YOUR WEEKLY DOSE OF WOWZERS AND WONDER FROM THE NATURAL WORLD
You know that the air surrounding you allows you to breathe, and the sun beaming down grows the plants and trees.
But do you know why all of that works?
What stops the sun from cooking us all? What keeps the air breathable, and the weather predictable?
It turns out that there’s a whole lot more going on in the sky than we might think.
In this issue, we’re exploring the atmosphere and how it makes life as we know it possible!
The atmosphere is essentially all of the stuff that exists between the ground and outer space.
Air, clouds, winds, gasses, the ozone layer, dust…all of these things help to keep temperatures stable, shield us from the sun’s dangerous radiation, allow food to grow, create weather patterns, and more.
According to NASA, the atmosphere is mostly Nitrogen (78%), followed by Oxygen (21%), Argon (0.93%), Carbon Dioxide (0.04%), and other trace gasses.
It’s broken into multiple zones, each with different names.
We live in the troposphere, which extends to 16 kilometres (9.9 miles) above sea level at the equator.
Interestingly, the atmosphere is not a perfect circle. The troposphere only extends 8 kilometres (4.9 miles) above sea level at the north and south poles.
Past the troposphere, you’ll find the stratosphere—the domain of weather balloons—which reaches all the way out to 50 kilometres (31.1 miles).
Keep going and you’ll reach the mesophere.
This is where meteors or “shooting stars” often burn up and create the spectacular lights you see streaking across the night sky. It ends at around 85 kilometres (52.8 miles) out.
Beyond the mesophere, you reach the thermosphere. Its in this zone where we typically say that “outer space” begins.
While there isn’t a concise border with “outer space” on one side and everything else on the other, most scientists consider the Kármán Line the official border.
This line exists at 100 kilometres (62 miles) above sea level and is named after an aeronautical engineer.
At this altitude, the air is so thin that generating lift with wings is essentially impossible, making rockets or thrusters the only way to continue travelling.
This is also roughly the height that the aurora borealis or “Northern Lights” appear at!
Further out in the troposphere—around 400 kilometres (250 miles) above our heads—you’ll find the International Space Station!
Finally, you reach the exosphere which starts at roughly 500 kilometres (310 miles) out.
It’s in this zone that most of the earth’s gasses finally dissipate and you enter “deep space.”
But there are other gasses found as far as 10,000 kilometres (6,214 miles) away!
Beyond that, there is radiation, dust, and all sorts of celestial bodies.
Most nights, the moon you see in the sky is roughly 384,400 kilometres (238,855 miles) away—though this varies based on the moon’s orbit.
Mars is roughly 54.6 million kilometres (33.9 million miles) away. And teams are currently working on ways to send people there—maybe even during your lifetime!
But all of this brings up one truly Wowzerful fact and a fun experiment to try.
Look at a map and draw a circle 100 kilometres wide around your home.
You are further from everything outside that circle than you are from the Kármán Line or outer space!
So the next time you’re cloud watching or stargazing—or you take a family road trip that feels just a little too long—remember that space is only a short distance away!
When compared to other planets in our solar system, our atmosphere is very unique. For example, Venus’ atmosphere is mostly carbon dioxide, nitrogen, and sulfuric acid. If you tried to live on Venus, you’d melt!
The outer regions of the thermosphere have very little protection from the sun’s radiation and can reach temperatures as high as 2,000C (3,600F). But because there are so few particles in the air, it actually feels cold.
The ozone layer isn’t actually a zone in the atmosphere. It is, however, a protective layer that sits in the lower portion of the stratosphere and guards us from the sun!
While it varies depending on how far you are from the equator, the atmosphere’s radius is nearly 50% larger than the radius of Earth!
Get a visual guide of the layers of the atmosphere courtesy of Seeker.