
‘Hypatia’ Stone Contains Compounds Not Found in the Solar System - curtis
http://www.popularmechanics.com/science/a15050414/incredible-hypatia-stone-contains-compounds-not-found-in-the-solar-system/
======
perlgeek
> A new study led by geologists at the University of Johannesburg found that
> compounds in the Hypatia stone are distinct from anything discovered in the
> solar system. The researchers therefore conclude that parts of the rock
> formed before the solar system, and if these compounds are not presolar, the
> prevailing idea that the solar system formed from a nebula of homogenous gas
> is called into question.

Couldn't it have come from outside our solar system, in which case it is
pretty much irrelevant whether it is presolar or not? Granted, that would also
make it pretty exciting :-)

It seems a bit premature to question the formation theory of the solar system,
based on a single rock from which we don't know if it even formed inside the
solar system.

~~~
acqq
Read the text 'russdill linked in another comment:

"Most (99 percent) of the meteorite inventory on Earth comes from the main
asteroid belt, between the orbits of Mars and Jupiter. A small fraction of
meteorites come from Mars (about 180) and the Moon (about 275). Some
meteorites have been suspected to come from comets. Famous astronomer Carl
Sagan once said, “It is unlikely that a single meteorite of extrasolar origin
has ever reached the surface of the Earth.” Numerical calculations suggest
that the possibility of exchange of meteoritic fragments between stellar
systems is highly unlikely. Indeed, extrasolar meteorites have not been
identified in our meteorite collections."

So it's still highly probable that it's still from the stuff of our solar
system, it's just the question how homogeneous the stuff was and did the stuff
coalesce before or after the Sun was formed. But we know that stuff formed in
the cold, from the University of Johannesburg press release:

[https://www.uj.ac.za/newandevents/Pages/UJ%E2%80%99s-newest-...](https://www.uj.ac.za/newandevents/Pages/UJ%E2%80%99s-newest-
A-rated-researcher-shows-Hypatia-stone-questions-formation-of-solar-
system-.aspx)

"What we do know is that Hypatia was formed in a cold environment, probably at
temperatures below that of liquid nitrogen on Earth (-196 Celsius). In our
solar system it would have been way further out than the asteroid belt between
Mars and Jupiter, where most meteorites come from. Comets come mainly from the
Kuiper Belt, beyond the orbit of Neptune and about 40 times as far away from
the sun as we are. Some come from the Oort Cloud, even further out. We know
very little about the chemical compositions of space objects out there. So our
next question will dig further into where Hypatia came from."

~~~
wiz21c
I'm not very knowledgeable about all of this but :

>> A small fraction of meteorites come from Mars (about 180) and the Moon
(about 275).

How come that the moon being closer to earth, we have just 50% more meteorites
Mars ? And how come we have so many more from the asteroid belt ?

~~~
Symmetry
You have to leave Mars's surface at 6300 m/s to get to Earth, ignoring slowing
down at the end which is accomplished by the atmosphere. To get to Earth from
the Moon takes 5670 ms/s. The Moon is much closer in Cartesian space, but that
just means that the delay from an object leaving the Moon's surface to getting
to the Earth's is much smaller, it affects latency but not throughput and on
geologic timescales both latencies are small.

EDIT: See this map of the solar system in delta-v terms:

[http://i.imgur.com/AAGJvD1.png](http://i.imgur.com/AAGJvD1.png)

EDIT2: Argh, I messed up my calculations and the distance from the moon is
just 2410 m/s. You have to factor in how often Mars gets hit by stuff and the
speed at which stuff is going given Mars's gravity well.

~~~
bostonpete
It seems like your comment ignores the relevance of proximity in the
likelihood that an ejected object with the necessary velocity ends up at
Earth. Wouldn't the probability of such an object hitting Earth from Mars
would be many orders of magnitude smaller than one from the Moon (like trying
to hit a target from 100x further away)?

I always understood the large numbers of meteorites from Mars to be related to
the fact that Mars is closer to the asteroid belt and therefore has had a lot
more impacts historically...

~~~
Symmetry
The levels of delta-v we're talking about here aren't nearly enough to knock
these objects out of the solar system. When they leave the Moon or Mars
they're still in orbit and will remain in orbit until they collide with
something. In the case of a moon rock that means either hitting the Earth or
returning to the Moon in what is likely a single orbit so 2 weeks. In the case
of Mars it will either hit Mars again or the Earth. Or possibly the Moon, one
Mars's moons, or an asteroid but probably the first two. The odds of this
collision taking place on any given orbit around the Sun are low but the
object isn't going anywhere and eventually, possibly millions of orbits later,
it will end up hitting something. So no, the probability that it will
eventually hit the Earth doesn't really go down with the distance in this case
since we're only talking millions of years for a collision to occur rather
than billions.

------
russdill
This should answer a lot of questions people have about the article:
[http://www.astronomy.com/magazine/ask-
astro/2017/10/meteorit...](http://www.astronomy.com/magazine/ask-
astro/2017/10/meteorite-origins)

------
intrasight
Title should have been "ratios of compounds"

~~~
theptip
> There are also grains of a compound consisting of mainly nickel and
> phosphorus, with very little iron, a mineral composition never observed
> before on Earth or in meteorites

The title is correct.

~~~
intrasight
Then I am just not familiar with this use of the term "compound". I was
thinking synonymous with "mineral", as in

[https://en.wikipedia.org/wiki/Mineral](https://en.wikipedia.org/wiki/Mineral)

"Minerals are chemical compounds, and as such they can be described by fixed
or a variable formula."

But now I think it means like: [http://www.scienceclarified.com/everyday/Real-
Life-Earth-Sci...](http://www.scienceclarified.com/everyday/Real-Life-Earth-
Science-Vol-2/Rocks-Key-terms.html)

"COMPOUND: A substance made up of atoms of more than one element, chemically
bonded to one another"

------
macinjosh
I do not see how they can categorically state the compounds are not from our
solar system. We've barely begun to explore our solar system. Seems arrogant
to assume such things.

~~~
simonh
Take a chill pill. They're not assuming anything, they're making a hypothesis
based on the available evidence. The paper title even includes the words "A
contribution to the debate on it's origin". That hardly looks like a final
pronouncement.

------
INTPenis
I understand what the article is trying to say but the title is kinda funny.

Compounds not found in the solar system. By the race that has not even left
its little corner of the solar system yet.

Sure we have spectral analysis but fact remains there are parts of the solar
system we can't investigate. So the title is a bit amusing and click-baitey.

It's like saying "I haven't found my keys yet and I've only looked around my
desk".

~~~
amelius
> The mysterious Egyptian rock contains micro-mineral compounds not found on
> Earth

And apparently, Egypt is not located on Earth.

~~~
em3rgent0rdr
And doesn't everything in the solar system ultimately have extrasolar origins?

------
jlebrech
now did it crash to earth or did it land?

------
calcifer
> Named for Hypatia of Alexandria, the first prominent Western woman
> astronomer

How is a middle-eastern woman who lived circa ~400AD "western"? "The west"
didn't take the lead in science until much, much later.

~~~
filmor
Alexandria was founded as a Greek city and stayed Hellenistic until the
Islamic Invasion 600 something.

Wikipedia lists Hypatia as "Greek", Greek and Roman culture is usually counted
as "western".

It could also be meant in contrast to "eastern" as in Chinese and Indian
astronomy.

~~~
weeksie
In any case Egypt is certainly not in the "middle east"

~~~
filmor
It is:
[https://en.wikipedia.org/wiki/Middle_East](https://en.wikipedia.org/wiki/Middle_East)
(the Near East then being the Balkan).

In other languages (e.g. in German) one calls this part "Near East", "Middle
East" is Iran -> India, "Far East" is South-East Asia, China, etc.

~~~
weeksie
Huh, never heard it used in such a way as to include Egypt. I've always heard
Egypt included in MENA (Middle East/North Africa). There you go.

~~~
JumpCrisscross
MENA includes Morocco, Tunisia, _et cetera_.

------
taneq
It was found, along with all of the compounds that it contains, in western
Egypt. Which, last I checked, is in the Solar System.

~~~
simonh
The idiom used in the title has a commonly well understood meaning in English.
It basically means ‘here is a thing found in this context that is usually not
found in that context and therefore probably came from somewhere else’. I can
see that technically it’s incorrect, but pretty much any native English
speaker would understand what is meant.

The contention is that the stone is not composed of material from the cloud of
dust and gas which formed our solar system, and therefore does not share that
common origin with the other material in our solar system we are familiar
with.

~~~
taneq
It's been interesting watching the score on my original comment, which was (I
thought) pretty clearly tongue-in-cheek. It first got quite a few upvotes, and
now is well on its way to being buried - I'm not sure if that's just noise, or
if it indicates changing demographics (with different attitudes towards
flippancy) reading HN at different times of day.

Anyway, yeah, it's not hard to figure out what the title meant.

~~~
Gravityloss
Usually jokes don't get better by explaining, but this was an exception.

