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Earth as seen from the Apollo 17 spacecraft.

Diameter 7,927 miles12,757.294 km
634,161.212 chains
Number of moons 1
Orbital eccentricity 0.0167
Orbital time (Earth time) 1 Earth year
Rotational time (Earth time) 1 Earth day

The third planet from the Sun, Earth is the only planet in the Solar system known to possess life or capable of supporting most forms of life.

Earth is the largest of the terrestrial planets, having a diameter of 7,927 miles12,757.294 km
634,161.212 chains
at the equator. It orbits the sun in 365.24 days and rotates on its axis once per day using the sun at zenith, or in 23h 56m 4.09s from fixed star to fixed star. The orbit of the Earth is almost circular but slightly elliptical,[note 1] and the point of closest approach to the sun (perihelion) occurs in early January. The Moon, Earth's only natural satellite, orbits at a distance of 238,000 miles every 29.3 days.

The Earth is not a perfect sphere but rather an oblate spheroid.

The Earth is composed of a core of molten metal (chiefly iron), with a thick crust of a mainly nonmetallic nature. Seventy-one percent of its surface is covered with water, and its atmosphere is a mixture of nitrogen, oxygen, argon, water vapour and carbon dioxide, the last two comprising less than 1%. The presence of a biosphere with large amounts of vegetation maintains the oxygen atmosphere. Without plant life, the oxygen would quickly be bound up chemically in surface rocks.

Age of the Earth

Biblical chronology can be used to calculate the age of the Earth to be about 6,000 years. There are a few small ambiguities in the biblical record, so different people have calculated slightly different dates for creation but Archbishop James Ussher derived the best-known date of 4004 BC in his Annales veteris testamenti, a prima mundi origine deducti (Annals of the Old Testament, deduced from the first origins of the world), published 1650 to 1654. Ussher further decided that creation probably occurred at nightfall before October 23rd, 4004 BC, in the Julian calendar.[2][3]

A date in the range of thousands of years has been widely accepted for most of the history of Christianity until secular views came to dominance in the last two centuries. Young’s Analytical Concordance of the Holy Bible (8th edition, 1939) said:

Dr Hales, in his work entitled, “A New Analysis of Chronology and Geography, History and Prophecy,”? (vol. 1, p. 210), remarks: “In every system of chronology, sacred and profane, the two grand eras—of the Creation of the World, and of the Nativity of Christ—have been usually adopted as standards, by reference to which all subordinate epochs, eras and periods have been adjusted.”? He gives a list of 120 dates, commencing B.C. 6984, and terminating BC 3616, to which this event has been assigned by different authorities, and he admits that it might be swelled to 300. He places it at BC 5411. The date commonly adopted is BC 4004; being that of Ussher, Spanheim, Calmet, Blair, etc., and the one used in the English Bible.[4]

Naturalistic scientists currently interpret the evidence, primarily radioactive dating, to indicate an age of approximately 4.5 billion years old. Counting layers in ice cores seem to indicate that the large ice sheets are hundreds of thousands or millions of years old, and counting growth rings suggests trees were living over 12,000 years ago. Young Earth creationists dispute the accuracy of the dating methods and assumptions used to support this "old" date, and interpret the extra-Biblical evidence to be consistent with a Biblically-derived age of approximately 6,000 years.[5]


  1. The eccentricity of the orbit is 0.0167, where 0 is circular and 1 is highly elliptical.[1]


  1. Randy Russell, Elliptical Orbits, Windows to the Universe, National Earth Science Teachers Association, Fri. 16th December, 2005Fri. December 16th, 2005.
  2. Morris, John, Can the Ussher Chronology Be Trusted? December 2003 (Institute for Creation Research)
  3. Ussher, James, Annals of the World (English translation by Larry and Marion Pierce), 2003, p. 17.
  4. Quoted by Batten, Don, Old-earth or young-earth belief: Which belief is the recent aberration?, Creation 24(1):24–27, December 2001. Dr. Hales' book is on-line here.
  5. Sarfati, Jonathan, How old is the earth?, Refuting Evolution Chapter 8.
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