Traveling to the southern hemisphere is a treat for anyone, but for astronomy enthusiasts, it holds a special appeal. The center of the Milky Way, hidden in near-horizon murk for those of us in the northern hemisphere, shifts to an overhead position early in the evening in mid-July. The greatest concentration of visible star clusters and nebulae is found here. Visible as well are the Large and Small Magellanic Clouds, dwarf galactic companions to our larger home galaxy, easily detectable by naked eye. It is a glorious sight!
I want to give you several ways of seeing our galaxy in its full beauty. First up is a remarkable 5 gigapixel image created by stitching together 37,000 individual images of the sky, taken at multiple locations around the world. The web site for the project, which includes a zoomable full-resolution version of the image can be found here: http://skysurvey.org/.
Next is a time-lapse video, several of them actually, taken at the Very Large Telescope site in Chile. Some explanations of what you are seeing: the sky first gets dark enough to see the stars at sunset, but the landscape is still visible. The sky gets really dark after the moon sets. The bright streaks across the sky are not meteors–remember that this is a time lapse, so whatever these objects are, they are moving slowly enough to be captured in multiple frames. They are satellites, any number of which you can see in a dark sky. The bright yellow beam that occasionally shoots from the telescope dome is part of the telescope’s adaptive optics system that compensates for atmospheric distortion. It creates an artificial “star” that the instrumentation can use to adjust its optics and create a much sharper image. More information about adaptive optics can be found here: http://en.wikipedia.org/wiki/Adaptive_optics
The apparent movement of objects in the sky is of course actually due to the Earth’s rotation. Want to make that more obvious? Then take the videos from above and edit them to keep the sky stationary while the Earth moves.
Be sure to view both of these in highest-resolution HD!
And finally, something completely different! It doesn’t want to let me embed it, so here is the link: http://vimeo.com/24064252. Mesmerizing!