Summer 2018 will be a good time for observing Mars. The planet will be at opposition in late July, meaning that it will appear brighter in the night sky. Let’s take a closer look at what’s involved.
What is a planetary opposition?
The opposition of a planet whose orbit is greater than the Earth’s occurs when it is situated opposite the Sun in relation to us. At that point in time, Earth and the planet are aligned on the same side of the Sun.
Earth turns around the Sun in 365 days, whereas Mars takes 687 days to complete one orbit, the result being that the two planets are aligned every 780 days or 26 months. The distance between Earth and Mars is shorter during the opposition, varying between 55.7 million and 101 million kilometers.
At opposition, the planet Mars is visible throughout the night, rising at sunset and setting at the first streaks of dawn, and its brightness is that much greater.
The opposition of Mars in 2018
This year, the opposition of Mars will occur on July 27. The planets evolving on elliptical orbits as they do, the minimal distance between the Earth and Mars will come a few days later, on July 31. On that occasion, Mars will be only 57.7 million kilometers away. It’s been 15 years since Mars got so close to the Earth. And we’ll have to wait until 2035 for the Earth-Mars distance to be closer than this year’s.
Normally, observation of Mars close to the opposition allows us a better look at the details on the planet’s surface. However, at this writing a dust storm has been blowing since the start of the month of June. That storm is so intense that it’s covering the planet’s entire surface. It could last for a few more weeks, or even a few months. It will therefore be of interest to track the evolution of that storm over the course of time.
Finally, it’s also during oppositions that space agencies send probes to the planet Mars. Thus, this past May 5, Nasa launched the Insight probe, which should touch down on Martian soil next November 26. A story to keep an eye on…