The obvious is...outside of the nearly 1/3rd martian gravity
all of the local conditions on Mars can be replicated in a laboratory.
Air pressure, temperature, radiation, atmospheric composition, soil composition
and [yes] even winds on a small scale...inside a LAB CHAMBER.

Even I, Nick, with the limited financial resources that I have can
build a crude but effective hermetically-sealed lab chamber
with a 6-8 millibar gas pressure inside; capable of being frozen repeatedly
down to dry ice temperatures; and the contents inside being
seared by a UV light installed.

DAMMIT, NICK!...IT'S NOT THE WORDS MOUTHED OR TYPED OUT
THAT PROVE ANYTHING!!!
It's the data obtained, THERE!!! [on Mars]...and also that which can
be reproduced in a lab chamber, HERE!!! [on Earth]