Millions of people spanning the globe will be able to see the planet Venus pass across the face of the sun in what will be a once-in-a-lifetime experience known as a “Venus transit.”
It will take Venus about six hours to complete its journey across the sun, appearing as a small black dot on the sun’s surface in an historical event that will not occur again until the year 2117.
Transits of the planet Venus occur only on the very rare occasions when Venus and Earth are both in a straight line with the sun. At other times, Venus passes below or above the sun due to the fact that the two orbits are at a slight angle to one another.
Transits usually occur in pairs separated by eight years, with the gap between pairs of transits alternating between 105.5 and 121.5 years. The last transit occurred in 2004.
Building on the original theories of Nicolaus Copernicus from 1543, scientists were thereby able to predict the transits of both the planets Mercury and Venus in the centuries that followed.
Not content with catching a glimpse of the 2012 Venus transit from down here on Earth, scientists in France will be using the Hubble Space Telescope to witness the effect of the transit as it ever-so-slightly darkens the moon.
Pasachoff and his colleagues hope to use the Hubble to watch Venus pass in front of the sun as seen from Jupiter – an event that will take place on September 20 of this year – and they’ll be utilizing NASA’s Cassini spacecraft, which is orbiting Saturn, to see a transit of Venus from that planet on December 21.
“We are fortunate in that we are truly living in a golden period of planetary transits and it is one of which I hope astronomers can take full advantage,” he writes.
- Venus to appear in once-in-a-lifetime event (eurekalert.org)
- Venus to appear in once-in-a-lifetime event (naturenplanet.com)
- NASA Astrophysicist Sten Odenwald to Discuss Transit of Venus (spacedaily.com)
- Looking forward to the Venus Transit by Deborah Lindsey (deretornoacasa.wordpress.com)