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 average distance from the Earth to Neptune is about 4,564 million km and the shuttle at top speed is about 27,870 km/h so forgetting about minor details of acceleration etc, and planets positions, in a straight line, you would reach Neptune in about 18.7 years. Paul Yost.t the fastest current spacecraft speed (other than re-entry from the Moon), which is about 60000 km/hr, it would take at least 100 days to reach Mercury, depending on its pos â¦ ition in its orbit. It could take as long as 120 days.