China Plans a New Geological Map of Mars by 2028
Chinese scientists are drawing up a new geological map of the whole planet Mars, with a completion target of the end of 2028, according to Hou Zengqian, an academician of the Chinese Academy of Sciences and chief scientist of the country’s Tianwen-3 Mars sample-return mission.
Hou disclosed the plan on September 28 while speaking at a seminar on high-quality development held by the Institute of Geology of the Chinese Academy of Geological Sciences in Beijing. He said the map will put forward a Chinese proposal for dividing Martian geological time, part of an effort to have a classification standard developed in China recognized internationally as a common reference.
Geological maps are not just drawings. They assign ages to surfaces and rocks, which lets researchers compare events across a planet and place samples in a timeline. For Mars, scientists still debate how to draw those lines, partly because the planet’s record is patchy and different research groups have used different anchor points. A single widely accepted framework would make it easier to compare results from orbiters, landers and rovers.
Hou said the new map will incorporate recent discoveries made by Zhurong, China’s first Mars rover, which landed in 2021 in a region called Utopia Planitia. According to the account he gave, Zhurong’s data suggest that a planet-wide ancient ocean existed on Mars around 3.5 billion years ago, and that short-lived flooding may have occurred as recently as about 1.6 billion years ago. Both findings would be reflected in the new map.
The project’s core output also includes a large-scale geological map of the mission’s landing area, drawn at a scale of 1:50,000, along with a set of specialized map collections produced at the same time. Such detailed local maps matter because they help engineers and scientists choose safe landing sites and interpret what a rover finds once it is on the ground.
Hou is not only a mapmaker. He is the chief scientist of Tianwen-3, a mission designed to collect samples from the Martian surface and bring them back to Earth — a technically demanding undertaking that only a handful of countries have attempted. China has already sent an orbiter, lander and rover to Mars, and is now working toward returning material for laboratory study.
The announcement fits a broader pattern in China’s space science: missions that generate large volumes of data are paired with efforts to organize that data into long-lived reference works. Similar work has been done closer to home, including detailed mapping of the Moon’s surface using data from Chinese lunar probes.
Whether a Chinese-led Martian timescale gains worldwide traction will depend on the science behind it and on how openly the underlying data and methods are shared. For now, the plan sets a concrete deadline — the end of 2028 — and a clear ambition: to help write the timeline of another planet.