Bob Doyle

Bob Doyle

Some people like to talk about the cruises, train rides or plane visits they have gone on.

I am in contrast a homebody; I hate all the preparations to get ready and then have to put all the stuff away when I return home.

But consider the larger picture.

We are all passengers on Spaceship Earth. Our flight path is our orbit around the sun.

Earth’s path is nearly circular with a radius of 93 million miles. So the distance we travel each year is the circumference of our orbit.

This is 2 x Pi (3.146) x 93 million miles or 584.3 million miles.

So even if you stay in your dwelling all the time, at each birthday, you will have added another 584.3 million miles to your personal odometer.

How fast is this in miles per hour? A typical year has 365.25 days. (The .25 is due to our adding an extra day to the end of February every fourth year.)

If we multiply 24 hours in a day by 365.25 days in a year, we get 8,766 hours. To find our speed in miles per hour, divide our orbital circumference by the number of hours in a year. This is 66,660 miles per hour!

The Earth’s diameter is about 7,947 miles. So every hour, Earth travels over 8 1/3 times its diameter. This speed doesn’t depend on our location on Earth whether you live at the equator or one of the poles.

 How far have you travelled by the age of 30? This would be 30 x 584.3 million miles = 17.5 billion miles.

This is two trips to Pluto and back!

Would the Earth’s rotation add much to your mileage? Our circumference at the equator is nearly 25,000c miles. So in 24 hours, equator dwellers are turning at 25,000 / 24 = 1042 miles per hour.

At our latitude (about 40 degrees north), we spin more slowly at nearly 800 miles per hour. This is 1.2% of our speed around the sun.

There are even bigger speeds such as our sun’s revolution about the center of our galaxy, which takes one-quarter of a billion years (a galactic year).

So no one is standing still, we are all flying through space.

This question, “How far have you travelled?” is one of my Space STEM exercises that I have devised.

In all, there are 12 of these STEM exercises: three for the early grades and nine for higher grades.

Each is one page in length (single side) and features one solved example. They require a basic calculator (can divide, multiply and square root) and a pencil.

Other STEM exercises involve the speed of other planets about the sun, your weight on other planets and their moons, how old you would be on another planet, how long would it take you to go from Earth to Mars or another planet, how many day/night cycles are there on the other planets, etc.

I want to share these with any interested readers of all ages, teachers, staff, etc.

There is no cost. Send an email to and I will send you a one page summary of these 12 STEM exercises.

Then pick three or four of these STEM exercises, which I will send to you as an attachment for each one.

Once you have tried these exercises and/or have some questions, email them to me and I will respond. I will be glad to supply further exercises.

I now have my 2020 Night Sky Highlights available to any interested readers.

This two-page document lists the four main moon phases for the year, when the bright planets can be seen, the best evening planet line ups, the dates when the sun is in each of the 13 zodiac groups, the best evening star groups and brightest stars in each quarter of the year (January through March) and more.

Finally on the back side are the Sunday sunrise and sunset times for nine different local communities from Maryland, West Virginia and Pennsylvania. Request your copy from No charge.

Bob Doyle, professor emeritus at Frostburg State University, invites any readers comments and questions. E-mail him at He is available as a speaker on his column topics.

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