Stryder50
Platinum Member
For a start, the term "fellow terrestrial planets" is incorrect and poor English language. "terrestrial" refers to Earth and the other rocky planets are not "terrestrial" i.e. capable of supporting life such as found on Earth.Really? A bit? explain this 'a bit'
If you are so bright about science I shouldn't have to explain a basic to you.
None of the other rocky planets show the extensive form as plate tectonics as found on Earth. Actually none at all. The tectonic plate structure appears the result of a major impact event. Most probable impactor would have been the Moon/Luna. And likely about 4 billion years or more back in time. That impact blasted off about half the original crust layer and the rounding by gravity of the remaining body, and the cooling of the exposed magma layer is how the oceanic crust was formed, along with both types broken up into plates.
Mercury and the Moon/Luna (which could almost be considered a planet, making Earth-Luna a double planet system) tend to be near total airless, very cold, no liquid water on surface, no significant rotation on axis, negligible magnetic field; in sum very different from Earth. To say "a bit" may be an understatement.
Mars would seem "a bit" closer in company with Earth, having about the same axial rotation rate, but at a quarter of size and gravity to Earth, an atmosphere about 1/100th as thick, also very cold, and little to no surface water it is a long way from being another "terrestrial". It may have been more "terrestrial", long ago; the optimistic is range of tens-hundreds of thousands of years ago, the more likely would be millions or more.
Venus is close to Earth's size, but an atmosphere several times thicker and mostly CO2, it is also very hot in atmosphere and on surface. Appears to be very volcanic, but no clear indication of tectonic plates, i.e. two forms of crust. Venus also has retrograde axial rotation. Being very hostile to Earthly forms of carbon based life, Venus is also far from being classed as "terrestrial".
More accurate classification for the three other rocky planets, and Luna would be rocky worlds/planets, with Earth also in that broad class, but having many factors unique to itself and such that would support carbon based life. Earth is the only one that could be correctly called terrestrial.
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