Pristine meteorite found within hours of hitting Earth | Hacker News Reader

Pristine meteorite found within hours of hitting Earth

astronomy.com

194 pointsgmays64 comments

They found amino acids as well, pretty strong evidence for a role in the delivery of organic compounds to the early Earth (though abiotic synthesis of such compounds at hydrothermal vents is also plausible):

> "The macromolecular organic fraction of a driveway fragment was analyzed by gas chromatography–mass spectrometry (GC-MS) and found to contain structural units similar to those in other CM chondrites, including substituted benzenes and naphthalenes, various thiophenes, and polycyclic aromatic hydrocarbons. The most abundant amino acids detected in the Winchcombe meteorite were α-aminoisobutyric acid (467 ± 17 ng g−1) and isovaline (391 ± 17 ng g−1; table S23). An extraterrestrial, abiotic origin for these compounds is supported by the racemic enantiomeric ratios detected in several protein and nonprotein amino acids (e.g., D/Lalanine = 1.13 ± 0.16; D/Lisovaline = 1.06 ± 0.15)."

https://www.science.org/doi/10.1126/sciadv.abq3925

Is it possible that the meteorite picked up the amino acids from Earth's atmosphere or during the impact?

If you collect a sample of biologically synthesized amino acids, the central carbon atom will have only one stereoisomeric form, i.e. like a left hand vs. a right hand, due to how these amino acids are synthesized by biochemical systems, i.e. enzymes which only generate L-amino acids from precursors (indeed protein structure depends on this asymmetry). There are a handful of exceptions but since the amino acids collected from the meteorite are a racemic mixture (equal amounts of both left and right handed molecules), this points to abiotic synthesis.

So... I understand like seven words in your comment so forgive me if I'm mistaken, but I don't think this answered the question in the comment you're responding to? They asked whether it could have been picked up in the atmosphere, not whether it's of biological origin in the first place (that would be the parent post).

The presumption is that it would necessarily be of biological origin if it were picked up in atmosphere.

I think the parent was asking if there's a separate family of abiotic amino acids in the upper atmosphere? Like from UV photochemistry stuff.

(I don't know the answer either)

That's an interesting question and I don't know the answer! But I'd expect any amino acids produced this way to diffuse and mix with the biologic amino acids from the surface. They'd be diluted by the overwhelming amount of biological "stuff." Stereoisomers should behave the same under the influence of gravity.

- "Stereoisomers should behave the same under the influence of gravity."

Only one way to find out!

https://sci-hub.se/https://doi.org/10.1103/PhysRevLett.121.2... ("Test of the Equivalence Principle with Chiral Masses Using a Rotating Torsion Pendulum")

Biological processes tend to clone the molecules perfectly right down to specific left or right handed orientations. So the molecules formed from a biological process will all be identical.

A process that just happens to form the molecules (eg. put a bunch of elements in a soup and heat and you can also get some proteins forming) form an even mixture of configurations.

Living organisms use nano machines called proteins which physically make molecules like glucose out of other molecules.

Some molecules can form in 2 ways that are mirror images of each other. However, making or using both versions would require having twice as many proteins so we only produce one version of anything.

To visualize this consider DNA is a spiral, you could reverse everything so the spiral rotated in the other direction. But then everything interacting with DNA would also need to be built for that orientation and so forth. https://en.wikipedia.org/wiki/Mirror_life

It hints at the answer. Most amino acids on Earth occur in the L configuration because they are mostly synthesized through biologic activity. This is not to say there are no D amino acids in living organisms -- they're just uncommon. And abiotic processes tend to produce racemic mixtures, but these products are in the minority. Basically, amino acids found on Earth, even in the atmosphere, strongly favor the L configuration. Analyzing the fraction of L and D amino acids within the meteorite would yield clues as to their origin.

Here is a video talking about molecular chirality and how nature really only produces one version of molecules https://www.youtube.com/watch?v=SKhcan8pk2w. If it picked up the molecules in the atmosphere those atmospheric molecules should have been made by life on earth and those have a handedness bias depending on the molecule, some are produced right handed only or left handed only because they are made one atom at a time and need to be one handed for life to use them. Abiotic synthesis produces a 50/50 bias of left and right handed molecules because they are made all at once.

It answers the question.

I did not understand a single thing you just said. I'm in awe.

As a follow-on question to this: what is the process by which meteorites are analyzed? It seems like the contamination problem could be solved by drilling.

If life arrived on Earth from space, that's kind of a bummer because now the mystery of life's origin (our pocket of life at least) is far out there, beyond our reach.

Sort of. Earth's surface is constantly being recycled. Rocks from when life began on earth have all but completely disappeared. Meanwhile, rocks from or older than that are still completely preserved whizzing around the solar system.

For those not familiar with meteorite identification: they can be tricky to tell apart from other rocks and random debris found on earth. I love this Professor's site [1], first attempting to deter people from sending him tons of useless rocks. Starts with some "Rude Admonishments" that are worth a read. His site is also at the top of the sites recommended by the Utah Geological Survey as resources for people who think they may have found a meteorite.

[1] https://sites.wustl.edu/meteoritesite/items/what_to_do/

That's a very interesting site! Thanks!

This was interesting:

>The incandescent (glowing) period of a meteor is only a few seconds as it passes through the upper atmosphere. Although the exterior gets hot enough to melt during the incandescent phase, most of the hot material immediately ablates away (the “tail” of the meteor), so conduction of heat to the inside of the rock is inhibited. Also, rocks are not good conductors of heat.

Also explains a thought I had of how why water can be retained in a landing meteorite.

I recently learned that we track fireballs like these. If you see a fireball, please report it. Your data helps track down more meteorites. The article includes the link, but it's not apparent that tracking is a large community effort.

https://fireballs.imo.net/members/imo_view/event/2021/1202

https://fireballs.imo.net/members/imo_view/browse_events

Is the free membership enough for reporting? Not quite clear whether one has to pay to report them

https://fireball.amsmeteors.org/members/imo/report_intro/ doesn’t require any account/membership whatsoever.

> A space rock generally stops burning by the time it reaches about 30km altitude.

When I was around 12 years old and friend and I were camping and staring up at the stars and a meteorite took a path very close above us. I remember hearing it (almost a crackling sound) and I swear even feeling a slight heat on my face momentarily.

And then we lost sight as it went below nearby tree line.

I’ve always been curious about how close it came to us. I guess it’s possible that my memory of noise and heat isn’t accurate and something I’ve imagined in the years since, but it was a very beautiful moment.

That looks like a turd. Remarkable that they spotted it. Some people find all kind of things in fields, like stone age spear tips etc. I guess the key is to keep your eyes open and not immediately dismiss what you see.

I had the same thought.

One time on a thru hike in Antarctica I came across what looked like a lump of shit. But there’s no large animals in Antarctica, it was a meteorite.

Well, the fact you were there indicates there was at least one large animal in Antartica.

Nobody Listens to Paula Poundstone (the comedy podcast) had scientist Ralph Harvey on to talk about collecting meteorites in Antarctica in episode 208. He made the point that any rock you find out there lying on top of the ice is probably a meteorite and there are scientists out searching for meteorites that have collected in water channels formed from melting ice in the warmer seasons.

https://podcasts.apple.com/us/podcast/ep-208-the-land-way-do...

Here's an article that also interviews Ralph Harvey:

https://www.nbcnews.com/science/space/hunt-meteorites-resear...

I think this comment wins today. But could sled dogs have left "signs of their presence" that would remain for a long time?

There have not been any dogs in Antarctica since 1994, so that would have to be a really long time.

>There have not been any dogs in Antarctica since 1994

Good: dogs have no business being in Antarctica. Usually, they turn out to be dangerous alien shape-shifters.

Except in that movie "The Thing".

It's kind of spooky to think that meteorites this large could've landed in someone's backyard and been forgotten, or worse yet, taken in and kept.

To me the spookiest thing is it landing on someone's head.

Too close for comfort: https://en.wikipedia.org/wiki/Peekskill_meteorite

"The meteorite broke up over Kentucky and passed over West Virginia and Pennsylvania on its north-northeast trajectory before striking a parked 1980 red Chevy Malibu at approximately 7:50 pm EDT. After traveling through space at a cosmic velocity of 8.8 miles per second (14 km/s, 31,600 miles per hour), the speed of the meteorite at impact had slowed to 164 miles per hour (264 km/h)."

Tough luck if you're commuting on the wrong day.

The meteorite was worth way more than the price of a new Malibu. And the Malibu itself sold at auction for way more, too. So, hope every day to have your car struck by a meteorite.

Sometimes I happen to sit in my car, so no, I do not hope for a meteorite strike on my car, wishes have a tendency to be fullfilled at the wrong time.

It's too bad the meteorite didn't do a lot more damage to the car: that car is really ugly.

If that happens, it will spark the creation of a new ICD-10 code, probably somewhere under W20.8 "Stuck by object falling from..." space.

There are quite a few space-related ICD codes (V95.4 and child codes - Spacecraft accident injuring occupant), due to NASA

But my favorite ICD code is V97.33XD - Sucked into jet engine, subsequent encounter.

Like that happens more than once...

Why spooky? It's not like meteorites are rare.

If I see a rock fall from the sky in my backyard and no one comes to ask to study it, you can bet I will keep it for myself.

Meteorites this large are rare, and extremely helpful to the scientific community, considering that going straight to the source is the only other way to retrieve samples. It's spooky because it could mean a huge discovery that's not being realized.

You can actually find micrometeorites in your rain gutters :) https://www.newscientist.com/letter/mg23331090-800-10-findin...

That headline: "Finding meteorites in your gutters is easy"!

Iron space dust that is fine enough to escape incineration as “shooting stars” when entering Earth's atmosphere drifts down continuously. To collect these small iron spheres, scrape several handfuls of mud from a convenient roof gutter, preferably a plastic one, add to a bucket of water and stir.

Fish for meteorites with a strong magnet wrapped in a plastic bag. Remove the magnet, carefully rinse the bag into a glass dish and look for fine, dark grey dust. Dragging the magnet underneath will concentrate the dust. A good magnifier will show tiny spheres, some of them up to 0.2 millimetres in diameter.

I collect my rainwater for household use. I must admit, until this moment I had never considered that I interact with space dust on the daily.

Once I found a small chondritic rock that was very likely a meteorite. My mom threw it away thinking it was just a random pebble.

If you're in the Grimsby/Niagara region of southern Ontario, they're looking for potential pieces of the meteorite from a few days ago:

https://www.cbc.ca/news/canada/hamilton/meteor-grimsby-scien...

> They contain complex carbon-based molecules called amino acids, which are regarded as the “building blocks of life”.

Just curious what could be the percentage of the readers of the article who never heard about amino acids. (I’ve been fascinated by popular articles, say, on physics research that never forget to explain to the reader what an atom or the electron is.)

Meteorite or meteor-wrong how to tell if that really is a meteorite. http://meteorite.unm.edu/meteorites/meteorite-museum/how-id-...

I read that these can sell for hefty sum. Anyone familiar with this market?

They can definitely be bought and sold. This lovely website [1] has a list and prices are displayed. Prices vary a lot: type/composition, origin, and of course size all matter. How pretty they are also matters. I have met a few people who thought they found large meteorites (right or wrong) and who understandably were very excited.

[1] http://www.meteoritemarket.com/mmhome.htm

A bit off topic, but can we start straight up catching these in Low Earth Orbit? What's the hard part here? Detecting them before they're close or getting a earth orbiting satellite to the precise right place at the right time?

Catch it with what?

A big net, or a gigantic baseball glove.

Like this: https://en.wikipedia.org/wiki/CORONA_(satellite)#Recovery

I was thinking something more like this: https://en.wikipedia.org/wiki/Baseball_glove

> What's the hard part here?

Detecting, then catching a small object, in space, traveling at 10-20 thousand kilometers per hour.

Much easier to go out to an asteroid. https://en.wikipedia.org/wiki/OSIRIS-REx

Even faster than that! Meteors have a relative velocity between 11 and 71 km/s (40,000-255,000 kph). Anything faster than that would be interstellar, which is uncommon but not unheard of.

Pedantically, the lower limit of velocity relative to low-orbiting satellites is around 3 km/s. The 11 - 71 km/s figure is relative to the ground.

https://www.nasa.gov/mission_pages/stardust/mission/index-ae... (but that's for comets)

"What's the hard part here?" hahahaha

> What's the hard part here?

Physics

Give kerbal space program a shot. It teaches you hard lessons about this and others.

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