National Astronomical Observatory of Japan

A Black Shape Passing Across the Face of the Sun—The 2012 Transit of Venus


A Black Shape Passing Across the Face of the Sun—The 2012 Transit of Venus

June 6, 2012. A “transit” occurred when Venus passed in front of the face of the Sun. From our point of view, Venus aligned with the Sun and floated like a jet black shadow over the backdrop of the Sun’s photosphere. We know that when jet black Venus passed over the edge of the photosphere, a ring of light appeared around Venus (the Aureole phenomena). This is thought to be caused by the Venusian atmosphere refracting light from the Sun behind it. During this transit of Venus, the solar observation satellite HINODE obtained images with unprecedented clarity.

A transit of Venus is an extremely rare event. These transits occur in a regular pattern separated by 8 years, 121.5 years, 8 years and 105.5 years. In recent years, transits occurred on June 8, 2004 and June 6, 2012 but the next one won’t be for over 105 years on December 11, 2117.

When the transit of Venus occurred on June 6, 2012 conditions were such that the complete phenomenon was visible from Japan, all six and a half hours from start to finish. Unfortunately due to weather, only certain locations successfully viewed the entire event. But across the entire country, the shape of Venus’s black shadow cutting across the Sun gathered attention.

Solar observation satellite HINODE captured this transit of Venus with its Solar Optical Telescope and X-ray Telescope. Impressive, sharp images without interference from instabilities in Earth’s atmosphere can be viewed on the Hinode Science Center webpage.

Author: Tomoko Ono (Public Relations Center)