Kikiの畫圈圈角落

THE MOON ILLUSION 靠近地平線的月亮比較大?
You've probably noticed that the full moon appears to be larger when it is near the horizon than when it is high in your sky. However, this apparent size change is an illusion. If you measure the angular size of the full moon on a particular night, you'll find it is about the same whether it is near the horizon or high in the sky. The Moon's angular size in the sky depends only on its true size and its distance from Earth. Although this distance varies over the course of the Moon's monthly orbit, it does not change enough to cause a noticeable effect on a single night. You can confirm that the Moon's angular size remains the same by measuring it. You may also be able to make the illusion go away by viewing the Moon upside down between your legs when it is on the horizon.

WHAT MAKES THE NORTH STAR SPECIAL 北極星的特別之處?
Most people are aware that the North Star, Polaris, is a special star. Contrary to a relatively common belief, however, it is not the brightest star in the sky. More than 50 other stars are either considerably brighter or comparable in brightness. Polaris is special because it is so close to the north celestial pole. This position makes it very useful in navigation, because it closely marks the direction of due north and because its altitude in your sky is nearly equal to your latitude.

STARS IN THE DAYTIME 白晝的星星
Because we don't see stars in the daytime, some people believe that the stars vanish in the daytime and "come out" at night. In fact, the stars are always present. The reason your eyes cannot see stars in the daytime is that their dim light is overwhelmed by the bright daytime sky. You can see bright stars in the daytime with the aid of a telescope, and you may see stars in the daytime if you are fortunate enough to observe a total eclipse of the Sun. Astronauts can also see stars in the daytime. Above Earth's atmosphere, where no air is present to scatter sunlight through the sky, the Sun is a bright disk against a dark sky filled with stars. (However, because the Sun is so bright, astronauts must block its light and allow their eyes to adapt to the darkness if they wish to see the stars.

THE CAUSE OF SEASONS 四季
When asked what causes the seasons, many people mistakenly answer that the seasons are caused by variations in Earth's distance from the Sun. By realizing that the Northern and Southern Hemispheres experience opposite seasons, you'll see that Earth's varying distance fromt the Sun cannot be the cause of the seasons. If it were, both hemispheres would have summer at the same time. The real cause of the seasons is Earth's axis tilt, which causes the Northern and Southern Hemispheres to alternately receive more or less direct sunlight.