CHAPTER XIV.. The Planet Mars.

THE PLANET MARS.

Next outside the pathway of Venus comes the pathway of another planet, named EARTH--this same globe on which we live. From it, as from a little boat on the great ocean, we look out upon other floating worlds, and upon the countless stars.

We can see the worlds and stars, but we cannot get to them. All of us are prisoners upon this little Earth-boat, during our earthly lives.

As a Planet our Earth is one of the smaller worlds. She is nearly 8,000 miles through, and about 25,000 miles round. She has a north pole and a south pole, and an equator. She has many continents and oceans, part of her surface being Land, and a larger part being Water.

The Earth spins on her axis once in twenty-four hours; and she travels round the Sun once in twelve months, going at a rate of about nineteen miles each second.

This is not so fast as Venus, and not nearly so fast as Mercury; yet it is seventy times faster than the speed of a cannon-ball.

Think of our whole big Earth, with all of us on board, rushing wildly through the sky more than seventy times as fast as a cannon-ball rushes through the air. Only it is not “wildly;” the movements of the worlds, though very rapid, are calm and quiet.

Our Earth, like Mercury, goes sometimes a little faster and sometimes a little more slowly. When nearer to the Sun she travels faster, and when farther off from him she travels more slowly. But the differences in her speed are much less than in Mercury’s, because her pathway is not so oval in shape, and so she is always more nearly at one distance from the Sun.

Outside Earth’s pathway is that of MARS, the last of the Four Lesser Worlds.

His untwinkling red gleam is easily seen. Not always in the east or west, like that of Mercury and Venus; but, like all the outer planets, in different parts of the sky at different times.

Mars is much smaller than our Earth. He is only some 4,000 miles straight through. A big knitting-needle which might run just through him would have to be twice as long as one for the Moon, but only half as long as one for the Earth.

It takes Mars about twenty-four hours and a half to spin once on his axis; so days and nights are much the same in length there as with us. His axis, too, seems to lean over very much as our Earth’s axis does, and that would give Mars seasons a good deal like ours.

Only, as the year of Mars is almost as long as two Earthly years, his seasons would last much longer. Spring and summer, autumn and winter, would be each about five or six Earthly months in length.

The distance of Mars from the Sun is about 140 millions of miles.

So Venus is somewhere about twice as far off from the Sun as Mercury. The Earth is about three times as far as Mercury. Mars is more than four times as far as Mercury.

Mars is a very interesting little world. Not so brilliant or lovely as Venus, but really more easy for us to study and examine. Venus seems to be so covered with masses of white clouds that we can see very little of the planet itself; but Mars is not covered with clouds.

Mars never comes so near to us as Venus does. Only, unfortunately, Venus at her nearest cannot be seen at all, because her bright side is turned away from the Earth and towards the Sun. While Mars at his nearest, being outside the Earth, can be looked upon nicely, for the Sun then shines full upon that side of Mars which is towards us.

When we talk of “studying and examining” a world which never by any chance comes closer than 35 millions of miles away, we have to be careful. It does not do to guess at things, or to be in a hurry to settle what cannot be truly known.

Even with the Moon we found that the biggest of telescopes cannot make her look very much less than one hundred miles away. But Mars is a great deal farther off than the Moon.

Just think of the difference! The 240 thousands of Moon-distance are changed into 35 millions of miles for the distance of Mars. And the most powerful telescope cannot bring down those 35 millions of miles to less than about 35 thousands of miles.

So when people talk about Mars, and about what may be seen on Mars, remember this--that at the very best we can only see Mars as we should see a world 35 thousands of miles away!

On the Earth even a hundred miles seems a long distance. From the top of a mountain one can see to a hundred miles no doubt, in clear weather; but very little can be made out at such a distance. Yet a hundred miles would be only a small piece of one country. It takes ten hundreds to make a thousand, and a thousand miles off seems to us very far indeed.

Nobody on the Earth can ever be farther from us than about 8,000 or about 12,006 miles off, that is, through the middle of the Earth 8,000 miles, or reckoning round the outside rather over 12,000. You know how distant Australia seems from us.

But Mars at his nearest, and looked at through the largest of telescopes, is still only seen as a world three times farther away than the very farthest off country upon this whole Earth from you or me.

Of course it is very wonderful that a planet thirty-five millions of miles away can be actually seen through a telescope as if it were only thirty-five thousands of miles away. Still, at the best, thirty-five thousands of miles is a pretty good distance.

Although we cannot find out half or a quarter of what we want to know about Mars, still we do know a good deal. The big telescopes tell us much, and another instrument, called a “spectroscope,” tells us yet more. But in this small book I cannot even try to explain to you what a “spectroscope” is.

See “Sun, Moon, and Stars,” page 307.

We know that Mars has some sort of air, perhaps rather like our Earth air, only more thin. We know that water floats in that air, as water floats unseen in our air.

As for climates, one might expect Mars to be terribly cold at such a distance from the Sun. He cannot have half the quantity of light or heat that we have. Yet, somehow, there seem to be signs that Mars is not a very much colder world than our Earth is.

At the north pole and the south pole of Mars tiny white caps, or patches, are seen; and these are most likely made of ice and snow. We on the Earth have always ice and snow at our two poles; and people on another world, a long way off, might perhaps see our polar ice and snow as white caps, or patches.

Sometimes clouds are seen to flit across Mars, white clouds, like the white clouds which cover Venus. This only means that they are white outside, on the upper surface, where the Sun shines. They may be gray below, like so many of our gray Earth clouds, though we also often see clouds white and shining in sunlight. And when a man gets up a high mountain above the clouds, and looks down upon them, he sees their upper surface, white as snow and beautifully bright.

Mars commonly looks red, when seen without a telescope. If seen through a telescope, greenish and purplish patches are found. It is very likely that the one color shows land and the other water. Since Mars has water-vapor in the air, and probably snow and ice at the poles, he is pretty sure to have oceans also. But the continents and oceans of Mars are differently shaped from ours. There seems to be more of land and less of sea.

Thus in a good many ways Mars is not so very unlike our Earth, his next-door neighbor. Day and night seem to be much the same in both worlds, also summer and winter. We think, too, that we find there air and water, snow and ice, lands and seas, changes of weather and differences of climate, more or less like those of the Earth.

But if you ask me whether animals and men and women and children live on Mars, I can only say that nobody knows. It may not be impossible, so far as we are able to judge. We feel pretty sure that no living creatures such as we ever see on the Earth could exist on the Moon or the Sun. And with Mercury, if not also with Venus, we are hardly less sure, when we think of the intense glare and awful heat in which those two worlds travel.

With Mars there is some difference. Knowing the little we do know, it certainly seems a thing by no means out of the question that living creatures might find a home on Mars--creatures not utterly unlike those upon the Earth. But we cannot for a moment say that they do.

One difference between Mars and the Earth which would make life there very unlike life on the Earth is its small size.

On Mars, as on the Earth, there is the “pull” of attraction. “Downward” all round the planet is towards the centre of Mars, and “upward” all round is towards the sky of Mars; and everything in Mars is heavy towards the centre of the planet.

But the pull there is much less than here, because Mars is so small; and the less pull means less weight. A lump of iron which weighs ten pounds on the Earth would weigh less than five pounds on Mars. If a man went to Mars he would be as light there as a boy on the Earth; and if a boy went there he would weigh as little as a baby on the Earth.

The two moons which travel with Mars are very tiny, perhaps only about eight or ten miles through.

Between the planet Mars and the planet Jupiter lies an enormous gap of millions of miles empty of all large worlds, even of worlds as big as our Moon.

Somewhere about the middle of that vast gap, about half-way between Mars and Jupiter, is the belt of PLANETOIDS.

Less than four hundred of them are as yet actually known to us; but perhaps thousands of them may be there. Each of these tiny planets has its own pathway round the Sun, and their pathways do not keep nearly to the level of the Earth’s pathway, like those of the bigger worlds.

Vesta, the largest of them all, is perhaps over three hundred miles through, and three others come rather near Vesta in size. The greater number are under one hundred miles through; some being mere balls, about the size of Mars’ moons.

QUESTIONS.

1. Which is the next planet outside Venus?

The Earth on which we live.

2. How far is the Earth from the Sun?

About 92 millions of miles.

3. How fast does our Earth travel?

About 19 miles each second.

4. How long is the Earth’s year?

About 365 days, or 12 months.

5. Which is the next planet outside the Earth?

Mars.

6. What is the diameter of Mars?

About 4,000 miles, or half that of our Earth.

7. How far is Mars from the Sun?

About 140 millions of miles.

8. How long is Mars’ year?

Nearly twice as long as our year.

9. Does Mars spin on his axis?

He is believed to do so, in twenty-four hours and a half.

10. How near does Mars come to us?

Never closer than 35 millions of miles off.

11. But how much nearer does the most powerful telescope seem to bring Mars?

Perhaps to about 35 thousands of miles off.

12. Are air and water found on Mars?

Some kind of air, and water also, and ice and snow.

13. Are there oceans on Mars?

There are patches of color which may be continents and oceans.

14. Where are ice and snow perhaps seen on Mars?

White caps are seen at the two poles.

15. Is Mars inhabited?

Nobody can tell. It does not seem to be quite impossible, so far as we understand what Mars is like.

16. Which planet comes next after Mars?

Hundreds of Planetoids come next.

17. Are they close to Mars?

No; there is a great space between Mars’ pathway and Jupiter’s pathway; and the Ring of Planetoids lies somewhere about the middle of that great space.

18. What is the name of the biggest Planetoid?

Vesta.