Rovers, landers, parachutes and fragments of failed landings: there's a plethora of objects on Mars, some of which are hiding a message.
There are several missions currently operating on the Martian surface: to go around the red planet, in fact, there are still veterans Curiosity and InSight, in addition to the two rovers quasi-twins sent last, by China and the U.S., to explore Mars.
In addition to Perseverance and Zhurong, the two large rovers engaged in the analysis of the Martian surface and atmosphere, the small InSight and Curiosity are therefore among the objects still "alive" on the surface of Mars.
And yet, since the first Soviet mission to Mars to date, we have left on the planet an amount of objects that, according to scientists, weighs more than 9 tons.
A small army of broken toys
The first object to arrive on Martian soil was, back in 1971, the very heavy Mars 2 probe, over a ton of the most advanced Soviet technology that, due to problems during its descent, crashed on the planet's surface.
Mars 3, identical in appearance and size to the first Martian host, arrived a few days later: unlike the previous lander, it managed to transmit data - but only for 20 seconds, after which it officially became part of the planet's collection of broken toys.
There are currently 21 such objects populating the red planet, from ESA and Roscomos' poor Schiapparelli destroyed in the 2016 surface impact to the legacies of much older missions, such as the old Viking 1 and 2 landers launched by NASA in 1976 and operating until the 1980s.
The first rover able to arrive in one piece on the surface of Mars and move was Sojourner, which also brought with it, on the Pathfinder mission, the lander that became the Carl Sagan Memorial Station.
Among the landing sites of the landers that have reached Mars since 71, some have become real memorials: the one of Pathfinder is dedicated to Sagan, the astronomer who inspired a generation of astronauts, while the one where Spirit landed in 2004 is now dedicated to the memory of the tragic mission of Space Shuttle Columbia, in which seven astronauts lost their lives.
It is not easy to establish the amount of objects present on the Martian surface: just think of those that have been destroyed in no one knows how many pieces, such as Schiapparelli, or the various pieces that physiologically a lander carries with it, including parachutes and heat shields.
There are also several objects in orbit around Mars that are just waiting to fall to the planet's surface: Mariner 9, the probe that sent us photos of the small moons Phobos and Deimos, for one, has been in orbit since 71.
The Perseverance case
But we have begun, perhaps with the increasingly vivid promise of finding life outside our planet, to send other objects to the surface of Mars: from the plaques, inspired once again by Carl Sagan's design, installed on Pioneer 10 and 11 in the 1970s, we have come a long way.
And so, while Zhurong seems to be more busy taking selfies, Perseverance has brought with him several objects to leave to posterity, on Mars.
The parachute itself used for the landing has become, in the will of NASA, a message: the huge white and orange parachute carries a coded message that has been deciphered via Twitter, and which bears the motto of the Jet Propulsion Laboratory "Dare Mighty Things", or "Dare extraordinary things". It would appear that only six people, worldwide, knew of this message before the deployment of the parachute.
Perseverance, launched at the height of the pandemic by Covid-19, also brought to Mars a tribute plaque to the health workers, a small metal plaque installed on the rover.
Aboard Percy, as those at JPL call her, also the more than 10 million names sent in by people around the world with the promise of having their name on Mars and all 155 essay finalists in the contest launched by NASA to name the rover.
Most visible, so much so that it immediately attracted the attentions of Earthlings, is the caliber plaque of Perseverance's powerful camera, bearing images of life on Earth but also the motto "Two worlds, one beginning."
Little Ingenuity, finally, the helicopter that first flew over a non-terrestrial atmosphere, carried with it, and presumably will leave on Mars, a small fragment of the aircraft designed by the Wright brothers in 1903.