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.

A sinuous glowing band of <a href="/earth/Magnetosphere/aurora.html&dev=1/earth/Atmosphere/moons/transport.html">aurora</a> (the Aurora Australis or Southern Lights) loops around the <a href="/earth/polar/polar_south.html&dev=1/earth/Atmosphere/moons/transport.html">southern polar</a> region in the distance as viewed by astronauts onboard the space shuttle on <a href="http://www.nasa.gov/mission_pages/shuttle/shuttlemissions/archives/sts-39.html">STS-039</a>. <a href="/earth/Magnetosphere/aurora/aurora_colors.html&dev=1/earth/Atmosphere/moons/transport.html">Aurora are produced</a> when <a href="/physical_science/physics/atom_particle/particle_radiation.html&dev=1/earth/Atmosphere/moons/transport.html">energetic particles</a> entering the Earth's atmosphere from space interact with <a href="/physical_science/physics/atom_particle/atom.html&dev=1/earth/Atmosphere/moons/transport.html">atoms</a> and <a href="/earth/geology/molecule.html&dev=1/earth/Atmosphere/moons/transport.html">molecules</a> in the atmosphere and release energy, emitted as light.<p><small><em>Courtesy of NASA, Astronaut Overmeyer and Dr. Hallinan</em></small></p>This first global map of <a href="http://www.windows2universe.org/earth/Water/ocean.html">ocean</a> surface saltiness, released in September 2012 by the NASA Aquarius mission team, shows the distribution of salt in the first 2 cm of the Earth's ocean. <a href="http://www.windows2universe.org/earth/Water/salinity.html">Salinity</a> variations are one of the main drivers of <a href="http://www.windows2universe.org/earth/Water/circulation1.html">ocean circulation</a>, and are closely connected with the <a href="http://www.windows2universe.org/earth/Water/water_cycle.html">cycling of freshwater</a> around the planet. High salinity is seen in the Mediterranean, Atlantic, and the Arabian Sea.<p><small><em>Image courtesy of NASA/GSFC/JPL-Caltech</em></small></p>As temperatures rise and soil moisture decreases, plants are stressed, which can lead to <a href="/earth/climate/crops_withering.html&dev=1/earth/Atmosphere/moons/transport.html">crop withering</a>. <a href="/teacher_resources/online_courses/health/events_health.html&dev=1/earth/Atmosphere/moons/transport.html">Droughts</a> accompanied by increased temperatures can lead to famine, social and political disruptions. Scientists are helping with early identification of drought that might trigger food shortages. Watch the NBC Learn video - <a href="/earth/changing_planet/withering_crops_intro.html&dev=1/earth/Atmosphere/moons/transport.html">Changing Planet: Withering Crops</a> to find out more.<p><small><em>Image taken by Tomas Castelazo, Creative Commons <a href=&quot;http://creativecommons.org/licenses/by/3.0/deed.en&quot;>Attribution 3.0 Unported</a> license.</em></small></p>An artist's rendering of the moment of impact of a massive <a href="/our_solar_system/meteors/meteors.html&dev=1/earth/Atmosphere/moons/transport.html">meteorite</a> at the end of the Cretaceous (at the end of the <a href="/earth/geology/hist_mesozoic.html&dev=1/earth/Atmosphere/moons/transport.html">Mesozoic Era</a>). Many scientists have concluded for decades that a meteorite four to six kilometers in diameter impacted the Earth at this time, resulting in a <a href="/earth/past/KTextinction.html&dev=1/earth/Atmosphere/moons/transport.html">mass extinction of dinosaurs</a> and many other life forms. Recent research suggests that perhaps <a href="/headline_universe/olpa/chicxulub.html&dev=1/earth/Atmosphere/moons/transport.html">massive volcanic eruptions</a> may be been responsible for the extinction.<p><small><em>Courtesy of Don Davis, NASA</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&dev=1/earth/Atmosphere/moons/transport.html">methane</a>, a powerful <a href="/earth/climate/cli_greengas.html&dev=1/earth/Atmosphere/moons/transport.html">greenhouse gas</a>. Watch the NBC Learn video - <a href="/earth/changing_planet/permafrost_methane_intro.html&dev=1/earth/Atmosphere/moons/transport.html">Thawing Permafrost and Methane</a> to find out more.<p><small><em>Image courtesy of the USGS</em></small></p>An <a href="http://earthquake.usgs.gov/earthquakes/recenteqsww/Quakes/usc000905e.php">8.6 magnitude earthquake</a> struck on 11 April 2012 off of Banda Aceh, Sumatra, Indonesia, followed by a strong aftershock. Earthquake motion was primarily horizontal. A tsunami warning was issued for the Indian Ocean, but was cancelled at 12:36 UTC. A tsunami was observed at 1 meter or less. Find out more about <a href="/earth/geology/quake_1.html&dev=1/earth/Atmosphere/moons/transport.html">earthquake</a> and <a href="/earth/tsunami1.html&dev=1/earth/Atmosphere/moons/transport.html">tsunami</a> processes. Check out the resources <a href="/teacher_resources/2011_AGU-NESTA_GIFT_Workshop.html&dev=1/earth/Atmosphere/moons/transport.html">here</a>.<p><small><em>NOAA</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?

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

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Earth and Space Science Concept of the Day

Do you know what this word or phrase means?

Plate tectonics
xPlate tectonics : The theory supported by a wide range of evidence that considers the Earth's crust and upper mantle to be composed of several large, thin, relatively rigid plates that move relative to one another.

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Research Highlights

Pollution from Asia Circles Globe at Stratospheric Heights

The economic growth across much of Asia comes with a side effect: pollutants from the region are wafting up to the stratosphere during monsoon season. The new finding, in a study led by scientists at the...Read more


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