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.

Scientists at the University of Michigan have found that <a href="/earth/polar/cryosphere_permafrost1.html&edu=high&dev=1/ozone_strato.html">permafrost</a> in the <a href="/earth/polar/polar_north.html&edu=high&dev=1/ozone_strato.html">Arctic</a> is extremely sensitive to sunlight. Exposure to sunlight releases carbon gases trapped in the permafrost, including <a href="/earth/climate/earth_greenhouse.html&edu=high&dev=1/ozone_strato.html">climate-warming</a> <a href="/physical_science/chemistry/carbon_dioxide.html&edu=high&dev=1/ozone_strato.html">carbon dioxide</a>, to the <a href="/earth/Atmosphere/overview.html&edu=high&dev=1/ozone_strato.html">atmosphere</a> much faster than previously thought.<p><small><em>George Kling, The University of Michigan</em></small></p>Coral animals build reefs in warm, tropical seawater. However, <a href="/earth/changing_planet/ocean_temperatures_intro.html&edu=high&dev=1/ozone_strato.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>This iconic image of Earth rising above the surface of the <a href="/earth/moons_and_rings.html&edu=high&dev=1/ozone_strato.html">Moon</a>, was taken on December 24, 1968 by astronauts on the <a href="/space_missions/apollo8.html&edu=high&dev=1/ozone_strato.html">Apollo 8 mission</a>. Apollo 8 was the first <a href="/space_missions/manned.html&edu=high&dev=1/ozone_strato.html">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>How did life evolve on <a href="/earth/earth.html&edu=high&dev=1/ozone_strato.html">Earth</a> during the <a href="/earth/past/Archean.html&edu=high&dev=1/ozone_strato.html">Archean</a>, when the <a href="/sun/sun.html&edu=high&dev=1/ozone_strato.html">Sun</a> was about 25% weaker than today? The Earth should have been <a href="/earth/polar/cryosphere_glacier1.html&edu=high&dev=1/ozone_strato.html">glaciated</a>, if <a href="/earth/climate/earth_greenhouse.html&edu=high&dev=1/ozone_strato.html">greenhouse</a> gas concentration was the same as today. <a href="http://www.manchester.ac.uk/aboutus/news/display/?id=10798">Researchers</a> studying the <a href="/physical_science/physics/atom_particle/isotope.html&edu=high&dev=1/ozone_strato.html">isotopic</a> signatures of Earth's early atmosphere in <a href="/earth/geology/rocks_intro.html&edu=high&dev=1/ozone_strato.html">rocks</a> from Northern Australia have ruled out high levels of <a href="/physical_science/chemistry/nitrogen_molecular.html&edu=high&dev=1/ozone_strato.html">nitrogen</a> as a possible way to increase warming from <a href="/earth/Atmosphere/overview.html&edu=high&dev=1/ozone_strato.html">atmospheric</a> <a href="/physical_science/chemistry/carbon_dioxide.html&edu=high&dev=1/ozone_strato.html">carbon dioxide</a>.<p><small><em>Image courtesy of Manchester University</em></small></p><p>Something on Earth is always burning! NASA's Earth Observatory tracks wildfires across the world with <a href="http://earthobservatory.nasa.gov/GlobalMaps/view.php?d1=MOD14A1_M_FIRE" target="_blank">maps available for viewing</a> from 2000-present. Some wildfires can restore <a href="/earth/ecosystems.html&edu=high&dev=1/ozone_strato.html">ecosystems</a> to good health, but many can threaten human populations, posing a natural disaster threat.</p> <p>Check out the materials about natural disasters in <a href="/earth/natural_hazards/when_nature_strikes.html&edu=high&dev=1/ozone_strato.html">NBC Learn Videos</a>, and their earth system science connections built up by the related secondary classroom activities.</p><p><small><em>NBC Learn</em></small></p>Sinkholes are <a href="/teacher_resources/main/frameworks/esl_bi8.html&edu=high&dev=1/ozone_strato.html">natural hazards</a> in many places around the world. They are formed when water dissolves underlying <a href="/earth/Water/carbonates.html&edu=high&dev=1/ozone_strato.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>

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 the Earth's magnetic pole in the Northern hemisphere is not aligned with the Earth's geographic north pole?

Did you know that the Earth’s lithosphere is broken into giant plates, which occasionally move and can produce earthquakes?

 

Earth and Space Science Concept of the Day

Do you know what this word or phrase means?

Tide
xTide : A tide is the regular rising and falling of the ocean's surface caused by the gravitational pull of the Moon and the Sun on the ocean and the Earth's rotation.

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


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