Name: Why does the north get more total eclipses?
Uploaded: 2024-03-28T21:11:13.000Z
Duration: 3 min 54 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

Every location on Earth has been in the  shadow of at least one total eclipse,  

but some places experience way more of these  events than others. Like, someone who lives  

North of the equator is about twice as likely  to see a total eclipse as someone south of  

the equator. Why on Earth would that be? Hi, I'm Cameron, and this is MinuteEarth. 

This disparity in total eclipses can only happen  because of a celestial coincidence; although the  

Sun is 400 times bigger than the Moon, it's  also 400 times farther away from us. So,  

as a result – from here on Earth – the Sun and the  moon appear to be almost exactly the same size. 

I say “almost” because the Earth's orbit around  the Sun is not perfectly circular. During some  

parts of the year, the Earth is a little farther  away from the Sun – so the sun appears slightly  

smaller than usual. During these times, when the  Earth, moon and sun line up, it's easier for the  

moon to effectively block the sun, causing a  total eclipse. But other times of the year,  

the Earth is closer to the Sun, so the sun  appears larger than normal. When the Earth,  

moon, and sun line up during these times of the  year, the Sun appears larger and the moon might  

not totally block it, creating an annular  eclipse, which is when the moon turns the  

sun into a bright ring of fire in the sky. And here's where the North-South divide fits  

in. In either hemisphere, eclipses are more  likely in the summer, when the sun spends  

more time above the horizon, since it has to  be daytime in order to see a solar eclipse. 

And it just so happens that summer in  the Northern hemisphere happens at the  

farthest-out point of Earth's orbit, while  Summer in the Southern hemisphere happens at  

the closest point. As a result, total eclipses  are more likely to happen North of the equator; 

for any given spot in the Northern  hemisphere, a total eclipse happens,  

on average, once every 330 years. In the Southern  hemisphere, it's more like every 550 years. 

But even within the Northern hemisphere, total  eclipses become more frequent with higher  

latitudes. There are a few different reasons why  this might be. For one, at the highest latitudes,  

the summer sun rarely dips below the horizon,  meaning that there is sunlight even at nighttime,  

as opposed to lower latitudes where nighttime  is dark during the summer. Then there's the  

curvature of the Earth, which causes the  moon's shadow to fall at a shallower angle  

at higher latitudes; eclipse paths near the  Arctic circle can be more than four times  

wider than eclipses at lower latitudes. So statistically, the best place to see  

a total eclipse is around 80 degrees north; any  given place along this line sees a total eclipse  

every 238 years on average. But remember,  all these numbers are averages taken over  

a long period of time. Carbondale, Illinois  – which sits at 38 degrees North latitude,  

which should see a total eclipse every 330  years on average – saw it's most recent  

total eclipse in 2017, yet will get its next  one in 2024. And Christchurch, New Zealand,  

which should get a total eclipse once every  420 years – saw its most recent total eclipse  

nearly two thousand years ago, and will have to  wait another four centuries for its next one. So  

when it comes to seeing a total eclipse, it's not  just about latitude – it's also a matter of luck.

If you live in North America, there's a great  chance to have that experience soon. There's a  

total solar eclipse on Monday April 8th, which  will take a long sweeping path through Canada,  

the US and Mexico. We're super excited  about it, and we've teamed up with NASA's  

Heliophysics Education Activation Team  to make videos like this to explore the  

science and wonder of solar eclipses. NASA HEAT's mission is to provide  

educational guidance for learners of all ages  to deepen their understanding of our sun and  

its effects on Earth and the solar system  in an effort to bring NASA out of the lab  

and into learning spaces like classrooms and  even YouTube to inspire future scientists.