Space is measured through three units known as kilometers (km), astronomical units (AU), and light years (ly). Space is measured in kilometers when the space can be measured in miles, or a smaller unit. When using astronomical units, the distance is determined by the distance between Sun and Earth. However, a light year is the largest unit, used only to determine sizes of spaces larger than astronomical units.

Earth and Mars are separated by a short 54.6 million kilometers. To travel between these two planets it would take roughly 1,100,000 hours. Despite this long distance, humans have succeeded after multiple decades in traveling to mars, and have been able to observe its incredible heat, small size, and barren outer crust.