About 17 Million years ago.*
Mars had an ocean and a very Active volcano. Then along came the Asteroid I call the "Fist of God" As picture in the simulation shows below, that impact did several things, one of which can explain why Martian rocks are found on Earth.
The Impact was deep enough that the top three layers of the planet were squashed. This SUDDEN mixing of these top 3 layers created a speed bump that the Inertial velocity of the spinning core did not overcome, as a result the CORE of Mars STOPPED spinning.
With the Core now stopped Mars was from that moment dead, Why?
Every single planet that is to have any sort of atmosphere needs a spinning metalic core to create the magnetic field that will hold that particular planet's atmosphere.
The "Fist of God" asteroid killed Mars because it stopped the Mars core from spinning, The spinning core is what creates the magnetic field, this magnetic field is what protects all life bearing planets because it stops the water vapor/atmospheric gases from escaping into space.
If you are going to quote this hypothesis and we know you will, give credit to this author.
ABRAHAM BEN JUDEA
That giant Asteroid that hit Mars about 100 Million yrs. ago created the magnificent canyons but it also killed the planet.
|This Crater I call "Fist of God" was created about 20 Million years ago...|
|See that Grand Canyon...Scientists today offer no possible explanation to its origin.|
|Vales Mariners was created by the Fist of God Asteroid impact on the other side of the planet. (See picture above with crater circled out)|
|Places like this false color photograph shows, are the last places where water was the last to evaporate.|
There are many places like this and in these places is where we will find FOSSILS.
* The theory holds that ALH84001 was blasted off from the surface of Mars by a meteorite impact about 17 million years ago and fell on Earth roughly 13,000 years ago. These dates were established by a variety of radiometric dating techniques, including samarium-neodymium (Sm-Nd), rubidium-strontium (Rb-Sr), potassium-argon (K-Ar), and carbon-14. Other meteorites that have potential biological markings have generated less interest because they do not originate from a "wet" Mars. ALH84001 is the only meteorite collected from such a time period.