“Almost Perfect” Samples are Scraped From Mars Surface For Analysis

With the Phoenix Mars lander in full science-operation-swing, the robotic arm has just scraped an “almost perfect” mix of regolith and water ice for its next analysis. Using a blade on the scoop, the robotic arm carried out 50 scraping actions across the bottom of the enlarged “Snow White” trench that was excavated on June 17th (22 sols since Phoenix touched down). Today, on Sol 33 of the mission, Phoenix has been preparing little mounds of dirt ready to be scooped up and dropped into the Thermal and Evolved-Gas Analyzer (TEGA) so the constituent minerals and water can be analysed. Besides, Phoenix has just built the first ever mini-sand castles on the Martian surface!

On Sol 24 of the mission, only 24 sols after it landed on Mars, Phoenix found the first evidence of water ice on the Martian surface. Pictures taken four sols apart showed a white substance had sublimed into the tenuous Martian atmosphere at about the correct rate for water ice under those conditions. This was after a bumpy start when the clumpy regolith didn’t make it past the TEGA screen in a preliminary oven experiment. Then last week, Phoenix carried out a preliminary “wet-lab” test with the Microscopy, Electrochemistry and Conductivity Analyzer (MECA) instrument and found the mix of minerals in the Mars regolith and its pH levels had a striking resemblance with soils commonly found here on Earth. With all these groundbreaking discoveries mounting up, what can we expect next?

Well, today’s announcement suggests the next step is to thoroughly prepare small piles of samples scraped from the bottom of a trench called “Snow White” dug on Sol 22. Once this is complete, each sample (containing approximately two to four teaspoonfuls) can then be sprinkled into the TEGA instrument so thorough analysis can take place. The bottom of Snow White appears to be rich in water ice, so the scraping action will have created small particles of regolith and small ice crystals. Having encountered the clumpiness of regolith before, the mission scientists are keen to push ahead with some flawless experiments.

Having overviewed the small samples, agreeing that the piles were “almost perfect samples of the interface of ice and soil,” Phoenix has been sent commands to scoop up each pile of dirt and sprinkle them into the TEGA. The instrument will then bake and analyse the soil to assess its volatile ingredients, like water. The melting point of the water ice can also be assessed. Once the data has been transmitted back to Earth scientists can begin to study the constituents of the sub-surface regolith, gaining a detailed look into just how hospitable the Red Planet could be.

Keep making those little sand castles Phoenix, we’re watching you very closely…

Source: Phoenix (University of Arizona)