Is it possible that the Atlanteans came from a planet in our own solar system?, page 8

Originally posted by fred3110

mars may have had an atmosphere like earths in this book i read by Graham Hancock (mars maystery) theres 3 huge craters each one a planet kiler on its own and these may have hit mars and basically obliterated it, further proof of this is the Hellas canyon which may have occured when the force traveled through the core of the planet and ejected it into space. scientists couldnt pin point exactly what time these occoured so it could be 20,000 years it could be 20 million years
(personally i think 20,000 as it would explain alot of these myths and legends!)

if there was any life forms there i doubt they lived on the red planet we know of but if there planet was going to be destroyed and they had forwarning of it they may have escaped to earth.

I suppose it's possible that Mars was once very different, prior to the impact you speak of.

But what is certainly not possible is that such an impact occured only 20,000 years ago. Mars would not have had nearly enough time since then to arrive at it's present known state. It's extremely unlikely that Mars would already have even coalesced back into planetary form, after being impacted in a way that would almost certainly have liquified much of the planet, interior and exterior. Let's not forget, as far as we can tell, volcanism is dead on Mars. 20,000 years is absolutely not long enough for that to have occurred.

The Hellas crater may well be the result of an impact that was powerful enough to create the Tharsis Bulge on the other side of the planet, but it's the Tharsis Bulge, not the Tharsis "hole where there used to be more mass before it was blown away 20,000 years ago."

Some info on the Tharsis bulge and possible relationship with the Hellas crater:

One of the theories put forward by Joe Kolecki to explain the formation of volcanoes on Mars was that of the meteor impact theory. It goes something like this: some of the volcanoes on Mars can be explained if we consider that a meteor had crashed into the planet at some point. The force of such an impact would reverberate through the planet and force volcanoes to 'bulge' out on the other side.

...On investigating Helles and Tharsis further we found that Tharsis was not actually on the point 180° from Helles as one would have expected if assuming meteor theory was correct. We questioned as to why this was not the case and figured that if Mars had a molten core, like the Earth's, then the energy waves that would have been given out by the impact would pass through this core and be refracted, thus changing the angle at which they would leave the core. This would result in the energy waves surfacing at a point not 180° away from the point of impact (see Fig. 1). This line of reasoning would then explain as to why Helles and Tharsis are where they are on Mars.

...These values that we calculated showed that the energy required to melt a mass the size of Tharsis would be produced by a meteor impact of the size of the diameter of the Helles.

Source
Real calculations avaliable on that page.

Dating the Hellas crater:

Detailed analyses of the SNC meteorites made it clear that not long after Mars accreted into a world, its interior was already hot and had differentiated into a nickel-iron core, mantle, and crust. Much of the heat at this stage must have come from the energy of the impacts themselves. Thus, Martian volcanism began early. During late Noachian and early Hesperian times, melted rock (magma) began to reach the surface. Extensive ridged plains were laid down in areas of the southern hemisphere; the so-called highland paterae also emerged, of which four are located near the Hellas basin and probably were formed in relation to deep-seated fractures produced during the impact that formed it.

My emphases.
Source
You see, some of the impacts on Mars, and even some of the volcanic activities there, have resulted in the ejection of some Martian material into space, and some of that material has actually fallen here on Earth. This, I think, is what the author refers to when he says the "SNC meteorites." These, in turn, give us at least some data on what Mars was like in it's infancy.
Remember that Martian meteorite that supposedly had possible signs of ancient fossilized bacteria in it a few years back? It was found in Antarctica.

We see from the above that the Hellas Crater, by the best estimates, predates the chronological boundary between the Noachian and Hesperian periods of Mars' geohistory. So, when were the Noachian and Hesperian periods?

Since we are trying to unravel the history of Mars we are always mentioning dates in the past when we think certain events ocurred. It is helpful, therefore, to note a few terms that photo-geologists use when talking about Mars. The first period of martian history ("morning" if you will) is called the Noachian period -- Noachis happens to be a good example of (ancient cratered highland) terrain that dates back to that time of heavy asteroidal bombardment (about 4.3 billion years ago to 3.5 billion years). The second period of martian history ("afternoon") is called the Hesperian period, the period after the heavy bombardment had tapered off. Hesperia Planitia is, naturally, a good example of (plains) terrain that dates back to that time (about 3.5 billion years to 1.8 billion years). The third period ("evening") is called Amazonian -- obviously, Amazonia Planitia is the type example of the (least cratered volcanic) plains that typify the last billion and a half years of martian history.

Again, my emphases.
Source

So, by the best estimates we have, the Hellas crater is at least 3.5 billion years old.
So, where did you get 20 million?

Regarding Hancock, it is just a complete waste of your time to read anything the man ever wrote. Unless, that is, you read it as fiction (which is what it actually is.) Of course, it's fun to read it and speculate. But another term for Science Fiction is Speculative Fiction.

Harte