Problem 9 - Astronomy: At Play in the Cosmos

Question

Which of the following geologic features is/are found on Mars? Choose all that apply. a. Ishtar Terra b. Valles Marineris c. Discovery Rupes d. Olympus Mons e. Stickney Crater

Step-by-Step Solution

Answer

b. Valles Marineris, d. Olympus Mons, and e. Stickney Crater are related to Mars.

Step 1: Identify the Features Associated with Mars

We first need to identify which of the given geologic features are associated with Mars. Mars is known for several key features, including the largest volcano and canyon in the solar system.

Step 2: Examine Each Option

- **a. Ishtar Terra:** This feature is associated with Venus, not Mars. - **b. Valles Marineris:** This is a large canyon system on Mars. - **c. Discovery Rupes:** This is a feature found on Mercury. - **d. Olympus Mons:** This is the tallest volcano and mountain in the solar system, located on Mars. - **e. Stickney Crater:** This is a crater on Phobos, one of Mars' moons, but associated with Mars.

Step 3: Select the Correct Features

From the analysis, the features associated with Mars are: - Valles Marineris (b) - Olympus Mons (d) - Although Stickney Crater is on Phobos, it is still related to Mars, hence it can be considered (e) as well.

Key Concepts

Olympus Mons

Olympus Mons is a magnificent geologic feature located on Mars and is recognized as the tallest volcano and mountain in our entire solar system. This extraordinary shield volcano stands at a remarkable height of around 13.6 miles (22 kilometers), making it nearly three times taller than Mount Everest.
Its base is equally impressive, stretching approximately 370 miles (600 kilometers) across. Such immense proportions are why this mountain garners global awe and significant scientific interest.

• One of the surprising aspects of Olympus Mons is the relative lack of steep slopes typically seen in terrestrial mountains.
• The gradual incline suggests that the lava flows during the volcano's active periods were highly fluid, aiding in the broad expansion rather than upward accumulation.
• In terms of age, Olympus Mons is believed to be just a few million years old, which is relatively young in geological terms. This suggests that the volcanic activity could have occurred recently on a geologic time scale.

Studying Olympus Mons gives scientists essential insights into Martian geological processes and the planet's past volcanic activity. Understanding how such a massive volcano could form provides clues about the internal dynamics and history of Mars.

Valles Marineris

Valles Marineris is a colossal canyon system on Mars, celebrated as the largest and deepest canyon in the solar system. This vast system extends over 2,500 miles (4,000 kilometers) across the Martian surface, with depths reaching up to 7 miles (11 kilometers).
It dwarfs the Grand Canyon on Earth, showcasing how dynamic and extreme Martian geology can be.

• The origin of Valles Marineris remains a topic of scientific inquiry. Geological evidence suggests it is not a product of water erosion similar to Earth's canyons.
• Some theories propose that the canyon resulted from tectonic forces and surface stretching, which caused large sections of the Martian crust to collapse.
• Influxes of lava flows from surrounding volcanic regions may have contributed to further expansion and deepening of the canyon over time.

Valles Marineris allows scientists to study the tectonic and volcanic history of Mars, providing insights into how the planet's crust evolved over billions of years. The canyon's diverse geographic features help researchers understand the complexities of Martian geology, offering clues about possible ancient water flow activities and the planet's climatic past.

Phobos

Phobos is the larger and closest of the two moons orbiting Mars, the other being Deimos. Named after the Greek god of fear, Phobos' pockmarked surface is indicative of its violent past, with a highlight feature known as the Stickney Crater.
This crater is large relative to the size of the moon itself, illustrating the intense impact forces Phobos has endured.

• The proximity of Phobos to Mars is quite peculiar; it orbits the planet at a mere distance of around 3,700 miles (6,000 kilometers), closer than any moon to its primary planet in our solar system.
• Due to this close orbit and the resultant tidal forces, Phobos is gradually being pulled towards Mars, with expectations of it breaking apart or crashing into the planet in around 50 million years.
• The moon’s surface is dominated by grooves and ridges, possibly created by marsquakes impacting it or stress fractures from its gradual descent towards Mars.

The study of Phobos is vital as it gives scientists a glimpse into the dynamic interactions between a planet and its moons. Understanding Phobos’ composition and history helps unravel Mars' past and evolution, and also acts as a prospective location for future human exploration and habitation.