Weymouth Astronomy

The Night Sky - August 2017

Following the extended twilight of recent months August brings a returntodarker and ever longer nights. On Moon-less evenings during the opening and closing weeks of August the Milky Way can be seen streaming north, up out of Sagittarius low to the south of the sky. By Midnght (BST) Sagittarius is starting to sink into the south south-west. This month also plays host to the Perseid meteor shower produced by debris from the comet Swift-Tuttle. From midnight to dawn on the 12/13th (if clear) is the best time to observe them. The Night Sky

Highlights of the Month:

  • 2nd (after sunset): The Moon and Saturn
  • 12th/13th (midnight to dawn): Perseid meteor shower peak
  • 16th (08:40 BST): A daylight Occultation of Aldebaran
  • 19th (before dawn): Venus and a thin crescent Moon
  • 25th (after sunset): Jupiter below a thin crescent Moon

Perseid Meteor ShowerPerseid Meteor Shower (Maximum on 12/13th)

The Perseid meteor shower occurs when Earth moves through the trail of dust and debris left by Comet Swift-Tuttle as it orbits the sun; the debris hits Earth's atmosphere and burns up, creating the white-hot streaks we see in the sky. Most of the pieces of debris which move at 37 miles per second (59 kilometers per second) are about the size of a grain of sand. The Earth is passing through a particularly dense clump of debris this year — the source of the outburst — caused by the influence of Jupiter's gravity on Swift-Tuttle's trail. The number of meteors is increasing as Earth penetrates the heart of the debris and will diminish again once it passes through


Noctilucent clouds

Noctilucent clouds Noctilucent clouds also known as polar mesospheric clouds are most commonly seen in the deep twilight towards the north from our latitude. They are the highest clouds in the atmosphere at heights of around 80 km or 50 miles. Normally too faint to be seen they are visible when illuminated by sunlight from below the northern horizon whilst the lower parts of the atmosphere are in shadow. So on a clear dark night as light is draining from the north western sky after sunset take a look towards the north and you might just spot them.

Information collated from Jodrell Bank and Astronomy Now magazine