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Who Needs a Moon?
Science ^ | 27 May 2011 | Govert Schilling

Posted on 05/28/2011 4:43:54 PM PDT by LibWhacker

BOSTON—The number of Earth-like extrasolar planets suitable for harboring advanced life could be 10 times higher than has been assumed until now, according to a new modeling study. The finding contradicts the prevailing notion that a terrestrial planet needs a large moon to stabilize the orientation of its axis and, hence, its climate.

In 1993, French mathematicians Jacques Laskar and Philippe Robutel showed that Earth’s large moon has a stabilizing effect on our planet’s climate. Without the moon, gravitational perturbations from other planets, notably nearby Venus and massive Jupiter, would greatly disturb Earth’s axial tilt, with vast consequences for the planet’s climate. The steadily orbiting moon’s gravitational tug counteracts these disturbances, and Earth’s axial tilt never veers too far from the current value of 23.5°, where 0° would mean the axis was perpendicular to the plane of Earth’s orbit around the sun.

Indeed, Laskar and Robutel also showed that the axial tilt of Mars, which has only two tiny moons, has varied between 10° and 60° in the past, which caused huge climate variations that in turn could have contributed to the loss of most of the planet’s atmosphere, leaving Mars the bone-dry desert world that it is now. Since then, most astrobiologists have assumed that Earth-like planets in other solar systems would need a comparatively large moon to support complex life over long periods of time.

Given the generally accepted idea of how Earth got its big moon—through an improbable, dramatic collision with a Mars-sized body that knocked a huge chunk of Earth loose—astronomers estimate that only 1% of all Earth-like planets in the universe might actually have such a hefty companion. That would mean that planets harboring complex life might be relatively rare.

However, Jack Lissauer, a theoretical astrophysicist at NASA’s Ames Research Center in Moffet Field, California, is much more optimistic. Together with Jason Barnes, a physicist at the University of Idaho, Moscow, and John Chambers, a theoretical astrophysicist at the Carnegie Institution’s Department of Terrestrial Magnetism in Washington, D.C., he has carried out large numbers of detailed numerical simulations of "moon-less Earths," which show that the consequences are less dire than is generally assumed.

That’s because really big changes in a planet’s tilt would occur only after a very long time, so there would be more than enough time for the evolution of life, Lissauer reported yesterday here at the summer meeting of the American Astronomical Society. “The variations in Earth’s axial tilt would indeed be substantially larger if there was no large moon,” Lissauer says, “but really big excursions from the current value would only occur on time scales of billions of years.” That would leave ample time for advanced land life to evolve under relatively stable climatic conditions—although what would happen to such life during an axial shift remains unclear.

When a planet rotates in the opposite direction to its orbital motion (which happens to be the case for Venus), the effect of gravitational perturbations on its spin axis would be even smaller, the simulations indicate. And, of course, if a planetary system contains only one planet, there are no perturbations at all. Nobody knows how common such single-planet system might be.

Not everybody is overwhelmed by the importance of the new results. “I don’t think [changes in a planet’s axial tilt] would be a problem for the development of advanced life,” as any type of life would adapt to changing circumstances anyway, says planetary scientist Sara Seager of the Massachusetts Institute of Technology in Cambridge.

But Bill Borucki of NASA’s Ames Research Center, who is the principal investigator of the planet-hunting Kepler satellite mission, says he is “surprised and delighted” by Lissauer’s conclusions. “Kepler is searching for Earth-like planets orbiting other stars,” he says, “and this means much more of them might be harboring complex life. It’s a wonderful result.”


TOPICS: Astronomy; Science
KEYWORDS: axis; billborucki; catastrophism; earth; earthwithoutamoon; effect; exoplanets; fauxiantrolls; freelazamataz; goldilocks; goldilocksplanet; goldilockszone; jacklissauer; jacqueslaskar; lunarcapture; lunarorigin; moon; philipperobutel; planets; rareearthnonsense; saraseager; seasons; stabilizing; themoon; tilt; velikovsky; xplanets

1 posted on 05/28/2011 4:43:59 PM PDT by LibWhacker
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To: LibWhacker
Well being that they discovered that Jupiter sized/type planets can exists close to their star, there's probably a lot of earth type planets orbiting these Jupiters

You wouldn't need a moon in those cases.

2 posted on 05/28/2011 4:58:27 PM PDT by qam1 (There's been a huge party. All plates and the bottles are empty, all that's left is the bill to pay)
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To: LibWhacker
astronomers estimate that only 1% of all Earth-like planets in the universe might actually have such a hefty companion. That would mean that planets harboring complex life might be relatively rare.

An assumption based on our circumstances.
3 posted on 05/28/2011 4:59:21 PM PDT by cripplecreek (Remember the River Raisin! (look it up))
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To: KevinDavis; annie laurie; Knitting A Conundrum; Viking2002; Ernest_at_the_Beach; Mmogamer; ...

Thanks LibWhacker.
 
X-Planets
· join · view topics · view or post blog · bookmark · post new topic · subscribe ·
Google news searches: exoplanet · exosolar · extrasolar ·

4 posted on 05/28/2011 5:00:27 PM PDT by SunkenCiv (Thanks Cincinna for this link -- http://www.friendsofitamar.org)
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To: LibWhacker; KevinDavis

bump


5 posted on 05/28/2011 5:00:27 PM PDT by GeronL (The Right to Life came before the Right to Happiness)
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To: LibWhacker
The number of Earth-like extrasolar planets suitable for harboring advanced life could be 10 times higher than has been assumed until now, according to a new modeling study.

Does this mean we have to start being sucked dry via taxation to save these planets from us for when we move there after destroying this planet as claimed?

6 posted on 05/28/2011 5:02:13 PM PDT by EGPWS (Trust in God, question everyone else)
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To: qam1

Also true. I know that at least a few of the Jupiter sized planets orbiting sunlike stars have been found with stable orbits in the goldilocks zone.


7 posted on 05/28/2011 5:02:57 PM PDT by cripplecreek (Remember the River Raisin! (look it up))
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To: cripplecreek

we believe we are special. Well, okay we might actually be special in the universe but we sure hope not because we want to find other worlds we can boast to


8 posted on 05/28/2011 5:09:32 PM PDT by GeronL (The Right to Life came before the Right to Happiness)
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To: GeronL

I’m not real interested in intelligent life.

What we need is life we can eat, air we can breathe, and water we can drink.


9 posted on 05/28/2011 5:13:04 PM PDT by cripplecreek (Remember the River Raisin! (look it up))
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To: cripplecreek

isn’t that the truth.

depending on what we find we either go and get away from here or we send all the leftists and perverts away. lol


10 posted on 05/28/2011 5:16:17 PM PDT by GeronL (The Right to Life came before the Right to Happiness)
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To: Lonesome in Massachussets

Lonesome in Massachussets, pardon the intrusion.
In 1993, French mathematicians Jacques Laskar and Philippe Robutel showed that Earth's large moon has a stabilizing effect on our planet's climate. Without the moon, gravitational perturbations from other planets, notably nearby Venus and massive Jupiter, would greatly disturb Earth's axial tilt
Over a very long period of time, the tugs from other planets would have a very small effect.

IOW, I very much doubt this.

When figuring out how much effect bodies have on each other, distance is more significant than mass.

The Earth's Moon is responsible for about 2/3rds of the tides.

The other third is due to the Sun.

Venus is closer than the Sun, but has a very tiny effect by comparison, which goes to show just how massive the Sun is, because, as noted above, distance is more significant than mass.

This looks like twaddle and poppycock growing out of the foolish book Rare Earth which makes the claim that conditions on Earth produced life, and that any kind of change would mean life wouldn't have arisen -- hence, it's not likely that there's any other life in the cosmos.

Ironically, YECs sometimes saddle on Rare Earth -- which is strictly materialist-reductionist -- as proof of their beliefs. That's just dopey.
11 posted on 05/28/2011 5:23:49 PM PDT by SunkenCiv (Thanks Cincinna for this link -- http://www.friendsofitamar.org)
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To: LibWhacker
Slightly off topic:

"Ever since the beginning of time man has dreamed of destroying the sun." -Montgomery Burns

12 posted on 05/28/2011 5:28:09 PM PDT by stevio (God, guns, guts.)
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50 posted on 03/18/2006 5:27:42 PM PST by Lonesome in Massachussets

13 posted on 05/28/2011 5:28:21 PM PDT by SunkenCiv (Thanks Cincinna for this link -- http://www.friendsofitamar.org)
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To: EGPWS
Does this mean we have to start being sucked dry

Of course! It's going to be very expensive sending spacecraft to every star, planet, moon, rock, lump of ice and wisp of gas out there. ;-)

14 posted on 05/28/2011 5:29:08 PM PDT by LibWhacker
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To: LibWhacker

numerical simulations of “moon-less Earths,” which show that the consequences are less dire than is generally assumed.

ORLY?


15 posted on 05/28/2011 5:46:13 PM PDT by BenLurkin (This post is not a statement of fact. It is merely a personal opinion -- or humor -- or both)
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To: SunkenCiv

That IS very cool! (pass the Dramamine please)

8^)


16 posted on 05/28/2011 5:48:51 PM PDT by BenLurkin (This post is not a statement of fact. It is merely a personal opinion -- or humor -- or both)
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To: SunkenCiv

Jupiter exerts the third biggest force on Earth, preceded by the Sun and the Moon. And it is a very poor third. Jupiter’s gravitational force on the Earth is greater than that of all the other planets combined. Simple - use Newton’s Law of Gravitation, and use relative masses and distances in Astronomical Units to keep it simple, and you will get the same scale differences.
As for Mars losing its atmosphere, I believe it was more due to the core solidifying. Loss of the core’s liquid state resulted in the loss of its magnetic field, shielding it from the solar wind. The solar wind then ablated away the atmosphere, aided by Mar’s lower gravity.


17 posted on 05/28/2011 6:07:47 PM PDT by Fred Hayek (FUBO, the No Talent Pop Star pResident.)
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To: Fred Hayek

Thanks Fred Hayek!


18 posted on 05/28/2011 6:35:21 PM PDT by SunkenCiv (Thanks Cincinna for this link -- http://www.friendsofitamar.org)
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To: BenLurkin

:’) Lonesome in Massachussets posted it in another topic, a while back (linked at the image).


19 posted on 05/28/2011 6:40:20 PM PDT by SunkenCiv (Thanks Cincinna for this link -- http://www.friendsofitamar.org)
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To: qam1
Well being that they discovered that Jupiter sized/type planets can exists close to their star, there's probably a lot of earth type planets orbiting these Jupiters

An earth type planet as the moon of a Jupiter sized planet would proably rotate with one side facing the planet, as our moon does, or Venus. It is possible to have life, but it would not be a greate climate.

20 posted on 05/28/2011 7:02:49 PM PDT by Vince Ferrer
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To: LibWhacker

Call me back when the aliens land.


21 posted on 05/28/2011 7:37:49 PM PDT by Venturer
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To: Vince Ferrer
An earth type planet as the moon of a Jupiter sized planet would proably rotate with one side facing the planet, as our moon does, or Venus. It is possible to have life, but it would not be a greate climate.

If the gas giant was several times more massive than Jupiter then the Earth like planet would zoom around it close to what we have now. You'd might have a longer day & night but it shouldn't be that bad.

Now if the Gas Giant was about the same size as Jupiter, day and night might last a week or two each. That would be extreme as you would essentially go through all four seasons in one day. Spring in the morning, summer in the afternoon, fall in the evening and winter at night.

And that's only if the gas giant and the earth like planet are like Jupiter and have a insignificant axis tilt, if the gas giant and/or the earth like planet was tilted like earth you'd get seasons within seasons, 4 yearly seasons to go with your 4 daily seasons.

22 posted on 05/28/2011 9:32:54 PM PDT by qam1 (There's been a huge party. All plates and the bottles are empty, all that's left is the bill to pay)
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To: SunkenCiv

That movie is Copyright Antonio Cidadao. The USNO uses it by permission, we should at least acknowledge the source. Dr. Cidadao is a physician who practices backyard astronomy from the balcony of his Lisbon apartment. The movie was made during March and April 1998.


23 posted on 05/29/2011 4:17:36 AM PDT by Lonesome in Massachussets (Somewhere in Kenya a village is missing its idiot)
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To: SunkenCiv
The article offers arguments against the thesis that the moon is essential for complex life forms to evolve. The arguments are not completely dispositive for either view, imho. I'd say the evidence indicates that the moon certainly does stablizes axial tilt and therefore climate as well, and consequently greatly facilitates the appearance of complex life forms.
24 posted on 05/29/2011 4:31:14 AM PDT by Lonesome in Massachussets (Somewhere in Kenya a village is missing its idiot)
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To: LibWhacker

God is smart!


25 posted on 05/29/2011 6:05:22 AM PDT by RoadTest (Organized religion is no substitute for the relationship the living God wants with you.)
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To: LibWhacker

26 posted on 05/29/2011 6:11:28 AM PDT by Daffynition ("Don't just live your life, but witness it also.")
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To: LibWhacker
Given the generally accepted idea of how Earth got its big moon—through an improbable, dramatic collision with a Mars-sized body that knocked a huge chunk of Earth loose—astronomers estimate that only 1% of all Earth-like planets in the universe might actually have such a hefty companion.

I've seen recent estimates that there were several Mars sized bodies in the early Solar System, so a collision may not be as improbable as once thought. The bottom line is that it is better for the evolution of higher life to a have a moon.

27 posted on 05/29/2011 6:22:03 AM PDT by Moonman62 (The US has become a government with a country, rather than a country with a government.)
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To: LibWhacker
Not everybody is overwhelmed by the importance of the new results. “I don’t think [changes in a planet’s axial tilt] would be a problem for the development of advanced life,” as any type of life would adapt to changing circumstances anyway, says planetary scientist Sara Seager of the Massachusetts Institute of Technology in Cambridge.

I'd like to see her tell that to all the so called scientists trying to stir up massive panic over relatively minor and mostly naturally caused climate change.

28 posted on 05/29/2011 6:24:21 AM PDT by Moonman62 (The US has become a government with a country, rather than a country with a government.)
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To: Lonesome in Massachussets

Thanks Lonesome in Massachussets.


29 posted on 05/29/2011 7:32:19 AM PDT by SunkenCiv (Thanks Cincinna for this link -- http://www.friendsofitamar.org)
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More Moons Around Earth? It's Not So Loony
by Robin Lloyd
October 29 1999
Earth has a second moon, of sorts, and could have many others. Cruithne, the 3-mile-wide (5-km) satellite, takes 770 years to complete a horseshoe-shaped orbit around Earth, and will remain in a suspended state around Earth for at least 5,000 years. Every 385 years, it comes to its closest point to Earth, some 9.3 million miles (15 million kilometers) away. Its next close approach to Earth comes in 2285. "We found new dynamical channels through which free asteroids become temporarily moons of Earth and stay there from a few thousand years to several tens of thousands of years," said Fathi Namouni, one of the researchers, now at Princeton University. Namouni's colleague Apostolos Christou said, "At specific points in its orbit, it reverses its rate of motion with respect to Earth so it will appear to go back and forth." In his view, there are three classes of moons -- large moons in near-circular orbits around a planet, having formed soon after the planet; smaller fragments that are the products of collisions; and outer, irregular moons in odd orbits, or captured asteroids like Cruithne. In the past year, astronomers have reported finding such objects around Uranus.

30 posted on 05/29/2011 7:46:24 AM PDT by SunkenCiv (Thanks Cincinna for this link -- http://www.friendsofitamar.org)
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Earth’s water:

http://www.freerepublic.com/focus/bloggers/1607979/posts?page=98#98


31 posted on 05/29/2011 8:17:52 AM PDT by SunkenCiv (Thanks Cincinna for this link -- http://www.friendsofitamar.org)
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