It may be millions of kilometres away, but Earth hasn’t forgotten Mars is having a big celebration. On 7 February 2021, the red planet celebrates the turn of a new year – at least according to our calendar-keeping on Earth.
Since one Mars year is 687 Earth days (and 668.6 Mars days, or sols), the occasion only comes around roughly every two Earth years, marked by the spring/autumn equinox in the northern and southern hemispheres respectively.
Since the current Martian calendar started in 1955, that makes the new year Mars Year 36.
It’s going to be a big one for our planetary friend. Three missions are due to arrive at Mars in the coming days. The United Arab Emirates has sent an orbiting probe named Al-Amal, or Hope, which is due to arrive first, on 9 February. It will study Mars’ atmosphere and weather, with an eye towards assessing the planet for a human settlement.
China’s Tianwen-1 is expected to reach Mars orbit on 10 February. The mission consists of an orbiter, a lander and a solar-powered rover, the latter two of which will be deployed to the surface in May, for a comprehensive study of the Utopia impact basin.
The US sent NASA’s Perseverance, a rover scheduled to land on 18 February in the Jezero Crater, a target rich in clays – evidence that the region was once contained water. The rover will look for evidence of past life and habitability, and collect samples to be returned to Earth by two other missions currently in development.
It’s no coincidence that all three missions are arriving at the same time: due to the challenges involved in sending a spacecraft to Mars, there’s a window that comes around roughly every two years and two months that allows a spacecraft to reach Mars with the minimum energy required. That window was most recently in July to September of last year.
That the new arrivals are all happening at the Mars new year is, therefore, a happy coincidence. Since all three missions will be exploring different parts of Mars, Mars Year 36 promises to be a brave new age for Mars science.
So happy new year, Mars! We hope you like your new robotic buddies. And may we celebrate with you in person sometime soon.
You can read more about the Martian year on the ESA website.