The Dance of Planets and Climate
Be reassured. The planets are not aligned. They wobble, each one in different directions. The planets are not aligned; they maintain chaotic oblique rotations; still, the harmony of the spheres remains in the sky.
Let’s take a tour of our solar system (Nerem & O’Donoghue, 2019) and check out how each planet dances around the sun! Starting closest to the sun, tiny Mercury has barely any tilt at all — just about 0.03 degrees. It’s like a top spinning straight up and down, which means it doesn’t really have seasons like we do on Earth.
Next up is Venus, and it’s a bit of an oddball. It’s tipped so far over that it’s practically upside down, with an axial tilt of about 177 degrees. However, its super-thick atmosphere means the heat gets spread around pretty evenly, so there are no real seasons there either.
Mars, our neighboring red planet, is more like us. It leans at an angle of about 25.19 degrees, which makes its seasons a bit more Earth-like — although they last nearly twice as long!
Big, blustery Jupiter, on the other hand, stands nearly upright at 3.13 degrees, so it doesn’t experience the seasonal changes we do here on Earth.
Saturn, with its beautiful rings, tilts similarly to Earth and Mars, at about 26.73 degrees. This means it has long, drawn-out seasons, each lasting more than seven Earth years.
Uranus is the wild one of the bunch. It rolls around the sun on its side, with an axial tilt of about 97.77 degrees! Imagine if Earth’s North Pole pointed directly at the sun— that’s what summer is like for Uranus.
Neptune, the furthest official planet from the sun, has a tilt of about 28.32 degrees. Like Saturn, its seasons stretch out over a whopping 40 Earth years.
Lastly, let’s not forget Pluto, even though it’s technically a dwarf planet now. It leans over at a crazy angle of 120 degrees, which means it has some really wild seasons. At its solstice, one part of Pluto gets constant sunlight, while another part is stuck in darkness.
Remember, these tilts stay pretty much the same over our lifetimes, but if you were to fast forward millions or even billions of years, they can shift due to the gravitational pull from other bodies in space. That’s a dance that takes a long, long time to play out!
Earth’s axial tilt experiences a cycle that approximately lasts 41,000 years, oscillating between about 22.1 and 24.5 degrees. That said, these cycles don’t directly translate into specific years with heightened warming or cooling, although they contribute to long-term climate trends such as ice ages.
In the present time, our planet’s tilt is on a decreasing trend and is nearly halfway through its cycle. It is estimated that the last time our Earth was at its maximum tilt (about 24.5 degrees) was approximately 10,500 years ago. Likewise, the next time it will be at its minimum tilt (about 22.1 degrees) is predicted to be about 10,500 years in the future. When the tilt is at its peak, our seasons become more extreme, which can mean that summers could be hotter.
Yet, it’s important to note that this does not mean certain years will automatically be hotter because the Earth’s climate is a result of multiple factors, not solely the planet’s tilt. For instance, other cycles like the precession of the equinoxes (which impacts the timing of seasons) and alterations in the shape of Earth’s orbit around the Sun also significantly affect our planet’s climate over lengthy periods extending into tens of thousands of years. Furthermore, events like El Niño and La Niña, which involve significant changes in sea surface temperatures in the Pacific Ocean, have major impacts on weather and climate patterns across the globe. These events are natural, but there’s ongoing research into how they might be affected by human-induced climate change. Among many factors, the ocean-atmosphere interaction is subject to complex turbulent phenomena, and the science of climate is at its beginnings.
Science is not simply a collection of agreed-upon doctrines or dogmas; it’s a process of inquiry and investigation. It’s about continually testing, questioning, and refining our understanding of the natural world.
