Why is it Comet McNaught can be seen in both the evening and morning sky? Doesn't seem right.?

Question

From the Earth's standpoint the comet is either behind (evening) or ahead (morning) of the sun. Is this a weird positional geometry peculiar to this particular object?

Answer 1

It's like this:



evening..........\.........................
____________\______*_______< west horizon
###########/ O #################
############ \ ##################
############# \ ###################
############# \ ###################






morning.............../......................
_______*______/___________< east horizon
############ O ##############
############ / ##############
########### / ##############




The slanted line is the sun's path, the O is the sun, the dark area is underground, and the star represents the comet.


Even at exact conjunction an object can be seen in the evening and the morning, if it's far enough north of the sun (in the northern hemisphere), and only if the object's bright enough.

At all other times you're right, it's either seen after sunset or before sunrise but not both.

Venus does this sometimes, due to it's higher inclination of any planet. (not including Pluto)

Answer 2

Mercury and Venus are between the Earth and the Sun. There is a time when each is seen in the morning sky and then some time later seen in the evening sky. They are an example of something that exhibits both of these attributes. I bring this up to demonstrate there is nothing unique about something being seen in both the morning and evening sky.
It is also possible for the comet to be out of the plane of the planets and thus on a sequence of days to be visible in both the morning and evening sky.