The planet nearest to the sun is named Mercury. It is distant from the sun about thirty-five millions of miles,[18] and is the smallest of the eight major planets. Mercury is so close to the sun that it is nearly always lost in the sun’s light, and can be seen by the naked eye only occasionally, immediately after a clear sunset, or before a clear sunrise. The telescope shows us that Mercury has phases as the moon has; possesses, as far as known, no satellites, and its path is not so nearly in a circle as that of other planets. To the naked eye it appears as a small star, with a white light faintly tinted with red. Lying so near to the sun it receives much more light and heat than we do. Its day is twenty-four hours long; its year has but eighty-eight days, and each of its seasons is but twenty-two days long. The shortness of the year and of the seasons is the result of the nearness of the planet to the sun, which so shortens its path that it can be traversed in less than three of our months. The next planet in order of distance from the sun is Venus, the most beautiful of what we popularly call stars. But Venus is a planet, not a star. Venus is visible nearly all the year, and is often the first star to shine forth in the evening or the last one to fade away in the morning. It has even been seen shining at noon-day. This dazzling light of Venus is supposed to be caused by a dense layer of cloud, which wraps the planet about, and proves an admirable reflector of the sun’s rays. The day of Venus is about half an hour shorter than our own;[19] its year is two hundred and twenty-four days. The French astronomer, Flammarion, tells us that mountains, much higher than any on our earth, have been measured on the planet Venus. The changes of temperature on Venus are much more sudden than on our earth; but it has no ice at the poles, for its winter does not last long enough for ice to accumulate as it does at the earth’s poles. As the orbit of Venus is between the earth and the sun, it happens that at certain times Venus lies between the sun and the earth, and so shows us its dark side. Again, when it is to the right or left of the sun, we see only a crescent formed by its quarter,[20] and it is at this phase that its mountains have been measured. Venus is sixty-six millions of miles from the sun, and when nearest us about twenty-six million miles from the earth, being, with the exception of the moon, our nearest neighbor in the skies.