Earth-sized planet found in habitable zone of red dwarf

[Motokid600]

Y'know... as soon as these discoveries are made. Why is it people constantly ask "How do we get there? When can we get there? WE MUST GO NOW NOW NOW." .. Is our own solar system really so boring? Im all for the scientific discoveries, but I don't have much .. if any interest in interstellar travel. SOL simply has too much going on.

[-Velocity-]

Y'know... as soon as these discoveries are made. Why is it people constantly ask "How do we get there? When can we get there? WE MUST GO NOW NOW NOW." .. Is our own solar system really so boring? Im all for the scientific discoveries, but I don't have much .. if any interest in interstellar travel. SOL simply has too much going on.

We don't need to go there, not yet; it's still much cheaper, and we can still learn vast amounts, just by building a telescope that can spectroscopically analyze it.

But... imagine, if you will, that we find a planet that has the undeniable spectroscopic fingerprints of life. Imagine how people would be aching to go there and explore it. And maybe we will never be able to I think we'd be dying for E.T. on that planet to "answer the phone" and tell us more about their world.

Edited April 18, 2014 by |Velocity|

[Brotoro]

Nevermind. I guess I'm not sure what you are saying.

Edited April 18, 2014 by Brotoro

[-Velocity-]

Nevermind. I guess I'm not sure what you are saying.

What I'm saying? About the last sentences? All I mean is, I think a lot of people would be incredibly curious about life on the distant planet, and I *jokingly* implied it would be incredibly convenient if there was an intelligent life form there would could just radio our questions to

[KASASpace]

This star is a Red Dwarf, and thus is not exactly a perfect star for life, let alone water. I would look at Tau Ceti a bit more, it has the possibility of five planets, unconfirmed, but it is the same spectrum class as Sol, and is half as luminous. But it is a low metallicity star, so, it probably has no planets......

Anyone know it's spectrum class?

Or do red dwarves have a general spectral range (in class of spectrum)

[-Velocity-]

This star is a Red Dwarf, and thus is not exactly a perfect star for life, let alone water. I would look at Tau Ceti a bit more, it has the possibility of five planets, unconfirmed, but it is the same spectrum class as Sol, and is half as luminous. But it is a low metallicity star, so, it probably has no planets......

Anyone know it's spectrum class?

Or do red dwarves have a general spectral range (in class of spectrum)

M spectral class. I don't know if any K stars are considered "red dwarfs" or not- I don't think so, I IIRC I remember hearing main sequence K type stars most often referred to as "orange dwarfs".

[Rakaydos]

This star is a Red Dwarf, and thus is not exactly a perfect star for life, let alone water. I would look at Tau Ceti a bit more, it has the possibility of five planets, unconfirmed, but it is the same spectrum class as Sol, and is half as luminous. But it is a low metallicity star, so, it probably has no planets......

Anyone know it's spectrum class?

Or do red dwarves have a general spectral range (in class of spectrum)

We are looking at Red Dwarfs because they're the easiest to detect small worlds in habitable zones.

Low thermal output means the habitable zone is closer in. Low mass star means the mass ratio of star to planet is higher. And two close objects with a (relatively) close mass ratio is easier to detect by wobble.

[KerikBalm]

So apparently the total insolation is only 1/3 that of Earth?.

Yea, I know, mars gets what, 25%? and it may have transient water, at least some areas get above freezing (although atmosphere-less bodies can get reasonably warm in the day, but very very cold at night)

The problem is that small starts mainly have an IR output, and a thick enough atmosphere to trap it would mean that very little direct insolation will reach the ground.

Not much photosynthesis potential.

[Tommygun]

Well I guess it will all come down to the atmospheric make up.

Venus is smaller than Earth but has a thicker atmosphere, but also reflects a lot of the heat because of all the sulfuric acid in the upper layers.

Venus's reflective albedo is 70% compared to earth 30%. It should be cooler even though it is closer to the Sun and only gets really hot because of all that carbon dioxide.

So basically I'm thinking it could almost be any temperature within reason, but we may never know in our life time.

It will probably take decades to design, build and launch the telescopes to find out.

[Klingon Admiral]

Given we have always done spectographic analyses of hot jupiters (namely HD 189733 , I doubt it would take decades. Maybe not doable with the current generation of telescopes, but as we have such a planet now, I would make sense to give the next generations of telescopes means to give us a better picture about the planets we find.

I still foretell that the planet is covered in ice.

[-Velocity-]

Well I guess it will all come down to the atmospheric make up.

Venus is smaller than Earth but has a thicker atmosphere, but also reflects a lot of the heat because of all the sulfuric acid in the upper layers.

Venus's reflective albedo is 70% compared to earth 30%. It should be cooler even though it is closer to the Sun and only gets really hot because of all that carbon dioxide.

So basically I'm thinking it could almost be any temperature within reason, but we may never know in our life time.

It will probably take decades to design, build and launch the telescopes to find out.

I'm fine with not finding out in our life time with this planet, as this is just the tip of the iceberg. There are sure to be a lot more like this one, much closer, and more promising for life, too. Those are the ones we can target in the relatively near future.

Edit- I'm not talking about Kepler results, I'm talking about planets we'll find and spectroscopically analyze with direct imaging. We really need to get a star shade up there for the JWST.

Edited April 20, 2014 by |Velocity|

[NERVAfan]

Incorrect for both planets-

1) Mars is not Earth-sized, it is much smaller than Earth.

2) Venus IS effectively Earth-sized, but it is not inside the habitable zone- it is too close to the Sun. Earth is, in fact, near the the inner edge of the habitable zone, or so they say.

Yeah, that's what I've heard, too.

Though I've also seen it said that Venus's temperature with an Earth-level greenhouse effect would be hot but livable, so...

Personally though, I wonder if Venus might always have had too thick of an atmosphere.

I've heard that Earth had a much more greenhouse-y atmosphere, with much higher pressure (maybe not as much as Venus today though) early on since it had non-frozen oceans quite early when the Sun was much dimmer (the "faint young Sun paradox"). But Earth's oceans and plate tectonics etc. locked up the CO2 in carbonate rocks. I've also seen odd things like high methane levels mentioned (a book called "How to Build a Habitable Planet").

EDIT: apparently there's debate about how MUCH more CO2 though... apparently one study said <0.7 bar, when other people talk about 10+ bar...

Edited April 20, 2014 by NERVAfan

[NERVAfan]

I'm more than a bit skeptical of the "no magnetosphere = solar wind rips off the atmosphere" bit; as |Velocity| said above, Venus has no magnetic field and way more atmosphere than Earth. I have no problem with the solar wind removing Mars' atmosphere; but if that is what happened to Mars, that doesn't necessarily mean it would do it to an Earth/Venus sized planet with much stronger gravity.

[Brotoro]

Plate tectonics does not help lock up carbon dioxide... it actually returns CO2 to the atmosphere by melting rocks that are subducted and spews the CO2 out of volcanoes.

[KerikBalm]

I'm more than a bit skeptical of the "no magnetosphere = solar wind rips off the atmosphere" bit; as |Velocity| said above, Venus has no magnetic field and way more atmosphere than Earth. I have no problem with the solar wind removing Mars' atmosphere; but if that is what happened to Mars, that doesn't necessarily mean it would do it to an Earth/Venus sized planet with much stronger gravity.

Venus' atmosphere is deficient in hydrogen:

http://en.wikipedia.org/wiki/Atmospheric_escape#Thermal_escape_mechanisms

The more massive the molecule of a gas is, the lower the average velocity of molecules of that gas at a given temperature, and the less likely it is that any of them reach escape velocity.

This is why hydrogen escapes from an atmosphere more easily than does carbon dioxide. Also, if the planet has a higher mass, the escape velocity is greater, and fewer particles will escape. This is why the gas giant planets still retain significant amounts of hydrogen and helium, which have largely escaped from Earth's atmosphere.

I doubt its coincidence that Venus' atmosphere is mostly CO2, and there is pretty much no hydrogen or H20 vapor.

http://en.wikipedia.org/wiki/Atmospheric_escape#Significance_of_solar_winds

A common erroneous belief is that the primary non-thermal escape mechanism is atmospheric stripping by a solar wind in the absence of a magnetosphere. Excess kinetic energy from solar winds can impart sufficient energy to the atmospheric particles to allow them to reach escape velocity, causing atmospheric escape. The solar wind, composed of ions, is deflected by magnetic fields because the charged particles within the wind flow along magnetic field lines. The presence of a magnetic field thus deflects solar winds, preventing the loss of atmosphere. On Earth, for instance, the interaction between the solar wind and earth's magnetic field deflects the solar wind about the planet, with near total deflection at a distance of 10 Earth radii.[2] This region of deflection is called a bow shock.

Depending on planet size and atmospheric composition, however, a lack of magnetic field does not determine the fate of a planet's atmosphere. Venus, for instance, has no powerful magnetic field. Its close proximity to the Sun also increases the speed and number of particles, and would presumably cause the atmosphere to be stripped almost entirely, much like that of Mars. Despite this, the atmosphere of Venus is two orders of magnitudes denser than Earth's.[3] Recent models indicate that stripping by solar wind accounts for less than 1/3 of total non-thermal loss processes.

photoionizing radiation (sunlight) and the interaction of the solar wind with the atmosphere of the planets causes ionization of the uppermost part of the atmosphere. This ionized region, in turn induces magnetic moments that deflect solar winds much like a magnetic field. This limits solar-wind effects to the uppermost altitudes of atmosphere, roughly 1.2–1.5 planetary radii away from the planet, or an order of magnitude closer to the surface than Earth's magnetic field creates. Beyond this region, called a bow shock, the solar wind is slowed to subsonic velocities.[2] Nearer to the surface, solar-wind dynamic pressure achieves a balance with the pressure from the ionosphere, in a region called the ionopause. This interaction typically prevents solar wind stripping from being the dominant loss process of the atmosphere.

Basically, its mainly size, temperature, and the molecular weight of the gas molecules that determine if you keep an atmosphere.

Also it should be kept in mind that high energy light can cause some molecules to decompose.

Venus, due to its temperature and isolation, has lost its lighter gas molecules.

Titan, despite its low mass, is able to hold on to an atmosphere because N2 is relatively heavy, and its very cold due to lack of sunlight.

The water vapor of venus would have escaped long ago.

N2 molecular weight: 28

H20 molecular weight: 18

CO2 molecular weight: 44

H2 molecular weight: 2

As you can see... it doesn't look good for water once the temperature/solar wind gets too high.

And if hydrolys is occuring, releasing free hydrogen, it happens even faster.

Some estimates indicate that nearly all carbon on Earth is contained in sedimentary rocks, with the atmospheric portion being approximately 1/250,000 of Earth's CO2 reservoir.[citation needed] If both of the reservoirs were released to the atmosphere, Earth's atmosphere would be even denser than Venus's atmosphere. Therefore, the dominant “loss†mechanism of Earth's atmosphere is not escape to space, but sequestration.

http://en.wikipedia.org/wiki/Venus#Magnetic_field_and_core

The weak magnetosphere around Venus means that the solar wind is interacting directly with its outer atmosphere. Here, ions of hydrogen and oxygen are being created by the dissociation of neutral molecules from ultraviolet radiation. The solar wind then supplies energy that gives some of these ions sufficient velocity to escape Venus's gravity field. This erosion process results in a steady loss of low-mass hydrogen, helium, and oxygen ions, whereas higher-mass molecules, such as carbon dioxide, are more likely to be retained. Atmospheric erosion by the solar wind probably led to the loss of most of Venus's water during the first billion years after it formed. The erosion has increased the ratio of higher-mass deuterium to lower-mass hydrogen in the upper atmosphere by 150 times compared to the ratio in the lower atmosphere.

Its also worth noting that water vapor is a more potent greenhouse gas, so thermal escape alone would have been higher when Venus still had water vapor.

http://en.wikipedia.org/wiki/Venus#Atmosphere_and_climate

Studies have suggested that billions of years ago, the Venusian atmosphere was much more like Earth's than it is now, and that there may have been substantial quantities of liquid water on the surface, but, after a period of 600 million to several billion years,[44] a runaway greenhouse effect was caused by the evaporation of that original water, which generated a critical level of greenhouse gases in its atmosphere.

(I don't know where they get "several billion years" from, the planet is likely not much older than 4 billion years old.

[nhnifong]

In the next 20 years we are likely to discover hundred or thousands more earth sized planets in habitable zones, and we will be able to determine their atmospheric composition as well with the JWST. I think we should start blasting a greeting and request for correspondence to every single one of them at full power around the clock.

[Tommygun]

We basically are with all the radio signals and military radar.

I know there are theories about attenuation, but some kind of odd looking "static" must get through, especially to all the relatively close ones that may matter.

I'm referring to the ones that are close enough to study in a meaningful way.

[NERVAfan]

Venus' atmosphere is deficient in hydrogen:

http://en.wikipedia.org/wiki/Atmospheric_escape#Thermal_escape_mechanisms

I doubt its coincidence that Venus' atmosphere is mostly CO2, and there is pretty much no hydrogen or H20 vapor.

Right, I get that, but the planet still has a significant atmosphere. It's not a wisp like Mars.

[Rakaydos]

We basically are with all the radio signals and military radar.

I know there are theories about attenuation, but some kind of odd looking "static" must get through, especially to all the relatively close ones that may matter.

I'm referring to the ones that are close enough to study in a meaningful way.

It gets jammed by solar output, without VERY sensitive intriments. Take a flashlight down to the ballpark, and go stand near the floodlights, and see how well it can be seen.

Mars is smaller, so it has a hard time holding heavier elements, like oxygen, against the solar wind. Venus is only a little smaller than earth, but has more solar wind to deal with- It's problem is having too MUCH heavier elements, like carbon and sulfur.

Edited April 21, 2014 by Rakaydos