While athletes from all around the world have gathered in Beijing to show their skills at the ongoing Olympic Games, China's Mars probe Tianwen 1 has sent a selfie video from 325 million kilometers away to celebrate the opening of the grand sporting event.

Tianwen 1 is the country's first independent Mars mission that includes an orbiter, a lander and a rover. The selfie video, released by the China National Space Administration, features Chinese national flag and Beijing 2022 Olympic and Paralympic Winter Games emblems, which were installed on Tianwen 1 orbiter before its launch. The video was taken by a camera mounted on a selfie stick attached to the orbiter. The selfie stick is made of shape memory composite and weighs only 800 grams. Its arm is 1.6 meters long that can unfold itself at a certain temperature.

"The main difficulty in taking pictures in Mars orbit is the uncertainty of the target characteristics of the objects being photographed," said Wu Di from an institute affiliated to the China Aerospace Science and Technology Corporation, who led the design of the camera.

Considering several shooting conditions, Wu's team designed an adaptive exposure imaging control strategy centered on the national flag on Tianwen 1 orbiter. "The exposure time can be actively adjusted through the calculation of the acquired images to ensure that a clear image of the national flag can be acquired under continuous changes in lighting conditions," Wu said.

Previously, Tianwen 1 orbiter had sent greetings from the Mars orbit on Lunar New Year's Eve with a selfie video taken by the camera.

As of Feb 4, Tianwen 1 orbiter has been working in orbit for 561 days. The rover Zhurong has been operating for 259 Martian days and has driven a total of 1,537 meters on the surface of the planet.