皆さん、窓を開けてご覧ください。今宵は満月です。デジカメで撮りました。ただ太陽光が正面【地球側から】から当たってるため、いつものように山脈やクレーターの影は見えません。
月の直径は約3470kmで、私たちの地球の直径は約12,742 kmですから、月の直径は地球の約4分の1です。
ところで、太陽の直径は月の直径の約400倍です。一方、月までの距離は約38万㎞で、太陽までの距離は約1億5000万㎞ですから、距離についても、太陽は月までの距離の約400倍です。つまり、宇宙空間で、両者は相似形の関係にあります。
このため、地球から見る満月と、地球から見る太陽の大きさはほぼ同じに見えます。
月は一ヶ月に一回公転し、一ヶ月に一回自転してるので、常に同じ月面を地球に向けてます。この理由については、あくまで「私の推測の範囲」ですが、月の内部の質量が均一でなく、月は中心より地球側の密度が高いことが理由と推測します。
Dear my earthlings
Everyone, please open the window now, and look the universe. There is a full moon tonight. I took it with a digital camera. However, since the sunlight hits from the front [from the earth side], the shadows of mountains and craters are not visible as usual.
As you know, the diameter of the moon is about 3470 km, and the diameter of our earth is 12,742 km, therefore, the diameter of the moon is about 1/4 that of the earth.
Not change the subject, but the diameter of the sun is about 400 times the diameter of the moon." On the other hand, the distance to the moon is about 380,000 km, and the distance to the sun is about 150,000,000 km, so the distance to the sun is about 400 times the distance to the moon. In other words, in outer space, the two celestial bodies have a similar relationship.
For this reason, the size of the full moon seen from the earth and the size of the sun seen from the earth look almost the same.
As you know, the moon revolves once a month and rotates once a month, so that the same lunar surface always faces our earth.
The reason for this is within the radius of my speculation, I guess it is because the mass inside the moon is not uniform and the density of the moon on the earth side is higher than at the center. What do you think of it?
最近のコメント