Which of the following best describes the current status of the evidence concerning whether life has ever existed on Mars?
A) Mars probably once had a habitable surface, but we do not know if it had life.
B) Clear evidence strongly suggests that life once existed on Mars.
C) Clear evidence indicates that Mars never had conditions favorable to life.
D) Although current evidence is mixed, ongoing studies should ensure that we will have a definitive answer to the question of whether life ever existed on Mars within about five years.
A) Mars probably once had a habitable surface, but we do not know if it had life.
You might also like to view...
A sample of tendon 3.00 cm long and 4.00 mm in diameter is found to break under a minimum force of 128 N. If instead the sample had been 1
50 cm long and of uniform composition and cross-sectional area, what minimum force would have been required to break it? A) 32 N B) 64 N C) 128 N D) 256 N E) 512 N
How much heat is required to raise the temperature of a 225-g lead ball from 15.0°C to 25.0°C? The specific heat of lead is 128 J/kg ? K
A) 725 J B) 576 J C) 145 J D) 217 J E) 288 J
In a two-body collision, if the kinetic energy of the system is conserved, then which of the following best describes the momentum after the collision?
a. must be less c. may also be conserved b. must also be conserved d. is doubled in value
I take 2.0 kg of ice and dump it into 1.0 kg of water and, when equilibrium is reached, I have 3.0 kg of ice at 0°C. The water was originally at 0°C. The specific heat of water = 1.00 kcal/kg•°C, the specific heat of ice = 0.50 kcal/kg•°C, and the latent heat of fusion of water is 80 kcal/kg. The original temperature of the ice was:
a. one or two degrees below 0°C. c. -120°C. b. -80°C. d. The whole experiment is impossible.