CRATERS ON MARS

Source: Hindu

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Context

• The Physical Research Laboratory (PRL) in Ahmedabad has made a significant discovery by identifying three new craters on the surface of Mars, located in the Tharsis volcanic region.
• This region is known for its volcanic activity and is a prominent feature on the Martian landscape.

Details

• A computer-generated view of Mars depicting the boundary between darkness and daylight (known as the terminator) helps to visualize the location and context of these newly discovered craters.

Details of the Craters

• Lal Crater
  • Named After: Devendra Lal, a notable Indian geophysicist and former Director of PRL.
  • Dimensions: 65 km in diameter.
  • Coordinates: Centered at -20.98° latitude and 209.34° longitude.
  • Scientific Significance: The Lal crater is particularly notable because its entire area is covered with lava. Additionally, geophysical evidence suggests the presence of a 45-meter thick sedimentary deposit beneath the surface, indicating that water once transported significant amounts of sediment into this crater. This discovery supports the theory that Mars was once a wet planet with flowing water.
• Mursan Crater
  • Named After: The town of Mursan in Uttar Pradesh, India.
  • Dimensions: 10 km in diameter.
  • Location: Superimposed on the eastern rim of the Lal crater.
  • Geological Context: The relationship of the Mursan crater with the Lal crater helps scientists understand the sequence of impacts and geological processes in the region.
• Hilsa Crater
  • Named After: The town of Hilsa in Bihar, India.
  • Dimensions: 10 km in diameter.
  • Location: Superimposed on the western rim of the Lal crater.
  • Geological Context: Similar to the Mursan crater, its position provides insights into the impact history and the geological evolution of the Tharsis region.Scientific Importance

• Evidence of Water: The sedimentary deposits found in the Lal crater provide strong evidence that water once flowed on Mars, moving large volumes of sediment. This adds to the growing body of evidence that Mars had a wet past, which is crucial for understanding the planet's climate history and its potential to support life.
• Volcanic Activity: The Tharsis region, being volcanic, helps scientists understand the volcanic history of Mars. The study of craters in this area can reveal information about the timing and extent of volcanic activity.
• Planetary Nomenclature: The naming of these craters by the International Astronomical Union (IAU) Working Group for Planetary System Nomenclature underscores the global collaboration in planetary science and honors significant contributions from Indian geography and science.

Mars

• Mars, the fourth planet from the Sun, is often referred to as the "Red Planet" due to its reddish appearance, which is a result of iron oxide (rust) on its surface.
• It is a terrestrial planet with a thin atmosphere, surface features both reminiscent of both Earth and the Moon, and is a primary target for ongoing and future space exploration.

Physical Characteristics

• Size and Structure:
  • Diameter: About 6,779 km, roughly half the size of Earth.
  • Mass: Approximately 0.107 Earth masses.
  • Density: 3.93 g/cm³, less than Earth's 5.52 g/cm³.
  • Surface Gravity: About 0.38 of Earth's gravity.
• Internal Structure:
  • Core: Likely composed of iron, nickel, and sulfur, with a radius of about 1,700 km.
  • Mantle: Silicate materials, partially molten.
  • Crust: Composed mainly of basalt, about 50 km thick.

Atmosphere and Climate

• Composition:
  • Primary Components: Carbon dioxide (95.3%), nitrogen (2.7%), argon (1.6%), with traces of oxygen and water vapor.
• Climate:
  • Temperature: Average surface temperature is around -80 degrees Fahrenheit (-60 degrees Celsius), with extremes ranging from -195 F (-125 C) during winter at the poles to 70 F (20 C) in summer.
  • Weather: Known for large dust storms, which can cover the entire planet and last for months.
• Atmospheric Pressure: Less than 1% of Earth's, equivalent to pressures found 35 km above Earth's surface.

Surface Features

• Olympus Mons: The largest volcano and highest known peak in the Solar System, standing about 22 km high.
• Valles Marineris: A system of canyons over 4,000 km long and up to 7 km deep.
• Craters: Numerous, with some well-known ones like Hellas Basin, a giant impact basin over 2,300 km in diameter.
• Polar Ice Caps: Composed of water ice and dry ice (frozen carbon dioxide), expanding and contracting seasonally.

Potential for Life

• Water: Evidence suggests that liquid water once flowed on the surface. Current water is mostly in ice form, though subsurface liquid water might exist.
• Past Conditions: Mars may have had a more Earth-like climate in the past, with liquid water bodies such as rivers, lakes, and possibly oceans.

Exploration

• Missions to Mars:
  • Orbital Missions: Mars Odyssey, Mars Express, MAVEN.
  • Rovers and Landers: Spirit, Opportunity, Curiosity, Perseverance.
  • Upcoming Missions: ESA's ExoMars, potential manned missions in the 2030s.

Sources:

Hindu

PRACTICE QUESTION Q.  The discovery of the Lal, Mursan, and Hilsa craters by PRL scientists highlights the dynamic geological history of Mars and provides further evidence of the planet's wetter past.  Comment. (150 Words)