Answer:
Mars is a popular point of interest due to how it likely used to be very similar to the Earth today. All three spacecraft sent to Mars have a common goal: To find evidence of previous or existing life. Perseverance and Tianwen-1 are both collecting Martian soil samples to be studied for past or present microbial life, and Tianwen-1 is also able to scan the underground for water reservoirs. The UAE's Hope orbiter will orbit the red planet to study its weather patterns to see how weather changes the release of hydrogen and oxygen into space and create a map of the Martian climate.
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I don't know how long the answer is supposed to be, so if it's supposed to be longer just try to stretch out some sentences, or use the sources I listed below to get more information. If I helped, Brainliest would be appreciated :)
Sources:
1) https://www.businessinsider.com/three-mars-missions-arrive-february-from-nasa-china-uae-2021-1
2) https://www.space.com/16777-curiosity-rover-many-mars-missions.html
3) https://hub.jhu.edu/gazette/2015/january-february/ask-an-expert-why-care-about-mars/
4) https://en.wikipedia.org/wiki/Tianwen-1