Today, we’re going to take a look into one of the big mysteries of our planet: Why is Earth tilted on its axis, and how is it linked to the formation of the moon? Let’s find out.
Unlike a perfect spinning top, Earth doesn’t spin straight up and down. Instead, it’s tilted at a slight angle. This angle is approximately 23.5 degrees relative to its orbit around the Sun.
But what caused our planet to lean like this?
To understand the reason behind Earth’s tilt, we need to take a trip way back in time, over 4.5 billion years ago, to the very beginning of our solar system. When Earth first formed, it was a chaotic and violent place, with countless celestial bodies colliding and merging.
Scientists believe that during these early days, a Mars-sized object named Theia smashed into the young Earth, releasing a massive amount of energy and debris.
This cataclysmic impact likely caused our planet to tilt, creating the axial tilt we see today.
The cloud of debris that orbited the earth would have eventually clumped together to form the moon
Just recently, scientists think they may even have found evidence of two large areas inside the mantle of the Earth that may be remnants of Theia after it collided and merged with the proto earth.
Now, you might be wondering: what difference does a little tilt make? Well, it turns out that Earth’s axial tilt has a HUGE impact on our planet’s climate, seasons, and even the length of our days and nights.
Thanks to the tilt, as Earth orbits the Sun, different parts of the planet receive varying amounts of sunlight throughout the year.
This creates our four distinct seasons: spring, summer, autumn, and winter.
In June – the northern hemisphere is tilted towards the sun. This means the light and heat from the sun is more concentrated, and so it is hotter. This means it is summer in the North. The southern hemisphere is tilted away from the sun – the light and heat is more spread out, so it is cooler for them and they have their winter.
In March and September, the earth is neither tilted towards or away from the sun – the light and heat is distributed evenly, and so the planet is in Spring or Autumn (equinox).
In December, the northern hemisphere is tilted away from the sun, so it is in Winter whilst the southern hemisphere is in summer.
Without the tilt, we’d have no seasonal changes, and the climate would be much more uniform across the globe.
So remember, Axial tilt is the reason for the season.
But our planet’s tilt isn’t set in stone. It actually wobbles very slowly, like a spinning top losing its momentum.
This wobble, called axial precession, causes the tilt to change over time, moving between 22.1 and 24.5 degrees over a 26,000-year cycle.
This wobble is so slow that it won’t have a noticeable impact on our climate or seasons within our lifetimes. But over thousands of years, these changes in tilt can contribute to shifts in Earth’s climate, playing a role in the onset and retreat of ice ages.
So, to summarise – Earth’s tilt is the result of a colossal impact in our planet’s early history, and it’s responsible for the cycle of seasons that we experience each year.
The post Why is the Axis of The Earth Tilted? appeared first on Danny Nic’s Science Fix. Written by Danny Nicholson