Seeing Mars.—We hear more of Mars than of any other planet for two reasons: first, because great lines can be seen on his surface which are thought to be canals, and second, since Mars sometimes comes almost as close to the earth as Venus, there has been a great deal of talk since the invention of wireless telegraphy about our signaling to him.
That people could live on Mars is possible, for the Red Planet is like our Earth, in that it has land, water and air, weather and seasons, with a warm equator and ice-covered poles. Seen through a telescope he looks like [Fig. 53], though much smaller.
Fig. 53.—Mars as Seen through a Telescope.
But Mars cannot always be seen, for sometimes he disappears for a couple of years, but when he finally does return he is a good planet, for he stays a long time, and you cannot mistake him, for he will shine ruddy and bright with never a merry twinkle.
Mars is 141 millions of miles from the sun.
- His diameter is 4,200 miles.
- His day is 24½ of our hours long.
- His year is 687 of our days long.
Seeing Venus.—Venus is so much brighter than any of the other stars or planets that you will know her the instant you see her. Indeed, when Venus is the brightest and the Sun is far enough away from her, she can often be seen with the naked eye in the daytime if the sky is clear. Three views of the phases of Venus are shown in [Fig. 54].
Fig. 54.—Three Views of Venus.