PLANET EARTH TO CATCH UP WITH THE RED PLANET MARS
Document Actions
TRAVELERS TO ASIA MAY OBSERVE LONGEST SOLAR ECLIPSE OF THE CENTURY
(July 2, 2009) – Astronomers at the Pisgah Astronomical Research Institute announce that on July 22 the longest total solar eclipse of the 21st Century will occur. However, to observe this spectacular event, one must do a bit of traveling.
What causes an eclipse of the Sun, also called a solar eclipse? As the Moon orbits the Earth, it comes to New Moon once every 29½ days. Most months when this happens, the Moon passes above or below the line between the Earth and the Sun and its shadow misses the Earth. However, twice per year, roughly six months apart, the Moon can pass near enough to the Sun-Earth line that its shadow hits the surface of the Earth. This is what is happening on July 22.
Predicting exactly where the Moon’s shadow will touch the Earth is straightforward although a bit complicated because one has to take into account both the motion of the Moon in its orbit around the Earth and the path of the Earth around the Sun. Then there’s also the rotation of the Earth on its axis that will determine which part of the Earth is facing the Sun when the Moon comes between the two.
The prediction for July 22 is that the shadow of the Moon will first strike the Earth’s surface just off the coast of west-central India north of Mumbai. Then it moves across Nepal, Bangladesh, Bhutan, Myanmar and China, passing directly over Shanghai, where more people may see this eclipse than any in history. Finally, it moves out into the Pacific Ocean including a pass over Iwo Jima where it reaches a maximum duration of 6 minutes and 39 seconds, the longest duration of the century.
For more information and a map see MacRobert, Alan. “The China-Pacific Solar Eclipse,” Sky and Telescope, Vol. 118, No. 1, July 2009, p. 53 or visit the US Naval Observatory Astronomical Applications website at http://aa.usno.navy.mil/.
The next total solar eclipse visible from the Americas will be on August 21, 2017.
About PARI
PARI is a not-for-profit foundation established in 1998. Located in the Pisgah Forest southwest of Asheville, NC, PARI offers educational programs at all levels, from K-12 through post-graduate research. The institute is affiliated with the 16-campus University of North Carolina system through PARSEC, a UNC Center hosted at PARI, and is a member of the NC Grassroots Museum Collaborative. For more information about PARI and its programs, visit www.pari.edu.