Is it possible to make an atmosphere

On the other hand, terraforming can be done with more or less gas. With less gas, you will have an atmosphere like on Earth's highest mountains, while with more gas, the effect will be the opposite. However, humans can adapt to these conditions. Comets are known to be made of dirty ice. They contain water ice, solidified gasses, salt and dust. They contain all ingredients needed for oceans and an atmosphere, but in different amounts. Before everything, we must pick the best candidates for diverting.

Some comets might contain too much deuterium, which will affect life. Other comets might have high amounts of toxins. Choosing the right celestial bodies for diversion is very important. And we could divert one singe object as well as we could use millions of small comets. Also, we must look at other icy objects found nearby. This can include Centaurs and icy moons. They are closer then Kuiper Belt objects and might be more easy to transport.

An advanced civilization will use a refinery. This way, some components will be left and others will be carried. First, volatile gasses like nitrogen and carbon dioxide can be covered with a layer of water ice, protecting them from immediate outgassing.

Basically, we have to send a spaceship where the icy celestial body is located. Further away, the speed is much slower. In case of icy moons that orbit around gas giants, we first must pull them away, into heliocentric orbit, then we will slow them. Overall, it will be more easy to divert a further object then to use a closer one, but also it will be faster to divert a closer object then a more distant one.

With current technology, one good way for transport is the use of ion engines, which are slow but highly efficient. We could also use water from the surface, split it into hydrogen and oxygen and use it in a chemical engine. In both cases, we will need nuclear power generators. And we will need to be patient. This takes some time. The diverted object will travel together with the spaceship. Small trajectory adjustments need to be made from time to time.

As the object gets closer to the planet, it starts outgassing and that can push it away from trajectory. Transport phase in the inner solar system must be fast, because outgassing will make us lose some of the volatiles and it might break the comet apart. When the diverted object comes close to the planet, there are two scenarios. Long ago, more than 3. And who knows, maybe even for life to begin. But since the magnetic field of Mars fell apart after its iron inner core was somehow undone, about 90 percent of the Martian atmosphere was stripped away by charged particles in that solar wind, which can reach speeds of to kilometers per second.

Mars, of course, is frigid and dry now, but Green said the dynamics of the solar system point to a time when the planet will warm up again. He said that scientists expect the gradually increasing heat of the sun will warm the planet sufficiently to release the covering of frozen carbon dioxide at the north pole, will start water ice to flow, and will in time create something of a greenhouse atmosphere.

But the process is expected to take some millon years. The increase in pressure causes an increase in temperature. We have not calculated exactly what the new equilibrium will be and how long it will take. The reason why is that Green and his colleagues found that they needed to add some additional physics to the atmospheric model, dynamics that will become more important and clear over time.

But he is confident those physics will be developed. So based on those new magnetic field models and projections about the future climate of Mars, when might it be sufficiently changed to become significantly more human friendly?

But the average daily range in temperature on Mars now is degrees F, and it will take some substantial atmospheric modification to make that more congenial.

About miles across, the white sections are primarily water ice. Frozen carbon dioxide accumulates as a comparatively thin layer about one meter thick on the north cap in the northern winter only. One of many intriguing aspects of the paper is its part in an NASA effort to link fundamental models together for everything from predicting global climate to space weather on Mars.

The modeling of a potential artificial magnetosphere for Mars relied, for instance, on work done by NASA heliophysics — the quite advanced study of our own sun. Chuanfei Dong, an expert on space weather at Mars, is a co-author on the paper and did much of the modeling work. Substantial enough, in fact, to greatly limit the loss of Martian atmosphere due to the solar wind.

As he explained, the artificial dipole magnetic field has to rotate to prevent the dayside reconnection, which in turn prevents the nightside reconnection as well. If the artificial magnetic field does not block the solar winds properly, Mars could lose more of its atmosphere. That why the planet needs to be safely within the magnetotail of the artificial magnetosphere. Red and pleasant land? Science fiction has long dreamed of turning Mars into a second Earth, a place where humans could live without having to put on a space suit.

The easiest way to do that would be to use carbon dioxide already on Mars to create a new atmosphere, but now researchers say that is impossible. Terraforming Mars to make its surface habitable for Earth life would involve raising both its temperature and pressure by adding an atmosphere made of heat-trapping greenhouse gases. The only ones present on Mars in any significant amounts are carbon dioxide and water vapour, both of which are currently frozen.

The fundamental question is, is there enough stuff? No, it turns out.