While reading an article about Mars and various reasons why scientists think we will still find life on Mars, I stumbled across this paragraph, and I want to explain something:
Just as Earth goes through ice ages and periods of warming, the climate on Mars changes over time. And just like Earth, the Red Planet’s climate oscillations happen because of changes in its orbit of the sun. The time scale of Martian climatic cycles are even similar to that of Earth — both take around 100,000 years to swing between a cold period and a warming period. But climatic swings on Mars are likely much more extreme than those on Earth, NASA’s Boston said. That’s partially because Mars wobbles much more on its axis than earth does. Earth axis only moves between 22 and 24.5 degrees of tilt, according to NASA. Over the past 3 million years, Mars’ axis has moved between an angle of 15 and 30 degrees. More than 3 million years ago, and its axis could have tilted more than 45 degrees.
Now let me tell you something I came across many years ago, when I was doing my own "wonky" digging into science.
I was astounded to discover that scientists know that planets wobble a LOT. A planet wobbles so much that it can "lie on its side" so that its north pole or south pole points to the sun. But worse still, this wobbling is a permanent feature of a planet’s existence. A planet is thus unstable. If you look at the planets in our solar system you’ll see the various angles at which they are tilted and these angles are constantly, but very slowly of course, changing.
This brings us to the topic of planets flipping over. There was a man who in the 1950s I think came up with the notion that the accumulation of ice at earth’s poles would cause the entire planet to tilt.
However, as you can see with Mars (and this is true for all planets except Earth), are constantly subject to this weird wobbling and tilting of the poles.
Now the bad side of this, for life on Earth has to do with the changes in temperature and weather from a planet wobbling around. It can cause life to die or the conditions for life to be so unstable that it won’t survive. Of course, with these changes taking place slowly, maybe many forms of life can survive. But there have to be some or perhaps many which cannot due to various factors.
This brings me to the Earth. The Earth is a very weird planet. The Earth has the Moon, but the Moon is not small. The Moon is very large compared to the Earth. The Earth-Moon system, which itself is unstable, but at an extremely slow rate because that distance is changing. However, it’s been stable enough to be around for billions of years. The moon formed by smashing into the Earth about 4 billion years ago.
Now the Earth-Moon system is basically a Binary Planet system. These two objects orbit around each other. I read a long time ago that a French scientist did calculations showing that this binary system allows the Earth to remain stable and to NOT flop around like the other planets do. The Moon’s presence allows the Earth to have a very limited amount of wobble (as mentioned above). It is the Moon and only the Moon that is responsible for this state of affairs.
This very limited wobble has made the Earth more stable than any other planet would be, and this stability thus allows the climate to be stable and for life to have formed.
This means that the Earth is a very exceptional planet. This is NOT NORMAL. This may mean that finding other life is going to be much more difficult than just finding "another earth". In order to evolve as we have, you would probably need a much more stable planet.
So we may be much more unique than you realise. Personally, I think that we, the European race, are unbelievably well placed. We could probably travel across multiple galaxies before we ever find anything even close to ourselves. We are probably amazingly unique. The universe … could be ours!