What information did the scientists miss in 1948 and 1966 that caused them to believe that the caps contained water ice?

The information from Mariner 6 and Mariner 7

Explanation:

Because they had not been launched yet

practical process described pest part of scientific investigation.

because practical knowledge is powerful then therotical knowledge.

the ideal gas law equation is as follows

pv = nrt

where p - pressure

v - volume

n - number of moles

r - universal gas constant

t - temperature

so if the pressure, volume and temperature are already known

we are left with n and r

since r is the universal gas constant that has a known fixed value then r too is known

so we are left with 'n'

once we know temperature volume and pressure

we can find the number of moles of gas present using the ideal gas law equation

this is not my own answer, this is an answer for the same question by the user blahblahmali. i do not claim ownership of this account.