Smallest planet outside solar system found

[Ziggy Stardust]

http://www.reuters.com/article/scienceNews/idUSL0956988620080409

MADRID (Reuters) - The smallest planet discovered outside our solar system has been found by Spanish scientists.

(planet on the left)

"I think we are very close, just a few years away, from detecting a planet like Earth," team leader Ignasi Ribas told a news conference on Wednesday.

The rocky planet, with a radius about 50 percent greater than the Earth's, circles a small red dwarf star 30 light years away in the constellation of Leo, said the scientists from Spain's Superior Council for Scientific Investigations (CSIC).

The planet, known as GJ 436c, was found by analyzing distortions in the orbit of another, larger planet around the star GJ 436, a technique similar to that used more than 100 years ago to discover Neptune.

With a mass about five times greater than Earth's, it is the smallest planet yet discovered outside the solar system and improving techniques are opening the way to discovering worlds ever more like our own.

"In a very short time, we are going to be able to see a planet with the same mass as the Earth, although it's going to be in an orbit much closer to its star than that of the Earth around the sun, so it won't strictly be a planet like the Earth," said Ribas.

"Planets with a mass similar to Earth situated at a distance from their star which allows liquid water on the surface, in other words, a habitable planet, we're probably a bit further from (discovering those), but we surely will in a decade."

Most of the 280 planets discovered until now are gassy giants like Jupiter. Scientists are increasingly finding small rocky worlds as they realize that planetary systems are extremely common in stars around our galaxy.

GJ 436 is not much bigger than the Earth and it orbits close to its small, relatively cool star once every five Earth days.

Its rotation means 22 Earth days pass between each time the red dwarf star rises on its horizon -- so its days are four times as long as its years.

The find was announced in Astrophysical Journal Letters.

Still pretty big, and too close to the sun to be Earthlike, but the important aspect is that progress made in discovering planets. If we learn more about the make-up of the universe, we learn more about ourselves and our place in it.

 

[Miles Teg]

Remember when pretty much all we were discovering were those gas giants practically on the surface of their star?

 

[Fifty]

THIS BELONGS IN SCI AND TECH

Random question: Do the people who know about this stuff think that a potential sentient-life-carrying planet would have to both consist in an earth-like planet, AND a sun-like sun? Could life develop with a much bigger or smaller or different star, do they think?

 

[Ecofarm]

Who still thinks we are the only planet with life?

<ducks>

 

[LightFang]

It's not a planet, it's a dwarf planet.

 

[Ziggy Stardust]

THIS BELONGS IN SCI AND TECH

There is a sci and tech forum?

This place has got everything

(edit, totally slipped my attention, while I always use that page to get to the funny forum) Colour me moron. *checks out Sci/tech.* Thanks for the heads up.)

Random question: Do the people who know about this stuff think that a potential sentient-life-carrying planet would have to both consist in an earth-like planet, AND a sun-like sun? Could life develop with a much bigger or smaller or different star, do they think?

I don't know much about this stuff, but seeing as there's life in any condition on Earth, even in vulcanoes, several miles down in the seas, and even in nuclear reactors, I suspect it can.

 

[Tee Kay]

Random question: Do the people who know about this stuff think that a potential sentient-life-carrying planet would have to both consist in an earth-like planet, AND a sun-like sun? Could life develop with a much bigger or smaller or different star, do they think?

Well, life doesn't have to be "life as we know it" (eg, carbon based, water dependent). The possibilities are pretty much limitless.

 

[Kraznaya]

It's not a planet, it's a dwarf planet.

So what are we, a midget dwarf planet?

 

[Knight-Dragon]

Moderator Action: Moved to S/T.

 

[EquinoxOmega]

http://www.exoplanet.eu/star.php?st=GJ+436

This planet hasn't been independly confirmed yet, but even if the measurement is correct, it need not be the smallest known planet. The mass mentioned in the paper is only a minimum mass because of the measurement methode (radial velocity), so it also possible that the planet has a much larger mass(up to 5 times).

 

[Defiant47]

THIS BELONGS IN SCI AND TECH

There's a Sci and Tech forum?? Oh, man, I gotta check it out more often!

 

[lutzj]

So what are we, a midget dwarf planet?

Nah, we're a gnome planet.

 

[Chandrasekhar]

I don't know much about this stuff, but seeing as there's life in any condition on Earth, even in vulcanoes, several miles down in the seas, and even in nuclear reactors, I suspect it can.

Ah, but the question is whether abiogenesis can occur in such a setting. It seems like the conditions for that would be much more narrow. Once life is started, it may be able to adapt to many different environments, but that says little about where it can start.

 

[J-man]

I hope I live to see the day when an earth-like planet will be discovered. With earth like I mean:
Same Size
Same mass
Orbits at 1 AU from its star
Orbits an star that has the same size and age of our sun.

 

[Perfection]

THIS BELONGS IN SCI AND TECH

Random question: Do the people who know about this stuff think that a potential sentient-life-carrying planet would have to both consist in an earth-like planet, AND a sun-like sun? Could life develop with a much bigger or smaller or different star, do they think?

Well, there are problems with bigger and smaller stars. Bigger stars have shorter lifespans giving life less time to evolve, and put out more dangerous radiation which damage organic molecules.

Smaller stars have more variability in luminosity, which can cause extreme temperature swings and atmopheric loss. Confounding that is the fact that because radiation output increases and decreases more then proportionally to mass, planets in the habitable zone of stars experience more stellar gravity; this makes tidal locking (where one side of the planet always faces the star, just like one side of the moon always faces us) more likely. This exacerbates variability and temperature extremes on a planet.