Is Earth Gaining Mass Or Losing Mass?

In Earth by Brian Koberlein28 Comments

We generally think of the Earth as having a constant mass. On a basic level that’s true, but the Earth’s mass does change very slightly. So is it’s mass increasing or decreasing?

Earth gains mass through dust and meteorites that are captured by its gravity. If you watched the recent meteor shower you know this can occur on a regular basis. In fact from satellite observations of meteor trails it’s estimated that about 100 – 300 metric tons (tonnes) of material strikes Earth every day. That adds up to about 30,000 to 100,000 tonnes per year. That might seem like a lot, but over a million years that would only amount to less than a billionth of a percent of Earth’s total mass.

Earth loses mass through a couple of processes. One is the fact that material in Earth’s crust undergoes radioactive decay, and therefore energy and some subatomic particles can escape our world. Another is the loss of hydrogen and helium from our atmosphere. The first process only amounts to about 15 tonnes per year, but the loss from our atmosphere amounts to about 95,000 tonnes per year.

So it’s most likely that Earth is losing a bit of mass each year, but if the rate of meteors is on the higher end of estimates, then it could be gaining a bit of mass.


  1. I’ve often had late-night musings about this, and it makes me wonder how much the composition of our atmosphere changes due to this balance of gains and losses. Obviously there are significantly greater factors affecting our atmosphere’s composition, so trying to extract the “cosmic” factors from the background noise in our atmosphere might be nigh impossible. I recently watched a short documentary about the loss of helium from our atmosphere and the relatively slow generation of new hydrogen through nuclear decay. Interesting stuff.

      1. What about decaying plants? If plants get energy to grow from the sun, wouldn’t there be a net positive gain in material?

        1. No, Light from the sun is the energy source used by plants to combine elements in the soil with gasses in the air to store energy as sugars in the plant structure. Since light is virtually massless there can be no net mass gain, or loss unless the plant has a by product lighter than air gas such as Hydrogen or Helium which the Earth’s gravity cannot hold on to, thus escapes into space. But plants do not synthesize Helium or Hydrogen.

    1. no it sends energy to earth. but it is possible for extremely minute amounts of hydrogen to be slingshotted towards earth but if so more hydrogen would probably come from sources that are not the sun.
      -im just a 16 year old with a love of science, great predictions and 140+ IQ

      1. well you’re partly right, but you’re missing the fact that because it sends energy in the form of photons, the objects in subject on earth would gain an extremely small amount of mass because of that energy. We know that when objects gain energy and mass simultaneously, because of Einsteins iconic equation, E=mc^2. This reply is almost a year late, so I probably shouldn’t even post it but whatever

  2. How many tons of our earth’s mass have been sent into space, through the past years, by the various space programs around the world?

    1. I don’t know. Let hope that they will trowing more spaceship back to recycling.

    2. joke: After abandonment the matter will inevitably fall back to earth in the grand scale of all of time so to answer your question none!
      Real answer: “Humanity has removed a few hundred tonnes from the vicinity of Earth since we began this activity in 1959” -Randall Clague, Amateur Astronomer, Rocket Engineer

  3. The article, when discussing the accumulation of space dust, simply considers this process to be linear, that is, 30,000. tonnes per year. I am very confident that this was NOT a linear process. The bombardment of Earth by space dust must have been much more intensive in the past. Actually, the Earth was formed through the condensation of space dust, right? This process must have NOT been an On/Off process right?

      1. hi Brian, so if we plant a lawn and trees on the moon (under right conditions of course), weigh it and then populate it with say 2000 young cows, go back few thousand years later, find few billions cows and trees on it, are you saying the moon will still weigh the same?.

      2. Hi Brian, not sure if you will read this..
        My observation was more driven by an idea that bugs me for a while. I have the impression that the animals during the dinosaur age (230-65 million years ago) were living in a lower gravity environment. What do you think?

        1. Author

          The mass of the earth hasn’t changed significantly over that time range. The gravity during the dinosaurs was basically the same as it was now. The atmosphere was a bit thicker, but that doesn’t effect their weight.

  4. Does photon escape universe ? If yes, is that mean universe lose mass and energy ? .. Last one , Is relativity applicable over the edge of universe ?

  5. If the meteor size of a meteor is large and if it falls routinely or regularly, does it affects the size of the earth?

    Suppose, the earth revolves around the sun.Now due to angular motion can the earth lose its mass?

    1. Animals & Plants don’t actually create mass (according to classical laws of physics & biology), they consume them from the environment – in other words plants convert CO2 & H20 into CnHxOz (Cellulose, wood, etc) plus nutrients such as nitrogen, phosphorus, magnesium etc (From the fertilizers/manure/etc in the ground). it’s just transfer/conversion from the molecules from around the plants into the plants (but the matter/atoms/molecule bonds re-arranged using light as one of the catalyst during photosynthesis).

  6. Question? How does the extraction of resources (oil, coal, timber extra) that are expelled effect the weight of the world? What about the increase in population? If any, how is this loss/gain compensated?

    1. Author

      Remember that oil is pulled from the Earth, and it combines with oxygen from the air when we burn it to produce carbon dioxide and such. But none of it really leaves the Earth to go into space. The same with people. We’re made of atoms here on Earth. So these things don’t really change the mass of the Earth.

  7. Does the metals are lost by sending satellite from Earth to space ?

  8. what force is holding the sun in its position/relative to the planets that revolve around it ?

  9. How does the potential mass from a fetis to full growth of a human being not add to the increase of the earths mass as our human population increases exponentially and the decay rate of a human being is slowed by cultural practices i.e. burial with caskets?

  10. The main thing is being lost in minutia. Look to the stars. Our solar system was created and is changing just like what we are seeing in other solar systems. In other galaxies. As matter has weight and sometimes like mercury drops it merges, because the more matter that merges it starts to develop its own gravity. Space although it seems empty, there is stuff out there. Galaxies, solar systems, planets, suns fly through space and vacuum this stuff up and at the same time losing small parts of it. We have found rocks/meteorites from Mars. We think Mars had larger amounts of water on it. What seems stagnant in our time is fluid like a river in the life and time of a solar system and a galaxy.

    Here is a thought that I have never heard espoused. Why does Earth have water on it. If as a solar system spirals through space all planets and suns vacuum up similar amounts of material. Why do we have water. The sun as a heat source either boils off/vaporizes the water that has landed on other planets closer to the Sun and maybe frozen water on other planets. But Earth was at the right distance from the Sun to attract water from space and keep it.

    On that thought, has anyone ever investigated wether the planets, when the solar system was forming, gathered material according to the atomic weight/ gravitation weight/pull from the Sun. Thus some planets may have more of certain types of material/atoms than others because of these forces. Why might this be important? If this is the case. Then probability of other “earths with life” on them has just shot up 1000 percent.

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