Does planet earth way more or less than when it was first created?

Question

A friend asked me this one day when we were wasted. I have always remembered it. I said heavier, he said lighter. Then we lit another spliff!

Answer 1

Earth has in its 4.5 billon years existence become heavier; due to constant pounding by meteorites, and smaller fragments of rock, most of which pose no danger to land living creatures as they burn up in the atmosphere and fall as dust, most meteorites contain heavy elements; such as Iron and Nickel. Pushing up the weight of the earth, not be much, but by enough to make a difference. Weight has of course been lost, from stuff humans have sent up into space (very small) and from the decay of Uranium and other radioactive elements in the centre of the earth (part of which causes the heat inside of the earth – like a nuclear reactor) the loss of alpha (a helium nuclei – 2 protons and 2 neutron) particles over the billions of years within the earths existence would have slowly lowered the mass, but it is likely that the mass coming onto the earth from interstellar bodies – bits of rock has outweighed the loss of helium nuclei.

Answer 2

It would be more proper to ask, "What is the mass of planet Earth?"1 The quick answer to that is: approximately 6,000,000,000,000,000,000,000,000 (6E+24) kilograms.

The interesting sub-question is, "How did anyone figure that out?" It's not like the planet steps onto the scale each morning before it takes a shower. The measurement of the planet's weight is derived from the gravitational attraction that the Earth has for objects near it.

It turns out that any two masses have a gravitational attraction for one another. If you put two bowling balls near each other, they will attract one another gravitationally. The attraction is extremely slight, but if your instruments are sensitive enough you can measure the gravitational attraction that two bowling balls have on one another. From that measurement, you could determine the mass of the two objects. The same is true for two golf balls, but the attraction is even slighter because the amount of gravitational force depends on mass of the objects.

Newton showed that, for spherical objects, you can make the simplifying assumption that all of the object's mass is concentrated at the center of the sphere. The following equation expresses the gravitational attraction that two spherical objects have on one another:

F = G * M1 * M2 / R2
R is the distance separating the two objects.
G is a constant that is 6.67259x10-11m3/s2 kg.
M1 and M2 are the two masses that are attracting each other.
F is the force of attraction between them.
Assume that Earth is one of the masses (M1) and a 1-kg sphere is the other (M2). The force between them is 9.8 kg*m/s2 -- we can calculate this force by dropping the 1-kg sphere and measuring the acceleration that the Earth's gravitational field applies to it (9.8 m/s2).

The radius of the Earth is 6,400,000 meters (6,999,125 yards). If you plug all of these values in and solve for M1, you find that the mass of the Earth is 6,000,000,000,000,000,000,000,000 kilograms (6E+24 kilograms / 1.3E+25 pounds).

1 It is "more proper" to ask about mass rather than weight because weight is a force that requires a gravitational field to determine. You can take a bowling ball and weigh it on the Earth and on the moon. The weight on the moon will be one-sixth that on the Earth, but the amount of mass is the same in both places. To weigh the Earth, we would need to know in which object's gravitational field we want to calculate the weight. The mass of the Earth, on the other hand, is a constant.

The earth would actually weigh heavier now as it has been bombarded with lumps of rock over millions of years!

Answer 3

The earths density is ~ 5518.0 kilograms/meter ^ 3
Which means it is massive very very massive. But infact young grasshopper it wieghs nothing. It is a waitless obect that floats in space like all the other wieghtless objects out there.

Now if you could take the Earth and put it on a scale hear on Earth. I suppose you would find that since it was formed some 5 billion years ago. infact yes. It did gain a few pounds we all do as we age. :) And I belive the number is 180 millions tons of debris fall to earth each year. But that is really nothing

Answer 4

On the whole the earth has not got significantly heavier. However, there are thousand of tonnes of space dust added to the earths atmosphere every year which in the great scheme of things is not much at all (our humble planet is extremely heavy).

Answer 5

Earth gains an annual 150 tons(I can't remember the exact #, but it's alot) in falling meteors that land on the earth as meteorites.
Thus our mass increases and our gravitational pull gets stronger, attracting even bigger space dust.

Answer 6

Oh I love this question! My friend and I had the same debate and I showed her the following website. You are correct my intoxicated friend, the Earth is getting heavier.

Answer 7

Heavier. Meoterites(about amillion) hit the earth every yr. Only recently have we thrown anything back.

Answer 8

Tough question. We lose some helium every day. It's probably more than offset by the dust, meteorites, and other stuff falling from space, though. I'll say it has gained weight.

Answer 9

More or less-if you don't count a few meteroids and one theory that says that the Moon was formed from spewed-off material when a wandering planetoid rammed into a primitive Earth.

Answer 10

The space mission and all that space junk was made out of Earth materials. Also satelites.