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.

The massive 9.0 magnitude <a href="/earth/geology/quake_1.html&edu=elem&dev=1/windows.html">earthquake</a> off of Honshu, Japan on <a href="/headline_universe/march112011earthquaketsunami.html&edu=elem&dev=1/windows.html">11 March 2011</a> generated a <a href="/earth/tsunami1.html&edu=elem&dev=1/windows.html">tsunami</a> that exceeded 10 meters on the coast near the epicenter. This image shows model projections for the tsunami wave height in cm which are in good agreement with the observed waves. Our thoughts and prayers are with those who were lost, and their families, as we remember this event.<p><small><em><a href="http://blogs.agu.org/wildwildscience/files/2011/03/680_20110311-TsunamiWaveHeight.jpg">NOAA Tsunami Wave Height Projections image</a></em></small></p>This iconic image of Earth rising above the surface of the <a href="/earth/moons_and_rings.html&edu=elem&dev=1/windows.html">Moon</a>, was taken on December 24, 1968 by astronauts on the <a href="/space_missions/apollo8.html&edu=elem&dev=1/windows.html">Apollo 8 mission</a>. Apollo 8 was the first <a href="/space_missions/manned.html&edu=elem&dev=1/windows.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>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=elem&dev=1/windows.html">full phase</a>. Secondly, the <a href="/sun/sun.html&edu=elem&dev=1/windows.html">Sun</a>, <a href="/earth/earth.html&edu=elem&dev=1/windows.html">Earth</a> and <a href="/earth/moons_and_rings.html&edu=elem&dev=1/windows.html">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>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>March 2012 marks the first anniversary of the 9.0 magnitude <a href="/earth/geology/quake_1.html&edu=elem&dev=1/windows.html">earthquake</a>, <a href="/earth/tsunami1.html&edu=elem&dev=1/windows.html">tsunami</a>, and resulting nuclear accident in Japan on <a href="/headline_universe/march112011earthquaketsunami.html&edu=elem&dev=1/windows.html">11 March 2011</a>. The tsunami did massive damage, wiping out entire villages and killing ~16,000 people, and leading to one of the most serious nuclear accidents in history. This image shows before and after photos of the area north of Sendai, where 10,000 people were lost.<p><small><em>Photos by <a href="http://www.nytimes.com/interactive/2011/03/13/world/asia/satellite-photos-japan-before-and-after-tsunami.html?hp">GeoEye/EyeQ</a>.</em></small></p><p>You don't normally see <a href="/space_weather/space_weather.html&edu=elem&dev=1/windows.html">space weather</a> forecasted on the evening news, but it does impact life on <a href="/earth/earth.html&edu=elem&dev=1/windows.html">Earth</a> in many ways. What are the threats posed from all of these natural disasters and how can we work to mitigate those threats beforehand? </p> <p>Check out the materials about natural disasters in <a href="/earth/natural_hazards/when_nature_strikes.html&edu=elem&dev=1/windows.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>

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 many different cultures had myths about Earth goddesses and gods?

Do you know why chromosomes, DNA, and genes are important?

 

Earth and Space Science Concept of the Day

Do you know what this word or phrase means?

Chinook
xChinook : A dry down-slope wind which occurs on the downwind side of a mountain range. It is a rain shadow wind which results from the subsequent (adiabatic) warming of air which has dropped most of its moisture on windward slopes.

Click on the word to find out!

Research Highlights

Soil Microbes Produce Less Atmospheric Carbon Dioxide Than Expected With Global Warming

In dark, rich soils on every continent, microbes dealing with the effects of climate change aren't accelerating global warming the way scientists had predicted, a study by researchers at the University...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