Which number is closest to the age of our solar system?

A. 450,000 years

B. 4.5 million years

C. 450 million years

D. 4.5 billion years

D. 4.5 billion years

Explanation:

Scientists study meteorites to determine the age of our solar system, since they are the oldest accessible material out there. Earth itself has rocks that are over 4 billion years old.

In recent times, meteorites have informed our view of, and our priorities about, what spacecraft - and perhaps, one day, human explorers - might find on Mars and other planets. And we now recognize that a cosmic delivery of life with an independent origin from our own would revolutionize our ideas about the extent of life throughout the whole known Universe.