This Is How Mars Looked Like Billions Of Years Ago
We know Mars as the red planet, but it used to be quite different in the past. This video shows what Mars looked like around 4 billion years ago. When lakes, oceans, and rivers covered the surface and the planet had a thick atmosphere, protecting it from the solar wind. This video shows how the surface of Mars might have appeared during this ancient clement period, beginning with a flyover of a lake.
Today, Mars is a cold, desert world. Liquid water cannot exist pervasively on its surface due to the low atmospheric pressure and surface temperature, although there is evidence for spurts of liquid flow that perhaps consist of a brine solution with reduced freezing temperature. Water under current conditions can be ice or sublimate directly into vapor without staying in a liquid phase.
Four billion years ago Mars was covered in water. It had a much thicker atmosphere that kept the planet warm enough for rivers to flow and for liquid water to stand.
The scene opens on a landscape covered in water with white, billowy clouds overhead. As the clouds begin to roll, it shows the passage of time. The atmosphere thins out, causing the water to evaporate. Gradually, all of the rivers and lakes dry up and the atmosphere is too thin to retain any of the sun’s heat. It ends with the Mars we know today: a barren, ice cold rock. Amazing!