Planets on Parade!
Mind Bending | May 1, 2018
Barlow SkyWatch: Opposition Series Part 1
By Alan J Peche, Director, Barlow Planetarium
The planets circle the Sun like a bunch of cars on a circular track.
The planets in the inner lanes move faster than the planets on the outer lanes. This summer the Earth – faster than Mars, Jupiter and Saturn – will be passing each of these planets causing what astronomers call an “opposition”. The opposition occurs when the Earth is directly between the Sun and the opposition planet. A planet that is at opposition will rise when the Sun sets and set when the Sun rises. As an added bonus, these oppositions will occur when the planets are the closest and the brightest to us on Earth.
May 8: Jupiter Opposition
Earth will pass directly between Jupiter and the Sun at 7:28pm (shortly before sunset) on May 8, 2018. Jupiter averages about 5.2 astronomical units (au) from the Sun. Scientifically, 1 au is about 93 million miles. At opposition Jupiter will be just 4.4 au from Earth. That is about 15% closer than the usual 5.2 au!
Although Jupiter will be super bright – the forth brightest object in the sky after the Sun, Moon and Venus – it will be best enjoyed through a small telescope or binoculars.
All three of the oppositions will occur within a short 79 days. This is the shortest span since 1984 when the three oppositions occurred in an even shorter 57 days. However, the most impressive occurred in 1980 when they all happened in less than 3 weeks – 18 days! The next triple opposition of the three outer planets that will be impressive will be in 60 years – 2078! Enjoy the planets this summer.
The best time to view each of these oppositions will be around midnight the days surrounding their opposition dates.
