Red Planet Proportions: Scale Properties of Mars Quiz

If Earth's radius is about 6,371 km and Mars's radius is about 3,390 km, then Earth's volume is significantly larger; if you calculate the volume ratio, then it takes about 6.3 Mars-sized spheres to fill the space of one Earth.

If Earth has a diameter of approximately 12,742 km and Mars has a diameter of approximately 6,779 km, then Earth is nearly twice as wide as Mars; therefore, Mars is smaller than Earth.

If a basketball is about 24 cm in diameter and Mars is about 53% the width of Earth, then the model must be about 12.7 cm; if a tennis ball or large orange is roughly half the width of a basketball, then it is the most accurate scale representation.

If the planets are ordered by distance starting from the Sun, then the sequence is Mercury, Venus, Earth, and then Mars; therefore, Mars occupies the fourth position.

If gravity depends on the mass and radius of a planet, and Mars has much less mass than Earth, then its pull will be weaker; if we measure the specific values, then an object on Mars weighs only about 38% of what it weighs on Earth.

If Earth is the largest of the terrestrial planets, then any planet categorized as terrestrial (Mercury, Venus, Mars) must be smaller; if Jupiter is a gas giant, then it is significantly larger than Earth.

If a volcano on Mars is three times the height of Mount Everest, then it is the largest in the solar system; if we identify this specific Martian landmark, then its name is Olympus Mons.

If Earth is 71% water and only 29% land, then its total land area is about 148 million square km; if Mars is a desert planet with about 144 million square km of surface, then the total land available to walk on is nearly equal.

If Earth rotates once every 24 hours and Mars rotates once every 24.6 hours, then the difference is only 36 minutes; if other planets have days lasting weeks or only a few hours, then Mars is the closest match.

If Earth's mass is 5.97×1024 kg and Mars's mass is 6.39×1023 kg, then Mars is about 10.7% the mass of Earth; if 10.7% is roughly one-tenth, then 1/10 is the correct scale property.

If we identify the natural satellites orbiting the fourth planet, then we find two small, asteroid-like bodies; if these bodies were named by Asaph Hall in 1877, then they are Phobos and Deimos.

If iron is exposed to trace amounts of oxygen and water, then it creates rust; if rust is technically iron oxide, then this chemical compound gives the Martian soil its reddish hue.

If Earth's atmospheric pressure is 101.3 kPa and Mars's is only about 0.6 kPa, then Mars's air is less than 1% as dense; therefore, the Martian atmosphere is extremely thin, not thick.

If Earth is 1.0 Astronomical Unit (AU) from the Sun and Mars is 1.5 AU from the Sun, then the distance ratio is 1:1.5; if the model Earth is at 10 cm, then the model Mars must be at 15 cm.

If Mars has a thin atmosphere and lacks the biological processes to produce high oxygen, then it retains volcanic gases; if we measure the composition, then we find it is almost entirely carbon dioxide.

If Mars is farther from the Sun than Earth, then it has a larger orbital path; if it travels a larger path at a slower speed, then it takes more time (687 days) to complete one revolution.

If both planets have tilted axes, then they both experience seasons and form polar ice; if both have geological activity and atmospheres, then they both feature canyons and cloud formations.

If the Inner Solar System is defined as the region containing the four terrestrial planets located inside the asteroid belt, and Mars is the fourth planet, then Mars is part of the Inner Solar System.

If Mars is further from the Sun and has a very thin atmosphere to trap heat, then it cannot retain warmth; if the average temperature is -62°C (-80°F), then it is much colder than Earth.

If a geological feature on Mars stretches over 4,000 km long and 7 km deep, then it is a massive rift; if such a feature is a valley or trench, then the correct term is a canyon.