The Crab Nebula (See Figure 1-8 of Universe, 11th ed.) is the result of a supernova explosion of a star that occurred at a distance of about 1.99 kpc from Earth. If people on Earth saw the explosion in the year 1054 C.E., when did the explosion actually occur?
A) 936 C.E.
B) about 1048 C.E.
C) about 5446 B.C.E.
D) 936 B.C.E.

Question

The Crab Nebula (See Figure 1-8 of Universe, 11th ed.) is the result of a supernova explosion of a star that occurred at a distance of about 1.99 kpc from Earth. If people on Earth saw the explosion in the year 1054 C.E., when did the explosion actually occur? 
A) 936 C.E. 
B) about 1048 C.E. 
C) about 5446 B.C.E. 
D) 936 B.C.E.

Quizplus · Accepted Answer

To determine when the explosion occurred, we need to subtract the distance between Earth and the Crab Nebula from the year the explosion was observed on Earth: 1054 C.E. - 1.99 kpc = about 5446 B.C.E. Therefore, the correct answer is C.

The Crab Nebula (See Figure 1-8 of Universe, 11th Ed