Does a similar high resolution image of the same region before date of impact exist? If so it would significantly strengthen the claim that both craters are due to the same recent impact.
Looking at the density of craters how can we exclude the possibility that one of the craters simply existed before the new one?
What alternative scenarios have been considered and ruled out? It would be nice to see what other explanations were considered but ruled out, and how it was ruled out. For example, did the object hit a lava tunnel? (I don't think so, nor do I see how it could explain a double crater, but I would like to see the thought processes of elimination of hypotheses).
If the conclusion is correct, what was the second mass on the opposite end of the rocket motor? Is it some taboo failed project? A "stillborn" crew capsule?
EDIT: the linked references actually show before and after images:
> Looking at the density of craters how can we exclude the possibility that one of the craters simply existed before the new one?
One thing to note is that the density of craters on the moon is a result of a relatively infrequent number of impacts over an astronomically long time. With no process by which impact craters are weathered (wind, seismic activity), craters remain essentially forever.
To this layman who knows very little about orbits and impact craters, that explanation makes a lot of sense.
But the professional software engineer in me knows that even people well skilled in adjacent fields dont understand the issues that makes things “obvious” in my own field.
I therefore don’t doubt that the experts who study space debris considered the obvious explanation and rejected it. Or concluded that it wasn’t as obvious as it may seem.
That they are willing to defer to the crater-formation expert shows an admirable humility and deference to someone who is far more likely to know.
It's highly unlikely they would remain that close unless they split apart very soon before impact. Solar radiation exerts a small force on any object in space that depends on the object's orientation, reflectivity, rotation, etc. This introduces a small variation in it's flight path that can add up to several kilometres of uncertainty in just a few weeks. So even objects with very close flight paths, but differences in structure and rotation, will diverge. Objects with low mass to surface area and an elongated shape, such as empty fuel tanks, are subject to particularly high uncertainty in their trajectory.
The entire point of imperial units is that you can always easily just take half of size. But yes, remembering if there are 36 vs 48 of them in a measure vs increments of 10 is the silliest part to me.
I think it is implied in the article that only the motor is massive enough to excavate a crater. The similarity in size of the craters suggests they were created by objects of similar mass.
At least one early rocket design (Atlas) had fuel tanks so insubstantial that they had to be pressurized until they were loaded with fuel on the pad, and a loss of pressure could be expensive...
That could still work: when the empty end hits first, it has the mass of the engine(s) behind it, and obviously after it bounces/rotates, the engine(s) hit the ground directly and use up the rest of the momentum. But this is just guessing on my part - and of course, if the Moon's gravity would rotate the engine downward as another commenter suggests, it wouldn't work out this way...
I don't think anything manmade and space-borne is going to have enough structural integrity to perform any kind of summersault upon impact at that velocity.
See the fighter jet vs concrete wall video [1]. That was going at 500mph, and notice how the tail of the craft doesn't even perceptibly slow down. And a change in velocity would be required for the tail to rotate around (whether the impact is on an angle or head on)
This space object was travelling at 5800mph, 11+ times the speed. Sure a meter or so of moon dust may be a bit softer, but its solid rock underneath right? I'd guess the equivalent would be putting a kitchen sponge between that fighter jet & concrete wall.
That's not a great source. By "of its kind" they must mean accidental booster stage impacts. NASA intentionally crashed 5 different Saturn V 3rd stages into the moon. At least some of those impacts were to generate vibrations for the seismometers they installed on the moon. See the Wikipedia article linked by the sibling post.
In reality, the motor end should hit first, since free-falling objects usually rotate in such a way that the heaviest part is positioned at the bottom. The atmosphere could influence and modify this behaviour on other celestial bodies, but the Moon does not have it.
> In reality, the motor end should hit first, since free-falling objects usually rotate in such a way that the heaviest part is positioned at the bottom. The atmosphere could influence and modify this behaviour on other celestial bodies, but the Moon does not have it.
Interesting. How does that happen without atmosphere? I thought the atmosphere is what creates this effect in the first place.
Possibly an electrostatic discharge "crater" as distance was finally short enough to be bridged by potential, and then the second crater is the actual impact.
Is that more plausible or probable than two small objects spread out very slightly in the tangent plane and also a bit in time? They say "the" object a lot but is that something we have the precision to know, i.e. that it was not two objects instead?
What I really want to know is if static discharge of that magnitude is common? If so, that's kinda cool.
This small difference would very likely be several kilometers at least. As the article mentioned even the push from photons is relevant for determining the impact site.
One of these objects will be closer to the moon and will be affected more by its gravity and less by its own momentum. This effect increases with time and in the end will amount to a large difference.
That’s an interesting observation. It makes me wonder if that charge can be channeled into a system that harvests the resulting energy. Basically, solar power collection but using static charge that would otherwise accumulate throughout the object.
At the very least, I expect a system to dissipate that energy would be required, or wild and crazy things would happen when such a charge suddenly finds a path to “ground”.
Since it seems the suspicion is it being a Chinese booster, two craters makes me wonder if the booster blew up during it’s active mission but remained tethered together. Not like explosions are known to routinely follow expectations.
Random Factoid: it's extremely rare but the reason why the moon appears the same size as the sun is that the sun is 400x wider than the moon, but also 400x farther from the earth than the moon is.
Our moon holds so many mysteries. Just the very fact that such a large object can be so close in proximity to us while also orbiting is mind boggling.
I’ve always found this to be a curious coincidence, that the Sun’s corona remains visible during total solar eclipses because the Moon blocks out the Sun just so.
But the really fun part is described in the link above:
> Tidal interactions cause the Moon to spiral about one inch per year away from Earth. In the distant past, the Moon was close enough to Earth so that it could block the Sun's entire disk and then some. Our prehuman ancestors would not have witnessed the beautiful coronal displays that we now enjoy. And about 50 million years from now, the Moon will be far enough away so that our descendants will only see annular eclipses.
1. A piece of unverified or inaccurate information that is presented in the press as factual, often as part of a publicity effort, and that is then accepted as true because of frequent repetition.
2. A brief, somewhat interesting fact.
3. An inaccurate statement or statistic believed to be true because of broad repetition, especially if cited in the media.
I assume the definition used here is #2. I’m actually surprised by 1 and 3. I have never heard it used in that context and it’s strange that one word would have 2 fairly contradictory interpretations.
That is interesting! I've never come across the second definition before. Wikipedia suggests that usage become common following CNN misusing the original Norman Mailer meaning during broadcasts in the eighties.
I have the same question, if anyone knows the answer it'd be awesome.
I mean, sure, simply by virtue of the moon's being there, it sort of fends some stuff off like a fence.
But beyond that, is its gravitational pull adequate to affect trajectories?
If so, wouldn't earth's trump it? (Although the inverse square here may play a big part, but that would also make me more inclined to disregard the moon's gravity pull as assisting in any protection it otherwise naturally affords.)
I think the effect of the moon is not so much "catching" things as it is perturbing orbits near earth such that things either crash into earth or moon or get flung away.
Without the moon we might have a lot more stuff in solar orbits that overlap earths orbit.
I expect this could be explained better (and I may well be totally wrong).
The first requirement for a piece of space junk to hit the moon is to be on an orbit that will cross the moon's. Most space junk is left over from launching things into earth orbit (geostationary or lower), and so will not be going fast enough.
The Moon does take slightly more than that proportion of impacts that would hit Earth, because the distribution of approach vectors of impacting bodies isn't uniform, but clusters around the ecliptic plane, and so does the Moon's orbit. But it's still a small number.
'space junk' has long been used as a colloquial term for human generated debris in space, sourced from all nations. This material was discarded by China.
Anything more that you read into that, may be due to some heightened sensitivity that your own flavour of propaganda has installed in you.
I never said I was "offended", I said the usage of the phrase stands out. Culturally, historically, China was known for producing "junk" products of lower quality throughout the majority of the 20th century. It used to be a common phrase in the 60's & 70's. Seeing the phrase in the article, and used in the same manner as during the 60's & 70' invokes those decades old attitudes.
And as another poster has pointed out, The Register tries to make every bad pun, regardless of national origin. In this case, a pun on the type of ship called a junk[0]. I lived in Hong Kong for 10 years, and weekend rental yachting is very popular, called "junk boat trips", even though they're rarely junks these days.
This is The Register we're talking about, a British tech news website known for its heavy sarcasm (largely a parody of the writing style of British tabloid journalists), with an official slogan Biting the hand that feeds IT. Some people find it's pretty funny, personally I'm not a fan and not a reader. But in any case, adjust your expectation accordingly, and don't confuse it with a serious publication.
El Reg is certainly mainly an exercise in entertainment; I enjoy their pastiche of UK tabloids.
But I find their reporting generally quite good. It's not strongly political (it has a slight left-wing bias, I'd say, but it doesn't generally report on politics as such).
> don't confuse it with a serious publication.
I think that's not fair. It's more reliably serious than e.g. Buzzfeed, which sometimes does excellent reporting, but is mostly tabloid style without the pastiche.
I would say CCP junk. The CCP tries to conflate their corrupt totalitarianism with the Chinese ethnicity in order to claim all criticism of them is racism.
I believe the parent thinks that the use of "Chinese junk" is a reference to the ship style from the 2nd Century. The "Junk" was a fully-battened ship, employed by the Chinese, during that time. Though similar junk ships were used throughout the whole of Asia, it became a symbol of Chinese expansion.
The use of the word "junk" when referring to the ship, is not actually an insult or anything of the kind. Practically all medium to large ships from South East Asia were referred to as junks, whether or not they actually had where we get "junk" from - a kind of rigging. (The exact etymology of the word is not, however, clear.)
Why the use of such a reference might be insulting... I have no clue. A junk is a junk. It would still be called a junk if you came across one, today. It's just a technical term, not an insult.
I said the usage of the phrase stands out. Culturally, historically, China was known for producing "junk" products of lower quality throughout the majority of the 20th century. It used to be a common phrase in the 60's & 70's. Seeing the phrase in the article, and used in the same manner as during the 60's & 70' invokes those decades old attitudes.
I think you are confusing China with Korea and Taiwan here.
Mainland China didn’t produce anything before the mid-1980 (when VW opened a factory in Shanghai) and started to export “cheap junk” only around the mid-1990s (after sanctions due to the Tiananmen Massacre).
You may not have had memories of very cheap toys in the 60's and 70's that had a "made in china" stamp on them. Back before any of this modern world, China was the source for extremally cheap, low quality products.
Apart from the geometrical explanation linked in the other comment, there's an Anthropic Principle angle here too -- the fact that eclipses seemed so "perfect and meaningful" to our ancestors was probably a big factor in the development of mathematics and engineering as they tried to predict the eclipses. another similarly intelligent species on a planet without such "perfect" eclipses wouldnt be intrigued by them enough to try to explain their timing. The fact that planets with such perfect sun/moon relationships are "rare" could be one of the missing factors in the Drake Equation. [something similar was a plot point in the scifi book Dragon's Egg]
I suppose one difference is that the pieces from Perserverance were _supposed_ to land on Mars. Whereas this object ended up floating around uselessly, like so much other "space junk". And because they suspect it's origin as being China, it makes sense to write it that way. Chinese junk, American junk, Canadian junk, although even these could be softened by "Chinese space junk, American space junk"... I wonder though if it is also being used in a retro sci-fi manner, in that there are crafts called "junks", particularly in English, "Chinese junks". See https://en.wikipedia.org/wiki/Junk_(ship) and https://www.newworldencyclopedia.org/entry/Junk_(ship)#:~:te.... Thus it is a chance to use the term for a sailing craft in a new context - a Chinese junk, but in space!
'Chinese' here isn't referring to the race, but to the country. So you shouldn't read it as implying racism in any way. In American terminology "American" is not a race nor is "Chinese". If they said "Asian Junk" that'd be racism.
What makes you say this? It is supposed to be a spent stage of a Chinese rocket booster - though there is no confirmation yet and this is the prevailing theory.
Right now it is space junk hitting the moon and it would be space junk no matter the origin of the spent rocket booster.
Agreed. I also don’t like the „Chinese junk“ in the subtitle. This is not what the OP was referring though? The article clearly states „space junk“ which I believe is correct.
But we wouldn't know if it was a Chinese satellite that suffered from a catastrophic failure would we? The Chinese state provides very little information on its space program.
It's The Register. If there's a bad pun somewhere remotely within reach, they'll use it. I don't think it reflects an anti-Chinese bias, just a deliberately irreverent style.
Exactly. Don't confuse The Register with a serious and professional publication. For your information, The Register is a British tech news website known for its heavy sarcasm, largely a parody of the writing style of British tabloid journalists. Its official mission statement is Biting the hand that feeds IT. Complaining a famous tabloid for being a tabloid is a waste of time. If you're not a fan of this writing style, you may want to avoid this website in the future. I'm certainly not one.
Looking at the density of craters how can we exclude the possibility that one of the craters simply existed before the new one?
What alternative scenarios have been considered and ruled out? It would be nice to see what other explanations were considered but ruled out, and how it was ruled out. For example, did the object hit a lava tunnel? (I don't think so, nor do I see how it could explain a double crater, but I would like to see the thought processes of elimination of hypotheses).
If the conclusion is correct, what was the second mass on the opposite end of the rocket motor? Is it some taboo failed project? A "stillborn" crew capsule?
EDIT: the linked references actually show before and after images:
https://www.nasa.gov/feature/goddard/2022/nasas-lunar-reconn...