According to the speaker, what do people often think about astronomers?

Most people think of astronomers as people who spend their time in cold observatories peering through telescopes every night. In fact, a typical astronomer spends most of his/ her time analyzing data and may only be at the telescope a few weeks of the year. Some astronomers work on purely theoretical problems and never use a telescope at all. You might not know how rarely images are viewed directly through telescopes. The most common way to observe the skies is to photograph them.

The most spectacular thing about the sea cucumber is the way it defends itself. Its major enemies are fish and crabs, when attacked, it squirts all its internal organs into the water. It also casts off attached structures such as tentacles. The sea cucumber will eviscerate and regenerate itself if it is attacked or even touched; it will do the same if the surrounding water temperature is too high or if the water becomes too polluted.