Planetary System Similar to Sol

sgtwilko writes "The BBC News site has an article about how astronomers have found several new planets including some that have a similar distribution to our own Solar System. They are finding planetary systems that are more and more like the one in which the Earth resides. It's only a matter of time until the Terrestrial Planet Finder program gets going and finds another Earth." There's another story on space.com. Update: 06/13 21:51 GMT by M : Space News and Wired have stories as well, with spiffy graphics and artists' renderings and so on.

Comments

WOOHOO!

[Bob McCown]

First we find the big planets

Then we find the small planets

Then we find the ones with intelligent life

Then we communicate

Then...

Alien Pr0n!

Re:WOOHOO!

[daeley]

Jack Handey had it right:

"I don't think I'm alone when I say I'd like to see more and more planets fall under the ruthless domination of our solar system."

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

"I can picture in my mind a world without war, a world without hate. And I can picture us attacking that world, because they'd never expect it."

Wouldn't start planning my move yet...

[bwohlgemuth]

The system also has a slightly smaller neighbor which whips around every 14.5 days. My guess is the tidal forces of these two planets would eventually rip anything in between to shreds.

Yes, TPF will be a nice box to have. However, I wouldn't plan on the longevity of HST since it will be located at one of the LaGrange points just outside earth orbit.

Brian

As it turns out..

[iforgotmyfirstlogon]

It is all just a hoax. As it turns out, a group of rival scientists went up into space and just put a REALLLY big mirror up there.

- Freed

Hmm...

[Dark Nexus]

Okay, so the planet 3-3.5 times the size of Jupiter, at NEAR the same orbit as Jupiter....

But that planet right near the star that's just a bit smaller than Jupiter is a BIG difference.

But hey, it's a start, and doesn't mean that there AREN'T planets geologically similar to Earth there.

Guess we might find out soon.

why so keen on earth-sized?

[macsox]

i don't get the thrust of the article focusing on finding earth-sized planets. is there some theory that necessitates a planet be our size to foster life? if so, why?

(here comes the (-1, Ignorant). bring it on.)

Re:why so keen on earth-sized?

[Jucius Maximus]

"i don't get the thrust of the article focusing on finding earth-sized planets. is there some theory that necessitates a planet be our size to foster life? if so, why?"

I'm taking a page from Spock here:

Are we humans so arrogant as to assume that life can only be found on planets that closely resemble our own? Why can't life exist in forms completely unimagined by us on red-hot planets close to suns or enormous gas plants? And if we ever saw that sort of life, would we recognise it even if it was staring us in the face?

Re:why so keen on earth-sized?

[bwohlgemuth]

Easy...the word is gravity.

Smaller planets like Earth with lower gravity wells allow (currently known) life forms to be able to move easily. The best analogy would be the shuttle. Takes a bunch of fuel to move it. If you don't put much cargo it the ship, you need less fuel to take off. However, if you max it out, you not only need fuel to move the bigger mass, but to move the additional fuel as well. Now apply that to animals, either they would be really tiny or really huge.

Now, if you want to get into the realm of life forms that exist either in a gaseous state or as energy, I'll have to refer you to Mr. Bisson's story in Omni from a while ago.

B

Re:why so keen on earth-sized?

[Zathrus]

Ok, ignoring the "our theories say" bit on finding life, let's look at it from another (perhaps even more improbable) angle.

If we want to terraform other worlds, our best bets are to find similar worlds to do that with. When you're building a house which do you look at first - the flat land that's already cleared or the swamp?

Even if we were to determine, definitively, that we are the only sapient species within 1000 light years, finding Earth-like planets means we have someplace to go that won't require too much work. Frankly, if we're stuck terraforming gas giants, then screw going elsewhere - let's build a Dyson sphere (or Ringworld, or what have you) here first. It's just about as feasible.

Re:why so keen on earth-sized?

[Restil]

Ever notice how all the small planets are rocky and all the large planets are gassy? This is not a coincidence. Jupiter and most likely the rest of the gas giants have solid cores, larger in fact than the earth, but due to their immense mass, they have an extremely dense atmosphere, which could not support life, at least as we know it.

As for smaller planets, you end up with situations like Mars. Mars has an atmosphere, although it has less than 1% of the air pressure that Earth has. .1% if I remember correctly, but don't quote me on that. The gravity of the planet is insufficent to maintain a signficant atmosphere. Atmosphere "leaks" off into space all the time, even on Earth. This lack of atmosphere creates several problems. First, breathing would be extremely difficult, so life forms that DO exist would have to sustain themselves on very little air. Meteors would also present more of a problem, as they can't burn up as easily.

Venus has sufficient atmosphere, but its proximity to the sun, as well as the contents of its atmosphere, creates an environment that's too hot for "conventional" life to survive.

Of course, you also have the issue of habitable zones and their relation to the size of the sun. Consider our solar system as one that works. We're not too close, nor too far away from the sun, and the sun has 10 billion years of life (half of which it has expended already). Say we're looking at a larger star, like a blue giant. The planet could orbit further away and maintain the same temperate zone, but in 10 million years that sun is going to go supernova and any life will have not had enough time to evolve from inception. It took longer than that just for the Earth to cool down.

Large planets orbiting close to the sun present a problem. The primary concern is how they got there. Chances are good that they didn't form that close to the star, but formed further out then migrated inward to their present positions. If this is the case, its a darn good chance that any planets within the habitable zones will have either collided with the gas giant or been kicked out of the solar system.

The lack of any gas giants is also a problem. Jupiter does a nice job of attracting and "removing" potential threats to Earth, mostly the very large rocks. Without the gas giants out there to help us out, the Earth would get battered far more frequently than it does. Life can handle a huge hit once every 60 million years or so. Long term evolution would be severely hampered, however, if it happened more frequently.

A potential alternative to the current solar system is a gas giant located in the habitable zone with a earth sized moon. The moons of Juipter would have a significantly more viable climate if they were orbiting at 1 AU. However, this would present other dificulties, namely tidal lock. The moon would have to be sufficiently close to the planet so it didn't roast any one side for any significant length of time, however, the planet itself would block the light to the moon, so the moon would have one side that was perpetually frozen and the other side that had to endure long days and long nights. And any moon close enough to the planet to orbit quickly enough would have severe tidal problems... think IO.

So anyway, our best bet... is to find a solar system that resembles ours. At least until we find another model that works. Sorry about the extended rant.

-Restil

Only 40 times the size of earth!

[quantaman]

They have also found the smallest exoplanet yet. It is only 40 times more massive than Earth.


The size of the planet isn't really the issue though,
Detecting Earth-sized planets is probably not possible using current ground-based techniques. That will have to wait for a new generation of satellite observatories, due in the next decade.

The important part is
Calculations made by Greg Laughlin of the University of California at Santa Cruz show that an Earth-sized planet could survive in a stable orbit between the two gas giants.

This of course doesn't mean that we found anything only that when we are able to look for earth-like planets this is our best bet for hitting the jackpot.

Also on this note...

[Dark Nexus]

A quote from the CNN article (which seems to be a bit more fleshed out) I didn't see in either of the ones listed at the top:

"We haven't found an exact solar system analog, which would have a circular orbit and a mass closer to that of Jupiter. But this shows we are getting close," said Paul Butler, another member of the planet-hunting team.

But the orbit of the Jupiter-like planet is stable enough to foster a benign, life-friendly environment in the inner solar orbit, Fischer said.

Reason we can't detect planets the size of earth.

[Ami_Chan]

The article doesn't give much information about this, so I figured I'd put in my 2 cents from what I learned in astronomy this year:

Currently, they have 2 ways (that I'm familiar with) to find an extra-solar planet. First, they can look for a "wobble" in the path the star takes. This wobble is caused by the gravitational pull of a large planet orbiting the star. Earth is so small that the tiny wobble caused by a planet similar in size would be impossible to view; or at least it would disappear with the systematical error.

The other way I've heard of to find extra-solar planets is similar to an eclipse. When the planet comes between the star and Earth, we can measure the changes in luminosity of the star. Obviously, with planets with small orbits, we can determine how quickly the planet orbits the star because of the pattern in the luminosity. Again, we can't detect earth size planets since earth is just too small.

Well... It'll just have to go.

[Rothfuss]

Start building the fleet!

I recommend employing shiny white robots as our attack force.

-Rothfuss

Re:Well... It'll just have to go.

[Dirtside]

No, no, we'll just use clones, they're more efficient -- and hey, I hear that the Kanadians just happen to have a fully-trained clone army ready to go. Man, those Kanadians are excellent cloners.

What? I've only seen it three times, why?

Human Arrogance

[hokanomono]

On the other hand, my uncle said:

The idea that there has to be life somewhere else in the universe too, is just based on the image that life is something superior, something special that the universe was just made for. As if it was not fair that only the earth carries life. If we leave our egocentric view and accept that the universe does not care about life, the belief in extraterrestrial life is absurd.

I completely agree with both, Spock and my uncle.

Re:Human Arrogance

[junkgrep]

A general rule here is that, in the abscence of a good causal model predicting why there would be more examples, you need at least two examples of something before you can conclude that it is likely that there are more than the one example you currently have. That's how you establish it as a possible reproducible pattern, rather than a one-off fluke. We currently only have one example of life appearing in the universe: here. So we really can't say too much yet about the odds of it appearing elsewhere.

Didn't you read the article

[NoBeardPete]

The astronomers said that an Earthlike planet _could_ survive in an orbit between the two large ones. Given a choice between your guess that it would get ripped to shreds, and the opinions of professional astronomers who've studied this specific solar system, and concluded that an Earthlike planet could be there, I'm going to side with the astronomers.

Re:Didn't you read the article

[barawn]

That's not exactly true: in our case, the Sun pushed (light pressure, and another effect I can't think of the name of...) or ate all of the light gaseous material inside the asteroid belt. At least, it did, viewing it from 6 or so billion years later.

Now, the next problem is that we do NOT know how these giant planets near their star formed. People suggest that the planets migrated inwards, which would make an Earth-sized planet unlikely. However, there are some suggestions that the gas giants CAN form that close to their star. In fact, I don't think that we would even KNOW if there had previously been a gas giant inside Mercury's orbit that has long since been devoured by the Sun. Thus we could be looking at a Sol-like system, just much earlier in formation.

It should be noted that Jupiter has some influence on Earth - but it's very minor. Venus has significantly more influence (Venus's rotation is actually in a resonance with Earth's orbit).

A planet that close to the Sun orbiting that quickly would, from Earth's (1AU) point of view, just look like an increase in the Sun's mass. Work out the differential force: With a differential distance swing of 1/40 AU, but the distance going as the cube, it's really going to be quite minor: about 1/200th the tidal force of the Sun, which is less than that of the Moon. It's not like the Moon's influence seriously screws up the planet. (Note that I'm talking about the differential force of the swing of the inner planet: that is, how much does the tug of the inner planet really change from Earth's point of view? Not much at all).

Gravitational perturbations are due to differential gravitational forces, and the forces on Earth due to a planet orbiting at 0.025 AU are trivial. As for asteroid components, it depends on how the planet formed, which we don't understand yet. If it formed far out, and moved in, then yes, it would be a menace. But if it formed close in, it's extremely unlikely to cause any "asteroid bombardment" or anything like that.

Keep in mind that you could consider a slight "bulge" in the sun to be a "giant planet" orbiting the Sun obscenely quick: if it was likely that this would disturb the Earth, the Earth would be in very bad shape: bubbles of different densities appear on the Sun all the time. The differential force just isn't that great.

Should we look there first? Yes. It's an IDEAL target, actually! It's a planetary system where both standard Sol planetary formation processes are occuring, and this "weird' giant planet stuff is happening. If it isn't the first stop for the TPF, I'd be amazed. That's a system worth studying. And would anyone be surprised to see an Earth like planet show up there? Not likely.

What do Christians think about this?

[Loundry]

This is not a troll -- I'm genuinely very curious.

What do Christians think about stories like this? I ask becuase, in discussions with Christians, I've heard Christians tell me that there is no intelligent life on other planets. This was usually in response to my questions like, "Did Jesus die for aliens on other planets?" Perhaps a silly question for me to ask, but the "There is no intelligent life on other planets" was not an uncommon belief among the Christians I've met.

So I've often wondered what Christians (particularly Christian nerds, who are probably significantly more friendly to science than some of the Christians I've met) think when stories like thit surface and hint at the possibility of finding other "Earth-like" planets that may have intelligent life on them.

Thoughts?

Re:What do Christians think about this?

[SteelX]

Perhaps this link may be helpful to you:

What does the Bible say about intelligent life on other planets?

Re:What do Christians think about this?

[meta-monkey]

Really, it depends on what kind of Christians you're talking to. I'm a Christian, and I believe there is most likely intelligent life somewhere else in the Universe. That is because I believe the Bible (New Testament, anyway) is a moral compass, not a historical record. I've seen cases made by "Every Word of the Bible is Absolute Truth" Christians, and I find them hollow...they make definitive assertions based on nuance of language. The Bible says "All of creation..." and they assume that means the entire Universe, not just Earth. I think of it more like this: Jesus taught in parables, why wouldn't God communicate in the same way to the authors of the bible? Do you really think the authors of Genesis would understand the formation of the solar system, the evolution of life on earth (guided by God), and time spans in the millions of years? Of course not! So He explained it in a way they could understand...through a parable about the creation of the Earth in the span of days.

Some Christians, however, do not understand this concept. This is the scariest glimpse into these peoples' minds I have from personal experience. When I was in the 9th grade, about 10 years ago, several of my friends at school and I were arguing about creation and evolution. One of the girls was a southern Baptist, and said her church was having a lecture on the topic for their youth group the next week. So the six or so of us decided to go. The guy leading the discussion was, of course, pro-creation, and that's fine...it's what I expected to find at a Baptist church event. Now, during the course of the lecture he asked the audience, "How old is the Earth?" One young adult raised his hand and responded "ten thousand years." Another said 6k. I raised my hand and said, "Four and a half billion years old."

They laughed at me. The entire audience turned around and laughed at me. I was speechless. I couldn't imagine that even being a topic of debate. The speaker went on to inform us that the Earth was, in fact, only six thousand years old, because the Old Testament listed the various ages of people who lived since Adam up until times of historical record, and with a little math... Draw your on conclusions, but that incident alone taught me I would have to approach my faith with a heavy dose of skepticism, so I wouldn't wind up spouting impossibilities simply because they're written in a book.

Re:What do Christians think about this?

[cford]

As a fundamentalist Christian, and an ordained Southern Baptist minister with an MS in Software Engineering, I'd be happy to offer my thoughts on your question.

First off, I would agree whole-heartedly with the previous poster who commented that much depends on whether the life discovered was (is) intelligent, and whether or not it has a soul.

As far as what I think about stories like this... I don't find any conflicts between my faith and these kinds of articles. The Bible makes mention of creatures such as the Nephilim who lived or visited Earth prior to the flood. And any Christian who would take the time to thoroughly study the Bible would be compelled (I think) to conclude that there is much that we don't know or understand about our situation in the grand scheme of things. If you're going to accept that there are angels, seraphim, cherubim, demons, etc... then they, by definition are "extra-terrestial." I do believe in a Creator, and that Jesus Christ was the Creator incarnate. Simple logic would lead one to believe that if He created life here, he could, at His discretion, have created it elsewhere. (One reason I run seti@home, just out of curiosity)

A thorough study of the Bible must entail at least a passing familiarity with the language(s) from which the version you're reading was translated. The gospel of John tells us that Jesus Christ died for the sins of the world. (...For God so loved the world...) The Greek word which was translated "world" is "kosmos: the world, the universe."

Like others, I'm saddened to find Christians, or for that matter, anyone, who seems to cling to the belief that they have the final answer to any question. From the Pope on down, none of us can pretend to even begin to comprehend the magnificence of God. Therefore, when I see articles like the one we're discussing, it thrills me to see that we've uncovered one more small piece of the mystery of God's creation.

One final note, I've had bad experiences with fundamentalists just like others have. Any group of people will have their lowest common denominators. Scientists can be just as dogmatic about their theories as many zealots are about their theology. Read / study the Bible for yourself, and draw your conclusions.

Hope I haven't been too tangential.

Still waiting...

[Peale]

It's only a matter of time until the Terrestrial Planet Finder program gets going and finds another Earth

Yep. And when that happens, I'm leaving.

Re:Still waiting...

[namespan]

Yep. And when that happens, I'm leaving.

Not if you have kids, you aren't.

"Are we there yet?"

"No."

"How much longer?"

"I just told you, we've got at least 75 light years!"

"But I have to go!"

"Dammit, if I have to decelerate below .5 c again, so help me..."

What isn't clear (yet is important)

[CheshireCatCO]

What bothers me about this is that while there is a quick mention of "formation models," most of the discussion of the potential existence of a terrestrial planet seemed focused on the stability of an orbit in the present configuration. In fact, it isn't clear to me that they've even considered the formation processes at all. (To be honest, I get the opposite sense.)

Why does this bother me, you ask? Because an orbit at 1 AU might be stable NOW, but if you have a giant planet migrating in through the inner solar system to an 15-day orbit, it'll wreck jolly hell with any planets it passes. The migration is slow enough that you are almost guaranteed a close-enounter of some kind. Once a Earth-sized planet gets near a giant planet, the orbit is in the very least highly perturbed. Odds are fair that it could be ejected altogher or will collide with the giant planet and be effectly lost. But even if it isn't, the eccentricity is probably going to be increases substantially. A planet that changes its distance from its star radically over a year is unlikely to be habitable, if you believe current models.

Re:Reason we can't detect planets the size of eart

[oni]

How likely is that, for any given star?

It's more likely than you might think. It has to do with conservation of angular momentum and it's the planets and even the moons in our solar system are all within a few degrees of the same plane.

Sure there are exceptions, but the chances of seeing a solar system on edge is considerably better than whatever it would be if they were just randomly distributed.

Not quite as far as quoted

[ThesQuid]

Quote from the Yahoo article about the same thing:

55 Cancri is located 41 million light-years from the Earth, in the constellation of Cancer. The star, believed to be around five billion years old, is visible to the naked eye, astronomers said.

HA! I don't think so. That's about 20 times the distance to the Andromeda Galaxy. Nice how the people they have writing these things up have a good grasp on the fundamentals of the subject matter.

The Odds

[extrasolar]

By now, I am readily convinced that there is other life in the universe. In fact, it seems that odds are greater that there isn't life in the universe.

But if I'm like most anyone else, the possibility of life on the western spiral of the Andromeda Galaxy just isn't useful. Its simply too far. We would never recieve a radio transmission from there and its too far to travel.

First, lets assume Einstein is correct and we can not travel faster than the speed of light. In addition, lets rid our minds of all this science-fiction crap like wormholes and warp-drive. While I am naive, I'm not *that* naive.

Lets take the nearest star. I've heard it is 4.3 light years away. That means a radio transmission originating their takes 4.3 years to travel here. Honestly, we could live with that. Of course that is not only assuming that that civilization has developed technology, but it also assumes that they haven't been exinct by some means.

But, we're pretty sure there isn't a planetary system around proxima centauri. So we have to look farther out. But how long are we willing to wait for a round of communication from us to them? One hundred years? One thousand years? A hundred-thousand years?

Okay, as a second consideration, how long does a civilization last once it discovers radio? We've only had radio technology for a relatively little time. How much longer will we continue to exist? Take HG Wells Time Machine. Will we unlearn our technology and instead progress towards a native happiness? What about other civilizations?

In all, what are the odds that not only life exists in the universe, but that it is close enough and that it is in their technological prime?

I'd fashion that the odds are astronomical against us.