This allowed observations to be made under all weather conditions.

The method is designed to allow ready observation of rare events with respect to time.

It seemed hours before the tumult had died down enough to allow direct observation of the world outside.

Nor could he allow approach or even prolonged observation of the system's gas giants that might, perhaps, have become stars themselves.

For solar observations, filters allow direct observation of the sun.

Several parks and ecological preserves allow observation of the local wildlife.

It was modified to allow solar observations in 1989.

It also allows observation of frequency bands that are blocked by the atmosphere.

The aircraft can also travel to almost any point on the Earth's surface, allowing observation from the northern and southern hemispheres.

The extra time would allow observations from the high point and low point in the 11-year cycle of solar emissions.