He often used a telescope for celestial observations from the roof of the house.

The parameters of a celestial observation that makes it significant in science, include the position, timing, and wavelength.

With t time moving so did the technology in celestial observation and physical science of astronomy.

These celestial observations made by simple men have resulted in further investigations by today's scientists.

Drew's first celestial observations were made with a three and a half foot refractor.

He used these figures for celestial observations to supplement his dead reckoning.

The navigator also had a position for celestial observation at the rear of the cabin.

A stop watch, either spring wound or digital, may also be used for celestial observations.

Not only did Brattle prepare almanacs, he also made celestial observations.

Unable to make celestial observations, the ship's crew was forced to rely on dead reckoning to determine their position.