Driving to another planet (please check my math)

Miscellaneous and Personal Stuff I Must Share
1

I’m giving a talk to some kids tomorrow about astronomy, and I wanted to give an idea of the distances we’re talking about. I researched lots of ways to demonstrate the scale of the solar system, but these are little kids, and none seemed appropriate.

So I had the idea to put it to them in what are hopefully familiar terms. Assume we are travelling on a school bus, and we’ve got the sucker cranked up to 100 mph. Using the average distances of the planets from the sun, I came up with these numbers for driving time to the planets:

                Point to point (years)   :    Cumulative

Mercury 41 : 41
Venus 35 : 76
Earth 29 : 106
Moon 99.52 (days)
Mars 55 : 161
Jupiter 390 : 551
Saturn 459 : 1011
Uranus 1025 : 2036
Neptune 1153 : 3189
Pluto 999 : 4189

This really blows me away. I had a hard time deciding to where to post this. I mean, it hardly seems mundane and pointless…

And could someone please check my math for me? I got my data from the JPL web site. They give one astronomical unit as 92,955,820 miles. Driving at 100mph I figure that distance to take 106.1139498 years. I used that figure, rounding off the decimals to make the other calculations (which is why they are slightly off - all those decimals eventually add up). Average distance to the moon from earth was listed as 238,855 miles. That would take just over 99 days. I fudged that, and called it a third of year.

Do I have it close enough to right to make my point?

2

Fred Hoyle used to say, “Space isn’t remote at all. It’s only an hour’s drive away if your car could go straight upwards.” Your project reminds me of that. :slight_smile:

My only criticism is that the average length of a year is 365.24 days (remember leap years!), and it looks like you used 365.

Also, you might want to remind your students that the planets never line straight up, and it would take even longer to take your tour of the Solar System if you consider that the planets are all in different parts of their orbits.

Otherwise, looks good to me. (Confession: I only spot-checked your math Pluto, Mercury, and Jupiter. Just by eyeball the rest looks good.)