As if to celebrate its second anniversary of launch, Tianwen-1, the China National Space Administration’s first Mars space probe, has sent a stunningly detailed snapshot of Phobos. It is the largest Martian moon, famous for its potato shape. This quality image provides valuable data for scientists to study the topography and environment of Phobos, bringing China one step closer to its goal of planetary exploration, competing with the United States.
La mission Tianwen-1, launched on July 23, 2020, was a great success for the National Space Administration of China. The probe escorted a lander and the Zhurong rover to Mars, making China the second country after the United States to successfully operate a rover on the surface of the planet. Conversely, American machines, Curiosity et Perseverance, Zhurong does not have a robotic arm. Its telescopic micro-imaging camera or the SWIR (short-wave infrared) spectrometer are used to study the minerals present on the Martian surface.
The Tianwen-1 probe entered Mars orbit in February 2021, and the rover has landed on the planet to begin operations in May 2021. Nevertheless, with falling temperatures during the Martian winter as well as poor conditions related to sand and dust, the latter entered a “hibernation” mode on May 18. Its revival is expected in December, when the landing zone enters the Martian spring, bringing better weather.
Recently, the Chinese probe delivered startling images of its surroundings over the past two years, including the entire surface of Mars at the beginning of the month, completing all the tasks assigned to him. To celebrate two years since its successful launch, the Chinese space agency released the most detailed snapshot to date of the larger of Mars’ two moons, Phobos, via the news agency. Xinhua.
Revealing images of the origins of Phobos?
The origin of the natural satellites of Mars is still debated within the scientific community. Moreover, in 2018, an international team of researchers raised a new hypothesis, published in the Journal of Geophysical Research: Planets. The authors advance the argument of the collision of Mars with a giant celestial body as the origin of Phobos and Déimos. This collision, with an object the size of Ceres (the only dwarf planet in the asteroid belt orbiting between Mars and Jupiter), sent debris of rocks and dust into space. This rubble would then have gathered under the gravitational effect of the red planet to form Phobos and Deimos.
You should know that Phobos – 22 kilometers in average diameter – is marked by impact craters and “grooves”. Traveling 6000 km above the Martian surface, it is the closest satellite to its planet, to the entire solar system, much closer than Deimos or even our Moon — the Earth-Moon distance is 384,400 km . Phobos circles Mars in just 7 hours and 39 minutes.
The Tianwen-1 operation team captured the moment when the orbital probe was close to Phobos, with the correct orientation. Thus, she obtained a clear image of the satellite in its state of ” full moon », a declared China National Space Administration.
This image, released by the China National Space Administration (CNSA) and China Planetary Exploration (PEC), will allow an in-depth study of the topography of Phobos and to learn more about its history. Moreover, on the photograph, the agency identifies the crater of Öpik, of circular shape. Its name honors the Estonian astronomer and astrophysicist Ernst Öpik, who postulated the theory of a cloud of comets and icy objects far beyond Pluto and the Kuiper belt — now known as the cloud. from Öpik-Oort. He had also predicted, as early as 1922, the impact craters present on Mars.
A sealed fate for Phobos
Phobos was discovered on August 18, 1877 by American astronomer Asaph Hall, a few days after the discovery of Deimos. Its surface is covered with a layer of dust about a meter thick and is dotted with craters and scars, caused by impacts of meteorites. The best known is the Stickney Crater, whose name refers to Asaph Hall’s wife, Angeline Stickney, and whose diameter reaches 9.5 km. First, the scientists estimated that the other streaks represented the beginnings of multiple breaks in this satellite. But, currently, they would lean for small pieces of Mars, attracted by Phobos, come to strike the latter. Moreover, this is what the Chinese agency also concludes, the streaks on the surface of Phobos, at the top left of the photo, could have been formed by these impacts. The most recent grooves are called stretchmarks by researchers.
But the fate of Phobos seems sealed. Indeed, in avril 2022NASA reported in a press release : « Scientists already know that Phobos is doomed: the moon is closing in on the Martian surface and is destined to crash into the planet in a few tens of millions of years “. This is how the Martian satellite would approach Mars by about two meters every hundred years, under the effect of gravity.
The orbiting probe will continue to perform tests and prepare for future tasks, the space agency said. Not to mention that with Tianwen-1, China was the first nation to attempt to send both a probe and a rover on its first mission to Mars. NASA sent several probes around Mars before attempting a landing.