Earth is constantly receiving and giving materials in the surrounding space within the Solar System like any celestial body. The planet receives new materials from space in the form of shooting stars, while Earth gives out elements when gases from the atmosphere regularly escape into space.

But this giving and receiving mechanism has scientists question whether the planet is expanding or shrinking. NASA senior research scientist Guillaume Gronoff, who studies atmospheric escape at Langley Research Center in Virginia, said that Earth is shrinking because of the atmosphere. However, it is not shrinking that much.

(Photo: Pixabay)
Earth is Shrinking! Scientists Reveal It's Due to the Atmosphere Which Affects the Planet's Mass


Atmospheric Escape: How Some Gases Evade Earth?

Earth's atmosphere is a thin layer of gas that keeps everything below warm and makes life on the planet possible. However, Britannica reported that the gases which make up the atmosphere also escape to outer space in a process called an atmospheric escape.

Although the rate of the leak is slow and scientists said the speed should be 34 times the speed of sound to be considered alarming. They added that a metric ton of TNT is needed to reach that speed. Today, the lightest elements in the universe, hydrogen, and helium are the only gases that regularly escape the atmosphere.

Scientists explain that there are many reasons why hydrogen and helium can escape from the atmosphere one of which is because some gases near the top get enough energy from sunlight to escape. Meanwhile, the fast-moving, charged particles are stopped from escaping the planet's magnetic field.

Sometimes, the speeding particles that lack electrons crash into a neutral molecule and knock loose and steal one of its electrons, becoming a neutral molecule itself and breaking free from the magnetic field. The molecules could go as far as the stars outside the Solar System if the collision happens to set its course on that track.

Lastly, some charged particles in the magnetic field affected by the solar wind can fly off the weak ends. But then, having no magnetic field is worse than having one because that would mean Earth would not be protected from the harmful solar wind just like Mars.


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How Does Atmospheric Escape Affect the Overall Mass of Earth?

Since scientists can not precisely know the mass of the planet, they can only estimate. Gronoff told Live Science that no one has measured the weight of Earth precisely to see if it is losing or gaining.

But scientists are able to estimate that the planet is visited by about 16,500 tons (15,000 metric tons) meteors every year, which adds to Earth's mass. They use satellite data and estimate the atmospheric escape by around 82,700 tons (75,000metric tons) annually. Gronoff noted that this number is considered a small amount considering it is the atmospheric escape for the whole planet.

Scientists calculated using estimates for atmospheric escape that has been there in the past 100 years that it would take 5 billion years for the planet to lose its atmosphere if there is no way to replenish it. But that is not the case because volcanic eruptions help replenish gases in the atmosphere.

RELATED ARTICLE: Volcanoes Provide Earth's Atmosphere First Oxygen 100 Million Years Earlier Than Great Oxidation Event

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