The Moon's surface is 100 times younger than previously thought

This is pretty fascinating.

By comparing images of the same area at regular intervals, a team of scientists led by Emerson Speyerer from Arizona State University in Tempe were able to tally the number of new craters and extrapolate to the entire surface of the Moon.

source: phys.org...

What they found is simply astonishing:

"We detected 222 new impact craters and found 33 percent more craters with a diameter of at least 10 metres than predicted" by earlier models, the researchers concluded.

According to the article, this means that the erosion of the lunar ground is happening a hundred times faster than previously thought.

Looks like stuff we send on the Moon will have to be better protected!

Unlike the Earth, the Moon has next to no atmosphere, so meteors don't disintegrate in any atmosphere before hitting the ground. An example is this new brand new impact on the surface of the Moon:



source: phys.org...

Scientists are concluding that the entire lunar surface and features becomes eroded after only 81,000 years.

This means that the Moon back then looked completely different than it does from now.

a reply to: swanne

Now this is interesting and would of course suggest a far more recent bombardment of the moon and indeed the EARTH as well by large and small debris from the solar system.

Wonder if this play's well into the exploding/destroyed planet hypothesis.

a reply to: swanne

Query...

Do the calculations that were done to come up with this alteration in surface age, account for the fact that we are headed through a generally busier patch of space, with regard to space rocks and so on?

a reply to: swanne

Well yah, still cratered though. Ongoing bombardment, just like almost every other moon in the catalog of the solar system.

The moon is remade by these 'erosive' impacts, into the same tortured looking scape, because erosive effects of wind and rain don't exist there like on Earth.

Neat before and after capture of an impact. That s*** can happen anytime, anywhere.

a reply to: TrueBrit

The Solar System is relatively contained. Most of the meteor showers we receive, for instance, come from periodic comets that orbit our Sun. We aren't really heading into a patch of space full of rocks, not that I know of. The only way for us to get more rocks in our solar system would be to run into an alien solar system, which would kind of be noticeable.

So I'd say that the rate of meteor showers in recent history would be pretty constant.

originally posted by: TrueBrit
a reply to: swanne

Query...

Do the calculations that were done to come up with this alteration in surface age, account for the fact that we are headed through a generally busier patch of space, with regard to space rocks and so on?

Most of the stuff that whizzes around inside the solar system is leftover from the formation. Not sure how they gauge what comes into our stellar shooting gallery from outside.

NASA

originally posted by: swanne
This means that the Moon back then looked completely different than it does from now.

Indeed, it did.

a reply to: BlueShaman

That's no moon!.... It's a space station.

a reply to: swanne

Really cool. Maybe it just means there's more random rocks floating around then we thought.

a reply to: swanne

Ah.

Perhaps I misunderstood...

Yes, now that I think about it, I might have been thinking of the tail of the comet that we recently passed through... never mind.

originally posted by: swanne
This means that the Moon back then looked completely different than it does from now.

That's a bit of a stretch. I'm sure the major feature on the Moon (such as the maria and mountain chains, as well as the largest craters) have been there for hundreds or thousands of millions of years. Tycho crater, for example, is estimated to be 108 million years old, and is considered a relatively young crater.

Rather, they mean that the surface cover of regolith itself is renewed from all those impacts.

a reply to: wildespace

I've looked into it for more information. Looks like they're saying that the top two centimeters of the Moon's dusty ground gets completely churned off after 81,000 years. You're right, major features would stay intact; however I don't know if flat features such as mares (which are balsatic rock plains) would keep their darker albedo after 81,000 years of bombardment by meteors of various size.

a reply to: swanne
My guess would be (and this is a complete guess) that the regolith dust in general comes from local sources, because with no atmosphere, the dust from an impact would not travel very far. Therefore perhaps impact events on the darker basalt rock of the mare results in regolith dust that is also darker in color falling back on those mare.

originally posted by: swanne
I don't know if flat features such as mares (which are balsatic rock plains) would keep their darker albedo after 81,000 years of bombardment by meteors of various size.

Are you saying they're not darker or they're not more than 81,000 years old? Seems to me like they are both darker and more than 81,000 years old so I don't understand why you would say "I don't know".

The impactors create a crater and debris field much larger than the impactor, so even if you get an impact on maria the primary effect is going to be pulverizing some of the maria material and re-distributing it, which won't change the color. The material of the previous impactors wouldn't be that much and I suspect would be buried by the maria dust from the latest impacts.

originally posted by: Box of Rain
a reply to: swanne
My guess would be (and this is a complete guess) that the regolith dust in general comes from local sources, because with no atmosphere, the dust from an impact would not travel very far. Therefore perhaps impact events on the darker basalt rock of the mare results in regolith dust that is also darker in color falling back on those mare.

Sounds right to me.

a reply to: Arbitrageur and Box of Rain

Yes, but on the other hand, the dust from pulverised balsalt would have a higher albedo than smooth basalt, for the reason that the dust particles would have random orientation and be more likely to catch sunshine than the original surface.

For instance, look at this picture of a mare area. The brighter streaks of pulverised dust can be clearly seen on the darker ground:



Now imagine countless more of this dust (81,000 years worth of impactors) - it's bound to cover the dark mares with brighter material.

a reply to: swanne
You might be able to use that argument to say the color of the maria changed over the 81,000 years after they cooled, but that hardly seems relevant to the present since they are billions of years old and that argument wouldn't suggest that the appearance of the maria colors would change significantly after that.

a reply to: Arbitrageur

I am using the argument to suggest that the mare's albedo will become brighter in 81,000 years because of the impactors which will keep on making more and more dust.

The basalt itself is dark, but as impactors keep on pulverising the surface, the brighter dust will eventually cover the mare.

a reply to: swanne

I'm not sure your assumption that the Mare are "smooth" is valid. While certainly of lower albedo than other areas, LROC shows is that they are already quite saturated with craters. 3 billion years is a very long time.

It would seem, by your line of reasoning, that the highlands would also increase in albedo.

a reply to: Phage

By "smooth" I am referring to the nature of basalt after it has cooled off.

originally posted by: swanne
The basalt itself is dark, but as impactors keep on pulverising the surface, the brighter dust will eventually cover the mare.

I already granted that may have happened in the 81,000 years after the maria cooled, so we can agree on that part. But after that 81,000 years it was already covered with a new surface of powder (mostly from debris of the mare itself which is greater in volume than the debris from the impactor) if I understand your link correctly. So then I don't expect to see much change in the subsequent 81,000 year periods, since most of what's happening is the mare material getting redistributed, and maybe the powder is getting covered with more powder so the powder is thicker, but the powder wouldn't be a significantly different color because the impactor debris is so small relative to the maria debris. Also I don't know if the colors of the impactors are lighter or darker than the moon materials, so you would need to know that if you thought the impactor material was going to have some effect on color or albedo.

What I do know is that the moon has the second lowest albedo in the solar system of all the known planets, dwarf planets, and moons, which doesn't tend to support that the albedo is getting higher when it's so low. That's based on average albedo, but if you consider just the maria, they are about tied with mercury for having the lowest albedo. That isn't proof the albedo didn't get higher, but still it's not very supportive of such a claim.

a reply to: swanne

"We detected 222 new impact craters and found 33 percent more craters with a diameter of at least 10 metres than predicted" by earlier models, the researchers concluded.

Shocking...

computer models being wrong/inaccurate. Now I've seen everything.



On a side note...does this in any way alter our understanding of the age of the Moon itself ?