偶发流星和月分、南北半球的联系？？？

As seen from the mid-northern hemisphere (45N) one would expect to seeapproximately seven Sporadic meteors per hour during the last hour before dawn as seen from rural observing sites. Evening rates would be near two perhour. As seen from the mid-southern hemisphere (45S), morning rates would benear thirteen per hour as seen from rural observing sites and three per hourduring the evening hours. Locations between these two extremes would seeactivity between the listed figures.

北纬45度在黎明前2小时可以看见7颗偶发流星，而南纬45度却有13颗。同时看到偶发流星数又随月份而改变

Sporadic rates are low but steady as seen from the
mid-northern hemisphere (45 N). Sporadic rates seen from the mid-southern
hemisphere (45 S) rise this month toward a maximum in July.

南半球中纬度地区所能看到的偶发流星数将在7月达到最大值，这又是为什么


产生这种现象的原因是什么，请各位大侠指教

？？？？？？？？？？？？？？？？？？？

?????????????????

！！！！！！！！！！！！
偶不知道~~偶是菜鸟~