Mars||Mars Atmosphere||Mars Missions||UPSC Current Affairs

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Context

A new study presents insights on how the Mars atmosphere went missing.

Read about Mars: https://www.iasgyan.in/daily-current-affairs/craters-on-mars

Read about Mars missions: https://www.iasgyan.in/daily-current-affairs/chapea-project

Background

Mars, now a cold and barren desert, was once believed to have a thick atmosphere that supported flowing water. However, approximately 3.5 billion years ago, the planet's carbon dioxide-rich atmosphere began to thin dramatically. Understanding why this happened is a key question for scientists studying Mars' history.

Highlights of the new study

Two scientists from the Massachusetts Institute of Technology (MIT) propose that a slow, natural process involving specific Martian rocks may have drawn carbon dioxide out of the atmosphere, leading to its eventual depletion.

Process

A type of clay called smectite acts as an effective carbon trap. Smectite grains contain folds where carbon can be stored for billions of years. When exposed to the atmosphere, smectite gradually absorbs carbon dioxide, potentially cooling a planet over time.

Martian water, interacting with a ferrous rock known as olivine (which is abundant on Mars), initiated a series of chemical reactions over billions of years. Over time, the olivine transformed into smectite, which then trapped the methane.

Benefit

Methane, which is theoretically stored for aeons in Mars' clay, could be a valuable resource for future missions and potential colonization.

Mars' Atmosphere

Aspect	Details
*Atmospheric Composition*	Carbon Dioxide: 95.32% Nitrogen: 2.7% Argon: 1.6% Oxygen: 0.13% Water vapor: Trace
*Surface Pressure*	It is about 0.6% of Earth's.
*Temperature Range*	-20°C to 20°C in day to -73°C to -125°C in night
*Seasons*	Length of Day is 24.6 hours but year is of 687 Earth days.
*Wind Patterns*	Generally mild, around 10-20 km/h but can reach 100 km/h during dust storms
*Clouds*	Thin, wispy clouds made of carbon dioxide or water ice.
*Greenhouse Effect*	Despite a high CO₂ concentration, the thin atmosphere doesn't retain much heat.
*Magnetosphere*	Mars lacks a global magnetic field. Solar winds strip away the atmosphere due to weak magnetic protection.
*Escape of Atmosphere*	Hydrogen and oxygen escape due to the lack of a magnetosphere.
*Atmospheric Gravity*	Mars’ gravity is about 38% that of Earth, contributing to the thinness of the atmosphere.

Sources:

IndianExpress

PRACTICE QUESTION

Q:Consider the following statements regarding Mars' atmosphere:

Mars’ atmosphere is only composed of carbon dioxide.
The thin atmosphere of Mars contributes to its inability to retain liquid water on the surface.

Which of the above statements is/are correct?

a) 1 only

b) 2 only

c) Both 1 and 2

d) Neither 1 nor 2

Answer: b

Explanation:

Statement 1 is incorrect:

Carbon Dioxide: 95.32%
Nitrogen: 2.7%
Argon: 1.6%
Oxygen: 0.13%
Water vapor: Trace

Statement 2 is correct:

The thin atmosphere of Mars, coupled with low atmospheric pressure, makes it challenging for the planet to retain liquid water on its surface for extended periods. Any water that exists is either frozen or evaporates quickly.

MARS ATMOSPHERE