NASA Solves Moon Mystery (+Geology Picture of the Week, February 16-22, 2003)

February 20, 2003 | Jet Propulsion Laboratory

[capitan_refugio]

Since the root "geo" is Greek for "earth, ground, or soil," geology is by definition, the study of the Earth as defined in the rocks.

The newest branch of the science of geology is known as "exogeology." Exogeology is the study of planetary bodies outside of the earth. I first heard the term several years ago from a firnd who worked at the JPL in Pasadena, CA. He was working on the exogeoglogy of the moons of Jupiter. I thought that was pretty neat.

[RightWhale]

how often ought it to happen on earth?

About every five years. Most detonate in the atmosphere rather than reach the ground.

[cogitator]

Really? That would be a quite noticeable impact. If this is thought to occur once every 50 years on the moon, how often ought it to happen on earth? Even given that most asteroids would land in the ocean, I would think we'd have more of a record of observed collisions in historical times if something of this size is coming in every 50 years or so.

They do. I wrote a FR editorial proposing that NASA should take up the SpaceGuard mission proposed by Arthur C. Clarke in Rendesvous with Rama, to become an international space organization with the capability to protect the Earth from asteroid impacts.

On June 30, 1908, the Tunguska impact caused a major event in Siberia.

The Tunguska Event (with pictures of the aftermath)

On August 10, 1972, a large asteroid or comet fragment passed over Wyoming and other western states before "skipping" back out of the Earth's atmosphere. Below is a picture of the fireball over the Tetons.

There was also a large fireball and possible impact on the Greenland ice sheet in the 1990s.

I should be able to find my editorial with a FR search; I'll post the link in a subsequent reply if I do.

[cogitator]

Now is the time for "SpaceGuard"

[sit-rep]

bttt...

[aruanan]

...so isn't the scientific term officially selenology....

Yes, sort of.

Main Entry: sel·e·nol·o·gy
Pronunciation: "se-l&-'nä-l&-jE
Function: noun
Date: 1821
: a branch of astronomy that deals with the moon
- se·le·no·log·i·cal /"se-l&-nO-'lä-ji-k&l, s&-"lE-n^&l-'ä-/ adjective
- sel·e·nol·o·gist /"se-l&-'nä-l&-jist/ noun

[null and void]

If his theory was right, Dr. Leon Stuart would be the first and only human in history to witness and document the impact of an asteroid-sized body impacting the Moon's scarred exterior.

Ummmm, didn't a few monks in England report an impact on the moon's top "horn", the resulting shower of sparks, and the appearance (illusion) of the moon shuddering in the 1200's? IIRC this tracks with the location and estimated age/youth of the Tico crater...

[Atlas Sneezed]

The bright flash would simply be the reflected light of the sun off the clould of particles. Kind of like how a cloud is bright white when sunlit. This is especially true for an event at or near the terminator, as above.

[RightWhale]

The kinetic energy of an asteroid stopping suddenly would be enough energy to ionize the body of the asteroid, which would be accompanied by a release of photons, AKA a bright flash. While not in the nuclear range, it would be easily match TNT pound for pound.

[Ichneumon]

OK, now they can explain this:

The Moon is plaid??

[coloradan]

Just where do you think the expression to "moon" someone came from?

[Nick Danger]

[Godebert]

[Axenolith]

Ancient alien lunoglyph representing the general frustrations of the leaders of that race of beings to successfully recruit polesmoking underlings...

[Swordmaker]

Geology doesn't HAVE to be on the Earth.

Actually, from the root of the word, Geo, it does - this is lunology :^

I think the actual term is "Selenology"...

[cogitator]

Ummmm, didn't a few monks in England report an impact on the moon's top "horn", the resulting shower of sparks, and the appearance (illusion) of the moon shuddering in the 1200's? IIRC this tracks with the location and estimated age/youth of the Tico crater...

Yes on the monk's observations (1178), but I don't think it was Tycho. One Web article says this might be the crater "Bruno".

[null and void]

One Web article says this might be the crater "Bruno".

What in the Dickens do you use a a key word for the search?

[cogitator]

What in the Dickens do you use a a key word for the search?

I used Google with "monks moon impact observation".

Here's the article with the reference I mentioned:

Leonid strikes the Moon

Here's another article about it, that throws doubt on the impact theory for the 1178 event and Bruno crater:

The Mysterious Case of Crater Giordano Bruno

Same article topic, better picture:

Lunar Impact or Heavenly Coincedence

This article also refers to the Stuart impact photograph.

[null and void]

Thanks! After caffination, I figured it out. I got a few different hits, and yours were interesting.