Miss*Pinocchio said:
It is that why we have all these funny weathers... is the earth moving
closer to Mars and Venus?
Mars is about the closest it will be to Earth this year and now Venus is at about the widest angular distance away from the sun as seen from Earth.
Now, Mars is about 69 million km or 43 million miles from Earth and Venus is at about 105 million km or 65 million miles away. The closer a planet is to the sun, the faster it orbits. Venus is closer to the sun than Earth, so it will go by Earth and get within about 40 million km or 25 million miles away. Earth will be moving away from Mars, which is further away from the sun.
How much would the gravities of those planets affect Earth? The acceleration of gravity of an object is a = Gm/r^2 where m is the mass of the object pulling on Earth, r is the distance between the planets and G is the gravitional constant. G is 6.67 × 10−11 N m^2/kg^2. The mass of Mars is 6.42x10^23 kg. The mass of Venus is 4.87x10^24 kg. 10^24 is 1 followed by 24 zeroes.
Currently, the acceleration of Mars's gravity on Earth is about 9x10^-9 m/s^2 or nine billionths meters per second squared, or 9 nanometers per second squared. The current acceleration of Venus's gravity on Earth is about 3x10^-8 m/s^2 or three hundred-thousandths meters per second squared or 30 nanometers per second squared. For comparison, the average acceleration of gravity for Earth's gravity on the surface is 9.8 m/s^2.
Here, it says that it is 9.780 m/s^2 at sea level at the equatorand 9.832 m/s^2 at the poles. That's a difference of 0.052 m/s^2. It happens because the Earth's rotations causes a centrifugal force that is the strongest at the equator and at zero at the poles.
This means the acceleration of Earth's own gravitional field varies by an amount of 1.7 million times more than Venus's pull and 5.7 million times more than Mars's current pull on Earth.
There is also a variation of 2 micrometers per second squared due to the tidial effects of the moon and sun. That is almost 70 times more than Venus's pull and over 200 times more than Mars's pull.
So, it looks like the gravities of Mars and Venus shouldn't have a big impact on Earth over human timescales, much less the weather.
Conditions that are conductive to the formation of hurricanes are given
here, which include things like warm water, a steep enough vertical temperature gradient and moisture.
