Michelle Firestone, age 10, of University Heights., Ohio..

Which planet is nearest to us?

In September 1956, Mars was the planet nearest to us, The earth and Mars were closer than 35 million miles. Then the two planets moved away from each other and about one year later they were more than 130 million miles apart, Sometimes Mars and the earth are 234 million miles apart. In September 1959, Venus was the closest planet and only wa,s 26 million miles away ‑ but not for long. In June 1960, nine months later, the earth and Venus were 160 million miles apart.

The planet Mercury can come no closer to us than 56 million miles but‑ when Mars and Venus are as far away‑as they can get, Mercury could be our nearest planet neighbor. Jupiter can dome no closer than 390 million miles and all the other planets must stay still further away from us. our nearest planet neighbor changes with the times. But it is always Mars, Venus or Mercury.

We can solve this problem with two looks at the Solar System. First, lens tell the whirling planets to stand still. We can then see where each one can go and where it can not go. For each must stay in its orbit and travel at its own speed.

The orbits are the planet paths around the sun. They are almost circles, though some are more oval‑shaped than others. Mercury has the inside orbit, about 36 million miles from the sun. The second orbit, about 6? million miles from the sun, belongs to golden Venus. The third orbits about 92 million miles from the sun, belongs to the earth, The fourth orbit belongs to Mars. It is an oval path with one end 129 million miles and the other end 1514 million miles from the sun. Our orbit is between the orbit of Venus and the orbit of Mars.

Now let’s set the planets whirling and being our still picture to life, Mercury traveling at 36 miles a second, whips around its orbit once every 88 earth days, Venus travels her yearly orbit in 225 earth days. Our earth takes us around. its orbit at about 18 1/2 miles a second. We make two circles around the sun while Mars is making only one. As they whirl around the sun, the inside planets patch up and pass the outside planets. The earth catches and passes Mars once in about two years. When this happens, Mars and earth are closest. Venus catches and passes the earth once in a little less than two years. When this happens, Venus and earth are closest.

Earth's orbit is an almost‑circle inside the oval orbit of Mars, At the closest point, the two orbits are less than 35 million miles apart. The planets whirl into this position every 15 or 17 years. The orbit of Venus is a. circle inside our orbit. The two paths are about 26 million miles apart, which means that Venus can come closer than any other planet. Earth and Venus whirl into this position once in every 591 days.