BRIGHT CELESTIAL NEIGHBORS—
Take a peek low in your southwestern sky at dusk one of these clear evenings and you will see two very bright “stars” close together.
They, of course, are not stars at all; they are the planets Jupiter and Venus.
Jupiter is the higher one. Venus is the brighter one.
They appear close together simply because their orbits around the sun have them coincidentally in a similar line of sight from Earth.
It takes one Earth year for us to orbit the Sun at our distance of 93 million miles. It takes Venus 6/10 of an Earth year to complete its orbit because it is closer to the sun at just over 67 million miles. Jupiter’s distance from the sun is over 480 million miles therefore its single orbit takes 11.9 Earth years.
So, while they appear close together from our angle of view they actually are about 413 million miles apart.
Venus is the brighter of the two simply because of its relatively close proximity to the Sun and to us. Remember, light loses intensity over distance traveled and Jupiter is much further away.
At 5:30 p.m. on a recent evening these were the only two celestial bodies visible in the remaining daylight, and, your thumb held horizontally at arms length should just cover the distance between the planets.
Try it. One bright body directly above the other, the bottom one the brighter of the two, and separated by the thickness of your thumb at arms length. Nothing else low in the southwest sky at this time will meet those specifications.
And, this little exercise will prove you have good eyesight. You will be able to legitimately claim you can see a recognizable object at nearly 300 million miles distance.
Take a peek low in your southwestern sky at dusk one of these clear evenings and you will see two very bright “stars” close together.
They, of course, are not stars at all; they are the planets Jupiter and Venus.
Jupiter is the higher one. Venus is the brighter one.
They appear close together simply because their orbits around the sun have them coincidentally in a similar line of sight from Earth.
It takes one Earth year for us to orbit the Sun at our distance of 93 million miles. It takes Venus 6/10 of an Earth year to complete its orbit because it is closer to the sun at just over 67 million miles. Jupiter’s distance from the sun is over 480 million miles therefore its single orbit takes 11.9 Earth years.
So, while they appear close together from our angle of view they actually are about 413 million miles apart.
Venus is the brighter of the two simply because of its relatively close proximity to the Sun and to us. Remember, light loses intensity over distance traveled and Jupiter is much further away.
At 5:30 p.m. on a recent evening these were the only two celestial bodies visible in the remaining daylight, and, your thumb held horizontally at arms length should just cover the distance between the planets.
Try it. One bright body directly above the other, the bottom one the brighter of the two, and separated by the thickness of your thumb at arms length. Nothing else low in the southwest sky at this time will meet those specifications.
And, this little exercise will prove you have good eyesight. You will be able to legitimately claim you can see a recognizable object at nearly 300 million miles distance.
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