[HN Gopher] Pristine meteorite found within hours of hitting Earth
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Pristine meteorite found within hours of hitting Earth
Author : gmays
Score : 156 points
Date : 2022-11-20 12:46 UTC (2 days ago)
(HTM) web link (astronomy.com)
(TXT) w3m dump (astronomy.com)
| photochemsyn wrote:
| 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 a-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
| lab14 wrote:
| Is it possible that the meteorite picked up the amino acids
| from Earth's atmosphere or during the impact?
| grog454 wrote:
| 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.
| photochemsyn wrote:
| 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.
| xenospn wrote:
| I did not understand a single thing you just said. I'm in
| awe.
| Aachen wrote:
| 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).
| thenewwazoo wrote:
| The presumption is that it would necessarily be of
| biological origin if it were picked up in atmosphere.
| perihelions wrote:
| 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)
| inportb wrote:
| 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.
| perihelions wrote:
| - _" 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"_)
| AnotherGoodName wrote:
| 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.
| Retric wrote:
| 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
| thinkyfish wrote:
| 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.
| inportb wrote:
| 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.
| Buttons840 wrote:
| 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.
| aflag wrote:
| 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.
| 1970-01-01 wrote:
| 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
| Aachen wrote:
| Is the free membership enough for reporting? Not quite clear
| whether one has to pay to report them
| macintux wrote:
| https://fireball.amsmeteors.org/members/imo/report_intro/
| doesn't require any account/membership whatsoever.
| prego_xo wrote:
| 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.
| sph wrote:
| 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.
| prego_xo wrote:
| 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.
| kuxv wrote:
| To me the spookiest thing is it landing on someone's head.
| lm28469 wrote:
| Too close for comfort:
| https://en.wikipedia.org/wiki/Peekskill_meteorite
| prego_xo wrote:
| "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.
| pencilguin wrote:
| 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.
| athenot wrote:
| 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_.
| kldavis4 wrote:
| You can actually find micrometeorites in your rain gutters :)
| https://www.newscientist.com/letter/mg23331090-800-10-findin...
| tpmx wrote:
| 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._
| rex_lupi wrote:
| 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.
| [deleted]
| MarcoZavala wrote:
| sopchi wrote:
| 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/
| pcrh wrote:
| 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.
| Gravityloss wrote:
| 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.
| xwdv wrote:
| 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.
| cardiffspaceman wrote:
| I think this comment wins today. But could sled dogs have
| left "signs of their presence" that would remain for a long
| time?
| bombcar wrote:
| Well, the fact you were there indicates there was at least
| _one_ large animal in Antartica.
| dboreham wrote:
| Except in that movie "The Thing".
| djbeadle wrote:
| 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...
| NetOpWibby wrote:
| I had the same thought.
| 3pt14159 wrote:
| 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?
| ligerzer0 wrote:
| Catch it with what?
| warmwaffles wrote:
| A big net, or a gigantic baseball glove.
| dboreham wrote:
| Like this:
| https://en.wikipedia.org/wiki/CORONA_(satellite)#Recovery
| warmwaffles wrote:
| I was thinking something more like this:
| https://en.wikipedia.org/wiki/Baseball_glove
| ceejayoz wrote:
| > 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
| ericbarrett wrote:
| 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.
| perihelions wrote:
| 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.
| throw1234651234 wrote:
| "What's the hard part here?" hahahaha
| treme wrote:
| I read that these can sell for hefty sum. Anyone familiar with
| this market?
| mathewsanders wrote:
| > 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.
| [deleted]
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