Is antarctica the closest thing to space exploration on Earth?
Yes, to a small extent. But Antarctica is a balmy sublime paradise compared with any other place we know of. Humans can survive there naked for a few minutes. But that isn't the case on the next most hospitable place in the solar system, which is our moon. Still we've learned many things about living in a closed environment there. And if we ever are to go living on the Moon, or Mars, or a planet of a distant star, that experience of Antarctica will be a valuable lesson for us. But we still have things to "learn" ... Like how to survive for years or centuries (or indefinitely) at a temperature of 4 degrees Kelvin, which is the temperature of interstellar space. Even the distant objects in our solar system would prove difficult for us. Pluto gets down to 30 K, but it gets as warm as 50 K ... That is in fact completely impossible for us with today's technology. Because we have no power source that could last long enough.