Friday, August 30, 2019

Incoming comet

A couple of weeks ago, I took a picture through the remote telescope of a comet coming in from the outer reaches of the solar system, an area called the Oort cloud. This is a theoretical cloud, thought to extend from about 2,000 AU (Astronomical unit - the distance Earth to Sun - about 150,000,000 km) to 200,000 AU. It supposedly contains icy planetesimals (Wikipedia contains some detailed information).

Because its outer reaches are so far from the Sun, the planetesimals can be affected by the gravitational influences of other objects in our galaxy, and occasionally my be deflected towards our Sun. There is a reasonable chance that this comet is one such object. Here's the picture:

The name of the comet is Comet C 2018 W2 Africano. It's the fuzzy spot to the right of the dashed line. At the time of writing, the comet is moving at 50 km/sec towards the Sun and will be at Perihelion (closest to the Sun) on Sep.5 and closest to Earth on Sep 27. It may become visible in common telescopes and possibly even binoculars. Africano is currently in the constellation Camelopardalis. Look for more current positions in as time progresses

Africano will be closest to Earth on Sept 27 at around 75 million km from Earth.