I think the planets will get warmer as their number increases.
Also, speed of rotation matters. If an area receives sunlight for a few years it will get warmer than one that receives sunlight for a few minutes. So the temperature difference across the planet will be increased if it rotates slower.
1. Will be affected by TSI.
2. Will be warmer because the planet will heat the atmosphere by conduction. So some warmth will be retained during the night.
3. Nitrogen absorbs at the UV end so should delay some release of energy. So as 2 but marginally warmer.
4. Even warmer than 3.
There are lots of assumptions though. Specific heat, approximate temperature (will anything be subject to a phase change), equilibrium, tilt (seasons) ...
You might like the link - Emission Temperature of Planets:
According to the Unified Theory of Climate, by Nikolov and Zeller, the temperature of a planet can be calculated by using the TSI and density of atmosphere, calculations on Mars Venus and Earth very closely match their equations, so according to them planets 2,3,and 4 would have identical temperatures, but I suspect greenhouse gases may have some effect, so I would say planet 4 might be 1 or 2 degrees higher.
Planet 1, well I cant imagine how this planet could have no atmosphere, but it would be colder.
Your saying a planet without an atmosphere would be warmer, rubbish, also talking about the moon, well average temperature just below the surface is a constant minus 35C (damn cold)
Mars has lost it's atmosphere mainly because of it's smaller mass, Mercury lost it's atmosphere because it is so close to the sun it was stripped away by solar wind.
I thought we were talking about identical sized planets all the same distance from the sun, with presumably similar magnetic fields.
Did I say I believed in the Unified climate theory, no. I consider it enlightening and interesting, but also remarked that I thought greenhouse gases can play a very minor role.
Kano has problems to address when he gives you his answer.
1. He is using the Unified Theory of Climate - http://tallbloke.files.wordpress.com/201... - and there are serious problems with this "theory", as noted here - http://tallbloke.files.wordpress.com/201...
2. His speculation of what planet 4's temperature would be is based on ????, I am not certain. Perhaps his best guess. But, if he is using the Unified Theory of Climate by Nikolov and Zeller, then Sweger has shown the folly in the methods used by Nikolov and Zeller in his response to the Unified Theory of Climate.
2. Any planet that lacks a magnetic field to deflect the solar winds will eventual have its atmosphere stripped from it. Mars. for one, has a very weak magnetic field and has had much of its atmosphere already stripped away from it by the solar winds.
3. A planet (planet 1) that is lacking an atmosphere will be subject to the direct TSI of the sun it revolves around. Our moon is not a true planet but is being hosted by our planet. Since it behaves as a planet would, on so many levels, and since it roughly occupies the orbit around our sun as we do, then it would be a prime candidate for showing temperatures a planet would have in the absence of an atmosphere. The difference between sunlit areas and non sunlit areas of the moon is a dramatic temperature change. The temperature between day and night drop from about 250F to -240F within a few minutes. In other words, without an atmosphere to alter the sunlight before it reaches the surface then the surface becomes much hotter than does an example of our planet. Like wise, without an atmosphere to help retain some of the solar energy received then this heat energy quickly escapes back into space when the sun is not shining on that surface area.
It probably depends somewhat on whether the planets are rocks or balls of gas, but Planet 4 would probably be hottest, for the reasons pointed out by others, and Planet 1 coldest. If the ultimate interest is conditions necessary to sustain life as we know it, other factors also come into play, e.g. sufficient carbon, oxygen, hydrogen in the atmosphere or rocks, rotation that is not too fast or slow, relatively stable axis of rotation, etc.
Planet 1 and planet 2 would have the same temperature. Planet 3 would be slightly warmer than planet 2, because I believe that nitrogen can absorb some UV, visible and near infra-red, although I can't confirm it because my google search only lead to frustration. Planet 4 would be the warmest. If they hypothetical star were identical to Earth's Sun and the distances the same as from Earth to its Sun, the temperatures of planets 1 and 2 would be -18C, planet 3 would be about -16C and planet 4 would be as warm as Earth.
Hi Chem Some1 has tried to spell it out in simple form and got a thumbs down for his trouble. The links I've provided reinforce his simple explanation The distance between 2 objects can be calculated by it's mass and temperature = distance apart
We have 4 hypothetical identical planets, orbiting identical stars at an identical distance (or, maybe the same star at 4 equidistant points in the same orbit). The only initial difference between the planets is their atmospheres.
Planet 1 has no atmosphere. Planet 2 has an atmosphere made of some (hypothetical) gas that does not absorb any component of solar radiation in any way, but can be warmed by conduction or convection. Planet 3 has a mostly nitrogen atmosphere, with no greenhouse gasses. Planet 4 has an atmosphere that is 99% nitrogen and other non-greenhouse gasses (the same composition as 3), and 1% greenhouse gasses. All planets with atmospheres have equivalent density and thickness of atmosphere, only the composition differs.
Can you describe roughly what the relative surface and (where relevant) atmospheric temperatures would be like amongst these planets? And, to the extent that you can explain it at a layman's level, why? If you can think of any other probable differences relevant to temperature, feel free to add those.
(this is inspired by my clumsy attempt to explain the issue to a Certain Party here, I'm sure I got at least something in my explanation Horribly Wrong)
