Rumor has it, that astronomers have discovered a planet outside our solar system that is very similar to earth. Has anyone else heard about this? Or is it old news?

http://en.wikipedia.org/wiki/OGLE-2005-BLG-390Lb
http://planet.iap.fr/OB05390.news.html

so basically its a hybrid of Titan and Encelados with a mass 5 g's of Earth.

The mass is 5gs, but gravity is theorized to be only 1.6 that of Earth's. Me weighing 170 here on Earth would be like weighing 250 on that planet.
Whoever thinks Earth is the only planet in the universe, or even the galaxy for that matter, that has life on it, is stupid.

The mass is 5gs, but gravity is theorized to be only 1.6 that of Earth's. Me weighing 170 here on Earth would be like weighing 250 on that planet.
Whoever thinks Earth is the only planet in the universe, or even the galaxy for that matter, that has life on it, is stupid.

noone is stupid for believing that which is in their soul.

Blind illusion of only home and Earth amongst vast cold cosmos as the harbor of this eternally warming peaciful home, warms the heart and begs for no other thought of any other Earth.

It is an interesting development though since it does orbit a red dwarf.

Did you see that Steven Hawkings is going for a zero g ride?

Blind illusion of only home and Earth amongst vast cold cosmos as the harbor of this eternally warming peaciful home, warms the heart and begs for no other thought of any other Earth.
No it isnt! How can you be so rude!

It is an interesting development though since it does orbit a red dwarf.

Did you see that Steven Hawkings is going for a zero g ride?

I never saw myself. As for Steven Hawking, I am happy he gets to experience the luxury of vomit comet

noone is stupid for believing that which is in their soul.

Blind illusion of only home and Earth amongst vast cold cosmos as the harbor of this eternally warming peaciful home, warms the heart and begs for no other thought of any other Earth.

Thanks for the philosophy lesson for today, Confucius.

And one can most certainly believe what is in their soul if they want; that doesn't absolve them from being stupid.

Thanks for the philosophy lesson for today, Confucius.

And one can most certainly believe what is in their soul if they want; that doesn't absolve them from being stupid.

love is blind, but not stupid.

What you call stupid is just them holding to the concrete understanding of their world, one God, one Earth, one home. When solid believes are challenged it is only natural to defend your stance so not to loose ground.

Yes there are worlds beyond with life and intelligent species. Is that planet amongst them? It bothers me that the planet does not rotate like Earth does...one side of it always faces the sun and the other the darkness of Cosmos everlasting. Could this really harbor life?

Yes there are worlds beyond with life and intelligent species. Is that planet amongst them? It bothers me that the planet does not rotate like Earth does...one side of it always faces the sun and the other the darkness of Cosmos everlasting. Could this really harbor life?
It could very well harbor life, but does that mean it actually does, no.
Even Mars, which is also believed to contain water, could contain life. Life does not necessarily mean intelligent life. Single-celled organisms are also considered life.
I say it could contain life because, take a look at our own planet. Look at the diversity of life here; how many different species living and thriving in so many different climates and terrain. Even if one side of the planet always faced its star, life could very well adapt and exist.

I am will go claim it before anyone does..Its Mine!

The planet which has recently been discovered is this one;
http://en.wikipedia.org/wiki/Gliese_581
it's only 20 light years away, and may be a hot-water-world.

More
http://www.space.com/php/video/player.php?video_id=070424_HabitableZone
and a different thread on this forum
http://www.sciforums.com/showthread.php?t=65818

The construct of my psyche shifted 60 degrees at the thought that we have found an HZ planet. The time of xenosociobiology has come.
:)

I wonder if it gets hit with an asteroid if it will start spinning.:rolleyes:

I am will go claim it before anyone does..Its Mine!Do not get too excited about your new property. From what I read the gravity is at least five times Earth's (humans could not live there.) If the line from Earth to that star is not in the the orbit plane, but highly inclined to it, then the mass and gravity are much greater. - I.e. the componet of the red/blue shift with its period is much greater, and vanishes entirely from Earth's POV if this line is at 90 degrees to the orbit plane. Just guessing, but I bet the gravity there is 10G or more.

it's between 2-3G depending on the planets parameters (how heavy is it exactly/how big is it exactly)

well all i can say this is the end for the human race only joking or am i?

well all i can say this is the end for the human race only joking or am i?
Well ours or theirs

hmm i see your point becuase man tends to atck what is unkown

The "pancake -flat" creatures living there, if any, are not much threat to humans and we can't live there*, so we are not much threat to them.
----------------------------------
*See post 16 for why.

ah well we will be we will be!

Excuse my, guys, but I think your G info is incorrect. I read in the newspaper (it's not from Wikipedia!) and it said 1.4-1.6gs. Since there is life at the bottom of our seas withstanding pressure that is much higher than 1.4-1.6gs. And those creatures in the Marianas Trench aren't pancakes right now.

Excuse my, guys, but I think your G info is incorrect. I read in the newspaper (it's not from Wikipedia!) and it said 1.4-1.6gs. Since there is life at the bottom of our seas withstanding pressure that is much higher than 1.4-1.6gs. And those creatures in the Marianas Trench aren't pancakes right now.

lol...

Maybe the intelligent species have got like tons of muscles there.

Do not get too excited about your new property. From what I read the gravity is at least five times Earth's (humans could not live there.)

It has 5X mass, but the surface gravity is estimated to be around 1.4-1.6 Earth gravities. You would probably just end up super-fit :D

withstanding pressure that is much higher than 1.4-1.6gs.
I've never heard that expression for ocean pressure ips megatons or longtons. Anyway 1.4-1.6 G would make it a pretty low dense planet, however if the planet is tidally locked then it might be possible that it's core has cooled down and has expanded together with the rest of the planet, this would make a totally new sort of planet with a relative low surface gravity but it isn't lickly

It has 5X mass, but the surface gravity is estimated to be around 1.4-1.6 Earth gravities. You would probably just end up super-fit
super retarded would be more lickly
http://www.umassmed.edu/shriver/Research/Biomedical/Projects/gravity.aspx

It has 5X mass, but the surface gravity is estimated to be around 1.4-1.6 Earth gravities....Thanks for the correction. My source was my local paper's science section - they often make confusions like this on science information, when translating something they have stolen some from another source.

A simple calculation shows that the free fall accelerations on the day and night sides of the planet would differ by 0.68m/sec^2 because of the high orbital velocity. For earth, this difference is 0.01m/sec^2.

oh so we start a colony there and wage war on finland and be carful of germany they been wuit for to long!

A simple calculation shows that the free fall accelerations on the day and night sides of the planet would differ by 0.68m/sec^2 because of the high orbital velocity. For earth, this difference is 0.01m/sec^2.

How did you arrive at this conclusion? The total centripetal acceleration of the Earth in its orbit around the Sun is only in the range of .006 m/sec^2, so how can the difference across its diameter be more?

Besides, while there would be a slight difference in free fall accelerations across the globe due to tidal effects, it wouldn't be between the day side and night side but between these two sides and the twilight regions.

Does anyone know the volume to surface area of a sphere formula? How much more surface area does this thing have than earth?

There are two very different models for the composition of this world; if it formed in the dry, inner part of the red dwarf's stellar nebula (more or less where it is now) then it would be mostly rock; if it had as much as 65% iron core it would have a diameter 1.5 times Earths and a gravity of 2.2 gees.

If it formed outside the snow line, where ice could form, then migrated inwards, it could be as much as 80% water, and would have a diameter twice that of Earth and a gravity of only 1.2 gees.

There is no way of choosing between these two options at the moment as far as I know.

There are two very different models for the composition of this world; if it formed in the dry, inner part of the red dwarf's stellar nebula (more or less where it is now) then it would be mostly rock; if it had as much as 65% iron core it would have a diameter 1.5 times Earths and a gravity of 2.2 gees.

If it formed outside the snow line, where ice could form, then migrated inwards, it could be as much as 80% water, and would have a diameter twice that of Earth and a gravity of only 1.2 gees.

There is no way of choosing between these two options at the moment as far as I know.
Imagine if the place as a civilization, the locals are like "the world is the light and dark, were in darkness is nothingness (the dark side of the planet)" The world is flat.

How did you arrive at this conclusion? The total centripetal acceleration of the Earth in its orbit around the Sun is only in the range of .006 m/sec^2, so how can the difference across its diameter be more?

Besides, while there would be a slight difference in free fall accelerations across the globe due to tidal effects, it wouldn't be between the day side and night side but between these two sides and the twilight regions.

The thing is that while this centripetal acceleration contributes to the planet's gravity on the day side, it reduces freefall acceleration on the night side. So difference is twise the centripedial acceleration.

The thing is that while this centripetal acceleration contributes to the planet's gravity on the day side, it reduces freefall acceleration on the night side. So difference is twise the centripedial acceleration.

Since when has the Earth's night side been twice as far away from the Sun as the day side?

My bad that I could not explain well. Suppose you are standing on the day side of the Earth. Then since you have to go around the Sun together with the Earth, the ground you are standing on should push your feet upwards to give you the centripetal acceleration right? Thus the net force applied from the ground to your feet would be bigger than the force your feet would get if the Earth was an inertial system. Now suppose you are on the night side. Then you cannot get the centripetal force from ground but from the Earth's gravity. The Earth has to pull you in order that you go with it around the Sun. So you will experience weaker force from the ground than it would be if the Earth was moving straight.

ps: In order to reduce gravitational force twice, you have to go appr. 1.4 times as far away but not twice.

Does anyone know the volume to surface area of a sphere formula? How much more surface area does this thing have than earth?

(4)(pi)(r^2)= (4)(pi)((6,356,750)^2) = 5.07785304 × 10^14 m^2

r earth = 6,356,750 m
mass earth = 5.9736×10^24 kg
mean density of earth = 5,515.3 kg/m³

------

r # = unknown
(4)(pi)(r^2)= Surface Area =
mass # = 5.5 x (Earth mass) = 5.5 * 5.9736×10^24 kg = 3.28548 × 10^25 kg
if we assumed that this planet's density is similar to that of Earth than...
lets say mean density = 5,515.3 kg/m³
M/V=density= (3.28548 × 10^25 kg)/(5,515.3 kg/m³)= (5.95702863 × 10^21 m³)=Volume of Planet #

Since we now know the Volume, the Volume equation is: (4/3)(pi)(r^3)=V

(((5.95702863 × 10^21 m³)/((4/3)(pi)))^(1/3))=radius of planet # = 11,245,541.2 meters

(4)(pi)(r^2)= Surface Area = (4)(pi)((11,245,541.2 m)^2) = 1.58917083*10^15 m^2


1.58917083*10^15 m^2/5.07785304 × 10^14 m^2 = Surface area of planet # is 3.1 times larger than that of Earth assuming it has the same mean density as that of Earth

---

However taking into account the fact that Gliese 581 c density as reported by wiki (http://en.wikipedia.org/wiki/Gliese_581_c) is: 8191.45 kg/m3

M/V=density= (3.28548 × 10^25 kg)/(8191.45 kg/m³)= (4.01086499 × 10^21 m³)=Volume of Planet #

Since we now know the Volume, the Volume equation is: (4/3)(pi)(r^3)=V

(((4.01086499 × 10^21 m³)/((4/3)(pi)))^(1/3))=radius of planet # = 9,856,358.2 meters

(4)(pi)(r^2)= Surface Area = (4)(pi)((9,856,358.2 m)^2) = 1.22079522 × 10^15 m^2


1.22079522*10^15 m^2/5.07785304 × 10^14 m^2 = Surface area of planet # is 2.4 times larger than that of Earth assuming it has the same mean density as that of Earth

My bad that I could not explain well. Suppose you are standing on the day side of the Earth. Then since you have to go around the Sun together with the Earth, the ground you are standing on should push your feet upwards to give you the centripetal acceleration right? Thus the net force applied from the ground to your feet would be bigger than the force your feet would get if the Earth was an inertial system. Now suppose you are on the night side. Then you cannot get the centripetal force from ground but from the Earth's gravity. The Earth has to pull you in order that you go with it around the Sun. So you will experience weaker force from the ground than it would be if the Earth was moving straight.



Here's the problem: you are treating the Earth like a rock spinning around in a circle on the end of a string, with the string supplying the centripetal force for the rock. In this case, then you would be right.
But this is not the case with the Earth orbiting the Sun. In this case, the centripetal force is provided by the Sun's gravity, and the Sun's gravity acts on everything, not just the Earth itself. So when you say that the ground pushing up on your feet gives you the Centripetal acceleration, this is not correct; the Sun's gravity is giving you the acceleration.

To see the true situation. let's start with the Earth in a circular orbit. In this situation, at the center of the Earth the the pull of the Sun's gravity is exactly equal to the the centripetal force needed to cause a circular path.

Now move to the night side at midnight. Your angular velocity is the same, but the radius of your circular path is larger so the centripetal force needed to hold you in a circular path is greater (centripetal force equals angular velocity times the radius). But you are also further from the Sun and the effect of its gravity on you is less, so the Earth has to make up the difference, so yes, you will be slightly lighter.

Now, the dayside: Your radius is smaller so the centripetal force needed is less. But you are also closer to the Sun, so its gravity acts on you more. Thus you want to fall in towards the Sun, and if it wasn't for the Earth's gravity, you would. Again, you would be slightly lighter,Not Heavier.

How much lighter? Somewhere in the order of 0.0000005 m/sec as this is the difference in the Sun's gravity over the radius of the Earth.

... Thus you want to fall in towards the Sun, and if it wasn't for the Earth's gravity, you would. ...Janus58 knows better than I that is is not exactly correct. He is just trying to make it simple enough for you to understand. Actually if at solar noon Earth's gravity were magically switched off, you would orbit the sun in a nearly perfect circle, not fall towards it. Janus58 know all this so well he can probably tell you in which month this should happen to make your new orbit about the sun more nearly circular than it currently is.

It is a minor point, but it is very hard to fall into the sun. - It is easier to escape the solar system entirely! (In sense would take less rocket fuel.) This fact is little known - You sometimes hear someone suggesting, in ignorance, that we should send the high level nuclear waste into the sun - deep space would be cheaper.

Thank you guys Janus58 and Billy T! If it was not for you, I would still be in the dark without knowing my mistakes.

Now here's something interesting. The planet apparently has an eccentricity of 0.16 (+/-0.07)

Now assuming the median value, this means there could be a 38% difference between periastron and apoastron of the planet.

So even if the planet is tidally locked, it could have "seasons". This much variation of orbit would result in almost a 100% difference in light intensity striking the planet over the course of its orbit.

Also, there would be a libration. So the red dwarf would not stay in the same spot in the sky, but would wander back and forth over a few degrees. So there would be areas in the twilight regions where it would actually rise and set. (It would dip below thew horizon, and then rise back up at the same spot.)

In addition, you would have a variation of tides (assuming we have oceans). The tidal force would vary by about 2.6 times over the course of an orbit. Considering that the tidal force at average orbital distance would be over 150 times that on the Earth( as compared to lunar tides), this could result some large tides.

So tidally locked in an averaged sense?

Supposing there are intelligent beings, since "year" is just 13 days, this "year" may constitute the basic time unit for them. And if the planet has moons, or if the other planets are visible periodic motions of those also could give some reference times.

I have knowledge of this place, 581c. most likely we should send a radio signal on all known frequencies, though it would take 20.5 years to get there. If they responded (intelligent life) it would be the biggest discovery ever made by science. The evidence that life DOES exist else where.

I have knowledge of this place, 581c. most likely we should send a radio signal on all known frequencies

we already do that, perhaps we chould look in low freq bands if they aren't already responding to alll our old data that we've been sending in the last 40 years.

So tidally locked in an averaged sense?

Supposing there are intelligent beings, since "year" is just 13 days, this "year" may constitute the basic time unit for them. And if the planet has moons, or if the other planets are visible periodic motions of those also could give some reference times.

The other planets are very visible; the innermost planet shows an easily visible disc in the sky of Gl 581 c. It is usually quite close to the star, though; if it transits it would make a very impressive sight.
This image is by Chris Laurel;
http://www.shatters.net/~claurel/celestia/images/gliese581-transit2.jpg