Meet KOI 172.02: The most Earth-like planet found yet.

[Kyle]

SPACE.com: http://www.space.com/19201-most-earth-like-alien-planet.html

A possible alien planet discovered by NASA's Kepler space telescope is the most Earth-like world yet detected beyond our solar system, scientists say.

With a radius that is just 1.5 times that of Earth, the potential planet is a so-called "super-Earth," meaning it is just slightly larger than the Earth. The candidate planet orbits a star similar to the sun at a distance that falls within the "habitable zone" — the region where liquid water could exist on the planet's surface. Scientists say the planet, if confirmed, could be a prime candidate to host alien life.

 

[garyw]

Several sites are carrying this story but remember that 'KOI' stands for 'Kepler Object of Interest'. It's not confirmed as a planet and no one is able to say where 'KOI 172.02' actually is. I'd like to know what star it's orbiting.

 

[BruceJohnJennerLawso]

Several sites are carrying this story but remember that 'KOI' stands for 'Kepler Object of Interest'. It's not confirmed as a planet and no one is able to say where 'KOI 172.02' actually is. I'd like to know what star it's orbiting.

So it could just be a small star?

 

[Kyle]

So it could just be a small star?

It does not have the density nor the mass to be even a small gas giant, but garyw is right. This is unconfirmed at this time, but further astronomical observations or further analysis of data will reveal the truth. :thumbup:

 

[BruceJohnJennerLawso]

It does not have the density nor the mass to be even a small gas giant, but garyw is right. This is unconfirmed at this time, but further astronomical observations or further analysis of data will reveal the truth. :thumbup:

Well, if one eliminates all that it cannot be...

Funny how these "new earth" sightings generate such interest in the media, then die so quickly.

 

[garyw]

So it could just be a small star?

It's nothing aside from some interesting data that's being analysed. it'll be months before it's confirmed IF it's a planet. It's not a star though as it's obviously something that's orbiting a star as it was detected due to radial velocity.

Funny how these "new earth" sightings generate such interest in the media, then die so quickly.

They aren't real stories. They are kept for a slow news day and right now it's just some interesting data.

 

[T.Neo]

It is a planet candidate. In other words, it is a pattern detected by the Kepler telescope, that could be the transit signature of a planet- but whether it is actually a transit signature, and not something else, is yet to be confirmed.

Also, anyone heard of Venus? It's the most earthlike planet known to the human race, beside Earth. It's only slightly less massive than Earth.

What a wonderful world that is!

 

[RisingFury]

We'll have to wait a few years for confirmation. Keep in mind that Earth's orbit takes a year to complete. So if you find a dip in the light curve in a planet with a similar orbit, you'll have to wait another year or so to get the period and another year or so for confirmation. On top of that, other methods of planet finding - mainly radial velocity - can be employed for confirmation.

 

[garyw]

This candidate was detected due to light curve so Rising Fury makes some valid points and already there is some argument about the data!

The simplest form of the calculation is this: the amount of energy (F) the planet receives is proportional to the 4th power of the star's temperature (T), the 2nd power of the star's radius (Rs), and inversely proportional to the 2nd power of the orbiting distance (a). In equation form (normalizing everything to the Earth-Sun system):

F = (T^4)*(Rs^2)/(a^2)

According to the Kepler database, for KOI-172.02 the star's temperature of 1.008 times that of the Sun, but the star is dimmer than the Sun because it is only 0.9 times the Sun's radius. The planet has an orbiting distance 0.762 times that of the Earth. Putting all that together,

F(172.02) = (1.008^4)*(0.9^2)/(0.762^2) = 1.44

So KOI-172.02 gets about 44% more energy than the Earth gets. According to the papers on this (see Kasting et al., 1997 or Selsis et al., 2007), that's enough to cause the planet's water to get into the upper atmosphere, where it can get blown up by radiation and the H atoms then escape to space. It's also probably enough to also trigger a runaway greenhouse.

Now... the caveats I posted above still apply. This planet could be habitable if any of these measurements are "off" and their actual values move things towards lower energy. Or it could be that KOI-172.02 has enough cloud cover to block lots of the incoming radiation from the star. Or we could just be wrong on whether or not a Venus planet could support life. But all those involve us being "wrong" in some way. If KOI-172.02 has life, that means either the properties in the database are wrong, or our habitable zone boundaries are wrong, or our understanding of the limits of life are wrong.

The data on the candidate can be found here -> http://archive.stsci.edu/kepler/koi/search.php

 

[kamaz]

It's not confirmed as a planet and no one is able to say where 'KOI 172.02' actually is. I'd like to know what star it's orbiting.

Wiki article has the coordinates, if you want to point your telescope, or fly there or something...

http://en.wikipedia.org/wiki/KOI-172.02

 

[garyw]

Oh! I didn't know the 172 was actually a reference to the star! thanks for that Kamaz.

The distance is 1,040 light years so not a candidate for an interstellar probe of any sort.

 

[tblaxland]

This candidate was detected due to light curve so Rising Fury makes some valid points and already there is some argument about the data!

There are plenty of arguments for surface water on Venus, possibly less than 3.5 billion years ago, and its insolation is 90 % more than Earth's.

Plotting the planet on the figures provided by Heller, Barnes & Laconte plonks the planet right in the middle of the habitable zone for tidal stability too, ie, ensuring tidal conditions are favourable to maintain habitability for long enough to allow life to evolve.

 

[Unstung]

I'd like to know what star it's orbiting.

A quick Google search yields an article for the candidate planet on Wikipedia, including which specific star it orbits. Wikipedia mentions that the star is somewhat cooler than ours, which is favorable in terms of lifespan.

EDIT: Didn't notice the post with the same link above mine