1) Which of the following is/are true regarding Mars?
1) On Earth, inverted channels often occur in rainforest areas or areas with high rainfalls.
2) Lack of inverted channels on Mars suggests that Mars had water long back but was more of a dry area.
a. Only 1
b. Only 2
c. Both 1 and 2
d. Neither 1 nor 2
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Answer
Explanation
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ANSWER: Neither 1 nor 2
Explanation:
- Since the 1970s, scientists have identified valleys and channels on Mars which they think were carved out and eroded by rain and surface runoff, just like on Earth.
- Similar structures had not been seen on Arabia Terra until the team analysed high resolution imagery from NASA's Mars Reconnaissance Orbiter (MRO) spacecraft.
- While a few valleys were identified, the team found the existence of many systems of fossilised riverbeds which are visible as inverted channels spread across the Arabia Terra plain.
- The inverted channels are similar to those found elsewhere on Mars and Earth. They are made of sand and gravel deposited by a river and when the river becomes dry, the channels are left upstanding as the surrounding material erodes.
- On Earth, inverted channels often occur in dry, desert environments like Oman, Egypt, or Utah, where erosion rates are low - in most other environments, the channels are worn away before they can become inverted.
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2) Arabia Terra is related to
a. Mars
b. Arabian Peninsula
c. Jupiter
d. Sun
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Answer
Explanation
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ANSWER: Mars
Explanation:
- Mars had a warm and wet climate about four billion years ago and provided a more favourable environment for life, say scientists who have discovered fossilised riverbeds on an ancient region of the red planet.
- The study identified over 17,000 km of former river channels on a northern plain called Arabia Terra, providing further evidence of water once flowing on Mars.
- While a few valleys were identified, the team found the existence of many systems of fossilised riverbeds which are visible as inverted channels spread across the Arabia Terra plain.
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3) Which unit is used to measure the number of Martian days?
a. Sol
b. SoM
c. Solar Day
d. Sod
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Answer
Explanation
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ANSWER: Sol
Explanation:
- The term sol is used by planetary astronomers to refer to the duration of a solar day on Mars. A mean Martian solar day, or "sol", is 24 hours, 39 minutes, and 35.244 seconds.
- Mars has an axial tilt and a rotation period similar to those of Earth. Thus it experiences seasons of spring, summer, autumn and winter much like Earth, and its day is about the same length. Its year is almost twice as long as Earth's.
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