Scientists have built Mars here on Earth -- at least within the walls of a simulation chamber that mimics conditions on the Red Planet down to its Martian dust, according to a paper out Tuesday.

The Spanish researchers built a vacuum chamber to reproduce conditions including temperature, pressure, gas composition and radiation on Mars, to help test gear designed for missions to the fourth planet from the sun.

The rovers -- and their advanced sensors and instruments -- are being used in NASA missions aimed at discovering whether the planet could ever have supported life.

"Mars is a good place to learn about planets similar to ours and, as such, is the target of many NASA and European Space Agency missions," explained lead researcher Jose Angel Martin-Gago, of Madrid's Instituto de Ciencias de Materiales.

His team is collaborating with NASA, mainly in helping develop meteorological instruments for upcoming rovers -- Mars vacuum chambers have already been used to test some of the weather sensors aboard Curiosity.

But the team has now incorporated another key factor in how sensitive instruments operate on Mars, they explained in their report in the journal "Review of Scientific Instruments."

"We're simulating the effect of the Martian dust -- one of the primary problems for planetary exploration -- to gain a better understanding of how instruments behave when covered in dust," said Jesus Sobrado, in charge of the machine's technical development.

Vacuum chambers can "answer many questions about Mars or other related planetary bodies -- both from scientific and technology points of view," he added.

NASA has two rovers actively exploring Mars -- the Curiosity rover which launched in 2012 and the smaller Opportunity rover which recently marked its tenth year in operation.

In addition to the Mars simulator, the team has also built vacuum chambers mimicking the environments on other planets and on Europa, one of Jupiter's icy moons, as well as the space between stars and between planets.