EARTH

From the perspective we get on Earth, our planet appears to be big and sturdy with an endless ocean of air. From space, astronauts often get the impression that the Earth is small with a thin, fragile layer of atmosphere. For a space traveler, the distinguishing Earth features are the blue waters, brown and green land masses and white clouds set against a black background.
Many dream of traveling in space and viewing the wonders of the universe. In reality all of us are space travelers. Our spaceship is the planet Earth, traveling at the speed of 108,000 kilometers (67,000 miles) an hour.
Earth is the 3rd planet from the Sun at a distance of about 150 million kilometers (93.2 million miles). It takes 365.256 days for the Earth to travel around the Sun and 23.9345 hours for the Earth rotate a complete revolution. It has a diameter of 12,756 kilometers (7,973 miles), only a few hundred kilometers larger than that of Venus. Our atmosphere is composed of 78 percent nitrogen, 21 percent oxygen and 1 percent other constituents.
Earth is the only planet in the solar system known to harbor life. Our planet's rapid spin and molten nickel-iron core give rise to an extensive magnetic field, which, along with the atmosphere, shields us from nearly all of the harmful radiation coming from the Sun and other stars. Earth's atmosphere protects us from meteors, most of which burn up before they can strike the surface.
From our journeys into space, we have learned much about our home planet. The first American satellite, Explorer 1, discovered an intense radiation zone, now called the Van Allen radiation belts. This layer is formed from rapidly moving charged particles that are trapped by the Earth's magnetic field in a doughnut-shaped region surrounding the equator. Other findings from satellites show that our planet's magnetic field is distorted into a tear-drop shape by the solar wind . We also now know that our wispy upper atmosphere, once believed calm and uneventful, seethes with activity -- swelling by day and contracting by night. Affected by changes in solar activity, the upper atmosphere contributes to weather and climate on Earth.
Besides affecting Earth's weather, solar activity gives rise to a dramatic visual phenomenon in our atmosphere. When charged particles from the solar wind become trapped in Earth's magnetic field, they collide with air molecules above our planet's magnetic poles.



Earth Statistics

Mass (kg)
5.976e+24
Mass (Earth = 1)
1.0000e+00
Equatorial radius (km)
6,378.14
Equatorial radius (Earth = 1)
1.0000e+00
Mean density (gm/cm^3)
5.515
Mean distance from the Sun (km)
149,600,000
Mean distance from the Sun (Earth = 1)
1.0000
Rotational period (days)
0.99727
Rotational period (hours)
23.9345
Orbital period (days)
365.256
Mean orbital velocity (km/sec)
29.79
Orbital eccentricity
0.0167
Tilt of axis (degrees)
23.45
Orbital inclination (degrees)
0.000
Equatorial escape velocity (km/sec)
11.18
Equatorial surface gravity (m/sec^2)
9.78
Visual geometric albedo
0.37
Mean surface temperature
15°C
Atmospheric pressure (bars)
1.013
Atmospheric composition Nitrogen Oxygen Other
77% 21% 2%

What and When Is Earth Day?

By John McConnell, Founder of Earth Day
When I first conceived of Earth Day, a global holiday to celebrate the wonder of life on our planet, I thought long and hard about the day on which it should fall. It must be meaningful. One that might be accepted universally for all of humankind.When the Vernal Equinox dawned on me, I immediately knew it was right. The Earth tremor that shook our California dwelling at that moment seemed an omen of confirmation. What could be more appropriate than the first moment of Spring, when day and night are equal around the world and hearts and minds can join together with thoughts of harmony and Earth's rejuvenation. Just as a single prayer can be siginificant, how much more so when hundreds, thousands, millions of people throughout the world join in peaceful thoughts and prayers to nurture neighbor and nature.And so it came to pass we initiated the celebration of Earth Day on March 21, 1970. The first Proclamation of Earth Day was by San Francisco, the City of Saint Francis, patron saint of ecology. Designating the First Day of Spring, March 21, 1970 to be Earth Day, this day of nature's equipoise was later sanctioned in a Proclamation signed by Secretary General U Thant at the United Nations where it is observed each year. Earth Day was firmly established for all time on a sound basis as an annual event to deepen reverence and care for life on our planet.While other dates have been called Earth Day it is obvious that a singular Earth Day is needed and that the original choice of nature's day is best. More attention for this fact will increase the influence of Earth Day and its benefits.Every effort to encourage Earth care is to be commended. But just as more than one birthday each year for an individual would diminish the real birthday, calling other dates Earth Day detracts from the authentic day -- which can provide a more meaningful focus and obtain more unity in our diversity. The nature of the March equinox provides a reason for an event at the same time all over the world.Other events leading up to or following could be called Earth Festivals, or given other names. Then events can complement each other and increase awareness and care for our planet and its people. In the midst of this will be Earth Day, where the United Nations Peace Bell rings at the moment Spring begins and hearts and minds join all over the world.


The original Earth Day, on the March equinoxEarth Day 2007MARCH 20, 2007 at 7:07 PM EST (Eastern Standard Time)or 12:07 UTC March 21 (Greenwich, England) -----------------------------------

"Minute for Peace," December 22, 2007
On December 22, just three days before Christmas, 1963, the first "Minute for Peace" was broadcast on radio and TV stations. This came one month after the assassination of President John F. Kennedy. Wire services featured the "Minute for Peace" in news stories that went around the world. The broadcast included the voice of President Kennedy addressing the United Nations with an urgent plea for peace, and asked each listener to dedicate his thoughts and action to peace.On June 26, 1965, the twentieth anniversary of the signing of the United Nations charter, a "Minute for Peace" message featuring UN Secretary General U Thant was broadcast on all major U.S. radio networks, by United Nations radio, by networks in other countries, and by international short wave radio.Since then, all over the globe, we who have pledged ourselves as Earth Trustees have taken a minute each December 22 to meditate and pray for peace. Again this year we ask you to join us in this effort to help bring peace.Can a "Minute for Peace" become a minute of goodwill observed in unison around the world? Will it irresistibly move the leaders of men into paths of peace? Will the hearts and minds of people in all countries be touched by the Holy Spirit with the peace and love that bring men into the Kingdom of God? What has happened so far seemed utterly impossible at first. Who knows what may happen if we put our faith to work and use the power of the Spirit to solve the problem of the sword?On December 22, 2007, join with Earth Trustees all over the world in dedicating your hearts during a "Minute for Peace." Let every radio and TV station fill the day with minutes of music and words that inspire peaceful actions. Help us unite as one human family in new understanding and care for this wonderful nest in the stars: Planet Earth, our home.