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ASTRONOMY COLUMN: As the Earth turns, quickly

Scientists are reiterating their 1992 warning about how human behaviours put planet Earth in jeopardy.
Planet Earth – Submitted

Islanders are travelling at about 1,000 km per hour

SUMMERSIDE, P.E.I. – Hi sky watchers. Let’s try a new thought this month.

Here we are on our planet Earth, and it feels so solid and sedate to us. But let’s think a little bit about how it really is. Imagine that the Earth is our race car and the orbit of the Earth (our path around the sun each year) is the speedway or race course. On top of that, remember that our race car – the Earth – is spinning around once on itself every 24 hours. Not many race cars do that!

Now remember that the Earth has a circumference of about 25,000 miles, or over 40,000 kms. To turn once in 24 hours, if you are at the equator you are travelling at about 1,000 miles per hour or 1,600 km per hour. Here on P.E.I., we are travelling at about 1,000 km per hour.

“As the Earth Turns!” Now that’s a good soap opera.

But it’s not over yet. In our orbit around the sun, we are travelling at about 1,800 km per hour. Even that is not all. In our galaxy, the Milky Way, our solar system (the sun and planets) is travelling around the galaxy at, oh my gosh, about 828,000 km per hour. I could go on!

So – don’t stop the world, because I don’t want to get off!

Thank heavens for gravity to keep me just where I am.


Now let’s see what’s in the sky this month of December.

First, the highlight of the month. On the night of Dec. 13, we can watch the Geminid Meteor Shower. You can watch this practically after it is dark and it gets better as the night goes on. You may be able to see as much as one a minute. Where to look, it’s best to look a little southeast, but they can be seen really in all parts of the sky. Dress well, stay out for a while, and enjoy.


Now, what about the rest?

In the evening sky, Mercury and Saturn are low in the southwest, but disappear into the sunset by the end of the first week.

In the dawn sky – much better. Near the southeast before sunrise, early in the month, Venus, Jupiter, and Mars form a beautiful elongated line from lower left to upper right. But don’t wait too long because Venus, which has been so beautiful in the morning sky, is rapidly sinking into the sunrise and will soon be lost to sight. As the month passes, Jupiter and Mars approach each other and are fairly close as the month ends.

New Moon is Dec. 18. The full moon of Dec. 3 is the closest full moon of 2017. It should look a little bigger and a little brighter. Finally by Dec. 25, Mercury appears low in the predawn sky and is getting better as the month ends.


That’s another month. Have a great holiday season and see you again as January 2018 approaches.


Dr. Rolly Chiasson of Summerside is "Your Sky Guy," who writes monthly astronomy columns for the Journal Pioneer.

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