The Ideal Planetary Model
Specifications For the Purpose of a Most Stable and Moderate Climate, Globally
In our quest to explore space, especially for the purpose of finding equivalent or even better planets for human habitation, then it helps to have a base line set of planetary parameters for the most ideal planet to live on. And then we have a reference point. Earth, with its ever warming climate and deteriorating conditions, perhaps even irreversible now, is by far, no longer the "ideal model" to look for in the cosmos. The set of planetary parameters, below, is what we would look for in our quest for other worlds that would be very close to the most hospitable for human habitat.
Our model planet starts with a 243 day "year", only two thirds the Earth year; and its orbital radius from the warming star is about 2/3 that of the earth from the sun (somewhat similar to Venus). The warming star of this model is about 44% the size and/or photo/thermal radiation output as the Sun. (Due to the inverse square law of thermal and light radiation - i.e., an object receiving only 1/4 as much radiation for every doubling the distance of the object from the source - the warming star needs only, and should only be, 44.4% output as the sun. This radiation would be from a combination of size and brightness of the star, and put an equivalent amount of surface radiation on our planet as received by the earth). The rotational period (day length) is the same as Earth's: 24 hours. A shorter year (eight months long) accomplishes the effect of lessoning sub-tropic heat shock. This intelligent design recognizes the need to shorten the time during the long solstice periods when the star's rays hover around the sub-tropic latitudes too long and create land/oceanic heat shock, which causes hurricanes, - as happens on Earth.
The climate benefits of this model are best achieved with a planet, of which, the axial tilt is much less than Earth. A tilt of no greater than 14 degrees N & S latitudes is needed. This mild seasonal lighting (the angle of the star's rays) received in temperate and polar latitudes doesn't create the extremes in heat and cold for summers and winters. In addition, the topographic features of this planet provide for seas at the poles down to 65 degrees latitude N & S, and, a mountainous, high altitude land belt around the equator to at least 17 degrees N & S latitude. The temperate latitudes alternate with one or two equal areas of land and sea in both N and S hemispheres. Polar seas provide warming moderation in the high latitudes, and, the equatorial high land provides cooling in the lower latitudes for overall global climate moderation and stabilization. The cool seas, (providing for low evaporation), as well as the orientation of mountains on the land to the trade winds and westerlies, would block and prevent humidity levels from rising above 10 to 20 percent. Contributing more to the climate moderation effect on the seasons, are shifts toward the equator of the westerly winds during the hemisphere's summer, and toward the pole of the westerly winds during the hemisphere's winter. Theoretically, and ideally, the global daily temperature would never drop below 50 degrees F for a low, nor exceed 85 degrees F for a high.
The atmospheric gas content and pressure would be different than Earth. Having a sea level pressure of 8 to 9 PSI instead of 14+ would enable less sense of "hot" or "cold". Additionally, less air mass would be not be able to feed or supply as much energy to storms. Doubling the oxygen content (to well over 40%), with appropriate lessoning the nitrogen content, would provide greater energy and vitality to animal life. Even at 8 PSI, this would provide more ppm (parts per million) of oxygen than Earth at sea level. The additional oxygen would supply the element for the "oxygen three", (ozone) for a protective atmospheric layer to the planet.
The gravity of our planet would be no greater than 2/3 that of Earth. Therefore, a combination of its size and density would have to provide for that, still allowing a rotating liquid iron sub core for the purpose of generating a vital protective electromagnetic field between its north and south poles. This is to stave off the highly charged particles reaching the planet from the solar wind that would be detrimental to all life if allowed to reach the surface.
Perhaps, if Carl Sagan were alive today, he would be advocating this ideal planet for us. Perhaps, too, this will be the heavenly design for the many planets that must accommodate the population of the human species, not only dead, but living now, eternally into the future cosmos.