Weymouth Astronomy

The Planets - August 2017

Observing the planets can be extremely rewarding. Everyone remembers the first time they observed Saturn and it's rings or the gas giant Jupiter and it's Galillean Moons. Solar System


Given a very low western horizon, the innermost planet might just be seen after sunset at the beginning of August. Binoculars may well be needed but please do not use them until after the Sun has set.


Venus is visible in the east before dawn this month, rising around 3 hours before sunrise. Its magnitude dims slightly during the month from -4 to -3.9 as its angular diameter shrinks from 14.5 to 12.5 arc seconds. Its elevation before sunrise is greatest on August 2nd when Venus lies close to the open cluster M35 in Gemini.


Mars passed behind the Sun in July, but will be hidden in the Sun's glare all month so cannot be observed.


Now four months after opposition, Jupiter can still be seen low in the southwestern sky after nightfall. It sets at about 11:30 BST as the month begins. Jupiter lies in Virgo initially some 8 degrees to the west of Spica, reducing to 4 degrees as the month progresses and will pass Spica on September 11th on its journey towards the lower parts of the ecliptic.


Saturn came into opposition on June 11th and will be at its highest elevation due south as darkness falls. Saturn ceases its westwards, retrograde, motion on August 25th. Saturn now lying in the southern part of Ophiuchus between Sagittarius and Scorpius, only reaches an elevation of 17 degrees above the horizon when due south so hindering our view of this most beautiful planet.

Information collated from Jodrell Bank and Astronomy Now magazine