The 2012 transit of 18 May 2012, By Dr. Tony Phillips

blinding glare. Instead, use some type of projection technique or a solar filter. A #14 welder's glass is a good choice. Many astronomy clubs will have solar telescopes set up to observe the event; contact your local club for details.

The June 8, 2004, photographed by Frans Snik at the Dutch Open Telescope in La Palma, Canary Islands. A double transit: the ISS+Venus on June 8, 2004. Credit: Tomas Maruska of Stupava, Slovakia

On June 5th, 2012, Venus will pass across the face of the , producing a silhouette that no one Transits of Venus first gained worldwide attention in alive today will likely see again. the 18th century. In those days, the size of the solar system was one of the biggest mysteries of Transits of Venus are very rare, coming in pairs science. The relative spacing of planets was separated by more than a hundred years. This known, but not their absolute distances. How many June's transit, the bookend of a 2004-2012 pair, miles would you have to travel to reach another won't be repeated until the year 2117. Fortunately, world? The answer was as mysterious then as the the event is widely visible. Observers on seven nature of dark energy is now. continents, even a sliver of Antarctica, will be in position to see it. Venus was the key, according to astronomer Sir Edmund Halley. He realized that by observing The nearly 7-hour transit begins at 3:09 pm Pacific transits from widely-spaced locations on Earth it Daylight Time (22:09 UT) on June 5th. The timing should be possible to triangulate the distance to favors observers in the mid-Pacific where the sun Venus using the principles of . is high overhead during the crossing. In the USA, the transit will at its best around sunset. That's The idea galvanized scientists who set off on good, too. Creative photographers will have a field expeditions around the world to view a pair of day imaging the swollen red sun "punctured" by transits in the 1760s. The great explorer James the circular disk of Venus. Cook himself was dispatched to observe one from Tahiti, a place as alien to 18th-century Europeans Observing tip: Do not stare at the sun. Venus as the or Mars might seem to us now. Some covers too little of the solar disk to block the

1 / 2

historians have called the international effort the "the Apollo program of the 18th century."

In retrospect, the experiment falls into the category of things that sound better than they actually are. Bad weather, primitive optics, and the natural "fuzziness" of Venus's atmosphere prevented those early observers from gathering the data they needed. Proper timing of a transit would have to wait for the invention of photography in the century after Cook's voyage. In the late 1800s, astronomers armed with cameras finally measured the size of the Solar System as Edmund Halley had suggested.

This year's transit is the second of an 8-year pair. Anticipation was high in June 2004 as Venus approached the sun. No one alive at the time had seen a Transit of Venus with their own eyes, and the hand-drawn sketches and grainy photos of previous centuries scarcely prepared them for what was about to happen. Modern solar telescopes captured unprecedented view of Venus's atmosphere backlit by solar fire. They saw Venus transiting the sun's ghostly corona, and gliding past magnetic filaments big enough to swallow the planet whole. One photographer even caught a spaceship, the International Space Station, transiting the sun alongside Venus.

2012 should be even better as cameras and solar telescopes have improved. Moreover, NASA's Solar Dynamics Observatory is going to be watching too. SDO will produce Hubble-quality images of this rare event.

Provided by Science@NASA APA citation: The 2012 transit of Venus (2012, May 18) retrieved 30 September 2021 from https://phys.org/news/2012-05-transit-venus.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

2 / 2

Powered by TCPDF (www.tcpdf.org)