File:Is it a Bird…?.jpg

English: Here we see a swirling starscape above ESO’s La Silla Observatory. A long series of individual images have been combined to form this striking shot, allowing the motion of the Earth to be captured as it rotates, with stars producing long trails around the sky’s south pole as it does so.

The familiar silver dome of the MPG/ESO 2.2-metre telescope is seen in the foreground. Moving into the shot, we next see the white dome of the ESO 1-metre Schmidt telescope, the rectangular building of the New Technology Telescope, and at the back, the double domes of the ESO 3.6-metre telescope with its adjacent smaller sibling, the now-decommissioned Coudé Auxiliary Telescope.

But what are those streaks in the sky? Is it a bird? Is it a plane? Well, yes, it is indeed a plane. In fact, if you look very closely, you can see not one, but three horizontal trails from three separate planes, moving from left to right in the sky. They are not rotating with the stars, so it is clearly something a little closer to home… In fact, La Silla lies near a fairly busy flight path, and those streaks in the sky are aircraft travelling from Calama to Santiago.

This image was taken by ESO Photo Ambassador Alexandre Santerne. When not taking these beautiful images, Alexandre travels around the world (including Chile) to pursue his research on extrasolar planets.