

Give Thanks to Jupiter, Our Little Planet’s Big Protector - dnetesn
http://nautil.us/blog/give-thanks-to-jupiter-our-little-planets-big-protector?utm_source=tss&utm_medium=desktop&utm_campaign=linkfrom

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saiya-jin
This article reflect things explored quite well in amazing BBC 5-piece
documentary Earth: Power of the Planet just few years ago (I envy the guy for
being narrator to this show, just see and you'll understand :))

First 4 episodes explore various elements on our planet, but last one is a
true gem - it deals with uniqueness of Earth in universe - like Jupiter
catching most dangerous asteroids/comets so earth gets just enough
catastrophes and not too many, moon stabilizing our orbit (and adding tides
which probably helped life to move from oceans), and so on.

I love documents about nature, and BBC has produced consistently great ones,
but this one stands above all... after seeing it, I do look at many things in
nature in a different view. I would put this little gem as mandatory at school
for all kids around the world, and you'll have a eco-friendly generation
guaranteed.

~~~
satuon
The fact we're assuming that all of those things are necessary highlights that
you can't make a statistic from one case.

How do we know which of the conditions on Earth were really necessary and
which were neutral to life?

~~~
saiya-jin
picking out one of many mentioned in documentary goes along these lines:

moon is a remnant of young earth colliding with its twin planet, part of it
was absorbed into earth (that's why we have so much iron & melted dynamic
core, which btw generates strong magnetic shield protecting us from sun's
solar winds). Rest formed moon over time, which is unusually big compared to
its parent planet and unusually close (all those stabilizing influences +
tides). If we haven't had moon, earth would be "wobbling" on its path around
sun frequently, causing very frequent glacial ages.

Necessary for life itself? Never said that. Stromatolites and similar single
cell organism can survive about anything short of earth being consumed by
black hole. Necessary for evolution of complex life and its explosion in
variety that we see today, and more importantly our society? I personally do
believe so. Just watch the document and then we can discuss.

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jakeogh
"318 times more massive and 11 times larger than Earth"

11 times larger is technically correct if you are talking about distance
across. By volume Jupiter is ~1300 times larger than Earth.

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autokad
to me, the story doesnt make a lot of sense. all around the universe big rocky
giants moved inwards and suddenly became gas giants of the inner solar system,
but in ours for some reason Jupiter got big and gracious and it blocked
Neptune and Uranus, and more perhaps.

I dont buy it, i think what others have said, that jupiter was pulled out from
the inner solar system along with the other large gas giants. and that earth
might have been a super earth, but its collision that created the moon threw
large portions into outer space.

this 2nd hypothesis makes more sense, especially when you consider that earth
is unusually dense. we should have been a larger planet, were like the denser
core of something else left behind. Much denser then even venus or mars.

~~~
dalke
The tricky part is that the techniques for detecting extra-solar planets work
best for large planets near its sun.

But to get to your question, see
[http://en.wikipedia.org/wiki/Orbital_resonance#Possible_past...](http://en.wikipedia.org/wiki/Orbital_resonance#Possible_past_mean-
motion_resonances) :

> A past resonance between Jupiter and Saturn may have played a dramatic role
> in early Solar System history. A 2004 computer model by Alessandro
> Morbidelli of the Observatoire de la Côte d'Azur in Nice suggested that the
> formation of a 1:2 resonance between Jupiter and Saturn (due to interactions
> with planetesimals that caused them to migrate inward and outward,
> respectively) created a gravitational push that propelled both Uranus and
> Neptune into higher orbits, and in some scenarios caused them to switch
> places, which would have doubled Neptune's distance from the Sun. The
> resultant expulsion of objects from the proto-Kuiper belt as Neptune moved
> outwards could explain the Late Heavy Bombardment 600 million years after
> the Solar System's formation and the origin of Jupiter's Trojan
> asteroids.[43] An outward migration of Neptune could also explain the
> current occupancy of some of its resonances (particularly the 2:5 resonance)
> within the Kuiper belt.

I think your statement "that earth is unusually dense" is incorrect. Earth's
density is 5.51 grams/cc and Mercury's is 5.427 grams/cc. These are quite
close. Earth's density is higher because of its higher gravity. When
considered as "uncompressed" density, Mercury is much more dense than the
Earth. See
[http://en.wikipedia.org/wiki/Terrestrial_planet#Density_tren...](http://en.wikipedia.org/wiki/Terrestrial_planet#Density_trends)
.

~~~
oinksoft
> I think your statement "that earth is unusually dense" is incorrect [..]
> Mercury is much more dense than the Earth.

To be fair, Mercury's basically a ball of iron.

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anigbrowl
I often wonder what state science might be in Greek & Roman pantheism had
persisted rather than being displaced by the monotheistic religions from the
Middle East.

~~~
cperciva
The line between polytheism and monotheism isn't all that clear. The
veneration of saints shares a lot of features in common with the worship of
lesser deities in the Greco-Roman pantheon.

~~~
aswanson
In addition, YHWH had many different names in the early Hebrew scriptures
which reveal a strong influence from the Canaanite pantheon. It isnt until the
Book of Judges that monotheism starts to become firmly established.

~~~
s_q_b
That's right. Early in Hebrew scriptures, there are several passages that
suggest, not an outright exclusion of the existence of other gods, but rather
an assertion that YHWH is the god of Israelites, which evolved into an
assertion that YHWH is the _only_ God.

Later in Christianity, not only Judaic influences, but the influences of
Persian Zoroastrianism (cherubim, seraphim, and God's angels), Manichaeism
(dual entities of good and evil under a single Monotheistic God), Mithraism
(risen son of the chief God from the dead), the cult of Dionysius (the
eucharistic ceremonies), various Pagan religions adopted by Constantine's
mother redesignating Roman pagan holy sites as Christian holy sites, the cults
of Mary Mother of God and Mary Magdalene in France, and finally the patron
saints, which are virtually indistinguishable from the concepts of caretaker
pagan gods with individual responsibilities.

Religions are all melting pots, adopting and co-opting the beliefs of the
native people as they spread. This makes them neither more or less valid, and
it is rather remarkable the dedication Christianity has preserved to the
teachings of a single man two millennia ago.

~~~
cperciva
_Early in Hebrew scriptures, there are several passages that suggest, not an
outright exclusion of the existence of other gods, but rather an assertion
that YHWH is the god of Israelites_

Indeed, even what is probably the best-known line, "I am the LORD _thy_ God",
doesn't rule out the existence of other gods; all that is commanded is that
the Israelites should not worship said other gods.

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andywood
I can never understand how Jupiter can be thought to have any significant
effect on the fate of Earth, given how tiny it is compared to the solar
system, or even just to its own orbit.

~~~
nitrogen
Try playing with an online solar system simulator some time. After thousands
of orbits, a tiny gravitational nudge can have a huge effect on a system. Also
read about the concept of orbital resonances.

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crimsonalucard
“Whether they find a life there or not, I think Jupiter should be called an
enemy planet.”

-Deep Thoughts by Jack Handy.

