In this article we will find out how real the planets in Star Wars are.
When you watched Star Wars: The Force Awakens in movie theaters, did you see any petty problems with gravity? Or the fact that alien worlds had a breathable atmosphere? Characters flew freely from one planet to another and walked on each surface without visible problems.
Is this really true for most exoplanets that we know? In the end, some of the planets in our solar system are not so convenient for a walk. The pressure of Jupiter will crush you long before you reach its surface - if it is under gas clouds. The spacecraft descent of Venus had to withstand the tremendous pressure on the surface of its dense clouds. The moon and Mars are past and future directions for astronauts — places where you can walk, although you need to get used to their gravitational fields.
A new article in the Astrobiology journal (also available in the Arxiv preprint version) concludes that the Star Wars problem is understandable because the shooting is done on Earth and the exact image of other gravitational fields will be technically difficult and expensive. "But is this characteristic of extra planets in general? Led by the scientist Fernando Ballesteros of the University of Valencia, the authors say that the reality may not really be too far away. They write that more than 2000 extrasolar worlds (confirmed and plausible) were discovered, with a speed of about three pieces per week since 2011, mainly due to the fertility of the NASA Kepler space telescope. While Kepler finds the planets, looking at the failure in the light they produce as they pass through the stars, other telescopes measure the gravitational vibrations that these planets create in the star. This swinging gives an estimate of the mass of the planet.
The authors classify the detected exoplanets into three categories:
1) masses below the Earth (like Mars);
2) the transition zone of the super-Earths, Neptune and some other planets of the solar system;
3) gas giants with masses hundreds of times larger than Earth.
It is surprising that the “transition zone” has several analogs of the planets in our own solar system with a similarity to the Earth: Venus, Uranus, Neptune and Saturn. (Again, note that gravity on Venus is similar to that on Earth, but its atmosphere can quickly be crushed by an unprotected spacecraft.)
But the exact relationship between the planetary masses and their diameters is still unclear. "For a given mass, one would expect a variety of sizes depending on the composition and size of the planetary atmosphere," the authors write. “We don’t even know if all the super-earths have a hard surface.” The authors add that, in theory, one could have a huge rocky planet without a natural atmosphere, but this is disputed by modern models of planet formation. As a rule, it is believed that the planets are an assembly of stones and gas that attract each other for a long time.
"One could, in principle, propose a rocky planet, as large and massive as we would like, without atmosphere at all, but this contradicts natural processes. The processes of accretion and competition of materials when forming planets impose serious restrictions on the types of possible planets," the authors write.
But the authors note that several super-lands that are rocky and that have a similarity to ours have already been seen with telescopes. “So, perhaps, in the Star Wars walks are not too flimsy,” they said.
"If, while watching The Force Awakens, the reader sees Harrison Ford walking along Takodana, as if he is walking along Hollywood Boulevards, then this is not too critical," they said at the end of the article. "In the end, it may not be far from the truth."