No verified form of life which originated outside of Earth has ever been observed. If life evolved on Earth, one would expect that the elaborate experiments sent to the Moon and Mars might have detected at least simple forms of life (such as microbes) that differed in some respects from life on Earth.a [See “Is There Life in Outer Space?” on page 530.]
Figure 6: Mars Lander. Many people, including Carl Sagan, predicted the Viking landers would find life on Mars. They reasoned that because life evolved on Earth, some form of life must have evolved on Mars. That prediction proved to be false. The arms of the Viking 1 Lander, shown above, sampled Martian soil. Sophisticated tests on those samples did not find even a trace of life.
If traces of life are found on Mars, they may have come from comets and asteroids launched from Earth during the flood—as did salt and water found on Mars. [A prediction, later supported by a NASA discovery, is on page 316. For a full understanding, see pages 303–362.]