I predict that nearly all .7 radius planets have nice atmospheres

[ScienceRocks]

I predict that nearly all .7 radius or .5 mass planets In the habitable zone of there star has atmospheres and probably liquid water.

Lets look at the facts within our own solar system: Water is everywhere...Look at the outer moons of our solar system and you will find subsurface-oceans having in some cases 2-3 times the water of earth! But that''s partly because they're so far out and away from the solar winds....Mercury, our moon and mars has some water but not as much as they're small bodies and have been stripped of their liquids by the solar winds. There low gravity allows the solar winds to peal off any atmosphere.

Mars has .1 or 10% of earths mass....Wasn't able to hold onto its atmosphere but on the opposite side of things Venus has ~.815 of our mass and has a atmosphere with about 90 times the surface pressure and would utterly destroy any mission to its surface! Venus is closer to our star too.

For such planets as the earth, Venus and upwards it would take a black hole or a quasar to take away that atmosphere within my opinion. I don't think solar winds from a m-class star could do it.

Lets look at a few of our habitable extrasolar planets.
1. Proxima Cen b Radius 1.3 and a mass around 1 earth...
2. GJ 667 C c 3.8 mass and 1.4 radius. I laugh at the idea that this doesn't have a atmosphere!
3. Kepler-442 b 1.4 radius and 2.3 masses
4. GJ 3323 b 1.3 radius and 2 masses
5. Kepler-62 e 1.6 radius and 4.5 masses
6. Kepler-452 b 1.6 radius and 4.7 masses

http://exoplanetarchive.ipac.caltec...ew?objname=Kepler-452 b&type=CONFIRMED_PLANET
All the planets above are in the habitable zone and are bigger then earth on both fronts...I find it utterly impossible that any of these could be a airless rock like our moon...Lets misspell that crock right now and feel good about saying, YES they have atmosphere...No it isn't impossible that a black hole or quasar fucked them over but the odds are way against such.

I feel good about this as it is physics and observations of our own planetary system that tells me how much "force" would be needed and it is not going to happen. Some of these larger planets then earth I am more scared that their atmospheres maybe filled with lighter gases such as hydrogen or helium.

 

[ScienceRocks]

What will a earth radius(.95 to 1.05) planet be like? This is for planets that rotate so most likely K, G, F star planets!
For a idea what is more likely as you grow radius or shrink it---->
*Larger planets will be more likely to have more water so such planets could be habitable closer to their star. The Gliese 667cc's and Kepler 62e's, Kepler 452b's are likely very much covered by water. Maybe a few islands sticking out of the massive ocean.
*Smaller planets have less water....

Lets say earth size .95 to 1.05 and use our solar system as the example...

Venus receives about twice the solar flex of earth at .72 Au's but you also have to consider scale of the atmosphere and other processes....But in Venuses case it is extremely likely that such a planet will be inhabitable at this size range.

Planets from earths 1 Au inward to Venuses orbit will become hotter...Such a planet at .88 to .95 Au would be utterly tropical in nature, huge mega canes and likely a means temperature closer to 40 or 50 million years ago.

Planets at earth size(percentage of surface water holding ability) inwards of .88 Au would become mostly inhabitable with probably only small salt like pools of water spotting the cooler parts of the polar regions being likely near the .85-.88 AU range. As you move to .8 to .85 Au's the solar flex has made such planets waterless and it is likely the co2 cycle is becoming out of control!

This same planet as you move inwards I believe that it's evolves into a venus like world. That is why so many scientist believe a planet with a high solar flex is likely to have a very thick atmosphere with a out of control green house effect.

What happens if we move outwards?

Lets say 1.1 Au to 2 Au---The planet will get colder is the simple answer...On the otherhand our planets gravity's ability to hold onto 100% of the water isn't perfect so such a planet could have slightly more water as you move outwards. Oceans moderate things! At least for a short time as we travel outwards.

Such planet at 1.2 AU probably had a colder history possibly having a majority of its history with polar ice caps unlike earth! Maybe even millions or even tens of millions of years being in a state that can only be described as earth ball earth...

This gets worse as you move outwards until such a world either has to have much more green house gas then earth or be one big hunk of ice. Of course, I am also assuming that our earth in Au's, atmosphere and that includes green houses are the example.

A planet with 10 times our co2 will probably be habitable far further out.

 

[ScienceRocks]

Atmosphere found around Earth-like planet GJ 1132b
By Rebecca Morelle Science Correspondent, BBC News

• 3 hours ago

Scientists say they have detected an atmosphere around an Earth-like planet for the first time.

They have studied a world known as GJ 1132b, which is 1.4-times the size of our planet and lies 39 light years away.

Their observations suggest that the "super-Earth" is cloaked in a thick layer of gasses that are either water or methane or a mixture of both.

The study is published in the Astronomical Journal.

Discovering an atmosphere, and characterising it, is an important step forward in the hunt for life beyond our Solar System.

But it is highly unlikely that this world is habitable: it has a surface temperature of 370C.

Dr John Southworth, the lead researcher from Keele University, said: "To my knowledge the hottest temperature that life has been able to survive on Earth is 120C and that's far cooler than this planet."

Chemical signatures

The discovery of planet GJ 1132b was first announced in 2015. It lies in the Vela constellation in the southern hemisphere.

One possibility is that it is a 'water world' with an atmosphere of hot steam
While it is a similar size to Earth, the star it orbits is much smaller, cooler and dimmer than our Sun.

Using a telescope at the European Southern Observatory in Chile, the researchers were able to study the planet by watching how it blocked some of the light of its host star as it passed in front of it.

"It makes the star look a little bit fainter - and it's actually a very good way of finding transiting planets - it's how this one was found," said Dr Southworth.

But different molecules in a planet's atmosphere - if it has one - absorb light in different ways, allowing scientists to look for their chemical signatures when the world transits its star.

The observations of planet GJ 1132b suggest that it has a thick atmosphere containing either steam and/or methane.

"One possibility is that it is a 'water world' with an atmosphere of hot steam," said Dr Southworth.

The researchers say while it is unlikely that any life-forms could survive on this world, the discovery of an atmosphere is encouraging in the hunt for extraterrestrial life.

Dr Southworth said: "What we have shown is that planets around low mass stars can have atmospheres and because there are so many of those in the Universe, it makes it that much more likely that one might have life."

Commenting on the research Marek Kukula, the public astronomer at the Royal Observatory Greenwich, said: "This is a nice proof of concept.

"If the technology can detect an atmosphere today, then it bodes well for being able to detect and study the atmospheres of even more Earth-like planets in the not-too-distant future."

Gliese 1132 b - Wikipedia

Atmosphere confirmed around a VENUS like planet around a red dwarf star!

This is huge as this planet is around a red dwarf star(m-class) and it only has a 1.6 day orbit! This supports my argument ithat all earth sized and bigger planets have atmospheres.

 

[ScienceRocks]

bump....

Every planet bigger then .7 earth masses will have a atmosphere unless it was blown off by a quasar. Mars at its .1 earth masses isn't a good analog at all.

 

[Correll]

imo, we should be building interstellar probe(s) to check.

 

[ThunderKiss1965]

There are to many variables.