home / medterms medical dictionary a-z list / ethmoid sinus definition Medical Definition of Ethmoid sinus Ethmoid sinus: A collection of air cells within the ethmoid bone, a spongy bone which makes up the front of the floor of the skull and the roof of the nose. From the Greek ethmos, sieve + eidos, resemblance = like a sieve.
Confidence votes 84.8K. It takes 4.05 hours to 4.12 hours for light from the sun to reach Neptune, depending where it is in it's orbit. It takes 4.05 hours to 4.12 hours for light from the sun to reach Neptune, depending where it is in it's orbit.
The 12 to 18 hour rotation periods found for the atmospheric features differ from the above value because of winds. (see the related link for additional information) It takes Neptune 16 hours and 6 minutes to rotate once on its axis.  This means that one day on Neptune is the same as about 16 hours on  Earth.