I often contemplate when I look up into the sky, how far back in time I am looking. How long does it take for light to travel from different extreme distances to my eyes. The numbers boggle my brain and I easily confuse myself in the process of converting units. But I do know that it takes approx. 8 min. 20 sec., + or – for light to travel from the sun to the earth and approx. 1.25 sec., + or – for light to travel from the moon to the earth. (more on the exact calculations soon.)
The last picture above, shows the furthest back in time that we have seen, so far. This image was taken in 2004 by the Hubble telescope and is one of the first “Ultra Deep Field” (HUDF) images captured. The HUDF images are said to contain approximately 10,000 galaxies and was just a small patch of sky observed in the constellation Fornax which is located in the region below the constellation Orion.
For more useful information regarding the Hubble Deep Field images, please check out an awesome post over at Deep Astronomy.
P.S. My Review of the 2010 Leonid Meteor Shower is now complete and will be published soon.