Signs and symptoms are both signals of injury, illness, disease â signals that something is not right in the body. A sign is a signal that can be seen by someone else â maybe a loved one, or a doctor, nurse, or other health care professional.
Besides silicon and oxygen, the most abundant elements in the Martian crust are iron, magnesium, aluminum, calcium, and potassium. Oxidation of the iron dust is what gives the surface its reddish hue. Composite image showing the size difference between Earth and Mars. Credit: NASA/Mars Exploration.
The approximate composition and characteristics of Mars were studied and was compared to the atmospheric compositions and descriptions of the Earth. It was found out that the Earthâs atmosphere is more than a hundred times denser as compared to Mars atmosphere. The Earthâs atmosphere is made up of 78% nitrogen, 21% oxygen and 1% other elements while Mars atmosphere is made up of 96% dioxide and certain percentages of elements like argon, nitrogen and others.