Locate Virginia on the Globe - and in the Galaxy

Northernmost : 39.455826 (we're in the Northern Hemisphere, so latitude is a positive number)

Southernmost: 36.549072

Westernmost: -83.667404 (remember the minus sign for our longitude; we're west of the zero degree or "prime" meridian)

Easternmost: -75.225754

We're Moving...

I asked an astronomy fan (Jim Blowers) to answer a few questions to put a particular location into context. We assumed that we were standing in the parking lot behind Slusher dorm at Virginia Tech. According to a rough calculation from Terraserver, it's at 37 degrees 13.30 minutes N, 80 degrees, 25.21 minutes W.

How fast are we moving, due to the spinning of the earth once a day around the axis?

In Virginia, we move a little slower around the axis that someone standing on the equator. The circle we spin on is smaller than the equator by a factor of cosine of the latitude. Naturally, you need an equation using math to measure the speed at a location "L," where L is the latitude. The equator is pi*r, where r = 7927 miles is the radius of our globe. Therefore we cover a distance of pi*r*cosL = 19830 miles in 23 hours and 56 minutes. Dividing yields 828.539 mph. A jet plane with a fierce tailwind just about could make this pace, which is why an afternoon flight westward to San Francisco will provide an extended sunset for the passengers. Note that the person standing on the equator moves roughtly 24,000 miles in 24 hours, but that is 24,000 miles per day rather than 24,000 miles per hour. At 24,000 mph, we would all be whirled off the globe and flung into space...

How fast are we moving around the Sun in our annual revolution?

Assuming the average distance is 93 million miles, the formula is 2*pi*r/t = 2 * pi*93000000/365.2564/24 = 66,658 miles per hour.

How fast are we and other parts of the Milky Way galaxy moving through intergalactic space?

Roughly 360,000 mph.

• One day is NOT the time it takes for the earth to revolve around it's axis completely. It is the time from mean noon to mean noon. The two differ because the earth revolves around the sun a little while it rotates once.
• A lunar month is NOT the time it takes for the moon to revolve around the earth. It is instead the average time it takes for the phases to repeat. The revolution period is 27.5 days. During this time, the earth has gone about 1/12.7 of the way around the sun. It takes an extra two days for the moon to catch up. So the phases repeat every 29.53 days.
• A year is NOT the time it takes for the earth to revolve around the sun. It is instead the time it takes for the seasons to repeat. That's the tropical year of 365.2422 days. The revolution time is 365.2564 days. The two are different because of precession - the earth revolves around like a top in 26,000 years. We go by the tropical year since it is more important that there be no snow in July than it is that we can see Scorpius and Sagittarius on July nights.