
Earth's mountains form in millions of years, Moon ones near instantaneously - uncertainquark
https://jatan.space/exploring-moon-mountains/
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kempbellt
Mountains on Earth are formed by tectonic shifts and volcanic eruptions,
which, yes, take millions of years.

Mountains on the moon (aka: crater walls) form nearly instantaneously because
of a violent impact.

You can make instant mountains on Earth too. Downside is, it'll probably kill
off most life on the planet.

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Natsu
We have a few craters already, e.g. -

[https://www.meteorcrater.com/](https://www.meteorcrater.com/)

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sushshshsh
A bit frustratingly, they mean "geologically instanteously" which is not the
same as "instaneous as per human perception".

I'm not sure how long rock takes to cool after an asteroid impact, maybe days,
maybe months or years depending on how large of an impact and how cold the
surroundings (no atmosphere soooo....)

These mechanics are not discussed in the article and are instead just
dismissed as "negligible"

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wahern
Wouldn't molten rock simply flow and flatten? Even if not yet rigid, I'd
assume the mountains do effectively form instantaneously (i.e. seconds or
minutes), possibly flattening some as they slowly cool.

EDIT: The PBS NOVA special "The Day the Dinosaurs Died" describes the
mechanics of the Chicxulub impact starting at about the 33 minute mark. It's
as instantaneous as one would intuit, given the magnitudes involved:

> NARRATOR: The asteroid had punched a hole nearly 20 miles deep, gouging a
> crater 124 miles wide. Over 40,000 cubic miles of rock were displaced,
> rising into towering mountains.

> JOANNA MORGAN: So, this is an absolutely amazing event, because that
> happened in less than two minutes, and if you think of it, mountains the
> size of the Himalayas were formed in seconds.

> NARRATOR: As the mountains collapsed, they formed what's known as a "peak
> ring," found only in the largest of super craters. It's the only peak ring
> left on Earth; the next nearest is on the moon.

[https://www.pbs.org/wgbh/nova/video/day-the-dinosaurs-
died/](https://www.pbs.org/wgbh/nova/video/day-the-dinosaurs-died/)

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Simon_says
They want me to pay $25 to watch something my tax dollars already paid for?

Edit: Nevermind, there's a torrent.

~~~
jws
US federal tax dollars no longer fund a significant portion of public
broadcasting. Only about 1/7th is federally funded.

~~~
Simon_says
If 1/7th that doesn't entitle me to watch it, it should be 0.

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nwallin
This article is barely mentions formation of mountains on Earth. The article
is almost entirely about lunar craters, lunar central peak craters, and lunar
peak ring craters.

Interesting article, terrible headline.

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EdwardDiego
> This article is barely mentions formation of mountains on Earth.

Isn't that pretty well understood already?

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garmaine
They both are.

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molmalo
It's interesting how my mind had some trouble processing some of those crater
images, because I saw initially some of them as circular buttons, going up
from the surface, instead of craters going down.

I had to stop looking, and look back several times before my mind could
actually see some of those pictures correctly.

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narag
It has happened to me since I was a child, at the time of Apollo. My trick was
turning the photo upside down so the light aligned with the room source.

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AaronM
I can't imagine the size of object that formed the Valhalla crater on
Callisto. The central region is 360km across, and the diameter of the entire
basin is 3,800km. That's a distance on earth from LA to Arkansas!

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LeifCarrotson
And the whole equator of Callisto has a circumference of 15,100 km.
Proportionately, that would be a basin the size of the Indian ocean!

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behnamoh
The second one is an amazing close up photo of a lunar mountain.

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tracerbulletx
There are mountains on earth that formed in a few years too, and in fact most
mountain ranges form pretty quickly as far as geology goes.

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HenryKissinger
Now I want to hike a mountain on the Moon. My Instagram needs new content.

