astronomy II - Mercury, Venus, Mars

How does the radius of Mercury compare to that of Earth?

Mercury's radius is 1/3 that of Earth.

What is the mass of Mercury relative to Earth?

Mercury's mass is 1/28 that of Earth.

What are scarps on Mercury?

Scarps are cliffs that formed from moving crust.

What is the Caloris Basin?

The Caloris Basin is the largest crater basin on Mercury, approximately 1000 miles across, with volcanoes around its edge.

What is chaotic terrain on Mercury?

Chaotic terrain refers to the crazy uplifted surface area directly opposite the Caloris Basin.

What are the temperature ranges on Mercury? Why?

Temperatures on Mercury range from about 800 to -300 degrees Fahrenheit due to its lack of atmosphere.

Does Mercury have an atmosphere?

No, Mercury has no atmosphere because of its low gravity and proximity to the Sun.

Where does the water ice on Mercury come from?

The water ice on Mercury is found at the poles in deep craters and likely came from comets and/or volcanic activity.

Does Mercury have a magnetic field?

Yes, Mercury has a magnetic field but it's about 1% the strength of Earth's.

What is unusual about Mercury's motion around the Sun?

Mercury spins 3 times for every 2 trips around the Sun due to its highly elliptical orbit.

How does Venus's diameter and mass compare to Earth?

Venus is about 95% the size and mass of Earth.

What are the main components of Venus's atmosphere?

The Venusian atmosphere consists of 96% carbon dioxide (CO2), 3.5% nitrogen (N2), and small amounts of water vapor and other gases.

Why is Venus so bright?

Venus is bright due to its thick atmosphere, which reflects sunlight.

How much denser is Venus's atmosphere compared to Earth's?

Venus's atmosphere is 100 times denser than Earth's.

What is the average temperature on Venus?

The average temperature on Venus is about 900 degrees Fahrenheit at the surface.

Why does Venus have a runaway greenhouse effect?

Venus has a runaway greenhouse effect due to high levels of CO2 and its proximity to the Sun, leading to the evaporation of water from past oceans.

How does it ‘snow’ on Venus despite the heat?

On Venus, galena and bismuthinite are vaporized at the surface and then settle on mountains, creating a type of 'snow'.

What are the dominant surface features on Venus?

The surface of Venus is mostly volcanic in origin, with features like volcanoes, pancake domes, and lava channels.

What evidence indicates that Venus has an active surface?

There are not many impact craters on Venus, suggesting geological activity.

What planet is Mars named after?

Mars is named after the Roman god of war.

How does the diameter of Mars compare to that of Earth?

Mars has a diameter that is 1/2 that of Earth.

What features can be found on the Martian surface?

Features include Valles Marineris (a rift), Tharsis bulge (upland area with volcanoes), and Olympus Mons (largest volcano).

What are Mars's polar ice caps made of?

Mars's polar ice caps are made of dry ice and water ice, which varies by season.

Why is Mars red?

Mars appears red due to iron oxide (rust) in its crust.

What evidence is there of past liquid water on Mars?

Evidence includes dried river beds, Martian blueberries, and teardrop water features.

What are the components of Mars's atmosphere?

Mars's atmosphere consists of 95% CO2, with traces of N2, O2, and H2O, and its density is about 1% of Earth's.

What is the average temperature on Mars?

The average temperature on Mars is cold, around -80 degrees Fahrenheit.

Why is Mars's atmosphere so thin now?

Mars's atmosphere has become thin due to impact blast, low gravity, and low volcanic activity.

What are the two moons of Mars?

The two moons of Mars are Phobos and Deimos, which are believed to be captured asteroids.

What are the commonalities between the interiors of the inner planets?

The commonalities include iron cores and silicate/rocky mantles.

What is a key difference in the interior of Mercury compared to other inner planets?

Mercury has a huge core relative to its crust.