Earth and Sky:Harvest Moon 秋分前后之满月

Harvest Moon 秋分前后之满月

Right now, as seen from the northern hemisphere, the ecliptic -- or path of the sun, moon and planets -- makes a narrow angle with the evening horizon. Learn more about the ecliptic -- and the Harvest Moon -- today on Earth and Sky..

DB: This is Earth and Sky -- Saturday, September 21. A listener asks, "Is the Harvest Moon bigger because it's closer to Earth than other full moons?"

JB: The answer is no -- the Harvest Moon isn't bigger or brighter or yellower or closer than other full moons. All full moons appear extra big just after rising, when they're still low in the sky. This is an illusion, which astronomers¹ call the "moon illusion."

DB: Meanwhile, the Harvest Moon is just one of many names for the full moon -- in this case, it's the full moon closest to the September equinox. The equinox is tomorrow or the next day -- depending on your time zone. So tonight's full moon is the Harvest Moon.

JB: The moon usually rises about 50 minutes later each day -- but at this time of year, in the northern hemisphere, the full moon rises around the time of sunset for several evenings in a row. In the southern hemisphere, the opposite is true. There's an extra long time between moonrises there. In both cases, the reason is the angle of the ecliptic -- or path of the sun, moon and planets.

DB: From the northern hemisphere now, the moon looks entirely² or nearly full for several evenings in a row -- as though September is a month with several full moons -- and with several chances to see the moon illusion. Maybe that's where the idea of the extra big size of the Harvest Moon came from.

JB: Special thanks today to Research Corporation -- a foundation for the advancement³ of science. We're Block and Byrd for Earth and Sky.

1 astronomers   

n.天文学者，天文学家( astronomer的名词复数 )

参考例句：

• Astronomers can accurately foretell the date,time,and length of future eclipses. 天文学家能精确地预告未来日食月食的日期、时刻和时长。 来自《简明英汉词典》
• Astronomers used to ask why only Saturn has rings. 天文学家们过去一直感到奇怪，为什么只有土星有光环。 来自《简明英汉词典》

2 entirely   

ad.全部地，完整地；完全地，彻底地

参考例句：

• The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。
• His life was entirely given up to the educational work. 他的一生统统献给了教育工作。

3 advancement   

n.前进，促进，提升

参考例句：

• His new contribution to the advancement of physiology was well appreciated.他对生理学发展的新贡献获得高度赞赏。
• The aim of a university should be the advancement of learning.大学的目标应是促进学术。