China's Tianwen-1 probe over 100 million km from Earth

Mars probe Tianwen-1 is seen in its first selfies in space on Oct 1, 2020. [Photo: CNSA]

The probe (探测器 tàncè qì) for China's first Mars (火星 huǒxīng) mission (任务 rènwù) Tianwen-1 is over 100 million kilometers (千米 qiānmǐ) from Earth (地球 dìqiú) after 144 days of travel, according to the China National Space Administration (CNSA).

As of 9:00 p.m. Monday, the probe, in sound condition, had flown for about 360 million kilometers and was at a distance (距离 jùlí) of more than 100 million kilometers away from Earth and 12 million kilometers from Mars.

The distance between the Red Planet and Earth varies periodically from 50 million to more than 400 million kilometers, and when the probe reaches Mars, it will be about 190 million kilometers from Earth.

The spacecraft, launched by a Long March-5 rocket on July 23, is expected to complete (完成 wánchéng) orbiting, landing and roving in one mission.

It has already completed multiple tasks, including capturing an image of Earth and the moon as well as a "selfie," three orbital corrections, a deep space maneuver and payload self-checks.

Several more orbital corrections will be conducted before the probe enters the Mars orbit around mid-February.

Customary units of length 常见长度单位:

[wēimǐ]微米 micron

[háomǐ]毫米 millimeter

[límǐ]厘米 centimeter

[fēnmǐ]分米 decimeter

[mǐ]米 meter

[qiānmǐ]千米 kilometer

[gōnglǐ]公里 kilometer

[chǐ]尺 equal to 1/3 meter

[cùn]寸 equal to 1/3 decimeter