How did Mars go from being covered in water to having no water left at all?

What needs to be made clear here is: Mars currently has water.

Previous detection data showed that there is a small amount of gaseous water in the atmosphere of Mars, and there is ice formed by water on the surface of Mars. Cooling and condensing water droplets (that is, dewdrops) were even found on the Mars rover. . The latest observational research shows that Mars has liquid water.

Mars is not the first celestial body discovered to have liquid water outside the Earth. Europa, Enceladus, Ganymede, Callisto, etc. may all have relatively large amounts of liquid water. There may even be more water beneath the surface of Europa than there are oceans on Earth.

Mars, this strange orange-red planet, has always been the focus of human space exploration because it has an environment similar to that of the Earth. It is also the first choice destination for our future interstellar immigrants.

In 2015, the Curiosity rover discovered traces of seasonal liquid water on Mars for the first time. Recently, some scientists have speculated that ancient Mars 3.5 billion years ago was similar to Earth, with vast oceans that at most accounted for 87% of Mars' surface area. In comparison, today's Earth's ocean area is only 71%.

Comparison between modern and ancient Mars

Dr. Wade from the Department of Earth Sciences at Harvard University used the data returned by the "Curiosity" Mars probe and model deduction to reveal the Martian ocean The mystery of disappearance.

This is all related to the "stunted development" of Mars.

Mars and the Earth are closely adjacent and formed almost at the same time. It should be similar in size to the Earth, but in fact the volume of Mars is only 15% of the Earth, and the mass is only one-tenth of the Earth. . Compared with Earth and Venus, Mars is like a malnourished little brother.

Comparison of Venus, Earth and Mars

It turns out that 4.6 billion years ago, when the solar system family began to form, the orbits of the planets changed dramatically, and the orbit of "big brother" Jupiter Gradually approaching the sun, clearing out a large amount of the original material of the solar system along the way, Mars was unable to obtain sufficient nutrients during its formation, and eventually became a low-mass planet.

Due to the small size and weak gravity, a large amount of iron elements diffused into the mantle when forming the core of Mars. In contrast, most of Earth's iron elements sank into the core during the early stages of Earth's formation.

Early Solar System

Dr. Wade said, “The iron content in the mantle of Mars is higher than that of the Earth’s mantle, so it is more likely to react with water.”< /p>

The researchers analyzed the mantle temperatures, pressures and early rock compositions of the two planets, and used models to deduce the difference in water absorbed from the surfaces of the two planets over time.

Research shows that the water absorption rate of basalt formed by volcanic eruptions on the surface of Mars is 25% higher than that of Earth rocks. The water in the original ocean of Mars reacted with the volcanic lava to form a "sponge"-like porous rock, which absorbed a large amount of water into the mantle. Eventually, the surface of Mars became extremely dry, suffocating all possible complex life forms in their infancy. .

Basalt minerals covering the surface of Mars

In contrast, the Earth's plate tectonics effectively prevent drastic changes in sea levels and provide a crucial breeding ground for the evolution of life.

In addition, another important prerequisite for the formation and evolution of life on earth is that the halogen content in rocks must be maintained at a certain level. Any more or less will have fatal effects. Compared with Earth rocks, the halogen content in meteorites is significantly higher.

Dr. Wade concluded, "The composition of the planets in the solar system is very similar. There are only slight differences, but they are enough to cause huge differences in the appearance of the planets."

So there are still some planets on Mars. Watery.