Friends, we are witnessing a rare event that only occurs twice in a lifetime.
At the moment, Venus has aligned with the Earth and Sun, and has begun to pass across the Sun's surface as I type this. Unfortunately, in the UK we will only be able to see the final 20 minutes or so at sunrise, and that is if the weather is not cloudy at 5.00am. Personally, I am getting up to watch this, as I have always loved astronomy and read solely books on natural geology and astronomy from age 5-11...
This image was taken by NASA a couple of hours ago. It shows Venus approaching the outer disc of the Sun.
Personally, I find this event absolutely fascinating. The reason it doesn't happen often is because the orbits of Venus and Earth are so different. Venus is on a different axial tilt to earth, and as a result it rarely intersects between Earth's orbit and the Sun. So a decent transit is VERY rare.
Indeed the last transits before today (and the 2004 first part of the pair) were in 1874 and 1882. The next transit is in 2117, in 105 years. So it is highly unlikely that any of us will be around to see it.
The main implication of it is that scientists are perfecting a method of using infra-red spectroscopy and emission spectra from atoms to actually analyse the atmospheres of planets hundreds of thousands of light years away. The atoms and particles only absorb certain frequencies of light, and by this individual signature you can calculate the atmosphere of a planet in transit by measuring the amount of light missing from the emission spectra (e.g. Hydrogen looks like this:
The scientists are using Venus to check that their equipment and methods of calculation work properly, and since the Sun is too close to actually measure Venus directly (it would fry the Hubble Space Telescope), they are using the Moon as a giant mirror and measuring the reflection off of that!
This method will be used to discover earth-like planets in the universe, and potentially find other Earths and Super-Earths (planets much larger than Earth but capable of sustaining life).
I had to share this, I find the topic to be incredibly interesting and I hope that some of you are also witnessing this spectacular cosmic event.
Here's some links:
Live feed of the transit: https://www.youtube.com/watch?v=t79iec2b-3Mhttp://www.wired.com/wiredscience/2012/06/watch-transit-venus/
Live blog noting pictures, events and times: http://www.guardian.co.uk/science/2012/jun/05/transit-of-venus-live-coverage
Site that will show you how to figure out when the transit occurs where you are: http://www.sunaeon.com/venustransit/