Were is Earths twin planet located?

Question

earth is supposed to have a twin or planet like it. were?

Answer 1

The questioner isn't asking about a counter-earth 180 degress from us on the other side of the Sun at the L3 Lagrange Point (the existence of which is easily refuted as all the probes we have sent towards the Sun have not spotted any such object) which is indeed a popular place for SF writers to locate one.

What he has picked up is the story of 5 weeks ago whereby a new planet, Gliese 581c, thought capable of sustaining life, that is both a rocky terrestrial planet and not a lot larger than earth, was discovered orbiting a nearby star.

GLIESE 581c

The new planet where life is thought to be feasible orbits Gliese 581, one of the nearest 100 stars to us, 20.4 light years away.

The new planet was found on 23rd April 2007 by a team led by Stephane Udry of Geneva University, The observatory they used was high in the Chilean Andes, where good viewing conditions would be available.

It is in the constellation Libra. It is the 87th closest star system to us. Its star (a Red Dwarf) is too faint to be seen with the naked eye, however. Its magnitude is 11.56.

What is unusual about Gliese 581c, amongst the 241 planets we have found orbiting other stars is

a) it is a rocky terrestrial planet not a gas giant

b) it is in the habitable zone i.e. with a temperature range at which water would be a liquid not ice. This is felt to be essential if it is to harbour life.

c) it has a radius 1.5 times that of earth (and a mass 5 x earth), the smallest yet,

(d) It orbits very close to its star (as the star, a Red Dwarf, is much cooler than our Sun, the planet needs to be nearer in to be warm enough to be habitable) and its year is a mere 13 Earth days in length.

There are two other planets in the same stellar system, one even further in (Gliese 581 b) a Neptune-sized planet of 17 Earth masses found in 2005 and one further out (Gliese 581 d) a planet of 8 Earth masses found in 2007.

The big question marks are:

(a) it is big enough to retain an atmosphere but is it breathable by humans?

(b) does it actually have (a plentiful supply of) water?

(c) how would we get there? (our present fastest rockets available would take 300,000 years)

(d) is the planet gravitationally locked to ts star, such that the same side of it always faces the star?

Many of the questions people will inevitably ask can only be answered when we can send an unmanned probe there. Meanwhile other planets will be found even nearer to us. (We know of a planet 10.5 light years away around Epsilon Eridani (the 9th nearest star) and 3 around Gliese 876, 15 light years away.)

One promising aspect of Gliese 581 is that it is both younger than our Sun (4.3 billion years) and it will outlive the Sun as it burns its hydrogen fuel up more slowly, so any colony we might one day establish there would not have to up sticks and be on the move again for a long time.

However a propulsion method that would get colonists there in less than half a human lifetime would need to be developed first, before colonisation is practical. And the practical problems of transporting enough fuel, food, water and air, for a crew of ten or more would need to be solved too. No easy undertaking!

Wilhelm Gliese was a German astronomer, best known for the Gliese Catalogue of Nearby Stars that he compiled.

Answer 2

The movie was called "Journey to the Far Side of the Sun" (where this idea came from). There is no evidence to prove such a planet exists. We would see some gravitational effects from this hypothetical planet... though there are a number of gravitational anomalies in our solar system that we don't understand. If such a planet existed, we should have been able to see it during changes in orbital speed as it revolves closer or further away from the sun in it's elliptical orbit. For such a planet to exist, it would have to be exactly opposite earth and of the exact same mass and of the exact orbital position with a moon of the exact same size and orbital speed... Hardly likely. Nothing in nature is that exactly balanced. Here's a great article on the subject.

http://www.newton.dep.anl.gov/newton/askasci/1993/astron/AST043.HTM

Answer 3

I have never read anywhere (and I read a lot of astronomy and science articles) that Earth has a twin planet.
They used to think Venus was our twin, but they realized it wasn't several decades ago.
They found a planet about 20 light years away (around star Gliese 581) that is the smallest they have found outside our system so far (only 5 times the mass of Earth).
Other than that, you have been misinformed.

Answer 4

There are science fiction stories about a second Earth in orbit around the sun. Note the phrase "science fiction." Fiction means it's made up. But how do you know it's not on the other side of the sun? my witless friend once demanded. Because if it were there, it would have measurable gravitational effects. The Lagrange points would be located somewhere else. But the L-points are consistent with the observed bodies in the Solar Sytem, because there is no Gor or other pseudoplanet other than in the imaginations who think that science fiction does not need to be scientific.

Answer 5

In your imagination. The Earth has no twin planet.

There may be earth-like planets orbiting other stars, but we haven't found them yet. However, even if a planet has the same size, temperature, and composition as ours, it would undoubtedly be very different from our planet in a number of ways.

Answer 6

Sounds like a scifi movie I saw many years ago. The lead character (an astronaut) found a mirror Earth om the opposite side of the Sun. Other than the fact that everything was reversed, it was identical to the Earth we know

Answer 7

Venus used to be considered as Earth's twin sister.

Answer 8

Venus is concired to be the earth twin.

Answer 9

Where did you read that?? The only way we could have a twin planet, should be in another dimension...
If that's the case, then, you must find a black hole and prey that it brings you close to our planet twin...

Answer 10

No twin, but there's Venus whose size is almost the same and the largest moon of Saturn - Titan. But their distance from the sun is different. Our day is 23 hours something. The two of them are different.
Why Mr.Alien? Are you looking for somewhere to relocate.
GO TO MARS!!!