Earth Today

Closed on May 23, 2011

Highlights:

Our Dynamic Planet

Our Earth is unique among the planets. Liquid water covers 70% of the surface and the atmosphere is rich in water vapor. It is a geologically active planet. Yet Earth's most unique characteristic is the presence and diversity of life. The animation to the left shows the Earth as viewed from the Apollo 17 mission on its way to the Moon.

Clouds over Earth

Atmosphere
The Earth is bathed in energy from the Sun. The oceans, land, and atmosphere absorb and are heated by this energy. The heat absorbed by the oceans and transported by its currents is constantly released into the atmosphere. Heat and moisture from the oceans drive atmospheric circulation and weather patterns. Moisture in the atmosphere forms clouds which cover an average of 40% of the Earth at any given time. Clouds are carried through the atmosphere by the wind. The patterns in cloud motion in this time-lapse sequence show how Earth's winds move in bands or zones which define regional wind directions.

Water Vapor in the Atmosphere

The movement of moisture or water vapor in the atmosphere is important in determining the weather. In the swirling motion of atmospheric water vapor, hurricanes can be seen. During the summer of 1995, a series of hurricanes formed off the coast of Africa -- Allison, Erin, Felix, Humberto, Iris, Luis, Marilyn, Noel, Opal, Roxanne, and Tanya -- then moved west across the Atlantic to the Caribbean and East coast of the United States. The white and light blue areas contain the most water vapor, while the dark areas are the driest. The small bright areas are storms and hurricanes. The big spirals show large-scale circulation patterns in the Earth's atmosphere.


Sea Surface Temperature

Hydrosphere
Our global climate is also influenced by the way heat is transported by the Earth's oceans. Here you can see where the surface waters of Earth's oceans are warm and cold. Red and orange areas indicate the warmest surface waters, while green and blue are the coldest.

Things to notice:

  • The north and south poles are colder than the equator, as expected.
  • The pattern moves north and south with the seasons. During summer in the Northern Hemisphere the surface waters of the northern oceans are warm. At the same time it is winter in the Southern Hemisphere, and the southern oceans are cold.

El Niño

An unusual rise in the temperature of the normally cool water of the Eastern Pacific is a phenomenon called El Niño, which means "The Child" in Spanish, since it occurs around Christmas some years. It can upset the global climate, causing droughts in some areas and flooding elsewhere. By monitoring global changes in sea surface temperature and circulation, scientists can now predict the onset of an El Niño.


Earth at Night

Earth at Night
The influence humans have had on the Earth can also be seen from space. Viewing the Earth at night, we see the light from countless villages, towns, and cities pour into space. Major urban population centers, shown in white, are prominent sources of light. Fires from slash-and-burn farming and the burn-off of natural gas in oil fields are shown in red and yellow. From this perspective, the scale of human activity on the Earth can be appreciated. It spans the globe.


Draining the Pacific

Geosphere
Draining the oceans reveals that the Earth's solid surface -- its crust -- is divided into highlands and lowlands. The highlands are the landmasses that form the continents and the lowlands form the ocean basins.

Things to notice:

  • The ocean floor has mountain chains, isolated peaks, and deep valleys.
  • The pronounced ridge in the middle of the Atlantic ocean marks the location of the Mid-Atlantic Ridge where new seafloor is being created by magma rising from the mantle. Thus, the Atlantic is getting bigger with time. The Mid-Atlantic Ridge, is also visible in the Tectonic Plates dataset.

Tectonic Plates

The Earth's crust is not a fixed, continuous shell. It is broken into a mosaic of moving plates. As these plates move and shift against one another they release enormous amounts of energy in the form of earthquakes.

Things to notice:

  • The boundary between the Pacific plate and the North American plate is located along the coast of California.
  • The movement or slip of the two plates past one another has created the San Andreas fault, the source of many earthquakes.

Earthquake Locations

This sequence shows the locations of strong earthquakes worldwide.

Things to notice:

  • Earthquakes tend to be concentrated at the boundaries of Earth's plates. Volcanoes are also more frequent along the plate boundaries.

 

Locations of Volcanoes

As oceanic plates are driven under continental plates, forcing them into the mantle, they begin to melt. This produces molten rock, which rises to the surface forming volcanoes. The locations of volcanoes which erupted between 1960 and 1995 are shown.

Things to notice:

  • Like earthquakes, volcanoes are concentrated along boundaries between Earth's plates.

Earth's Vegetation

Biosphere
The oceans, atmosphere, and land all play critical roles in sustaining life on Earth. The characteristics of ocean currents, wind patterns, and topography can make one area a desert and another a rain forest.

Seasonal changes greatly affect Earth's plant life or vegetation. The shades of green and yellow show how leaf bearing plants "green up" and decline through the seasons of a year. The vast deserts of North Africa, the Arabian Peninsula, and central Asia are easily recongnized because of the lack of vegetation.

This image displays the composite of SeaWiFS land and ocean data. Land and cloud features are represented in "true color".

Earth's True Color

Seasonal changes greatly affect Earth's plant life or vegetation. The shades of green and yellow show how leaf bearing plants "green up" and decline through the seasons of a year. The vast deserts of North Africa, the Arabian Peninsula, and central Asia are easily recongnized because of the lack of vegetation.

This image displays the composite of SeaWiFS land and ocean data. Land and cloud features are represented in "true color".


Near Real-Time

Earth-orbiting satellites and global monitoring networks are continously collecting images and data on our planet's atmosphere, hydrosphere, geosphere and biosphere. This makes it possible to see conditions such as the extent of cloud cover and the temperature of the ocean's surface waters as they are on the Earth today.

Clouds over Earth

Global Cloud Cover
See a near real time data set of Global Cloud Cover from The University of Wisconsin Space Science and Engineering Center (SSEC).

For more information about this data set and other views of global cloud cover see: SSEC at the University of Wisconsin.

Sea Surface Temperature

Sea Surface Temperature
See a near real time data set of sea surface temperature from the Naval Oceanographic Office at Stennis Space Center, Mississippi

For more information about this data set see: SSEC at the University of Wisconsin.

Global Biosphere

Global Biosphere
Life on Earth is directly influenced by conditions in the oceans and atmosphere. The extent of plant life on Earth can be seen in satellite maps of the global biosphere. These maps are constructed by combining strips of data collected by the SeaWiFS satellite as it orbits the Earth. Each strip reflects data collected from one orbit of the satellite. By averaging many days of overlapping strips of data, areas obscured by cloud cover on one day are revealed on a clear day, and a cloudless map of global plant life created.

For more information on SeaWiFS and the global biosphere see: SeaWiFS Project at the NASA Goddard Space Flight Center.

Water Vapor in the Atmosphere

Global Water Vapor
See a near real time data set of global water vapor hosted at the University of Wisconsin Space Science and Engineering Center

For more information about this and other global data sets see: SSEC at the University of Wisconsin.

Earthquake Locations

Earthquakes
See a near real time data set of earthquakes from the United States Geological Survey

For more information about this data set and an interactive listing of current earthquakes see the USGS National Earthquake Information Center.