13-14th December 2012,
Geminids Meteor shower over Paranal Observatory.

© Stéphane Guisard, Los Cielos de América

The Geminids are a meteor shower caused by the object 3200 Phaethon. This would make the Geminids, together with the Quadrantids, the only major meteor showers not originating from a comet. The meteors from this shower are slow moving, can be seen in December and usually peak around the 13th - 14th of the month, with the date of highest intensity being the morning of the 14th. The shower is thought to be intensifying every year and recent showers have seen 120160 meteors per hour under optimal conditions, generally around 02:00 to 03:00 local time. Geminids were first observed in 1862, much more recently than other showers such as the Perseids (36 AD) and Leonids (902 AD). The meteors in this shower and on this picture appear to come from a radiant in the constellation Gemini (hence the shower's name). However, they can appear almost anywhere in the night sky. In the southern hemisphere where this picture was taken, the radiant appears only around local midnight or so. The meteors travel at medium speed in relation to other showers, at about 22 miles per second, making them fairly easy to spot. The Geminids are now considered by many to be the most consistent and active annual shower. Geminids disintegrate while at heights above 38 kilometres (24 mi).

The picture was taken at ESO-Paranal observatory in the Atacama desert in Chile. The 9 telescopes of the observatory main platform can be seen on this image : the four 8m diameter mirror main telescopes (also called the "VLT, Very Large Telescope", the 4x 1.8m auxiliary telescopes and the 2.5m diameter VST ("VLT survey telescope"). All the 9 telescopes telescope are opened and observing.

For sake of clarity, this picture is not a "one-shot" picture. It was obtained by combining a selection of ~30 pictures of a total of 1500 taken continuously that night. Since Earth rotation provokes the stars to move with respect to the landscape, the selected pictures where registered precisely one by one onto one of them, "the main picture" containing the foreground in order to have the stars and meteors aligned to the same sky-referential. I consider it as a "Fake" (and I am not proud of it, this was the first and last time I do such a thing, I promise !) since it makes the viewer believes that I had the chance to capture dozens of meteors during the apparent short exposure time of this image, and this was obviously not the case (I say "apparent short exposure" because the image is obviously not tracked since foreground is neat, and the stars are not trailed).