Possilbity of past life on Mars?

[ewq1938]

So there was never a "life-protecting" magnetosphere around Mars.

Yes there was. Science knows it once existed. What evidences are you using to say they are wrong and one never existed?

 

[GodLovesCats]

Mars could never have been like Earth.

But then, "Earth-like" has become a very loose characteristic in some astronomy circles...primarily to gain public attention.

Mars really does have notable ocmparisons to Earth. The evidence is clear that, although totally different, the Martian landscape used to have oceans and other bodies of water. Whether it was possible for life to exist is the question.

 

[RDKirk]

Yes there was. Science knows it once existed. What evidences are you using to say they are wrong and one never existed?

You just said so yourself. Go back and look at your own post.

 

[GodLovesCats]

Mars has never had a life-protecting magnetosphere of Earth.

What I said was correct. Four billion years ago, there was no life on Earth, much less Mars.

So there was never a "life-protecting" magnetosphere around Mars.

And there was certainly not a magnetosphere comparable to the Earth's magnetosphere, which is believed created by the fusion of a Mars' sized proto-planet with the earth eons before life developed.

How do you know there was never a magenetosphere on Mars that was capable of protecting life? Do you know with absolute certainly such an atmosphere must be just like ours to support living organisms?

Earth is 4.6 billion years old. I am not so sure it took 600 million years for the first living organisms to be.

 

[RDKirk]

How do you know there was never a magenetosphere on Mars that was capable of protecting life? Do you know with absolute certainly such an atmosphere must be just like ours to support living organisms?

Earth is 4.6 billion years old. I am not so sure it took 600 million years for the first living organisms to be.

From the original accretion of the debris disk, up to 4 billion years ago, the Earth was in its Hadean phase.

There were not even solid rocks during the Hadean phase.

The Earth's magnetic field was established 3.5 billion years ago. The solar wind flux at that time was about 100 times the value of the modern Sun, so the presence of the magnetic field helped prevent the planet's atmosphere from being stripped away, which is what probably happened to the atmosphere of Mars. However, the field strength was lower than at present and the magnetosphere was about half the modern radius.

There was no life possible in this region of the Solar System during the period that Mars had an effective magnetosphere.

 

[GodLovesCats]

So there was only one period in time when a different planet could have been similar to ours based on an assumption their climatic changes must be syncrhonized. I don't believe it.

Because liquid water is on Mars today, we know it was not even close to 4 billion years ago that lakes and rivers existed worldwide.

 

[RDKirk]

So there was only one period in time when a different planet could have been similar to ours based on an assumption their climatic changes must be syncrhonized. I don't believe it.

Because liquid water is on Mars today, we know it was not even close to 4 billion years ago that lakes and rivers existed worldwide.

Water on Mars today does not indicate lakes and rivers ever existed planetwide.

 

[46AND2]

Mars Exploration does not benefit anyone but feed our speculation...

You didn't read the "spinoff" section, did you? Matter of fact, you didn't even click the link, right?

 

[Tom 1]

A waste of money going to NASA that does not benefit the people that live on earth.

The population is rising, the climate is worsening. Just two reasons why humankind will eventually need to expand out and colonise other planets. Enormous investment is needed to even make it a distant possibility, starting from scratch at the last minute would be impossible, one thing builds on another and 300 years from now there are possibilities we can't yet conceptualise.

 

[SkyWriting]

Mars really does have notable ocmparisons to Earth. The evidence is clear that, although totally different, the Martian landscape used to have oceans and other bodies of water. Whether it was possible for life to exist is the question.

The existence of water means that mars has one of the hundreds of requirements to sustain life.

 

[Shemjaza]

The population is rising, the climate is worsening. Just two reasons why humankind will eventually need to expand out and colonise other planets. Enormous investment is needed to even make it a distant possibility, starting from scratch at the last minute would be impossible, one thing builds on another and 300 years from now there are possibilities we can't yet conceptualise.

I'm a huge proponent of exploration and colonisation of the planets... but overpopulation and climate failure can not be directly helped by a colonisation program.

Even overcrowded, in climate collapse and devastated by nuclear war, Earth would still be the most hospitable place in the universe for humanity.

(Of course research into dealing with our problems on Earth would help with colonisation and vice versa).

 

[Tom 1]

Even overcrowded, in climate collapse and devastated by nuclear war, Earth would still be the most hospitable place in the universe for humanity.

That we know of or can currently conceive of terraforming.

 

[Shemjaza]

That we know of or can currently conceive of terraforming.

Even then, terraforming technology would work better on a planet with right basic materials, right gravity and right distance to the sun.

Also the real advantage of Earth is that it's free to get your colonists to your site... because they already live there.

 

[RDKirk]

I'm a huge proponent of exploration and colonisation of the planets... but overpopulation and climate failure can not be directly helped by a colonisation program.

Even overcrowded, in climate collapse and devastated by nuclear war, Earth would still be the most hospitable place in the universe for humanity.

(Of course research into dealing with our problems on Earth would help with colonisation and vice versa).

And, for that matter, moving and living in the most remote, hostile regions of Earth would be easier than colonizing any other planet.

 

[GodLovesCats]

The existence of water means that Mars has one of the hundreds of requirements to sustain life.

At this time. I am interested in finding out if Mars ever met the other requirements (which do not number in the hundreds).

 

[Larniavc]

and Mars has never had a life-protecting magnetosphere of Earth.

Not true.

 

[Tom 1]

Even then, terraforming technology would work better on a planet with right basic materials, right gravity and right distance to the sun.

Also the real advantage of Earth is that it's free to get your colonists to your site... because they already live there.

Yes, I imagine that is all true. But sooner or later I think the need to build habitats elsewhere will become a necessity.

 

[RDKirk]

RDKirk said: ↑
and Mars has never had a life-protecting magnetosphere of Earth.

Not true.

Mars has never had a magnetosphere that protected life. Mars lost its magnetosphere before life could have existed on the planet.

 

[Shemjaza]

Yes, I imagine that is all true. But sooner or later I think the need to build habitats elsewhere will be a necessity.

Absolutely they should be goal to continually strive for... but on the scale of centuries they won't really solve any problems on Earth.

 

[GodLovesCats]

Water on Mars today does not indicate lakes and rivers ever existed planetwide.

A lot of evidence has piled up supporting the idea that there was water worldwide. It doesn't have to come from water itself. Geoologists found areas that clearly look like dried-up lakes, rivers, and oceans.