A. So far, no pieces of evidence pointing to extraterrestrial life have been found
--> correctly uses present perfect .So far represent something is going on
B. So far, no pieces of evidence pointing to extraterrestrial life were found
C. So far, no pieces of evidence pointing to extraterrestrial life are found
D. No pieces of evidence pointing to extraterrestrial life are being found, so far
E. No pieces of evidence pointing to extraterrestrial life had been found, so far
...
--> correctly uses present perfect .So far represent something is going on
B. So far, no pieces of evidence pointing to extraterrestrial life were found
C. So far, no pieces of evidence pointing to extraterrestrial life are found
D. No pieces of evidence pointing to extraterrestrial life are being found, so far
E. No pieces of evidence pointing to extraterrestrial life had been found, so far
...






