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.
Orbit and Rotation of Neptune. The average distance between the Sun and Neptune is 4.55 billion km, and Neptune completes its orbit every 164.79 years; a year on Neptune is 164.79 Earth years. Despite this fact, it never appears in the same position in our sky because the Earth would have rotated in a different location during its 365.25 day orbit.