Free Astronomy Magazine July-August 2016

13 JULY-AUGUST 2016 SPACE CHRONICLES inner Solar Sys- tem and preserved in the deep freeze of the Oort Cloud for billions of years. The Oort Cloud is a huge region sur- rounding the Sun like a giant, thick soap bubble. It is estimated that it contains trillions of tiny icy bodies. Occasionally, one of these bodies gets nudged and falls into the inner Solar Sys- tem, where the heat of the Sun turns it into a comet. These icy bodies are thought to have been ejected from the region of the giant planets as these were form- ing, in the early days of the Solar System. Karen Meech explains the unexpected observation: “We already knew of many as- teroids, but they have all been baked by bil- lions of years near the Sun. This one is the first uncook- ed asteroid we could observe: it has been pre- served in the best freezer there is. ” C/2014 S3 ( P A N - S T A R R S ) was origi- nally iden- tified by the Pan - STAR - RS1 tele- scope as a weakly active comet a little over twice as far from the Sun as the Earth. Its current long orbit- al period (around 860 years) suggests that its source is in the Oort Cloud, and it was nudged comparatively recently into an orbit that brings it closer to the Sun. The team immediately no- ticed that C/2014 S3 (PANSTARRS) was unusual, as it does not have the characteristic tail that most long-period comets have when they approach so close to the Sun. As a result, it has been dubbed a Manx comet, after the tailless cat. Within weeks of its discovery, the team obtained spectra of the very faint object with ESO’s Very Large Telescope in Chile. Careful study of the light reflect- ed by C/2014 S3 (PANSTARRS) indi- cates that it is typical of asteroids ormation years