Tag Archives: sun

Contrails Crossing the Sky

The jets have been active tonight. I counted six individual jet contrails in the sky. Very interesting.

And there was a nice sunset.

I hope you enjoyed April. Coming up is a very warm start to May!

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Leap Year Explained Simply

It’s Leap Day today, and that means people born on February 29th finally get to have a birthday. But why do we have Leap Years? What’s the purpose? Well, it ensures that our seasons don’t drift.

You see, it takes the Earth 365.256363004 days to orbit the sun (this is known as the sidereal year). The calendar year is 365 days. But every 4 years, we have an extra day. So, we add a day to the years that can be divided by 4. This year is 2016, and is divisible by 4.

Sounds simple, doesn’t it? But it gets a bit complicated.  This accounts for 365.25 days. But what about the extra 0.006363004 days? This accumulates, and after 400 years, it equals about 3 days extra. So, we have 3 too many Leap Days every 400 years. So what do we do? We just drop the Leap Days that happen on century years, but keep the ones that can be divided by 400. As a result, the year 2000 was a Leap Year, but 1900 and 2100 are not.

Leap years fall on years that can be divided by 4, except if they can be divided by 100 (not including the ones that can be divided by 400). This balances the calendar and seasons, and we don’t have any drift.

But why is it called Leap Year? Well, in normal years, let’s say that March  31st is a Monday, then the next year it’s a Tuesday, and then it’s a Wednesday the following year. But then, on a Leap Year, we leap over the next day (Thursday) so it’s on a Friday. And that is why we call it a Leap Year.

Any questions?

Sundog and Unusual Clouds

Yesterday, I was able to see a great phenomenon known as a sundog. These things are part of a halo around the sun and created by hexagonal ice crystals in the air, usually with cirrus clouds. Well, there were plenty of cirrus clouds yesterday. This sundog that I saw was rainbow coloured, though it didn’t turn out very well in the picture. You can see it below.

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Sundog in the cirrus clouds.

And cirrus clouds are interesting to look at, too. They have a lot of patterns, like waves or feathers. I got some pictures of those, too.

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Rippled cirrus clouds.
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Rippled and feathery cirrus clouds.
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Fluffy cirrus clouds on the right, wispy cirrus clouds behind the building and in front of the sun.

Have you ever seen a sundog? Cirrus clouds are pretty common, but you have to be lucky to see a sundog.

The Solar System One Probe at a Time

In honour of Dawn’s successful orbit of Ceres and New Horizons’ flyby of the Pluto-Charon system in July, I thought I’d take you all on a tour of the solar system one probe at a time.

What does this mean?  I’m going to go all the way back to the first lunar probe, Luna 1 in 1959, and talk about each probe that was launched from Earth in chronological order.  I’ll look at what they achieved, what they saw, and what happened if they failed.  I’ll even include the ones that never made it out of the atmosphere and crashed back into the ocean.

I will not look at any spacecraft that were only intended to orbit the Earth.  I’ll look at every probe that went to the moon, the planets, asteroids, comets, and even the sun.  Just anywhere but Earth.

I will provide some pictures when available of the probe, as well as some things they took photos of.  I may even embed the launch videos if I can find them.

I hope you’ll enjoy this look back through the history of solar system exploration.

Honestly, Earth is Tiny

Ever wonder how Earth compares in size with Jupiter?  How about the Sun?  I found this article with some pretty good pictures showing just how big the Earth is.

Not impressive enough?  Well, how does it compare with stars?  You know, the Sun isn’t that big when compared to the biggest stars in the galaxy.  This video illustrates that perfectly.

Impressed?  Discuss below.