Why Does An Astronaut Weigh Less On The Moon? [This Makes Sense]

By now, we’re all fully aware that life in space is pretty different compared to down here on Earth. Not only are the laws of nature different up there but so too are we. For instance, do astronauts look the same? Sound the same?….. Weigh the same? Well, let’s find out.

So, why does an astronaut weigh less on the Moon? Astronauts weigh less on the Moon due to there being a much weaker gravitational pull on its surface there than there is on Earth. On the Moon, your feet aren’t as firm on the ground because gravity isn’t pulling as much of you down. Consequently, you weigh less.

It actually makes sense when you come to think of it.

And that’s the gist of it.

Whilst you’re here though, stick around and find out all the answers about weight in space. Good luck! 

Why Is An Astronauts Weight Different On The Moon?

The Moon has less mass, meaning the gravitational force is weaker, therefore astronauts walk around lighter on the surface. 

The Earth is significantly bigger than the Moon.

It also has a much greater mass.

The larger a gravitational source’s mass, the stronger its gravitational pull will be.

So, because the Moon is pulling an astronaut down to its surface less, they appear lighter.

Why does gravity have anything to do with how much astronauts weigh, you may be thinking?

Surely astronauts are still just made up of the same parts that weigh the same wherever they go?

Well, here’s the thing.

The weight of a mass (a human body) is attracted, by gravity, to a bigger mass (Earth, the Moon) that generates gravity.

So, yes, astronauts don’t go up to space and lose weight.

They will still measure up the same as they did back home on our metric systems because your mass is still the same.

What changes in space, or on the Moon’s surface, in this case, is that gravitational force.

The stronger the force, the more astronauts weigh despite still having the same mass. 

Yep. That’s right.

Gravity is up to no good again.

Does An Astronaut’s Weight Change On the Moon?

Yes, an astronaut does weigh less on the Moon, but only because they are on the Moon. 

Gravity is generated by mass.

The more elements, objects, solids and liquids etc within a mass, the stronger its gravitational pull.

We know that the mass of the Moon is much smaller than that of Earth, but how much smaller is it?

Well, the Moon’s mass is only 1.2% of Earth’s.

So you’d think the difference would be incredibly vast, wouldn’t you?

Well, it’s actually not.

This is because the Moon is only 27% the size of Earth.

So when an astronaut is standing on the Moon, they are much closer to the center of gravity than when they stand on Earth.

So the Moon’s gravitational pull is bumped up a little by being such a small mass.

How do we measure all this gravitational pull stuff?

Well, I’ve got some figures for you.

Gravitational field strength varies depending on the size and mass of its center point, as we have learned already.

This is measured in Newtons per Kilogram (N/kg).

At Earth’s surface, its gravitational field strength is recorded at 10 N/kg.

At the Moon’s surface, the gravitational field strength is 1.6 N/kg.

Starting to understand why an astronaut weighs less on the Moon now?

How Much Would An Astronaut Weigh On The Moon?

Astronauts weigh six times less than what they do on Earth, when on the Moon.

So far, we know that the Moon is smaller than Earth.

Hopefully, we all knew that before this article!

We now also know that the Earth has a much greater mass than the Moon.

For this reason, the Moon has a much weaker gravitational pull than Earth.

Maybe the clever clogs amongst us knew this as well!

But let’s get this sorted out once and for all.

The Moon has ⅙ the gravity that Earth possesses.

Or in other words:

“The moon’s gravitational force is only about 16.6 percent of Earth’s gravity”

Space.com

So, an astronaut would weigh six times less on a set of scales placed on the Moon, than they would on a set back home.

If an astronaut weighs 70kg on Earth, they’ll weigh about 11.6kg on the Moon!

These laws of physics apply to everything, remember!

Astronauts and objects all weigh six times less than what they do when on our home planet.

The lack of gravitational pull on the Moon can actually provide some opportunities for activities you couldn’t necessarily do on Earth’s surface.

Let’s face it when you can jump six times higher when on the Moon, you’re going to have some fun!

Finally

Once again, we discover that life is different up amongst the stars. Once again, we discover that gravity has a big part to play.

Masses, gravitational centers, Newtons per Kilograms have all led us to the conclusion that astronauts weigh less on the moon.

They’d also weigh less on Mars, and Jupiter, and all the other masses in the universe. 

But when they return to Earth, they’ll weigh the same as they did when they left….unless the space diet has had anything to say about that.

Related Questions

Love learning about astronauts? Then why not read my other articles:

• What Happens If An Astronaut Floats Off In Space?
• Can Astronauts Walk After Returning From Space?
• What Do Astronauts Do When Not In Space?
• What Happens If You Take Your Helmet Off In Space?
• Can You Survive In Space With Only A Helmet?
• How Do Astronauts Train For Zero Gravity?