Xiao Long, a planetary geoscientist at the China University of Geosciences (Wuhan) Photo: Courtesy of the Beijing Association for Science and Technology

Xiao Long, a planetary geoscientist at the China University of Geosciences (Wuhan), estimates that the first human landing on Mars will occur in around 2050. 

We no longer face any significant technological barriers in unmanned missions to Mars, but still have difficulty in completing manned missions, which require larger rockets with greater thrust and the technology to safely return from Mars to Earth, Xiao said in an exclusive interview with the Global Times. 

He noted that both the US and China are currently developing heavy launch vehicles. The technology for a safe return from Mars is expected to be preliminarily validated by around 2030.

"In addition, there is also a significant amount of work to be done regarding the physiological and psychological issues faced by astronauts during the interstellar long-distance journey, which would last at least 500 days," he said. 

Xiao started his career in planetary geology research exactly 20 years ago when China kicked off its Chang'e lunar exploration program [in 2004]. Before that, he focused on Earth studies. 

Mars shares many similarities with Earth and holds special significance in our understanding of the formation and evolution of planets and the solar system, as well as the search for extraterrestrial life, Xiao continued. 

To Xiao, the ultimate goal of Mars studies is to scientifically elucidate the formation and evolution process of Mars from its early stages to the present and into the future, find out the driving factors behind the process, and discover whether life exists on the planet. 

From an application perspective, scientists like Xiao are also trying to figure out whether Mars can become a second home for humans. "Short-term visits or immigration to Mars are possible for some individuals and are likely to be realized within this century. However, it is impossible for the entire human population to migrate to Mars," Xiao said.

Xiao shared with the audience at a New Year's Eve event hosted by the Beijing Association for Science and Technology how his team analyzed scientific data from China's Mars rover Zhurong's multispectral camera and for the first time found petrological evidence of marine sedimentary rocks on the surface of Mars. 

"We analyzed the 106 groups of photos from Zhurong daily, trying our best to look for a tale-tell signature of the existence of an ocean on Mars. But before finding any evidence, my teammates and I started to have similar dreams about oceans on Mars. In my dream, the ocean on Mars was restored and was surrounded by lush and dense forests. I could even identify each type of vegetation in the forests," Xiao told the audience.

"It is not rare for people to dream of things that are on their minds during the day. But for scientists, it could be a problem as we have to stay objective throughout the research and prevent our subjective interpretation from getting in the way," Xiao said. He and his teammates kept reminding each other to stay cautious and realistic until evidence waw found.

"This case clearly illustrates how we do science research. We have to stay grounded while looking up to the sea of stars," Xiao said. 

Xiao also shared a global image map, created by China's Tianwen-1 Mars probe using data captured by a medium-resolution camera at the event. He said that the image has a spatial resolution of 76 meters, making it the highest-resolution global color image of Mars publicly available to date. This image also demonstrates that China's Mars exploration capabilities have reached a high level, he noted.

Currently, humans have conducted nearly 50 Mars explorations, and our understanding of the macroscopic topography and geomorphological features of Mars is relatively clear. However, exploration is still ongoing regarding the early Martian atmosphere, climate, geological environment, magnetic field evolution, and whether conditions for the creation of life exist. China has successfully achieved its first Mars exploration, accomplishing the three major objectives of orbiting, landing, and rover exploration in this single mission. China is the first country to have accomplished this in the history of Mars exploration and the second country globally to have completed a similar mission, according to Xiao. 

Stepping into 2024, Xiao hopes China can continue to make progress in lunar, Mars, and asteroid exploration missions. "We hope that the Tianwen-1 satellite will return more high-quality data, and that the Zhurong rover will be able to continue its work. We also hope that the Tianwen-2 asteroid sample return mission will be implemented on schedule, and that the Tianwen-3 Mars sample return mission will be approved as soon as possible," he told the Global Times.