Bright Explosion on the Moon

NASA ^ | 5/17/13 | Tony Phillips

[DuncanWaring]

Due to Global Warming.

[onedoug]

What? How to eat other people.

[LibWhacker]

I'm sorry, I can't. I've never heard of it. I did a quick search and could only come up with this:

“Now there was a bright new [thin crescent] moon, and as usual in that phase its horns were tilted toward the east and suddenly the upper horn split in two. From the midpoint of this division a flaming torch sprang up, spewing out, over a considerable distance, fire, hot coals, and sparks. Meanwhile the body of the moon, which was below, writhed ... like a wounded snake.”

But that description came from some Canterbury monks in 1178 AD. I think most astronomers today believe the monks witnessed the effects of the impactor that created the Bruno Crater on the far side of the Moon, at least such effects as were visible to them on the near side.

But I'll keep looking!

[LibWhacker]

That’s my guess. I think the earth is shielding the moon from some of the impacts. But you’d think it would show up as a fairly circular area that was relatively free of hits. So why there’s also a lack of observable impacts at the poles stumps me. Perhaps most of the meteoroids come in along the ecliptic, which is oriented in such a way wrt the moon that it shows up as fewer strikes near the poles??? Total WAG.

[pax_et_bonum]

“Now there was a bright new [thin crescent] moon, and as usual in that phase its horns were tilted toward the east and suddenly the upper horn split in two. From the midpoint of this division a flaming torch sprang up, spewing out, over a considerable distance, fire, hot coals, and sparks. Meanwhile the body of the moon, which was below, writhed ... like a wounded snake.”
~~~~~~~~~~~~~~

Never heard of this! Wow!

[LibWhacker]

Okay, just came across this: There are no active volcanic features on the Moon. Most of the volcanic activity took place early in the Moon's history, before about 3 billion years ago. The most recent lava flow occurred about 1 billion years ago. .

Interesting, no? It means there can't have been any basaltic flows due to volcanism on the moon in the 17th Century. Which means... the flow, if it happened, would have to have been caused by an impact of some kind.

But that is a problem because even the Chicxulub impactor 65 million years ago on Earth (where molten material is much closer to the surface than on the moon) didn't cause balsaltic flows. And that asteroid was miles across. It's a pretty safe bet that no such impact has happened on the moon during historical times. imho only.

[LibWhacker]

Cool! Look what I just found on Wiki (which is news to me). They never taught this when I took astronomy! From Wiki:

Five monks from Canterbury reported to the abbey's chronicler, Gervase, that shortly after sunset on June 18, 1178, (25 June on the proleptic Gregorian calendar) they saw "the upper horn [of the moon] split in two". Furthermore, Gervase writes:

From the midpoint of the division a flaming torch sprang up, spewing out, over a considerable distance, fire, hot coals and sparks. Meanwhile the body of the Moon which was below writhed, as it were in anxiety, and to put it in the words of those who reported it to me and saw it with their own eyes, the Moon throbbed like a wounded snake. Afterwards it resumed its proper state. This phenomenon was repeated a dozen times or more, the flame assuming various twisting shapes at random and then returning to normal. Then, after these transformations, the Moon from horn to horn, that is along its whole length, took on a blackish appearance.[2]

In 1976, the geologist Jack B. Hartung proposed that this described the formation of the crater Giordano Bruno.[3]

Modern theories predict that a (conjectural) asteroid or comet impact on the Moon would cause a plume of molten matter rising up from the surface, which is consistent with the monks' description. In addition, the location recorded fits in well with the crater's location. Additional evidence of Giordano Bruno's youth is its spectacular ray system: because micrometeorites constantly rain down, they kick up enough dust to quickly (in geological terms) erode a ray system,[4] so it can be reasonably hypothesized that Giordano Bruno was formed during the span of human history, perhaps in June 1178.

However, the question of the crater's age is not that simple. The impact creating the 22-km-wide crater would have kicked up 10 million tons of debris, triggering a week-long, blizzard-like meteor storm on Earth – yet no accounts of such a noteworthy storm of unprecedented intensity are found in any known historical records, including the European, Chinese, Arabic, Japanese and Korean astronomical archives.[5] This discrepancy is a major objection to the theory that Giordano Bruno was formed at that time.[6]

This raises the question of what the monks saw. An alternative theory holds that the monks just happened to be in the right place at the right time to see an exploding meteor coming at them and aligned with the Moon. This would explain why the monks were the only people known to have witnessed the event; such an alignment would only be observable from a specific spot on the Earth's surface.[7]

Love this stuff!

[Dr. Bogus Pachysandra]

http://www.latimes.com/news/science/sciencenow/la-sci-sn-asteroid-1998-qe2-20130516,0,548201.story

[pax_et_bonum]

This is really cool.

I think hubby needs a telescope for his birthday. No - Memorial Day!

:-)

[Crusher138]

Man has never been to the moon! My muslim friends tell me so!

[Gandalf_The_Gray]

I wonder why impacts in the central region are essentially nonexistent.

Picture yourself high above the north pole looking down on the earth from a vantage point at a right angle to the plane of the earths orbit. The earth is traveling an orbital path with a radius of 93 million miles which is nearly circular. The circumference of that path is a bit over 584 million miles and the travel time is 365.25 x 24 hour days. The tangential speed of the orbiting earth is therefore the circumference divided by the orbital period which is about 66,700 miles per hour. Looking down at the earth from "above" the plane of the ecliptic. (the remnant of the dust cloud that collapsed/condensed into the solar system) The hemisphere facing into the direction of travel is moving "forward" into the path of space junk moving through our orbital path and overtaking that moving junk at 66,700 mph. Conversely, the trailing hemisphere (looking back along our orbital path) is moving away from any space junk crossing our path which would have to catch up with us in order to score a hit.

The moon always keeps the same face toward the earth as it orbits us every 28 and some spare change days. It's orbit is very nearly circular and it is inclined slightly to the plane of the ecliptic.

When the moon is "full" it is fully illuminated by the sun because of it's orbital tilt which tells you it is either above or below the earth's shadow. From our observation point it is directly in line to the earth and then to the sun. Fourteen some days later it will be a "new" moon and completely dark. It is now halfway around it's orbit and is therefore between us and the sun.

When the moon is "full" only the hemisphere facing into the direction of travel(that is one half of the face of the moon visible to us and one half of the side we never see) around the sun is subject to collisions with "space junk" as it is moving through the debris at the same speed as earth (66,700 mph). It rather like bugs hitting a cars windshield, it's easy to visualize bugs hitting you (or you hitting bugs, macht nichts) while moving forward. It's also hard to picture a bug moving fast enough to hit the back window.

In seven days or so, the moon is waning and the hemisphere facing into the debris is the side we never see from earth. The Apollo missions brought back photographs giving humans their first view of the unknown face which appeared to be more ruggedly cratered.

Seven more days and the moon is "new" and the hemisphere facing into the direction of travel(that is the other half of the face of the moon visible to us and the other half of the side we never see)

Seven more days and the moon is "waxing" and the hemisphere facing into the direction of travel and the debris is the only face of the moon we can see from earth. However, the big difference and the answer to you original question is the earth is directly in front of the moon as we sweep through the debris field. In effect the earth is running interference for the moon and sweeps up the junk that would logically hit the central region of the visible face.

If this seems hard to visualize, think of what it must have been like for those shepherds watching their flocks by night?

Regards,
GtG

PS That's my story and I'm sticking to it...

[Graewoulf]

Thanks. I’ll dig my reference to the Monk’s observations and post it here.

[LibWhacker]

Okay, onedoug, GtG’s nailed it (good job, GtG!). Applying his explanation, I think it’s even easy to see why the poles aren’t getting hit as often (how often do bugs smack into the side of your car?) as the rest of the moon (excluding the part shielded by the earth).

[SunkenCiv]

Thanks LibWhacker.

• A Celestial Collision
• NASA Solves Moon Mystery (+Geology Picture of the Week, February 16-22, 2003)
• Moon's Youngest Crater Discovered
• Moon younger than previously thought
• The Moon reveals its weirder side - SELENE mission reports on gravity anomalies.
• Moon Has Iron Core, Lunar-Rock Study Says
• Landscapes from the ancient and eroded lunar far side
• The Moon Revisited - Resource-rich lunar south pole is seen as perfect area to explore
• Long-Destroyed Fifth Planet May Have Caused Lunar Cataclysm, Researchers Say
• Comet or Meteorite Impact Events in 1178AD?
• Cosmic Impact Site That Created Earth's Axial Tilt and Fault Lines

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[lbryce]

So Ralph finally made good on his promise.Well worth posting!

[lbryce]

What is it about Islam that would preclude Man from landing on the moon?

[RegulatorCountry]

I think the earth is shielding the moon from some of the impacts

I've thought the same but not just that, the moon in turn shields the Earth to an extent as well. More serious astronomers dismiss such a contention, but do a search and find some photos showing the "far" side of the moon, the side we never see from Earth. I'd do it myself but it's a pain on mobile devices.

The far side is majorly pockmarked by comparison, riddled with impacts actually, looking more like a very large asteroid than the moon we know and love.

It's startling.

[glock rocks]

Far side of the moon:

http://upload.wikimedia.org/wikipedia/commons/thumb/0/04/Moon_Farside_LRO.jpg/768px-Moon_Farside_LRO.jpg

[LibWhacker]

That’s a good point. And before someone says, “But at any given moment, the moon (or earth) only blocks a small portion of the sky as seen from the other. How much difference can that make?” Over billions of years, it adds up. And that’s what the far side of the moon is showing us. (Not sure, but I think the moon has been tidally locked to the earth for that long.)

[RegulatorCountry]

That photo looks less pronounced than some I’ve seen, the angle of the sun was more oblique, which really highlighted just how much variation there is in relief. Many of those craters are fairly impressively elevated around the rim, which is not all that obvious without heavy shadow and highlight. First time I saw a photo of it, it was sort of foreboding for some reason.