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.
A year is defined as the amount of time it takes for a planet to make an orbit around the sun. On Earth, this amount of time is 365 days and that's what we call a year. On Neptune, which is 30 astronomical units away or 30 times the distance, a year takes 165 Earth years so it takes 165 years for Neptune to complete its orbit and that is how long a Neptune year is. I'm Christopher Snead, a graduate student at UCLA's Department of Earth and Space Sciences. Thanks for watching.