An astronomer, or an astronomical scientist. People who combine astronomy with physics to try and learn more about how the Universe was formed and what it consists of, are called Cosmologists.
space scientist Astronomers is the correct name for your question.
An astronomer or an astro physicist.
The general name used for a person who studies space is an astronomer. Astronomers study everything from the stars, the planets and anything else involved with planetary science.
An astronomer.
A general term would be Solar physicist.
They could either be a planetologist, a planetary scientist, or planetary astronomer.
The name for someone who studies caves is a speleologist or a spelunker.
Someone who studies planetary systems is called a planetary scientist
There is no special name for someone who studies Hebrew.
Geologist.
microbiologist :)
chemist