June 8th, 2012
1086 Origin and Geology of the Solar System
Table of Contents
1.0 Introduction 2 2.0 Mars Basics 3 2.1 Geology of Mars 3 2.2 Atmosphere on Mars 3 2.3 Water on Mars? 6 2.4 Natural Satellites 6
3.0 The Mars Exploration Mission 7
4.0 Rover Data To-Date 8
5.0 Conclusions 8
6.0 References 10
7. Illustrations Figure 1- The Solar System 2 Figure 2- Mariner 4 about 12,500 kilometers from Mars 2 Figure 3- Olympus Mons 3
Figure 4- Earth’s vs. Mars’ Atmosphere 5 Figure 5- Mars 8
Before being able to understand the goals and discoveries of the most recent missions to Mars we must understand where the planet is placed within our solar system. Mars, the red planet, is fourth in order from the biggest star we are familiar with (Figure 1), Sun in contrast with earth, which is third. Sun helps us measure the distance of all planets using it as the initial spot (zero km).
Astronomical units (AU) are used and are easier to understand. Each unit is 150 million kilometers. Mars is about 1.52 AU from the sun compared to Earth being 1.0 AU. Mars is one of the smallest planets in diameter with only Neptune being smaller. The axial tilt on Mars is 25.19 degrees, whereas Earth is tilted at 23.5 degrees, therefore both have seasons. Finally, Mars has a much longer year than Earth containing 686.97 days, almost twice as long as one year on Earth (1.88 Earth years). Many of the first missions to Mars failed. Spacecraft’s either did not leave Earth’s orbit, communications failed or equipment failed. The first successful fly-by attempt was Mariner 4 from USA (Figure 2).
It flew by Mars on July 14th, 1965 and passed within 10km of the surface after an eight-month journey. As the missions to Mars continued numerous attempts we made to fly-by or land on Mars. Many attempts failed, but many were successful and these were the missions that drove our thirst for knowledge further, eventually leading to the Rover missions. Two twin robot geologists were launched to Mars in 2003 and landed in 2004 to reveal the unknown history of water on Mars. The four long-term science goals of the Mars Exploration Program are to: determine whether Life ever existed on Mars, characterize the climate, characterize the geology and prepare for human exploration. The goals and most significant discoveries of the Mars Exploration Program will be introduced and studied in this short, attention-grabbing report.
2. Mars Basics
2.1 Geology of Mars
The geology of Mars and the geological processes that take place on Mars are different from any other planet. Some of the processes that form our Earth’s surface are similar to those of Mars. When the planet was finally mapped in detail in 1971, young volcanoes, sand dunes, dry riverbeds and many more surface features were photographed. Mars’s surface is much different than that of Earth’s because it has not split into plates, but has stayed as a one-plate planet. Huge volcanoes on Mars are most like due to mantle plumes and mantle development. In the western hemisphere there is a region called the Tharsis dome, where volcanoes are located on huge uplifts of magma including Olympus Mons, the largest volcano in our solar system (Figure 3). Olympus Mons has yet to sink into the crust on Mars leading us to believe the crust is thicker than the crust on Earth. All volcanoes on Mars are shield volcanoes formed by low viscosity lava. Other evidence such as the Valles Marineris, a network of canyons, leads us to believe the crust was once thinner and more active. Without plate tectonics the crust over the plume stays motionless and the lava continues to pool under the surface. Mars’ core is rich in iron and low-density materials. It