Labels: text | screenshot OCR: Composition of the Martian soil: MARS: GENERAL INFORMATION Oxygen: 50% MARS'S SATELLITES Silicone: 20% Iron: 14% Magnesium: 4% Sulfur: 3.7% Calcium: 3.7% Aluminum: 3.5% Titanium: 0.4% Certain areas show concentrations of phosphorus (up to 10%), manganese (7%), and chlorine (3%). Mars has a low atmospheric pressure, similar to that inside a plane at cruising speed. Viking I measured Martian atmospheric pressure at an average 7.6 millibars. (This low pressure explains the absence of liquid water on Mars: when ice on the planet warms, it is "sublimed" or undergoes "sublimation," meaning it passes directly from Olympus mons a solid to a vapor state.) The surface of Mars is very rough. Several hundred craters and mountains much higher than any on Earth have been identified. The highest peak on the planet is Olympus Mons, which rises to an astounding 26,400 meters. MARS BETAT