# Introduction

Terraforming other planets is a long-standing human goal. With the ever-increasing threat of global nuclear warfare, the need for a back-up planet has become more real. Mars is a great candidate for terraforming due to its similarity to Earth and its relatively close proximity. Humans could effectively solve two problems at once by terraforming Mars using radioactive material. Our project will investigate the amount of energy needed to terraform Mars and to see if radioactive material can realistically provide that amount of energy.

Before bombarding Mars with nuclear weapons, we have to decide what terraforming would entail and what we would consider to be habitable conditions. We intend to addresses several key questions: What does “habitable” mean for a planet? And how much additional energy does Mars require to be habitable?

For the purposes of this project, we have decided to set a surface pressure of 1 bar and a surface temperature of 300 K +/- 50 K as our terraforming goals. An Earth-like surface pressure is important for the human body and most of our human technology and practices. Mars also has reduced gravity compared to Earth, so an increase in surface pressure would further help humans adjust to a terraformed Mars. We have a somewhat wide temperature range because humans have the technology to survive those temperatures. There are also accurate in situ temperature measurements from the various spacecraft at Mars, so we can more accurately discern the energy difference between Mars today and our Terra-Mars by using temperature as our benchmark.

We are using a very simplified model of Mars for our calculations. We are approximating Mars as a spherically symmetric, Earth-like terrestrial planet with a metal-rich core and a liquid mantle. We are assuming net heat flow moves radially outwards because the core is the hottest portion of the planet. The moment of inertia of Mars ($$I/MR^2$$ = 0.366) indicates that the interior Mars is less differentiated than Earth, so we can assume a constant density within each layer of our simplified model of Mars.

Figure 1: Diagram of our simplified model of Mars. The core has a radius of 1500 km, the mantle has a radius of 1830 km, and the crust has a radius of 3390 km.