Beta

Slashdot: News for Nerds

×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Is Jupiter Earth's Cosmic Protector?

Soulskill posted more than 4 years ago | from the sounds-like-we-should-deify-it-oh-wait dept.

Space 222

Hugh Pickens writes "Last Sunday, an object, probably a comet that nobody saw coming, plowed into Jupiter's colorful cloud tops, splashing up debris and leaving a black eye the size of the Pacific Ocean — the second time in 15 years that this had happened, after Comet Shoemaker-Levy 9 fell apart and its pieces crashed into Jupiter in 1994, leaving Earth-size marks that persisted up to a year. 'Better Jupiter than Earth,' say astronomers who think that part of what makes Earth such a nice place to live is that Jupiter acts as a gravitational shield, deflecting incoming space junk away from the inner solar system where it could do to humans what an asteroid apparently did for the dinosaurs 65 million years ago. 'If anything like that had hit the Earth it would have been curtains for us, so we can feel very happy that Jupiter is doing its vacuum-cleaner job and hoovering up all these large pieces before they come for us,' says Australian amateur astronomer Anthony Wesley, who first noticed the mark on Jupiter. But others say the warm and fuzzy image of the King of Planets as father-protector may not be entirely accurate. In 1770, Comet Lexell whizzed by the earth, missing us by a cosmic whisker after passing close to Jupiter. The comet made two passes around the Sun and in 1779 again passed very close to Jupiter, which then threw it back out of the solar system."

cancel ×

222 comments

On a galactic note... (5, Insightful)

Anonymous Coward | more than 4 years ago | (#28827171)

It's a bit like saying one speck of dust is protecting another speck of dust from other, smaller dust, as they swirl around an eddy of warm air in a coliseum.

Luckily... (1, Interesting)

denzacar (181829) | more than 4 years ago | (#28827307)

The Earth has not yet faced a galaxy coming straight at it.

This reminds me of that anti-tiger rock I keep in my sock drawer?
That rock is so good, damn tigers are dieing out in India. Maybe Jupiter has similar effect on galaxies?

Re:Luckily... (1)

navygeek (1044768) | more than 4 years ago | (#28827949)

You mean "dying", right? Or are the tigers getting cast and molds made of themselves?

Re:Luckily... (3, Insightful)

derGoldstein (1494129) | more than 4 years ago | (#28828065)

There's actually no "Present Participle" for making/molding/pressing dies. The action itself is usually "pressing", "blanking", or "broaching". More information here [wikipedia.org] .

On a side note, the Bengal tiger is quite intelligent and resourceful. I wouldn't be surprised if they did decide to go into the manufacturing business.

Re:Luckily... (3, Interesting)

mrsquid0 (1335303) | more than 4 years ago | (#28828189)

> The Earth has not yet faced a galaxy coming straight at it.

The Earth is facing a galaxy coming straight at it. The Andromeda Galaxy is on a collision course with the Milky Way, and there is a very real possibility that the Sun will be ejected from our Galaxy when this happens. Fortunately, this is not going to happen for about three billion years

Scatter! (2, Insightful)

Anonymous Coward | more than 4 years ago | (#28827463)

We have to get our eggs off this speck of dust.

Re:On a galactic note... (5, Funny)

erroneus (253617) | more than 4 years ago | (#28827537)

No, it proves that "God" is the planet Jupiter and we were created in his image... so keep eating! To be more god-like, you must be more round, heavy and gassy.

Re:On a galactic note... (5, Funny)

jimmydevice (699057) | more than 4 years ago | (#28827583)

Got that covered.

Re:On a galactic note... (0)

Anonymous Coward | more than 4 years ago | (#28827755)

Seeing as how Jupiter has 120 times the cross sectional size of the Earth, and the huge gravitational increase, it's hardly surprising that Jupiter gets hit much more often, regardless of whether or not "it sweeps the solar system clean"

Re:On a galactic note... (2, Informative)

FatdogHaiku (978357) | more than 4 years ago | (#28828181)

It's a bit like saying one speck of dust is protecting another speck of dust from other, smaller dust, as they swirl around an eddy of warm air in a coliseum.

Right, if the dust is going fast enough to vaporize on impact... Hey, that might be pretty except for the UV damage to the eyes. Anyway, as someone stuck on the "protected" speck, I'll take any extra protection I can get... Sure hope our magnetic field "condom" continues to hold up against all the nasty stuff in the sunlight too...

Re:On a galactic note... (1)

DJRumpy (1345787) | more than 4 years ago | (#28828311)

IMO, this is more about Jupiter tossing regular visitors to the inner planets out of the system rather than randomly snagging non regular objects, since they tend to have eliptical orbits that often take them out past the outer planets and then back around the sun. Although it's unlikely it would hit a planet, it is likely that over thousands of passes, the gravity well from the large bodies will end up ejecting the object in a close pass due to a slingshot.

Jupiter or Uranus... (-1, Troll)

Anonymous Coward | more than 4 years ago | (#28827177)

Would it also be news when stuff hits Uranus?

Re:Jupiter or Uranus... (-1, Offtopic)

Anonymous Coward | more than 4 years ago | (#28827427)

only when it's a big nigger cock

A New Criteria? (4, Interesting)

eldavojohn (898314) | more than 4 years ago | (#28827179)

Is Jupiter Earth's Cosmic Protector?

If this is true, it gives us another criteria to look for in distant solar systems that we suspect may harbor life or that we would like to colonize: a large shield planet in the same system capable of leaving the smaller world to develop uninterrupted.

It is interesting to wonder if our odds increase or decrease on being hit when there is a large massive body in our solar system. Like the article and summary say, some objects that would not have come close could be put on course for earth via Jupiter's gravitational forces. Who knows, maybe massive bodies like Jupiter pull more space debris into our system and make it more hostile than if it were just the earth orbiting the Sun?

Re:A New Criteria? (-1, Offtopic)

Anonymous Coward | more than 4 years ago | (#28827211)

This theory fails to take into account the giant space goatse [goatse.fr] monster.

Re:A New Criteria? (1, Insightful)

Anonymous Coward | more than 4 years ago | (#28827479)

It is interesting to wonder if our odds increase or decrease on being hit when there is a large massive body in our solar system.

They decrease, since another big planet will more likely absorb other space bodies than emitting them ...

Like the article and summary say, some objects that would not have come close could be put on course for earth via Jupiter's gravitational forces.

But others will be sent elsewhere. TFA and TFS are utter rubbish, in this respect. And the Sun exerts more gravitational force than any planet ... therefore (and contrary to what I said about planets), our odds of being hit are indeed increased by the Sun.

Re:A New Criteria? (3, Interesting)

VulpesFoxnik (1493687) | more than 4 years ago | (#28827633)

Or a bisolar system, however the radiation levels and orbits may be too chaotic in such system.

Just to put things in perspective, Jupiter is about 9/1000 the mass of the sun. However I would point to the multitude of our gas giants. Saturn is about 2/1000 the mass of the sun, which is also significant. The other two gas giants are significantly smaller. I'd say the existence of gas giants within the carbon--water habitable zone can provide safe harbors for life as well. But I'd say a stable environment in any case is good for any sort of life form, allowing time for them to adapt without being destroyed by physics mechanics.

Re:A New Criteria? (2, Informative)

liquiddark (719647) | more than 4 years ago | (#28827731)

This isn't a new criterion. Jupiter's role as a protector of life on Earth has been recognized for a long time. As an example of its mention,this [nationalgeographic.com] article starts from the assumption that it's understood that Jupiter has a role as a protector (and then goes on to suggest that recent research may debunk that idea, but that doesn't change the original sentiment).

Re:A New Criteria? (2, Interesting)

oiron (697563) | more than 4 years ago | (#28827745)

Of course, the truth is that we're guessing out of our hats there...

What makes you think that there could not be a life-form adapted to living in a planet/moon which gets regularly hit by various bits of artillery bombardment from space? Bacteria have proven that they can live in space. All it takes is a little weird evolution to make lifeforms that can (as a group, at least) survive such a major blow. Possibly a planet-wide organism, or at least, a planet-wide ecosystem?

Come to think of it, we already have one of those - except that the dominant life-form seems hell-bent on destroying it!

Re:A New Criteria? (2, Interesting)

Anonymous Coward | more than 4 years ago | (#28827833)

Jupiter is like seat belts. Seat belts save lives and that is a fact. Thousands of lives are saved every year due to them but every once in a while there is the odd exception where wearing a seat belt would have killed them. Jupiter acts the same way. There may be the odd rock thrown out way because of the planet but more often than not Jupiter will throw it out of the system or eat it up.

Is that something we should bet our existence on? (3, Insightful)

BadAnalogyGuy (945258) | more than 4 years ago | (#28827189)

Sorry for the dangling preposition in the subject, but regardless of whether or not Jupiter acts as a magnet for dangerous astral bodies, I wonder how risky it is to leave that job to Jupiter.

We have seatbelts in cars despite the mandatory brakes which are installed. We have random personal screenings at the airport even though we have a standardized process of metal detection and baggage scanning. We should not just sit idly without a comet/asteroid detection and elimination system just because Jupiter is catching the big ones for us.

We've been hit before. I don't want to get caught in the slamming door. How about some information, please!

Re:Is that something we should bet our existence o (1)

denzacar (181829) | more than 4 years ago | (#28827365)

I don't want to get caught in the slamming door. How about some information, please!

We have reason to believe that you have fallen a victim to weapons of psychological warfare. [lyricsmode.com]
For your own good, turn of your audio and video receiving devices as well as any audio or video player and go get some sleep.

Re:Is that something we should bet our existence o (1)

Ragzouken (943900) | more than 4 years ago | (#28827389)

Why not correct your dangling preposition rather than apologize for it?

Re:Is that something we should bet our existence o (0)

Anonymous Coward | more than 4 years ago | (#28827399)

The subject line is limited to an insufficient number of characters.

"Is that something on which we should bet our existence?" is about 5 bytes too long.

Re:Is that something we should bet our existence o (-1, Offtopic)

Anonymous Coward | more than 4 years ago | (#28827511)

Hi, I'm BadAnalogy Guy, folks, due to a recent string of brilliant postings, I have found myself at so much more intelligent than you that I am at the short end of the Karma stick.

If you are a moderator, fuck you. You have three choices facing you. First, do nothing and affect me neither positively nor negatively. Second, you can mod me down as off-topic, which I will not agree is an appropriate moderation for this post because I'm so much more intelligent than you. Finally you can consider my productive and lively posting history and moderate this comment up. Don't consider this post, consider my history of posts. That is what you should do when you moderate, read the entire comment history of the person and mod them up or down based on that.

I'm not begging you, moderators, because I have a spine unlike you. I know you have your own agendas which are all trivial compared to my desperation for karma. Some of you are staunch Open Source dumbshits and are searching for heretics to burn. Others are pedants who see no benefit in posts that are even slightly divergent from your perspective. Your agenda is your business, and since Slashdot has awarded you with moderation points, your agenda and perspective must have some merit. Notice that I do not agree with that. What I'm doing on this site is still not clear to you but I need karma.

What I would ask is simply that you spare a point in rescuing me from an automatic -1 posting level. It doesn't take any extra work on your part except for your moderation rights, and it will only take 4 of you to put this particular post up to +5. Also, when it ends up -1 and the metamods come in to play, you will never get moderation points again. So help me if you have a spine.

Thank you for exercising your moderation rights and following my suggestions like a bunch of sheep. You have the freedom to go against the system and listen to me.

This is a follow up attempt to earlier postings [slashdot.org] . Posting anonymously because you should mod my parent post up instead of this one to give me karma.

Re:Is that something we should bet our existence o (1)

sillybilly (668960) | more than 4 years ago | (#28827651)

This is the exact reason we need thermonuclear hydrogen bombs stationed in outer space, ready to shoot: Unlike the dinosaurs, we don't have to be sitting ducks, we have the ability to defend ourselves against incoming comets. The problem with stationing bombs in outer space is an issue of trust: people down here still haven't figured out how to live in peace and leave each other alone, the UN is still not a functioning body of world government, people still play the "I don't trust you, I'll kill you before you kill me"- game, and call it self defense. So there is a distinct possibility that bombs stationed in outer space are directed back at Earth by people who are mad at each other, and can't just take it like a man, or can't stop dishing it out so others have to take it like a man. Possibly the bombs could be stringed out and stationed very far, into solar orbit past Mars near the asteroid belt, and Earth could carry many layers of inner defense shields, that stop any stray bombs that are hijacked, with some finite reaction time still left. The good part about having the bombs(and their observatories) extremely far is that the farther the comet is deterred by a minute angle on its path, the less effort is needed. So the benefit to risk ratio is better, because a bomb hitting Earth would only cause a localized damage, compared to the same force being able to deter an object the size of our moon by that 1 degree on its path to just miss Earth. The downside of going very far, is that it's easy to have stringed out objects in a solar orbit in a plane, as a circle, but it's hard to cover a sphere, like GPS does, because the paths might cross, and minute gravitational fluctuation might cause some of the objects to collide. Maintaining very many bombs that are far, compared to the much fewer required that are very close is also an issue, especially from a hijacking standpoint. A few bombs hijacked and hitting Earth would cause a local catastrophy, but if all the bombs that are very far are hijacked simultaneously, and redirected to Earth, that could be worth than the problem they are meant to defend against. A possible best solution is having habitable outer space stations, http://en.wikipedia.org/wiki/O'Neill_cylinder [wikipedia.org] , cylinders that provide artificial gravity on the inner surface by rotation/centrifugal force, and are built triple layered gradual vacuum against air diffusion/leaks, and extremely heavy walled to protect from outer space radiation to replace Earth's atmosphere (this means complete artificial lighting/farming/silicon solar panels, except a very few lead glass windows. In such case you don't keep all your eggs in one basket - whether there is a major asteroid hit, or a global nuclear war wiping out all life on the planet, we would still have people and plants and animals, we would still have Life to come back and reseed and repopulate the planet. Life would not die. Such space stations traveling to the region of Mars then could take on the job of watching for comets and taking care of them, and though there is a distinct possibility of interstellar war between such space stations, at least having the technology and ability to live in a space station in pure vacuum/cold/intense radiation, whether that space station is landed on Earth, under water in Earth's oceans, under the clouds of Venus, behind Jupiter, or far past Pluto running on nuclear fuel alone, each of these give Life and humanity a better chance to survive. All it takes is at least a few people to make it after a global catastrophy. The real danger is making robots smarter than us that hunt us down and exterminate us. Back in the old days there was such a thing as defense - walls, trenches, fortifications. These days, because of technology, the only defense is attack: the equilibrium of mutually assured destruction. Yes we did gain the ability to beat the odds that dinosaurs couldn't, but we also gain the ability to destroy all life within a few months. As technology progresses, our ability to destroy everything will go from a few months to a few hours to a few milliseconds to a few nanoseconds, all not happening because of the equilibrium of mutually assured destruction. I don't like that scenario. Maybe that's why we can't find life in outer space - as soon as they develop intelligence sufficient to start listening to radio signals, they find themselves caught in a game of mutually assured destruction, and like in any wild western movie, somebody ends up pulling the trigger in a standoff, and both heros stare at the holes in their bodies, and fall to the ground, mutually destructed.

Re:Is that something we should bet our existence o (2, Interesting)

hedwards (940851) | more than 4 years ago | (#28827763)

We don't do that because the likelihood of somebody abusing the weapons to kill us is substantially higher than the risk of being killed by an impact. Further more you're assuming that we'd get it right, and let's face it we tend to be kind of hit or miss on things like that. We were able to more or less successfully fight the ozone layer problem, but pretty much completely refuse to do anything about global climate change.

I'm not sure what makes you so sure that there'll be much left by the time a space object becomes a risk or that we'll be able to spot it in the first place. Many of those meteors move pretty damn fast.

Re:Is that something we should bet our existence o (0, Offtopic)

Dog-Cow (21281) | more than 4 years ago | (#28827863)

So far, none of the cures for "Global Climate Change" are better than the problem.

It seems to me to be a fact that life would only get worse for me if we were to implement any of the more drastic solutions. As most everyone on the planet feels the same way, there's no logical reason to do anything.

The absolute worst possible outcome is that we consume all technologically-related resources and have to fall back on subsistence living. That's only a tragedy if you happen to be alive during the change.

Re:Is that something we should bet our existence o (2, Insightful)

Artifakt (700173) | more than 4 years ago | (#28828195)

The absolute worst possible outcome is that we have made so many other species extinct by that time that there is no stable ecological niche for humans and we go extinct too. I'm not arguing that this is particularly likely, but it's definitely worse than your worst case, unless you were counting subsistence 'living' with population = 0. However, adding that to your list of consequences with a small probability (0.5% or so) shouldn't make any difference to you. In fact, adding it with a very large probability (99,99995% or so), given your 'logic', doesn't make any difference either, so carry on.
      Just as a hint, real logic means, if you introduce different facts, you just might reason to a different result. Your real, if unstated 'logic' is 'If it's not me it hurts, it's not a tragedy'. Since you didn't state it openly, but a bunch of unconnected claims you call logic, you don't have to be concerned that someone would point out that you are a sociopath, using an entirely emotional argument to provide pseudo-justification for being a rat-bastard who has basically told every single person reading this you don't care if their loved ones and descendants live or die.

A good reason for manned exploration... (4, Insightful)

blahplusplus (757119) | more than 4 years ago | (#28827195)

... is the fact that eventually we have to get off earth and learn how to survive in the hostile universe anyway.

hence the ongoing LEO beta test. (1, Insightful)

Vandil X (636030) | more than 4 years ago | (#28827295)

The current STS-127/Expedition 20 mission has shown us that troubleshooting a malfunctioning urine-recycling toilet and a tripped circuit breaker on a carbon scrubbing unit are far easier to fix in LEO than out father, especially considering how critical both systems are to a more distant mission.

Re:A good reason for manned exploration... (0)

Anonymous Coward | more than 4 years ago | (#28827593)

the fact that eventually we have to get off earth and learn how to survive in the hostile universe anyway.

I'd rather say we should learn how to survive on this hostile fucking Earth without destroying the resources we need to live, first.

Uhhhhhh.....NO (0, Insightful)

Anonymous Coward | more than 4 years ago | (#28827205)

Think of a sphere whose radius as at the center of the sun and whose radius is at the center of Jupiter. Do you want to take a shot at how many orders of magnitude the inscribed area of Jupiter is to the entire sphere?

Do you want to take a shot at how weak Jupiter's gravitational field is? How about compared to the other gas giants? Within an order or two.

How about when Jupiter is in a phase of its orbit not anywhere "close" to the earth?

Re:Uhhhhhh.....NO (2, Funny)

Macrat (638047) | more than 4 years ago | (#28827451)

Stop making sense!!!

Re:Uhhhhhh.....NO (1)

cupantae (1304123) | more than 4 years ago | (#28827685)

...and that's why we still get hit by meteors every now and then. But listen, what you're saying only really applies to something coming straight at the solar system from outside and managing to hit one of the planets. Do you realise how unbelievably unlikely this is? The majority of the things that hit planets are wandering about in our solar system. Over a (very) long period of orbiting, the weak gravitational effects can play a considerable role in deflecting meteors.

That's something which seems to be ignored in the mention of Lexell's comet: if something passes quickly by Jupiter, it will not be affected, but if takes an inwardly-spiraling orbit - and think about it. That's more likely to be one that collides with something - then it's given sufficient time to be affected.

an ideal s--- collector (2, Funny)

Anonymous Coward | more than 4 years ago | (#28827215)

Now if Jupiter were like my boss, it would fling those comets at the earth with the message: "This issue is escalating rapidly. I need you to work on this today; send me status before you leave."

So what is he trying to tell us? (4, Funny)

3seas (184403) | more than 4 years ago | (#28827229)

That Jupiter really sucks?

Re:So what is he trying to tell us? (0)

Anonymous Coward | more than 4 years ago | (#28828205)

Always the pathetic big guy protecting the little bitch... I wonder who is the bad-boy asshole fucking Earth every night...

Is Jupiter Earth's Cosmic Protector? (0, Troll)

4D6963 (933028) | more than 4 years ago | (#28827263)

Yes, and so is the Moon, as its cratered far side will show you (the far side is much more cratered than the front side which shows how the Earth attracts asteroids towards the far side and away from the near side).

Next question?

Re:Is Jupiter Earth's Cosmic Protector? (0)

BadAnalogyGuy (945258) | more than 4 years ago | (#28827289)

Um. What?

What the craters on the far side of the moon tell us is that the asteroid field is mostly outside the moon's orbit radius.

Re:Is Jupiter Earth's Cosmic Protector? (3, Interesting)

4D6963 (933028) | more than 4 years ago | (#28827493)

Well, kind of, but look at it this way. If the Moon was a lone planet, it'd get craters everywhere equally. But it's not a lone planet, instead it has a bigger body always on the same side of it. Therefore, that there should be more impacts on the opposite side tells you that asteroids are quite attracted to Earth and that the Moon catches a lot of the when its on their way.

Re:Is Jupiter Earth's Cosmic Protector? (1)

nedlohs (1335013) | more than 4 years ago | (#28827783)

It tells you nothing about how "attracted" asteroids are to the earth, it tells you that a lots of asteroids on target for the near side of the moon, hit th earth instead.

To provide evidence that the Earth attracts asteroids (which it obviously does, you know gravity and all) you would need to see more craters on the far side of the moon then you see on a once side of a similarly sized body in a similar obit that does not have a larger body nearby to do the attracting.

Re:Is Jupiter Earth's Cosmic Protector? (1)

4D6963 (933028) | more than 4 years ago | (#28828097)

it tells you that a lots of asteroids on target for the near side of the moon, hit th earth instead.

lol, wtf?? Asteroids don't absolutely have to hit something you know, if they don't hit something they most likely won't hit anything.

Re:Is Jupiter Earth's Cosmic Protector? (0)

Anonymous Coward | more than 4 years ago | (#28827563)

Craters are caused by something crossing the moon's orbit, not by something that is safely in or safely out. What you mean is that there are more asteroids entering the moon's orbit region than asteroids exiting it.

BTW it's great to see you post at 0! When you hit -1, you'll discover that your top level posts cannot be seen by anyone.

Re:Is Jupiter Earth's Cosmic Protector? (1)

GIL_Dude (850471) | more than 4 years ago | (#28827683)

OK, I think I fail orbital mechanics - however, it seems that since the moon's face is tidally locked to earth (near side of the moon I guess is the colloquial) - that since the moon spends an equal amount of time "closer" to the asteroid field than Earth as it does "farther" from the asteroid field than Earth (meaning that the moon spends 1/2 of its time "sunside" of Earth) that asteroids ENTERING the moon's orbit region from farther out would have equal chance of impacting either face - EXCEPT for the influence of Earth's gravity probably either causing those rocks to impact Earth or at least redirecting them away from the moon.

Re:Is Jupiter Earth's Cosmic Protector? (1)

Artifakt (700173) | more than 4 years ago | (#28828317)

A rigorous experiment would probably involve comparing lots of roughly moon sized objects, in isolated orbits, in tidally locked orbits around larger bodies, and in orbits where they don't keep one face pointed at a nearby larger body.
        But, there's something else to consider for our specific, real moon, besides orbital mechanics. There were probably a lot more hits in the early era of the solar system (more rocks then, a lot of what we see is the result of most rocks having been used up). In that era, the Moon probably still had a molten core. Tidal effects from Earth might mean more lunar lava erupted on the side facing us, and more of the craters there were covered with fresh material.
        That's an old (1810 to 1950's) theory that was just assumed for a lot of textbooks, and not necessarily the one Selenographers today prefer, but it's not a rejected or disproven idea, just one that there's little interest in doing more work on to make it more rigorous. It got a bit of a nudge from Russian photos of the far side and from the same sort of observations by the Apollo missions in the early and late sixties, respectively, and then all the researchers decided working on it more would probably require someone digging some holes on the moon, so it's simply languishing unless somebody goes back.

Re:Is Jupiter Earth's Cosmic Protector? (4, Informative)

drinkypoo (153816) | more than 4 years ago | (#28827395)

the far side is much more cratered than the front side which shows how the Earth

...which is much larger than the moon, protects the moon from impacts more than the other way around.

Re:Is Jupiter Earth's Cosmic Protector? (1)

4D6963 (933028) | more than 4 years ago | (#28827505)

Are you sure about that? Because while it surely attracts asteroids away from the Moon, it always attracts asteroids towards the couple to begin with. So are you really sure that the Moon is getting less than it would if it was alone?

Re:Is Jupiter Earth's Cosmic Protector? (1)

drinkypoo (153816) | more than 4 years ago | (#28827981)

So are you really sure that the Moon is getting less than it would if it was alone?

Nope.

Re:Is Jupiter Earth's Cosmic Protector? (0)

Anonymous Coward | more than 4 years ago | (#28827477)

The near side craters were filled in by the maria-producing lava flows.

Re:Is Jupiter Earth's Cosmic Protector? (1)

4D6963 (933028) | more than 4 years ago | (#28828109)

Not everywhere, only in the "seas", so that's irrelevant.

Re:Is Jupiter Earth's Cosmic Protector? (1)

brentonboy (1067468) | more than 4 years ago | (#28828009)

I had always thought that had something to do with the earths gravity smoothing out the craters over time. Does anybody know if any actual research has been done on this?

Re:Is Jupiter Earth's Cosmic Protector? (2, Interesting)

RubberDogBone (851604) | more than 4 years ago | (#28828119)

Wrong. Both sides of the moon have had the same level of impact, and the 'far' side is not facing the asteroids any more than the 'near' side. The earth-moon system rotates in space and the moon rotates around the earth so both faces are in the direction of the asteroids all the time.

The 'near' side of the moon only looks smoother because mare lava flows have smoothed it out somewhat. It's just chance that put those flows on the side we see.

Fun fact: if the earth had no weather, it would look just like the moon in terms of impact craters. The earth is much bigger and has actually been hit more often. But our weather has eroded most of them.

Re:Is Jupiter Earth's Cosmic Protector? (2, Informative)

4D6963 (933028) | more than 4 years ago | (#28828333)

Wrong. Both sides of the moon have had the same level of impact

Wrong, the far side has about 1.67 times more recent impacts than the near side (citation [citeulike.org] ).

The 'near' side of the moon only looks smoother because mare lava flows have smoothed it out somewhat. It's just chance that put those flows on the side we see.

No, we don't know that, there surely is a reason other than chance, we just don't know for sure what it is yet. Also, not all of it was covered by lava flows, and you can tell these areas look different from the far side. Well at least they look different to me.

Fun fact: if the earth had no weather, it would look just like the moon in terms of impact craters.

I'll assume that you chose the word weather instead of atmosphere for a reason, not too sure why, but the Earth is geologically active and has an atmosphere (assuming you weren't talking about there not being an atmosphere) then it would look more like Venus. And Venus doesn't have so many visible craters. Yeah, there's quite a difference between a body that died over 3 billion years ago and one that's still active, radiating and erupting.

Re:Is Jupiter Earth's Cosmic Protector? (0)

Anonymous Coward | more than 4 years ago | (#28828243)

The moon is cratered because it has no atmosphere.

Greater benefic (5, Interesting)

MadLad (1331393) | more than 4 years ago | (#28827273)

In astrology, Jupiter is considered the "greater benefic," the planet that bestows fortune, luck, and positive benefits.

Just sayin'.

Re:Greater benefic (2, Insightful)

momerath2003 (606823) | more than 4 years ago | (#28827875)

Are you feeling jovial?

Re:Greater benefic (1)

bazorg (911295) | more than 4 years ago | (#28828113)

And in Roman mythology Jupiter is the god of all gods, god of sky and thunder. Clearly the astrologers don't know jack shit.

Re:Greater benefic (1)

c6gunner (950153) | more than 4 years ago | (#28828337)

A little known fact about astrology is that most of it's principles originated from Uranus.

It just means Jupiter has a playful side (0)

Anonymous Coward | more than 4 years ago | (#28827287)

"In 1770, Comet Lexell whizzed by the earth, missing us by a cosmic whisker after passing close to Jupiter. The comet made two passes around the Sun and in 1779 again passed very close to Jupiter, which then threw it back out of the solar system."

Better known as "the great snowball fight."

Hey! Leave the big guy alone... (3, Funny)

denzacar (181829) | more than 4 years ago | (#28827407)

He just had a bad day.

After realizing what he did, he flicked that comet as far away from Earth as possible. And he said he was sorry.

The comet was never seen again. Lexell, after conducting further work in cooperation with Pierre-Simon Laplace, argued that a subsequent interaction with Jupiter had further perturbed its orbit, either placing it too far from the Earth to be seen or perhaps ejecting it from the Solar System altogether.

Re:It just means Jupiter has a playful side (0)

Anonymous Coward | more than 4 years ago | (#28827659)

The Wikipedia page for Lexell says it missed by 2,184,000 kilometers, which is far more than a "whisker". The moon is continually "missing" us at one fifth the distance. If somebody shot at you with an elephant gun, but the bullet impacted a football field away, you couldn't say it missed by a whisker.

The end is nigh (5, Insightful)

bitemykarma (1515895) | more than 4 years ago | (#28827291)

The Earth will eventually be wiped out, obviously. We can't get lucky forever.

We'd better spread outselves out.

Re:The end is nigh (0)

Anonymous Coward | more than 4 years ago | (#28827459)

We'd better spread outselves out.

That's what I'm always trying to do. Unfortunately, I'm not a lucky man.

Re:The end is nigh (1)

catmistake (814204) | more than 4 years ago | (#28827739)

I figure we have about 60 million years [wikipedia.org] , give or take a few million, before Jupiter Defense Shield fails.

Re:The end is nigh (4, Funny)

noidentity (188756) | more than 4 years ago | (#28827813)

The Earth will eventually be wiped out, obviously. We can't get lucky forever. We'd better spread outselves out.

I think getting crushed by a large object would spread us out quite well.

Re:The end is nigh (2, Insightful)

dicobalt (1536225) | more than 4 years ago | (#28827973)

True, but do you wanna be the one to tell NASA they have to stop playing with model rockets and develop a real method of space travel.

Probabilities are hard to calculate... (2, Interesting)

spleen_blender (949762) | more than 4 years ago | (#28827329)

Is it actually more likely for a body to be directed away from Earth than to Earth by Jupiter? I mean, it seems that a body not destined for Earth could otherwise hit if affected by Jupiter's gravity sufficiently.

Re:Probabilities are hard to calculate... (1)

cupantae (1304123) | more than 4 years ago | (#28827743)

The solar system is far too sparse for that to work. Don't be fooled by those posters that show the planets nicely lined up pretty close together - there are huge distances between all of them; distances far too great for the solar system to act as one body, as you appear to be suggesting.

If you're saying that Jupiter affects the trajectory in such a way as to "throw" things towards Earth, then RTFA! That's what the critic of the theory said, but I don't buy it.

Re:Probabilities are hard to calculate... (1)

liquiddark (719647) | more than 4 years ago | (#28827793)

The proportion of objects which follow this relationship is almost by definition no greater than that which would have hit Earth but for Jupiter's influence, unless there's some cosmic pinballer out there who is specifically banking shots off of Jupiter to try to hit the Earth specifically. Jupiter is gigantic. Just by looking at the"shadow" created by its bulk, not counting the additional deflection from gravity, it creates a zone 22 earth radii wide where nothing coming into the solar system will pass.

Orbital Mechanics, not Conscious Intention (5, Interesting)

DynaSoar (714234) | more than 4 years ago | (#28827359)

Jupiter is the only planet in our system close enough to the sun and with a deep enough gravity well for them to have a barycenter (common orbital center) outside the sun's surface. That sort of wobbly orbital mechanics has far more effect on trajectories of small bodies than a nice, neat set of concentric circular orbits. The sun-Jupiter system will be more likely to cause fluctuations that result in small interlopers to get thrown out of the system or sucked into one of their gravity wells. Seeing the result on Jupiter is rare. Seeing it at the sun is more common. Between the two they're going to suck up far more than hit elsewhere.

But their influence is only the majority of a chaotic multi-body system. Just because they account for the most hits doesn't mean they take them all and nothing gets through elsewhere. Of course some will miss the big guys and hit (or nearly so) some of the others. That's the nature of a chaotic system of orbital mechanics. They are not exerting influence in an intentional manner, rather a deterministic but fairly unpredictable manner.

To assume a certain thing always happens because it has happened, and also to say it not accurate because there is an exception, is the sort of low caliber absolutist thinking that's common in "modern" science reporting. I have no doubt the parties credited with these viewpoints understand quite well the situation, and the apparent controversy is a function of the author of TFA.

Re:Orbital Mechanics, not Conscious Intention (2, Informative)

Anonymous Coward | more than 4 years ago | (#28827425)

The author of TFS obviously didn't claim that Jupiter takes them all since he mentioned the dinosaur extinction. Since your post is devoted to attacking something that wasn't said, we can safely ignore it. Thanks.

Re:Orbital Mechanics, not Conscious Intention (1)

Yvanhoe (564877) | more than 4 years ago | (#28828209)

Earth has a magnetic shield. Earth has a gravtational shield. Whil I agree that all of these are completely natural, they both strike me as a improbable and essential to mankind. Discovering such things makes us realize that Earth is an exceptionnal place, and lowers the result of the Drake equation by a few orders of magnitude. If it takes such coincidences for life to develop, then life may be rarer in the universe than we first thought.

The answer is "no". (0)

heptapod (243146) | more than 4 years ago | (#28827391)

Claiming that Jupiter's purpose is our solar system's vacuum cleaner is preposterous.
Yes, it will catch more stuff due to its surface area but the volumes involved make Jupiter's influence negligible.

Re:The answer is "no". (1)

rubycodez (864176) | more than 4 years ago | (#28827457)

the planets orbit in a plane, and the origin of most comets is in the outer solar system. Therefore, over time, Jupiter has indeed cleaned up many comets for the Earth.

Re:The answer is "no". (1)

dimeglio (456244) | more than 4 years ago | (#28827787)

Well it depend if you buy in the rare earth hypothesis or not. It might be interesting to do a mathematical model of the solar system and throw a few large objects towards the Earth and see how Jupiter plays its role. I believe this was part of the hypothesis by Ward and Brownlee.

It might be interesting? (1)

Jeremy Erwin (2054) | more than 4 years ago | (#28827931)

Only a programmer well versed in orbital mechanics could make it "interesting." The average slashdot commenter apparently isn't.
see http://jontihorner.com/index.php?p=1_10_Publications [jontihorner.com] > Horner, J., & Jones, B. W for the results of (non-brain-dead) modeling.

That's a lot of added mass... (1)

Mashhaster (1396287) | more than 4 years ago | (#28827441)

It makes me wonder if, over time, all that added gravitation might not start to degrade the orbit somewhat, to say nothing of a possible single large impact.

Amazing (5, Interesting)

Corson (746347) | more than 4 years ago | (#28827475)

I find it amazing and worrisome that an object that size can get so close to Earth and hit Jupiter without astronomers learning about it until after the fact. To me, it is an indication that current near-earth object surveillance systems are not worth much.

Re:Amazing (4, Insightful)

ceoyoyo (59147) | more than 4 years ago | (#28827623)

Jupiter isn't exactly "near-earth," and doesn't count as "close to Earth" when you're talking about asteroids and comets hitting or almost hitting planets.

Re:Amazing (2, Interesting)

FiveDozenWhales (1360717) | more than 4 years ago | (#28827663)

Except that the object isn't that massive. To create a hole the size of the Pacific Ocean in Jupiter wouldn't require a very large object at all--try flicking a pebble into a cloud created by a fog machine.

Re:Amazing (2, Insightful)

Translation Error (1176675) | more than 4 years ago | (#28827667)

Well, perhaps (and this is just a guess, mind you), astronomers didn't have equipment quite as advanced as current near-earth object surveillance systems back in 1770 when the incident occured.

Re:Amazing (1)

Translation Error (1176675) | more than 4 years ago | (#28827709)

And of course, you're obviously talking about the more recent event that just happened... This is what happens when you don't delay the starting of the Slashdot Posting service until the brain is fully booted.

Re:Amazing (1)

sdhoigt (1095451) | more than 4 years ago | (#28828045)

> I find it amazing and worrisome that an object that size can get so close to Earth and hit Jupiter without astronomers learning about it until after the fact.

Amazing... maybe. But I wouldn't waste too much energy worrying about such an event.

> To me, it is an indication that current near-earth object surveillance systems are not worth much.

Correct. The effort is at an infantile stage.

Even if we knew a year ahead of an asteroid that was on target for the Earth, there's nothing in our current technological capabilities that could be done to divert the event. Our nuclear missiles weren't designed to go beyond Earth's gravitational pull, so they wouldn't be useful. And we most likely won't have a years warning; it'd be more like weeks if even that.

Some rough estimates put the number of asteroids in our own solar system to be about a billion. We're currently tracking an extremely small percentage of them; and that task is difficult enough as the asteroids make such infrequent appearances, and they're "small". But if even a small asteroid a few miles across in size traveling 60,000 miles/hr were to strike the Earth, it would drastically overshadow your bad hair day.

SD

Reference.
Bryson, Bill. A Short History of Nearly Everything.

Re:Amazing (1)

mrsquid0 (1335303) | more than 4 years ago | (#28828211)

Jupiter is not in near-Earth space. There is not a lot of effort being put onto looking for small objects at the distance of Jupiter. This is because the distance makes them very hard to find, and a lot of effort is being put into finding objects that are on Earth-crossing orbits.

Astrologically speaking (1)

moon3 (1530265) | more than 4 years ago | (#28827515)

If the word logically doesn't offend you in that context. The largest temple in Rome was that of Jupiter Optimus Maximus on the Capitoline Hill (Wiki). So the Romans at least worshiped deities of some real world benefit.

/s

Hmmm (1)

sonicmerlin (1505111) | more than 4 years ago | (#28827569)

I think it's telling that most of the comments in the summary come from amateur astronomers.

Jupiter: Friend or Foe? (3, Interesting)

Jeremy Erwin (2054) | more than 4 years ago | (#28827611)

Jonti Horner and BW Jones [jontihorner.com] have written a series of papers on this, summarized in this Astronomy and Geophysics article [jontihorner.com] The first paper deals with the Asteroids [jontihorner.com] . The second, in press, considers the Centaurs [jontihorner.com] The third, of perhaps most relevance to this discussion, considers the Oort Cloud objects.

(To simplify the simulations, Earth was inflated to one million times its actual size. A juicy target indeed)

Question about the mechanism (1)

kanweg (771128) | more than 4 years ago | (#28827621)

With Shoemaker-Levy I could understand how Jupiter could catch a comet, but what I don't understand is that the comet subsequently can run into Jupiter. I mean, shouldn't it continue orbiting around Jupiter just like the other moons around Jupiter do?

Bert

Doesn't this only work in a 1-D universe? (2, Insightful)

pdhenry (671887) | more than 4 years ago | (#28827697)

The whole notion that some body that is on the other side of the sun from us half the time is protecting us doesn't really work in my mind. It seems that it only works if you imagine the universe is laid out on a line. Put the Sun at zero, the Earth at 3 and Jupiter at 10 and then anything heading your way from >11 has to get past Jupiter first. In reality we can't even rely on foreign objects coming in along the ecliptic.

Re:Doesn't this only work in a 1-D universe? (1)

nedlohs (1335013) | more than 4 years ago | (#28827857)

Some objects that would have hit earth will hit Jupiter instead, obviously not all since the Earth and the Moon have been hit a lot. Hence Jupiter protected the Earth from those particular objects. Hence Jupiter is protecting us.

considering the past (1)

FudRucker (866063) | more than 4 years ago | (#28827765)

the earth has had several mass extinctions in the past, the most recent was 65.5 million years ago when it is believed a meteor impacted the earth causing the demise of the dinosaurs, there

there was a few others that may or may not been caused by cosmic impacts

He ain't Heavy, He's Jupiter (1)

ssintercept (843305) | more than 4 years ago | (#28827811)

i was under the impression that Jupiter was our protector, isn't that prevalent theory in science today? didn't Carl Sagan talk about this in Cosmos?
unless drugs have totally fried my brain- isn't Jupiter's mass (gravitational pull) what causes the huge asteroid field between Mars and Jupiter?
i had better dust off those Cosmos tapes and find my bong...

Re:He ain't Heavy, He's Jupiter (1)

ssintercept (843305) | more than 4 years ago | (#28827915)

sorry to reply to my own post -
http://www.teachersdomain.org/resource/ess05.sci.ess.eiu.jupitersrole/
that is a link to a short video-Jupiter: Earth's Shield

Better than those comets hitting Uranus (1)

hamburgler007 (1420537) | more than 4 years ago | (#28827849)

It would be a lot more painful.

thought behind it seems to be rather simple ... (0)

Anonymous Coward | more than 4 years ago | (#28827851)

Eventually all comets, who run on an elliptic orbit around the sun and repeatedly cross the earth orbit have a good chance to hit us sooner or later, I suppose. If those comets also pass Jupiter regularily, there is surely a good chance that Jupiter throws them away or catches them, before they hit us.
On the other hand there is also a chance that Jupiter throws one or the other asteroid at us that was on an unproblematic orbit around the sun, before it came into the influence of Jupiters gravity. To decide if Jupiter is good or bad seems to be just comparing those risks/chances, like getting safed by jupiter from some comet that might hit us otherwise sooner or later or getting a big asteroid thrown at us due to Jupiters gravity.

The comet was not even a coup de gras ... (1)

Herschel Cohen (568) | more than 4 years ago | (#28828199)

for the dinosaurs, they were dying out before it hit and others survived well beyond the collision. Moreover, one cannot state with certainty that a similar event might mean to humans. It would depend where it hit and the response. In some sense it might stop us from our dangerous current course where significant opinion welcomes easily seen disaster. Some blinded by myopic short term interests and others believing, at least some humans, are special and will be protected by their deity of choice. A cosmic event might cause some to rethink was is really important not just for themselves, but for the species. But perhaps not, the survivors may just believe some strayed enough that wholesale punishment has been inflicted upon nearly all. Therefore, their deity (and their's alone) must be placated.

If the latter becomes the predominant voice, at least we can be consoled the planet might not go the way of Venus.

Better Jupiter than Earth, huh? (1)

ion_ (176174) | more than 4 years ago | (#28828235)

'Better Jupiter than Earth,' say astronomers

I think I speak for all of us Jupiterian slashdotters when I say I have a problem with that statement.

Re: Jupiter, our guardian angel? (1)

hcs_$reboot (1536101) | more than 4 years ago | (#28828241)

Maybe. But I find a bit scary that nobody noticed in space the large "object" before it crashed into Jupiter.

Logical fallacy (1)

tnmc (446963) | more than 4 years ago | (#28828247)

Exactly how does "which then threw it back out of the solar system" disprove the theory?

Load More Comments
Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>
Create a Slashdot Account

Loading...