New solar system near by with 7 planets, three habitable.

[Sparko]

Your over stating and warping the conclusions of the article, as usual.

No the article is the one doing the overstating

[Adrift]

Your over stating and warping the conclusions of the article, as usual.

And, as usual, you're using the possessive form of "you", which is "your", when what you really want is the contraction for "you are" which is "you're". As I've previously advised, if you get confused sound it out. Does it sound right when you say "You are overstating"? If so, go with the contraction.

[shunyadragon]

And, as usual, you're using the possessive form of "you", which is "your", when what you really want is the contraction for "you are" which is "you're". As I've previously advised, if you get confused sound it out. Does it sound right when you say "You are overstating"? If so, go with the contraction.

Everyone needs their own anal grammarian. Thank you! Again, again, and again . . .

[Adrift]

Everyone needs their own anal grammarian. Thank you! Again, again, and again . . .

Well I think I finally got you saying "anal retentive" instead of "anal attentive". I consider that progress. The you're/your distinction will hopefully click in one day if we keep at it.

[Jedidiah]

How similar to earth are the "magnificent 7"

http://www.reasons.org/blogs/todays-...really-similar

[Tassman]

How similar to earth are the "magnificent 7"

http://www.reasons.org/blogs/todays-...really-similar

Yeah right! A religious web site with the stated mission to "spread the Christian Gospel" is the place to look for rigorous , impartial scientific investigation.

[Jedidiah]

Yeah right! A religious web site with the stated mission to "spread the Christian Gospel" is the place to look for rigorous , impartial scientific investigation.

Please reveal any errors of a scientific nature. Where does this Christian astrophysicist err in what he says?

[Tassman]

Please reveal any errors of a scientific nature. Where does this Christian astrophysicist err in what he says?

[Roy]

Please reveal any errors of a scientific nature. Where does this Christian astrophysicist err in what he says?

The first obvious issue is the claim that the seven planets are tidally locked. They may well be, and certainly would be if they've been in their current orbits for a substantial time, but we don't actually know for certain.

There's also this misleading claim: "

All those planets are much closer to Earth's size than Mars is, as Mars is only 1/10 the mass of Earth, so the claim they are Earth-sized in the same sense as Mars is incorrect.

Then there's this: "This orbital synchrony means that these four planets exert periodic gravitational influences on one another. These periodic gravitational influences rule out the possibility of life on these planets."

This is complete bollocks. They give no reason why periodic gravitational influences would rule out life. They don't even compare these gravitational forces with those caused by the moon, which clearly hasn't prevented life here. A quick mental calculation suggested these gravitational forces would be around ten times that of the moon, which while it would cause massive tides wouldn't appreciably affect deep oceans and is still negligible compared to the gravitational forces of the host planet.

Further, the article states: which would allow life to arise while the planets were further from the star and less affected by each others' gravity.

[Sparko]

Yeah right! A religious web site with the stated mission to "spread the Christian Gospel" is the place to look for rigorous , impartial scientific investigation.

Genetic fallacy. Address the article, don't shoot the source. The points it makes are scientific facts (coolness of the star, distance from the star, tidal locking, radiation flares, etc) - the likelihood of life on those planets is very small, They are not "earthlike" in anyway other than size.

[Sparko]

The first obvious issue is the claim that the seven planets are tidally locked. They may well be, and certainly would be if they've been in their current orbits for a substantial time, but we don't actually know for certain.

There's also this misleading claim: "

All those planets are much closer to Earth's size than Mars is, as Mars is only 1/10 the mass of Earth, so the claim they are Earth-sized in the same sense as Mars is incorrect.

Then there's this: "This orbital synchrony means that these four planets exert periodic gravitational influences on one another. These periodic gravitational influences rule out the possibility of life on these planets."

This is complete bollocks. They give no reason why periodic gravitational influences would rule out life. They don't even compare these gravitational forces with those caused by the moon, which clearly hasn't prevented life here. A quick mental calculation suggested these gravitational forces would be around ten times that of the moon, which while it would cause massive tides wouldn't appreciably affect deep oceans and is still negligible compared to the gravitational forces of the host planet.

Further, the article states: which would allow life to arise while the planets were further from the star and less affected by each others' gravity.

no. because if they were farther away they would not have been in the goldilocks zone and been able to have liquid water and develop life. Also what about the statement of frequent flares of such a star? The radiation would sterilize any life that close to the star.

[Roy]

no. because if they were farther away they would not have been in the goldilocks zone and been able to have liquid water and develop life. Also what about the statement of frequent flares of such a star? The radiation would sterilize any life that close to the star.

Good point - although there would have been a period during their inward migration after they entered the 'goldilocks' zone but before they reached their current orbits.

I agree radiation flares are a possible issue (though I'm not sure whether it would penetrate an ocean). But there's no reason to think the gravitational effects from planetary interactions is at all problematic. That's a major failing by the author.

[Sparko]

Good point - although there would have been a period during their inward migration after they entered the 'goldilocks' zone but before they reached their current orbits.

I agree radiation flares are a possible issue (though I'm not sure whether it would penetrate an ocean). But there's no reason to think the gravitational effects from planetary interactions is at all problematic. That's a major failing by the author.

[TheLurch]

Good point - although there would have been a period during their inward migration after they entered the 'goldilocks' zone but before they reached their current orbits.

Two things here: these planets would be large enough to sustain plate tectonics for a long time, and so the possibility of a sub-ice ocean (assuming water) is very real.

The second thing is that the migration would have occurred early in the system's history, since it's dependent on friction from the disk in which the planets formed. Over a relatively short period of time, the planets gather most of the material in that disk, and the remainder is drive off by radiation pressure once the star ignites. So the 7 should have been in their current positions for most of their existence*.

*Of course, we don't know how long their existence has been. TRAPPIST-1 is a class of star called (not making this up) an "ultra cool dwarf". These stars burn very slowly, and have a 100 billion year period or so where you can't tell where they are in their timeline.

[Roy]

Perhaps, but that wasn't what he wrote. The gravitational effects themselves don't preclude life, although if they cause wobble that affects the twilight zones then that might. Or might not, depending on how great the wobble is and how fast it occurs. Jupiter's moons are in a similar resonance, and they don't wobble much.

Personally I think the radiation and flares would be the biggest problem. Only 4-6 million miles from the star, I think radiation would be a big problem for life.

Agreed, unless the life is sheltered somehow. But my point was simply that the author is wrong on some specifics, including that periodic gravitational effects do not rule out the possibility of life.