Gallery | My Favorite Planet Pics | Venus
In 2004, I was able to witness an almost literally once-in-a-lifetime event: the Transit of Venus across the Sun. Because of the odd geometry of our sister planet's orbit, it crosses the Sun's face in pairs: one transit following the other after a period of about 8 years, but then no other for over a century. The last pair was in 1874 and 1882. We're in the middle of a pair right now; the last was in 2004, and the next in 2012.
While I watched the 2004 transit myself with my own eyes, NASA's solar-observing TRACE satellite saw it as well. Pictured above, you can see the transit in visible light (top) -- scattering of sunlight by the thick atmosphere of Venus makes it look like a complete ring -- ultraviolet (bottom left) and the far UV (bottom right). Astronomers were able to learn about Venus's air during this event. Also, planets around other stars have been detected when they transit their stars, so observations like this in our own solar system give us insight into the physics of these events.
Credit: NASA/LMSAL
While I watched the 2004 transit myself with my own eyes, NASA's solar-observing TRACE satellite saw it as well. Pictured above, you can see the transit in visible light (top) -- scattering of sunlight by the thick atmosphere of Venus makes it look like a complete ring -- ultraviolet (bottom left) and the far UV (bottom right). Astronomers were able to learn about Venus's air during this event. Also, planets around other stars have been detected when they transit their stars, so observations like this in our own solar system give us insight into the physics of these events.
Credit: NASA/LMSAL
