Who was the astronomer who worked at a space observatory trying to find signs of life on other planets and later nasa plan several crewless missions to explore the solar system?

a.
jonas salk

b.
carl sagan

c.
john f. kennedy

d.
carrie chapman catt

B. Carl Sagan

Explanation:

Carl Edward Sagan was an American astronomer, astrophysicist, cosmologist, astrobiologist, writer and popularizer. He was an advocate of scientific skeptical thinking and scientific method, pioneer of exobiology, promoter of the search for extraterrestrial intelligence through the SETI Project. He promoted the sending of messages aboard space probes, destined to inform possible extraterrestrial civilizations about human culture. Through his observations of the atmosphere of Venus, he was one of the first scientists to study the greenhouse effect on a planetary scale.

true

explanation: