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astronomical unit
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Edmond Halley
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astronomical unit Article

astronomical unit summary

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Below is the article summary. For the full article, see astronomical unit.

astronomical unit (AU), unit of length effectively equal to the average distance between Earth and the Sun, defined as 149,597,870.7 km (92,955,807.3 mi). The astronomical unit provides a convenient way to express and relate distances of objects in the solar system and to carry out various astronomical calculations.

Edmond Halley
Edmond Halley Summary
Edmond Halley was an English astronomer and mathematician who was the first to calculate the orbit of a comet later named after him. He is also noted for his role in the publication of Isaac Newton’s Philosophiae Naturalis Principia Mathematica. Halley began his education at St. Paul’s School,