what-is-tianwen-1-chinas-mars-mission

Context: China is going to launch its first Mars mission, the ‘Tianwen-1’, which is expected to land on the Red Planet’s surface in mid 2021. 

More about the news:

  • The success of the mission will make China the third country to achieve a Mars landing after the USSR and the United States.
  • China’s previous ‘Yinghuo-1’ Mars mission, onboard a Russian spacecraft, had failed after it could not leave the Earth’s orbit and disintegrated over the Pacific Ocean in 2012.

About the Tianwen-1 mission:

  • The Tianwen-1 mission will lift off on a Long March 5 rocket, a launch system developed by China from the Wenchang launch centre, and will carry 13 payloads (seven orbiters and six rovers) that will explore the planet.
  • The Tianwen-1 is an all-in-one orbiter, lander and rover.
  • Two candidate landing sites on Mars have been identified, one of them being Utopia Planitia, according to Space News.
  • Objectives: It will search the Martian surface for water, ice, investigate soil characteristics, and study the atmosphere, among completing other objectives.
    • The Chinese mission will be the first to place a ground-penetrating radar on the Martian surface, which will be able to study local geology, as well as rock, ice, and dirt distribution.

Previous Mars missions:

  • The USSR in 1971 became the first country to carry out a Mars landing - its ‘Mars 3’ lander being able to transmit data for 20 seconds from the Martian surface before failing. The country made its second and Mars landing two years later in 1973.
  • The second country to reach Mars’s surface, the US, holds the record for the most number of Mars landings. 
  • India and the European Space Agency have been able to place their spacecraft in Mars’s orbit. 
    • India’s Mars Orbiter Mission (MOM) or ‘Mangalyaan’ was able to do so in September 2014.
    • The Rs 450 crore project was placed in the orbit by the PSLV rocket on November 5, 2013
    • It’s big achievement has been the preparation of a Martian Atlas using the thousands of images sent by MOM.
    • India became the fourth nation after the US, Russia and EU to reach the Red Planet orbit, and also did it in the first attempt. It was hailed as the most cost effective mission, being cheaper than NASA's Maven Orbiter.
    • Mars Orbiter Mission 2 (MOM 2) also called Mangalyaan 2 is India's 2nd interplanetary mission planned for launch to Mars.

NASA missions 

  • Since 1976, it has achieved 8 successful Mars landings, the latest being the ‘InSight’ in 2019 (launched in 2018).
  • Newer missions have since transitioned from their earlier strategy of “Follow the Water” to “Seek Signs of Life”.
  • The twin Viking landers of 1976 were NASA’s first life detection mission, and although the results from the experiments failed to detect life.
  • The Pathfinder mission and Mars Exploration Rovers (Spirit and Opportunity) were sent to Mars to “Follow the Water,” recognizing that liquid water is necessary for life to exist on Earth.
  • The Mars Science Laboratory (which includes the Curiosity rover) was sent to Mars to determine whether Mars had the right ingredients in the rocks to host life, signaling a shift to the next theme of “Explore Habitability”. 
  • Upcoming mission: NASA is also launching its own Mars mission– the ambitious ‘Perseverance’ which aims to collect Martian samples and bring them back to Earth in a two-part campaign.
    • It marks a further shift to the current science theme “Seek the Signs of Life” using Astrobiology. Astrobiology is a relatively new field of study, where scientists from a variety of disciplines (astronomy, biology, geology, physics, etc.) work together to understand the potential for life to exist beyond Earth.
    • Finding fossils preserved from early Mars might tell us that life once flourished on this planet. 
    • We can search for evidence of cells preserved in rocks, or at a much smaller scale: compounds called biosignatures, which are molecular fossils, specific compounds that give some indication of the organisms that created them.

 

Image source: NASA

Significance of  Mars exploration: After the Moon, the most number of space missions in the Solar System have been to Mars. 

  • Earth like features: Although Mars is starkly different in many ways from the Earth, it has several Earth-like features– such as clouds, polar ice caps, canyons, volcanoes, and seasonal weather patterns.
  • Signs of presence of water: In the past few years, Mars missions have been able to discover the possible presence of liquid water on the planet, either in the subsurface today or at some point in its past.
  • May support life: Possible presence of water has made space explorers more curious about whether the planet can sustain life. 

About Mars

  • Mars, fourth planet in the solar system in order of distance from the Sun and seventh in size and mass. 
  • It is a periodically conspicuous reddish object in the night sky. 

Mars’ atmosphere is composed primarily of carbon dioxide (about 96 percent), with minor amounts of other gases such as argon and nitrogen. 

  • The atmosphere is very thin, however, and the atmospheric pressure at the surface of Mars is only about 0.6 percent of Earth’s (101,000 pascals).
  • The primary reason for Mars’ atmospheric loss is the solar wind!

Temperature: Without a "thermal blanket," Mars can't retain any heat energy. 

  • On average, the temperature on Mars is about minus 80 degrees Fahrenheit (minus 60 degrees Celsius). 

Mars has two small moons: Phobos and Deimos. Both Phobos and Deimos were discovered in 1877 by American astronomer Asaph Hall. 

  • The moons appear to have surface materials similar to many asteroids in the outer asteroid belt, which leads most scientists to believe that Phobos and Deimos are captured asteroids.

Earth Vs. Mars

image Source: NASA