Dawn Schmitt, age 12, of Coventry, Rhode Island, for her question:
What does the earth look like from other planets?
We always knew that our earth is a lovely planet. But until it was photographed from outer space, we never imagined its real breath taking beauty. Seen from above the atmosphere, its round disk is scrolled with the flowing lines of pastel continents and sapphire seas, revealed and concealed by scarves of shifting clouds. These jewel toned features of our beauteous earth can be seen from as far away as the moon.
As we know, our planet is a solid globe and from outer space its daylight side shines with reflected glory from the sun. This is true of the other planets and at least some of them must see us more or less as we see them. Venus should have the biggest and brightest view of the earth but it does not. This is because its deep, dense, dusty atmosphere blots out everything in the Vesuvian sky.
From Mercury, whenever the earth is in sight, it must appear as a big bright round disk. This is because Mercury has an inner orbit and it sees only the side of our globe that faces the sun. If there were Martians, they would see the earth very much as Venus appears to us. They would watch it play the roles of the Morning and Evening Stars. And, because our orbit is closer to the sun, the view from Mars would show our daylight side fn sections, much as we see the changing phases of the moon.
Giant Jupiter is li times wider than the earth. When it is visible in our skies we always see the full disk of its daylight side and sometimes it outshines all the stars in the sky. But if there were Jovian astronomers, they would need better eyes than ours to see the earth in their skies. Observers on Saturn and the other outer planets would need superior telescopes to find our little planet.
Jupiter's huge orbit is almost 400 million miles farther from the sun than ours. Viewed from out there, our planet would appear to weave from side to side of the sun. It is never farther from the dazzling, sun than 12 degrees, which is about 24 times wider than the full moon appears to us. From Mars, the earth appears to weave about 48 degrees on each side of the sun. On Earth, our views of the other planets change from day to day. From the other planets, the earth also appears to change from day to day.
Venus should have the best view of the earth when we are both on the same side of the sun. Then the distance between us may be merely 24 million miles. If Venus were cloudless, an observer would see our full daylight side in all its golden glory. At this time, however, Venus would be invisible to us. This is because its dark, nightside is then turned to face outward in our direction.