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 view of the Earth as seen by the <a href="/space_missions/apollo17.html&dev=1/k=/teacher_resources/teach_pluggedCO2.html">Apollo 17</a> crew while traveling to the <a href="/earth/moons_and_rings.html&dev=1/k=/teacher_resources/teach_pluggedCO2.html">Moon</a> on December 7, 1972. Africa, Madagascar, and the Arabian Peninsula are visible, and you can barely make out the <a href="/earth/polar/antarctica.html&dev=1/k=/teacher_resources/teach_pluggedCO2.html">Antarctic</a>, shrouded in the heavy <a href="/earth/Atmosphere/cloud.html&dev=1/k=/teacher_resources/teach_pluggedCO2.html">cloud</a> cover in the southern hemisphere. Arching cloud patterns show the presence of <a href="/earth/Atmosphere/front.html&dev=1/k=/teacher_resources/teach_pluggedCO2.html">weather fronts</a>.<p><small><em>Image courtesy of NASA/Apollo 17.</em></small></p>Sinkholes are <a href="/teacher_resources/main/frameworks/esl_bi8.html&dev=1/k=/teacher_resources/teach_pluggedCO2.html">natural hazards</a> in many places around the world. They are formed when water dissolves underlying <a href="/earth/Water/carbonates.html&dev=1/k=/teacher_resources/teach_pluggedCO2.html">limestone</a>, leading to collapse of the surface. Hydrologic conditions such as a lack of rainfall, lowered water levels, or excessive rainfall can all contribute to sinkhole development. On 2/28/2013, a sinkhole suddenly developed under the house outside of Tampa, Florida, leading to the tragic death of its occupant, Jeff Bush.<p><small><em>Image courtesy of Southwest Florida Water Management District</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/k=/teacher_resources/teach_pluggedCO2.html">crop withering</a>. <a href="/teacher_resources/online_courses/health/events_health.html&dev=1/k=/teacher_resources/teach_pluggedCO2.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/k=/teacher_resources/teach_pluggedCO2.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>Coral animals build reefs in warm, tropical seawater. However, <a href="/earth/changing_planet/ocean_temperatures_intro.html&dev=1/k=/teacher_resources/teach_pluggedCO2.html">seawater can be too warm</a> for their liking. If waters get too warm, coral animals lose the algae that live within their little bodies, a process called coral bleaching. Without the algae, corals have less nutrition. Unless cooler temperatures return, allowing algae to return, the coral dies.<p><small><em>Credit: UNC</em></small></p>Scientists are concerned that melting Arctic sea ice will increase the amount of fresh water in the <a href="/earth/polar/arctic_currents.html&dev=1/k=/teacher_resources/teach_pluggedCO2.html">Beaufort Gyre</a>, which could spill out into the Atlantic and cause major climate shifts in North America and Western Europe. Watch the <a href="/earth/changing_planet/freshwater_arctic.html&dev=1/k=/teacher_resources/teach_pluggedCO2.html">Changing Planet: Fresh Water in the Arctic video</a>.<p><small><em> Courtesy of Jack Cook, WHOI (<a href="http://www.whoi.edu">Woods Hole Oceanographic Institute</a>)</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/k=/teacher_resources/teach_pluggedCO2.html">earthquake</a> and <a href="/earth/tsunami1.html&dev=1/k=/teacher_resources/teach_pluggedCO2.html">tsunami</a> processes. Check out the resources <a href="/teacher_resources/2011_AGU-NESTA_GIFT_Workshop.html&dev=1/k=/teacher_resources/teach_pluggedCO2.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?

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

Did you know that the Earth’s magnetic field has reversed its orientation irregularly many times over Earth’s history?

 

Earth and Space Science Concept of the Day

Do you know what this word or phrase means?

Umbra
xUmbra : The shadow cast by a celestial body

Click on the word to find out!

Research Highlights

Geologists Uncover Major Ancient Human Ancestor in South Africa

Researchers working in South Africa have discovered two remarkably well-preserved fossil skeletons of an ancient human ancestor dating to almost two million years ago. The discovery is described in two...Read 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