A comet is a small icy body that travels in an elliptical orbit around the sun. Halley’s Comet, or 1P/Halley, is the most well-known “periodic” comet that orbits the solar system and returns to Earth’s vicinity approximately every seventy-six years. It is one of the only comets that can be seen from Earth that is visible to the naked-eye, and can appear twice in one’s lifetime. The comet’s last visit was in the year 1986, and it is calculated to return mid-2061.
Halley’s Comet has been sighted and recorded for thousands of years by humans. A comet recorded in ancient Greece around 468 B.C. is thought to be Halley. However, the first ever collection of records about Halley’s Comet is from China in 256 B.C. Two Babylonian clay tablets also reported an appearance of Halley’s Comet from 164 B.C. Halley’s passing of 12 B.C. was noted in the Book of Han by Chinese astronomers of the Han Dynasty, who traced its path from August through October. It passed by within 0.16 Astronomical Units (AU) of Earth. This appearance of Halley in particular led some astronomers and theologians to believe it explained the biblical story of the “Star of Bethlehem;” its arrival was mysteriously close to the birth of Jesus.
Halley’s Comet may have passed within 0.03 AU, or 3.2 million miles from Earth in 837 A.D., which is its closest approach. The comet’s tail extended nearly 60 degrees across the sky. This sighting was written by astronomers in Japan, China, Germany, and the Middle East. Halley was seen in England in 1066, and it was thought to be a bad omen, for later that same year, Harold II of England died. William the Conquerer interpreted Halley as the cause for his success in battle, as the comet is depicted on the Bayeux Tapestry as a flaming star in William’s honor.
Additionally, in 1301, the Italian painter Giotto di Bondone made a skillfully precise painting of Halley’s Comet in a family chapel based on its passing that year.
This comet was named after Edmund Halley, Savilian Chair of Astronomy at Oxford and good friend of Sir Isaac Newton. Newton published “Principia” in 1687, where he explained his laws of gravity and motion. Halley predicted the bright comet’s return in 1758 after carefully examining its past appearances and other’s observations from 1531, 1607, and 1682. He noted the periodicity and determined that these were the returns of the same object every 75-76 years. In 1705, Halley published his work, “A Synopsis of the Astronomy of Comets”; he used Newton’s new theory of gravitation to conclude the orbits of comets from their registered points in the sky as a function of time. The comet was seen in late 1758 when it passed perihelion (closest distance to the sun), and proved Halley’s calculations correct. Sadly, Edmund died before he could witness the return of the comet. However, it was named in recognition of the astronomer because of his bold, yet accurate speculation. Furthermore, Halley verified that some comets actually orbit the sun,...