Did Viking Find Signs of Life on Mars?
The primary goal of the Viking mission to Mars was to figure out whether its red soil contained life. The two landers conducted experiments on the Martian soil involving heating, wetting, and adding nutrients to test for signs of biological activity. None were found. In fact, the experiments showed a planet so dry and so blasted by ultraviolet radiation that almost all scientists concluded that the surface of Mars was not inhabited. Not everyone was convinced, however. More recent missions have not detected life, either, and this debate continues.
Purpose: to study the geology and atmosphere of Mars and look for signs of life
Spacecrafts: Viking 1 and 2, identical orbiters and landers
Lander touchdowns: Viking 1, July 20, 1976; Viking 2, September 3, 1976
Conclusions: found no clear evidence of life
Significance: the first successful landing of an Earth spacecraft on Mars
The Viking 2 Lander performed the same tasks as Viking 1, except that it:
took movies
climbed a mountain
recorded a Marsquake
Correct!
Unlike its sister spacecraft, Viking 2's seismometer worked—and recorded the vibrations of the Martian version of an earthquake.
The orbiters and landers of both Viking 1 and 2 were sterilized before they left for Mars.
Fact
To avoid contaminating Mars with microscopic organisms from Earth, all of the spacecrafts were treated to kill any possible life on board.
Viking images showed a dark blue Martian sky.
Fiction
Scientists expected the sky to be blue, but it's pink. It's caused by sunlight reflecting off reddish dust particles in the thin atmosphere.