Comet is seen after a long period of time. Why?​

Long-period comets have orbital periods longer than 200 years. ... Since it is the sublimation of these volatiles from the nucleus of the comet as it nears the Sun that gives rise to the coma and highly-visible tails, long-period comets have more material with which to put on a show.

Explanation:

in this image, you can see solar radiation going through ocean water.

no image, but probably absorption