The discovery of the moon has made scientists worried about the mission.

In fact, scientists themselves worry considerably, sometimes to great effect.

Some scientists worry that we have reached a plateau of understanding from which further progress will be difficult and unlikely.

This is no walk in the park, but these scientists worry about gathering accurate data, not hardship.

Bears are not the only animals the scientists must worry about.

Russian nuclear scientists themselves worry about the security around non-military or research institutions.

For example, scientists worried that the first nuclear test might ignite the atmosphere.

And scientists worry that the public and Congress don't understand the distinctions.

European governments and scientists worry about another form of backlash.

Human scientists worried about all these questions, too, in the days before we met the Heechee.