m e a s u r e a u t u m n t i m e
A s t r o n o m y o c t. 2 o l 5
Venus attains its greatest brilliancy (at mag. -4.5) on Sep. 21st. On Oct. 8th the Moon passes very close to Venus, an event called a lunar occultation. On Oct. 9th Venus passes Leo's brightest star Regulus (mag. +1.4). Mercury (mag. +0.9) reaches its greatest western elongation (angular distance from the sun is at its greatest and half-illuminated (50%) in sunshine) on Oct. 16th. On Oct. 17th Mars and Jupiter experience their own planetary conjunction. Venus reaches its greatest western elongation on Oct. 26th. By a wonderful coincidence, Venus, Mars (mag. +1.7) and Jupiter (-1.6) form the closest grouping at around 03 hours.
A grouping of three planets inside a circle having a 5-degree diameter on the sky’s dome is known as a planetary trio. Venus, Jupiter and Mars will form a planetary trio in the east before dawn from Oct. 24 to Oct. 29. Another grouping of three planets won’t happen again until January 10, 2021. p i c 1, 2, 3