Mars in opposition: 27 July 2018

Dark sky gazing: Mars in opposition to the Sun.

On the night of 27 July 2018 Mars will reach opposition – ie. Mars & the Sun are on directly opposite sides of the sky as seen from the Earth. Dark sky observers will see Mars rise in the east as the Sun sets in the west and the dark skies of Barrington Tops are the perfect place to see the red planet!

Opposition is also the best time to be viewing Mars, as the distance between Earth and Mars will be minimal, around 58 million km or so. This is the most favourable opposition since the really close one of 2003, so it’s an event to get excited about.

Oppositions in the early months of the year, when Mars is furthest from the Sun, are always poor. The best oppositions occur around August which is very good for Southern observers, as Mars is high in the sky, and the winter sky is usually still and transparent, ideal conditions for watching Mars. The 2018 opposition occurs during July & conditions are good for Southern observers. The cold weather makes warm clothes a must, but atmospheric turbulence is low and skies are likely to be very clear, making Mars’s markings easier to distinguish.

Mars only comes into opposition once every two years and 50 days, and even then it may not be particularly close. Since Mars has the most elliptical of all the planets in the solar system, it can be as far away as 101 million km at a bad opposition, or as close as 55 million km at a good one. That 56 million km difference really matters when you are trying to make out some detail in the surface features in Mars in a telescope!

Although the small red ball is easily visible to the naked eye, you’ll need a telescope to see any of the planet’s markings. If using telescope to see the surface of Mars more closely, be aware that a Mars dust storm started on 30 May that kept growing and by 12 June it was observed to be encircling the entire planet!

Mars Facts:

  • Diameter: 6,794 km
  • Two moons: Phobos & Demios (Fear & Terror)
  • Year: 687 days
  • Day: 1.026 Earth days
  • Mass: 0.107 Earth Mass (0.64 x1024 Kg)

(Article courtesy of The Sky Tonight and

Photo by

#stargazing #darkskies #marsopposition #barringtontops #backtonature #wildernessculture