9781422283721

  All three near planets   can be seen shining like   stars in the night sky. Wander ing Stars

On many evenings of the year, a bright star appears in the twilight of the western sky. Only later, when the sky darkens, do the other stars come out. But this bright eve- ning star is not a star at all. It is the planet Venus. In a similar way, the two other near planets, Mercury and Mars, can at times be seen shining like bright stars in the sky. But even though they look like stars, the three planets are quite different from real stars. Real stars remain fixed in their constella- tions , or the star patterns we see in the sky. The planets change their positions among the constellations all the time. The ancient astron- omers saw this, which is why they called them planets, a Greek word meaning “wanderers.”

∆ Venus shines in the dawn sky as the morning star.

∆ A planet can be a morning star (left) or an evening star (right) depending on which side of the Sun it is.

10