6 Fun Facts about our Skies!
6 Fun Facts about our Skies 🌎☀️
Here's some interesting facts about our skies:
The moon is actually lemon shaped! Most likely the moon got its shape due to the gravitational pull of Earth. However, since it’s pulled directly towards Earth, it still looks like a perfect circle to us!
Clouds are actually quite heavy! Different types of clouds have different densities and volumes. However, for cumulus clouds which have a density of around 0.5 grams (0.001 pounds) per cubic meter, that means a typical cloud can weigh up to 1 million pounds!
While that seems quite heavy, they're still able to stay afloat because of raising air currents and because clouds are less dense than the air beneath them.
Not only are clouds heavy, but they can be quite fast as well! While it depends on the cloud type and wind conditions, some high-level clouds can move as fast as 100 mph!
Our galaxy contains more than 100 billion stars!
And some of these stars are incredibly far away. V762 Cas is the farthest star that’s still visible to the naked eye, and it’s 16,000 light-years away! One light-year is 5.8 trillion miles, so that’s quite a distance! That means that the light we see when we look at it is actually quite old.
And finally, did you know that the sky is blue due to something called Rayleigh scattering?
Sunlight is made up of many different colors of light, all traveling at different wavelengths. When all these colors and wavelengths combine, they appear white - which is why sunlight appears white. But, as the sunlight enters Earth's atmosphere, it collides with air particles, causing the light to scatter in all directions. Because blue light has one of the shortest wavelengths, it scatters the most. (Violet light actually has an even shorter wavelength, but the sun emits more blue light than violet.)
Also, our eyes are more sensitive to blue light. That's because the cells in our eyes (iPRGCs, or intrinsically Photosensitive Retinal Ganglion cells) are particularly sensitive to blue light (these cells also affect our circadian rhythm, which is why having too much blue light from our screens can affect our sleep!).
So, because the blue light scatters more and because our eyes are more sensitive to blue light, the sky looks blue to us!
Interested in learning more? You can find more fun facts here: