Feb 13, 2022 09:00:00

Is the mass of the earth gradually decreasing?

The earth does not always maintain a constant mass, and objects flying from space may fall on the earth as meteorites, or the atmosphere may flow out into outer space

or be sent to the moon . Then, Live Science, a scientific media, explains the question, 'Is the mass of the earth gradually decreasing or increasing?'

Is Earth expanding or shrinking? | Live Science
https://www.livescience.com/is-earth-expanding-or-shrinking

Planets such as the Earth are formed through the process of accretion , in which particles accumulate due to gravity in an accretion disk formed by gas and dust that revolve around heavy celestial bodies. Guillame Gronoff, a senior researcher at NASA's Langley Research Center in Virginia, USA, said that even after the Earth was almost formed about 4.6 billion years ago, a small amount of meteorites continued to fall from the outside. It states that it is.

However, after the planet is formed, another process called ' atmospheric escape ' will start. Atmospheric escape is similar to water evaporation, but there is a big difference in its scale. The mechanism of atmospheric escape is that atoms such as oxygen, hydrogen, and helium get energy from the sun, and when they reach kinetic energy that exceeds gravitational energy, they dissipate into space.

'It is difficult to measure the mass of the earth in real time and it is a topic under study,' Gronoff said, pointing out that it is not possible to know what the mass of the earth is actually. However, it is possible to estimate the approximate mass change from the amount of meteorites that fall and the measured values of atmospheric escape.

First, researchers estimate that '

the mass of meteorites before entering the atmosphere is about 15,000 tons per year ' from the observation results of meteorites, which is added to the mass of the earth every year. Furthermore, from the observation results of satellite data, it is estimated that about 75,000 tons of the atmosphere is lost from the earth every year. Taken together, these results result in the loss of about 60,000 tonnes of mass annually across the globe.

It sounds like a huge mass when you hear about 60,000 tons a year, but from the perspective of the entire globe, it is 'very, very, very small,' Gronoff commented. Estimates of atmospheric escape over the last 100 years indicate that it will take about 5 billion years for the Earth's atmosphere to reach zero, even if it is not replenished at all.

Furthermore, in reality, the atmosphere of the earth is constantly being replenished by processes such as ocean activity and volcanic eruptions, so it takes 15.4 trillion years for the atmosphere to actually disappear from the earth. This is about 100 times the life of the universe, and the life of the earth itself is estimated to be about 5 billion years later , so Mr. Gronoff said, 'Atmospheric escape is not a problem in the long run.' I did.