All planets shown above will kill you in less than 1 hour. I can't see all the gasses on the list for RS 7066-35-7-982909-1456 4 though.

Basically the ones elemental found all have too much O2. Starlight Glimmer, all yours would poison any surface explorers with SO2.

A quick glance will tell you, any SO2 without a negative exponent of -5 or less would be deadly within at least an hour if not sooner. (.0001 means less than 1 hour to live. .00009 or 9.00*10^-5 ~ to ~ .00005 or 5.00*10^-5 means up to 1 hour before you have a schizoid embolism).

If you find one with enough O2 but its not over 60% and with partial pressures less than .6 but over .08, then look at SO2. You want one with a -6 exponent or better (lower). Then you can check CO2 and H2S.

Usually however the current algorithms create atmospheres with too much SO2 for humans to tolerate. You might find a few breathable one after checking a million or so planets. They DO exists!

After a long....Long...LONG time searching with lots of frustration and tedious clicking I found 2. 2 which may or may not be habitable.

Heres the rest of the list for RS 7066-35-7-982909-1456 4

2 planets I found.

This one may have too much SO2

Wow, they'er all pretty hot. :o  Besides the temperature, the main problem with the first is too much SO2 & H2S, while the rest have too little oxygen.  The O2 pressure really needs to be greater than 0.1atm, and not more than 0.6.

Keep trying though!  You've found some really nice and close ones so far.

I've found 2 on the VERY border....Is there a way to adapt to SO2? 

Is there a way to adapt to SO2? 

Apparently yes, but probably not to a degree that would be useful at these levels for permanent habitation.  There was a study in rats, where one group was exposed to 400ppm and died after 22 hours, while another group exposed to 567ppm for 6 hours per day died after 12 days (72 hours of exposure).  For context, 400ppm at Earth pressure is 0.0004, or 4x10^-4, atm.  So it seems there may be a limited adaptation effect, provided that there is a sufficient recovery period between each exposure.  Source and other good info on SO2's effects on animals and humans.

A big problem with SO2 in humans is that at high concentrations, the damage doesn't all go away after the exposure.  A 13-year follow-up study of seven miners who were briefly exposed to SO2 in a mining explosion found that while there was some recovery, "acute inflammatory obstruction caused by exposure to sulfur dioxide left, as sequelae, obstructive impairment of ventilatory function and permanent bronchial hyperreactivity. The clinical picture displayed by these patients was named the "reactive airways dysfunction syndrome" (RADS) in 1985. Four of the patients also showed symptoms of chronic bronchitis."  

SO2 is just really nasty stuff.  We're sensitive to only 1ppm (10^-6 atm) of it, and anything above 10ppm (10^-5) starts to get really dangerous. It has a cumulative effect with exposure, so that the more you're exposed to it, the more damage it causes.  I guess the best way of dealing with SO2 on these worlds is to imagine using some filtration system or carrying your own air.

One other thing to reiterate from discussion on the old forum is that this is still the early implementation of atmospheric composition in Space Engine, and it will likely be revised.  On real exoplanets, it should probably not be so common for SO2 concentrations to be this high, since there are ways for it to be quickly removed from many different kinds of atmospheres.

Is there a way to adapt to SO2? 

Apparently yes, but probably not to a degree that would be useful at these levels for permanent habitation.  There was a study in rats, where one group was exposed to 400ppm and died after 22 hours, while another group exposed to 567ppm for 6 hours per day died after 12 days (72 hours of exposure).  For context, 400ppm at Earth pressure is 0.0004, or 4x10^-4, atm.  So it seems there may be a limited adaptation effect, provided that there is a sufficient recovery period between each exposure.  Source and other good info on SO2's effects on animals and humans.

A big problem with SO2 in humans is that at high concentrations, the damage doesn't all go away after the exposure.  A 13-year follow-up study of seven miners who were briefly exposed to SO2 in a mining explosion found that while there was some recovery, "acute inflammatory obstruction caused by exposure to sulfur dioxide left, as sequelae, obstructive impairment of ventilatory function and permanent bronchial hyperreactivity. The clinical picture displayed by these patients was named the "reactive airways dysfunction syndrome" (RADS) in 1985. Four of the patients also showed symptoms of chronic bronchitis."  

SO2 is just really nasty stuff.  We're sensitive to only 1ppm (10^-6 atm) of it, and anything above 10ppm (10^-5) starts to get really dangerous. It has a cumulative effect with exposure, so that the more you're exposed to it, the more damage it causes.  I guess the best way of dealing with SO2 on these worlds is to imagine using some filtration system or carrying your own air.

One other thing to reiterate from discussion on the old forum is that this is still the early implementation of atmospheric composition in Space Engine, and it will likely be revised.  On real exoplanets, it should probably not be so common for SO2 concentrations to be this high, since there are ways for it to be quickly removed from many different kinds of atmospheres.

Acknowledged. So far theres only 4 or 5 breatheable atmospheres we have discovered. I spent at least 4 hours total today, and I refined my efforts and found 2 planets which were barely over the limit. The SO2 generation in planets in spaceengine should probably be changed at a future date. I hope it is revised someday, too loosen the hasstle of finding breatheable atmospheres on planets. 
One of which I have found previously.

I actually like the idea of breathable atmospheres being exceedingly rare -- it makes them special and a real treat when you do find one.  But SE is motivated by realism, and in this case realism should make breathable ones a little bit less difficult to find than they currently are.

I actually like the idea of breathable atmospheres being exceedingly rare -- it makes them special.  But SE is motivated by realism, and in this case realism should make breathable ones a little bit less difficult to find than they currently are.

True. And realism also should dictate SO2 worlds which are everywhere shouldn't be as common. SO2 everywhere isn't that realistic.

Precisely.

Precisely.

I also think there should be a search filter for atmospheric composition or something of that sort implemented in the future. 

For how long can we breathe on this planet I wonder?

For how long can we breathe on this planet I wonder?scr00028.jpg

Too much oxygen in the air of this planet. Too much SO2 also. Probably less than an hour. 

I do think that's the highest concentration of O2 I've seen on a planet with that much O2 altogether.  Neat.

One other factor not included in Space Engine, so far, is to include condensation temperature for gasses. On planets with higher pressures, temperatures can be higher for certain gasses to fall out of the air as snow. At atmospheric pressure, pure SO2 will begin to condense at –10.1°C (13.9°F).  If the gas is compressed to 3.829 atm, or 388 kPa, or 56.3 psig, SO2 will begin to condense at 32.2°C (90°F), high enough that normal cooling water can be used to condense SO2 (in a closed system). When the concentration of SO2 in the gas is low (typically 7-14%), it becomes impractical to attempt to fully condense all the SO2 contained in the gas.  Extremely high pressures are required in order to use cooling water to condense SO2 from the gas.  The alternative to full condensation is partial condensation of the SO2 using refrigeration only, which can achieve temperatures as low as –55°C (-67°F).  Typically, only 50% of the SO2 can be condensed from the gas with refrigeration at normal atm.

So, if your atm is high and temperature low, most SO2 would likely form snow caps at the poles. Maybe.

So I should look for planets that are colder?