October 17, 2012
Astronomers Study Venus Atmosphere During Transit
[WATCH VIDEO: Ultra-High Definition View of 2012 Venus Transit]
Lee Rannals for redOrbit.com — Your Universe Online
It won't happen again until 2117, but one team ensured everyone at the 44th meeting of the American Astronomical Society's Division for Planetary Sciences in Reno, Nevada that they got plenty of data as Venus transited the Sun earlier this year.
Jay Pasachoff of the Williams College and Caltech, Glenn Schneider of University of Arizona, Thomas Widemann of Paris Observatory in Meudon, and Paolo Tanga of Observatoire de la CÃ´te d'Azur in Nice were the heads of the international team that captured the rare event as Earth's sister planet passed in front of the Sun on June 5th and June 6th 2012.
One major observing site used by the team was the 10,000-foot-high volcano Haleakala on Maui, Hawaii.
The first major goal set out by the astronomers when observing the transit was to study the atmosphere of Venus as it bent sunlight toward Earth.
The second goal was to provide an analog in our own solar system to the now-observed transits of thousands of exoplanet candidates discovered in recent years by the Kepler spacecraft and other telescopes on the ground and in space.
About 80 to 90 percent of those exoplanet candidates are real exoplanets, and detailed observations made by the team may help scientists determine methods to tell which faraway events are real exoplanet transits.
The team had one of nine coronagraphs at Haleakala, which are specialized telescopes to block out bright objects to reveal faint ones beside them. The rest of the coronagraphs were spread out at sites throughout the world.
The astronomers even used the Hubble Space Telescope to try and detect the transit of Venus that was visible from Jupiter on September 20.
During this transit, they took a total of 124 images through an ultraviolet filter and a near-infrared filter for 10 hours. They saw the sunlight that reached Jupiter and reflected off the planet's clouds dim by a hundredth of a percent as Venus slightly obscured Jupiter's view of the sun.
Scientists will also be looking at Saturn on December 21, using the Cassini spacecraft to look directly at the Sun as Venus transits in front of it. These observations from Saturn and Jupiter are just adding to the data planetary scientists and astronomers have taken during Venus' transits this year.