This month, Mars will come the closest to Earth it will be for the next 17 years, making it bigger and brighter than usual.
Both Earth and Mars follow elliptical (oval-shaped) orbits around the Sun. However, because Earth is closer to the Sun than Mars, it speeds along its orbit more quickly than the red planet. We take two trips around the Sun in about the same time it takes Mars to take one! When Earth lines up directly between Mars and the Sun, we say that Mars is in opposition. This happens every two years or so, and this year will occur on 27 July.
If this is a common occurrence, what makes this year’s opposition so special?
Mars perihelion is the point when the planet is closest to the Sun in its orbit. When this occurs within a few weeks of opposition, we get a perihelic opposition and Mars appears even bigger and brighter. These perihelic oppositions are not nearly as common, happening only every 17 years or so!
Not to complicate things further, but other elements in nature such as gravitational tugging from giant planets like Jupiter, means Mars’ and Earth’s orbits aren’t perfectly stable. This means that some perihelic oppositions bring us closer than others. The 2003 opposition was especially significant, being the closest opposition in the last 60,000 years! While not quite as favourable this year, Mars will still only appear about 4% smaller than the 2003 viewing. The view through a telescope will greatly improve compared to our usual sight of the planet, so it’s well worth catching a glimpse. It’s more than likely the next time the two planets are at perihelic opposition in 2035, humans will have walked upon the surface of Mars!
When can I see Mars?
Luckily, viewing Mars during this exciting celestial event is not restricted to the 27 or 31 of July. You will still catch superb views for several weeks on either side of opposition. While telescope viewing will yield the best results, the unaided eye will still spot Mars looking like the brightest, reddest ‘star’ in the night sky. In early July, you’ll have to stay up until the early hours of the morning for a perfect view of the planet overhead. However, as the weeks go on, suitable viewing will occur earlier each night so you should be able to spot the beauty in the sky as it rises in the east shortly after dinner time. Check out the handy table below.
We are hosting an array of Mad About Mars events to celebrate the two months of stellar Mars-Gazing…extended Zeiss telescope hours, a family-friendly open night and two Mars-themed sci-fi nights!