Venus, Earth, and Mars
Now we see the inner solar system, or at least a portion of the orbits of three of the four inner planets. Mars' orbit is just visible in the upper left and Venus lies inside Earth's orbit. Earth and Venus are nearly identical in size, Venus being just 5% smaller than Earth. Mars is substantially smaller, just 2/3 the size of Earth and with less than half of Earth's surface area. Currently a spacecraft from Earth is launched toward Mars on a trajectory that takes about six months to reach Mars. This portion of Earth's orbit spans about six weeks in the months of July and August.
Copyright © 2016 by Bruce Bryson