34 replies to this topic

[Waspie_Dwarf]

Earth-like Planets Are Right Next Door

Harvard-Smithsonian Center for Astrophysics said:

Cambridge, MA - Using publicly available data from NASA's Kepler space telescope, astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA) have found that six percent of red dwarf stars have habitable, Earth-sized planets. Since red dwarfs are the most common stars in our galaxy, the closest Earth-like planet could be just 13 light-years away.

"We thought we would have to search vast distances to find an Earth-like planet. Now we realize another Earth is probably in our own backyard, waiting to be spotted," said Harvard astronomer and lead author Courtney Dressing (CfA).

Dressing presented her findings today in a press conference at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.

Read more...

[the L]

So many theories yet we didnt find any earth like planet.

[Waspie_Dwarf]

the L, on 06 February 2013 - 05:39 PM, said:

So many theories yet we didnt find any earth like planet.

Yet!

The techniques used for finding planets favour large planets close to their star. This is why virtually all the initial finds were hot Jupiters. Smaller planets and those further from their stars take longer to locate. This is why after the Hot Jupiters came the Neptune size worlds and then the Super-Earths. As time goes on more smaller planets will be found.

[the L]

But how many planets did we discovered so far? And none of its earth like.

[Waspie_Dwarf]

the L, on 06 February 2013 - 06:03 PM, said:

But how many planets did we discovered so far? And none of its earth like.

Good grief, give the astronomers a chance. They hadn't found any until 1988. The total now rests at just over 860 out of an estimated 100 billion in our galaxy.

[Mikko-kun]

If you take into account all the stars which could have a planet satellite like earth bound to them.... 860 is still a small fraction.

[bison]

The idea that the nearest Earth-like planet is 13 light years away is based on a statistical argument. Since we are just on the edge of being able to detect Earth size planets, this estimate may be overly conservative. I find it interesting to learn that there are no fewer than 20 star systems with M (red dwarf) stars *less* than 13 light years distant from Earth. These range from Proxima Centauri and Barnard's Star at 4.24 and 5.96 light years, respectively, to the rather obscurer Lacaille 8760 at 12.87 light years. Wikipedia has an interesting list of all the nearest stars, out to 16 light years.

Edited by bison, 06 February 2013 - 08:48 PM.

[Waspie_Dwarf]

Mikko-kun, on 06 February 2013 - 08:08 PM, said:

If you take into account all the stars which could have a planet satellite like earth bound to them.... 860 is still a small fraction.

Exactly my point. Incidentally I've found more up to date figures which say there are now 909 confirmed exoplanets and a further 2740 candidates awaiting confirmation.

My figure of 100 billion was the lower estimate of the number in our Milky Way galaxy, with some estimates as high as 400 billion. If we take a "best case" scenario and assume the lowest number of planets in the galaxy and assume all candidates will be confirmed then we have found 3,649 planets out of a total of 100,000,000,000. That works out at 0.000003649% of the planets in the galaxy.

[psyche101]

Waspie_Dwarf, on 06 February 2013 - 06:20 PM, said:

Good grief, give the astronomers a chance. They hadn't found any until 1988. The total now rests at just over 860 out of an estimated 100 billion in our galaxy.

Hi Waspie

What about the claims of "Earth Like Planet Found"? Such as the recent KOI 172.02?

[Frank Merton]

Now let me see if I've got this straight.  Being dimmer and smaller than "normal" stars, the habitable zone as we define it by our peculiar needs is closer to the star and narrower.

Since red dwarfs last, as such, a good deal longer than regular stars last, as such, planets orbiting such a star could be as much as ten billion years old.  (I take it that limit is based on the ages of the oldest stars, since red giants would in fact last much, much longer).

Now my understanding is that red dwarfs are the end product of a normal star after it goes through the red giant phase, and said red giant phase would evaporate any nearby planets, including the earth.  I also understand that novas (not super-novas) are explosions on the surface of red dwarfs, and, when they occur, would also evaporate any nearby planets.

You can no doubt see where my thinking is leading.  Planets close in to the red giant should simply not exist.  Now, if Kepler and other searches finds them, the question arises, how is it that they do exist?  I can imagine two ways -- they are born immediately after the red giant phase, when no doubt a lot of gas and dust are around, or the planetary nebula phase puts enough material further out to cause in-migration of planets that were earlier further out.

If it weren't for the fact that red dwarfs sometimes go nova, that would be an exciting place to look for advanced societies.  I have a feeling that maybe only a few red dwarfs sometimes go nova.

[WoIverine]

I wonder if the advance of quantum computing will, or could somehow lead to a significant technological jump in regard to the tools used for astronomy. We could all use much better telescopes, especially if we end up stuck here on this rock for who knows how much longer.

[WelshRed]

I am going to go on record now and say that at some point in the future the nearest "habitable zone" "planet" outside of our solar system will be proven to be from our nearest neighbours system the Alpha Centauri triple star system (Alpha A, Alpha B & Proxima Centauri)

[MJNYC]

Isn't it a wonderful thing that here we are looking for life elsewhere in the universe.

But, why?

We can't get along with our own planet, so are we looking for others to argue and fight with or hopefully by the time we find life we will have evolved enough to accept them as equals no matter what.  

Maybe that's why we haven't found anything yet or why those that (perhaps) have been here have not contacted us.  

I'd say if that's the case, they are very very very smart.

[bison]

Frank Merton, on 07 February 2013 - 07:55 AM, said:

Now let me see if I've got this straight.  Being dimmer and smaller than "normal" stars, the habitable zone as we define it by our peculiar needs is closer to the star and narrower.

Since red dwarfs last, as such, a good deal longer than regular stars last, as such, planets orbiting such a star could be as much as ten billion years old.  (I take it that limit is based on the ages of the oldest stars, since red giants would in fact last much, much longer).

Now my understanding is that red dwarfs are the end product of a normal star after it goes through the red giant phase, and said red giant phase would evaporate any nearby planets, including the earth.  I also understand that novas (not super-novas) are explosions on the surface of red dwarfs, and, when they occur, would also evaporate any nearby planets.

You can no doubt see where my thinking is leading.  Planets close in to the red giant should simply not exist.  Now, if Kepler and other searches finds them, the question arises, how is it that they do exist?  I can imagine two ways -- they are born immediately after the red giant phase, when no doubt a lot of gas and dust are around, or the planetary nebula phase puts enough material further out to cause in-migration of planets that were earlier further out.

If it weren't for the fact that red dwarfs sometimes go nova, that would be an exciting place to look for advanced societies.  I have a feeling that maybe only a few red dwarfs sometimes go nova.

Red Dwarf stars are not the remnants of the terminal (Red Giant) phase of stars. They are stable, main sequence stars. It is perfectly conceivable that they should have planets. Because they are very long-lived, they could easily have planets twice the age of our Sun, and these could be the seat of very advanced forms of life. I wouldn't be surprised if the nearest of these, Proxima Centauri, only ~ 4 & 1/4 light years distant, turned out to have a planet of about Earth's size, and within that star's habitable zone. This would presumably be a tidally locked planet; one side always facing the star. There are possible mechanisms for diffusing the heat around such a planet, and so reducing the severity of heat at the sub-stellar point, and the cold  at the anti-stellar point. Even advanced life may be possible on such planets.

Edited by bison, 07 February 2013 - 07:26 PM.

[Andromedan Starseed 333]

that's awsome and great.more worlds to live and travel to:)but also guys we need to start with mother earth and the planet we have here already though.what i mean is that we need to take care of mother earth better and with respect first.because humans are destroying the planet with wars,polluting the earth with chemicals and etc.mother earth don't like that and will cleanse the planet and those who keep poisioning the planet and destroying but other than that thats a great discovery guys.