a href="http://www.exeter.ac.uk/news/featurednews/title_278202_en.html">press release</a>.<p><small><em>Image courtesy of Toby Hudson (Wikimedia Commons)</em></small></p>Lunar eclipses are special events that only occur when certain conditions are met. First of all, the Moon must be in <a href="/the_universe/uts/moon3.html&edu=high&dev=1…">full phase</a>. Secondly, the <a href="/sun/sun.html&edu=high&dev=1…">Sun</a>, <a href="/earth/earth.html&edu=high&dev=1…">Earth</a> and <a href="/earth/moons_and_rings.html&edu=high&dev=1…">Moon</a> must be in a perfectly straight line. If both of these are met, then the Earth's shadow can block the Sun's light from hitting the Moon. The reddish glow of the Moon is caused by light from the Earth's limb scattering toward the Moon, which is reflected back to us from the Moon's surface.<p><small><em>Image credit - Doug Murray, Palm Beach Gardens, Florida</em></small></p>This is an artist's conception of the Earth and the inner and outer <a href="/glossary/radiation_belts.html&edu=high&dev=1…">radiation belts</a> that surround it. The Earth's radiation belts are just one part of the system called the <a href="/earth/Magnetosphere/overview.html&edu=high&dev=1…">magnetosphere</a>. The radiation belts of the Earth are made up of <a href="/physical_science/physics/atom_particle/electron.html&edu=high&dev=1…">electrons</a>, <a href="/physical_science/physics/atom_particle/proton.html&edu=high&dev=1…">protons</a> and heavier atomic ions. These particles get trapped in the <a href="/earth/Magnetosphere/earth_magnetic_field.html&edu=high&dev=1…">magnetic field of the Earth</a>. These belts were <a href="/earth/Magnetosphere/radiation_belts_discovery.html&edu=high&dev=1…">discovered</a> by James Van Allen in 1958, and so they are known as Van Allen Belts.<p><small><em>Courtesy of Windows to the Universe</em></small></p>Greenland's <a href="http://www.windows2universe.org/earth/polar/cryosphere_glacier1.html">ice sheet</a> saw a record <a href="http://www.windows2universe.org/headline_universe/olpa/greenland_10dec07.html">melt</a> in July 2012. Scientists studying this event have found that this melting event was triggered by an influx of unusually warm air and amplified by the presence of a blanket of thin low-level <a href="http://www.windows2universe.org/earth/Atmosphere/cloud.html">clouds</a> which pushed temperatures up above freezing. For more information see the <a href="http://www.news.wisc.edu/21638">press release</a> from the University of Wisconsin Madison.<p><small><em>Image courtesy of University of Wisconsin-Madison</em></small></p>As permafrost thaws, the land, atmosphere, water resources, ecosystems, and human communities are affected. Coastal areas and hillsides are vulnerable to erosion by thawing of permafrost. Thawing permafrost also causes a positive feedback to global warming, as carbon trapped within the once-frozen soils is released as <a href="/physical_science/chemistry/methane.html&edu=high&dev=1…">methane</a>, a powerful <a href="/earth/climate/cli_greengas.html&edu=high&dev=1…">greenhouse gas</a>. Watch the NBC Learn video - <a href="/earth/changing_planet/permafrost_methane_intro.html&edu=high&dev=1…">Thawing Permafrost and Methane</a> to find out more.<p><small><em>Image courtesy of the USGS</em></small></p>

Explore Earth

Earth's Interior and Surface

Earth, the largest and densest rocky planet, was formed about 4.5 billion years ago. The Earth's ...Read more

Atmosphere

The atmosphere is a mixture of nitrogen (78%), oxygen (21%), and other gases (1%) that surrounds ...Read more

Magnetosphere

The Earth has a magnetic field with north and south poles. The magnetic field of the Earth ...Read more

Moon

The Earth's one natural satellite, the Moon, is more than one quarter the size of Earth itself ...Read more

Earth's Polar Regions

Do you wonder what Earth's Polar Regions are like? Where do polar bears live? Where do penguins ...Read more

Climate and Global Change

Warm near the equator and cold at the poles, our planet is able to support a variety of living ...Read more

Water (The Hydrosphere)

Water is found in many places on Earth including on the surface of the planet, within rocks ...Read more

Life and Ecology (The Biosphere)

What is life? Why is there life on Earth, but not on any other planets in the solar system ...Read more

Natural Hazards

The United Nations estimated that between 1994-2015, there were 6,873 natural disasters worldwide, ...Read more

More about Earth

Historical Events

Full Earth and Space Science    History Calendar (Members only)

Teacher Opportunities

Full Teacher Events Calendar (Educator Members only)

Did you know?

Do you know what causes the different phases of the Moon?

Did you know that most of the Earth's clouds and weather are found in lowest level of the Earth’s atmosphere?

 

Earth and Space Science Concept of the Day

Do you know what this word or phrase means?

Seismogenic
xSeismogenic : Capable of producing earthquakes

Click on the word to find out!

Research Highlights

A Star Is Born... But How?

Created in the first three minutes after the Big Bang, hydrogen and helium gave rise to all other elements in the universe.  Stars made this possible. Through nuclear fusion, stars generated elements such...Read more


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