PyEphem-为什么行星位置不匹配？

Question

这是我的简单代码

from ephem import *
sun = Sun()
moo = Moon()
northwich = Observer()
northwich.lat = '53.15'
northwich.lon = '02.31'
northwich.elevation = 36
northwich.date = '2008/1/1'
sun.compute(northwich)
print('%s %s %s' % (sun.ra, sun.dec, sun.mag))
//outputs - 18:43:12.00 -23:04:05.0 -26.8
moo.compute(northwich)
print('%s %s %s' % (moo.ra, moo.dec, moo.mag))
//outputs - 13:01:37.97 -10:19:59.3 -11.64

如果我将上述代码的输出与Astrology site进行比较，则位置/角度将不匹配-为什么？