Is Curiosity only an advanced science lab?

Published in The Hindu on December 1, 2011

curiosity rover

Curiosity has a suite of 10 scientific instruments including the very sophisticated instrument Chemistry and Camera (ChemCam). — Photo: NASA

Of course, it has a suite of 10 scientific instruments and is rightfully named the Mars Science Laboratory. Many of the instruments on board are first of their kind and will help in fulfilling the main objective of finding out if the conditions on Mars many millions of years ago ever favoured the existence of life.

For instance, it has very sophisticated instruments like the Chemistry and Camera (ChemCam). The laser in ChemCam can vaporise thin layers of material of rocks less than one millimeter in diameter from a distance of seven metres and identify the chemical composition.

According to scientists, the telescope in ChemCam will register the flash of glowing plasma created by the vaporised material and record the colours of light. The colours, which are nothing but spectral signatures, will be analysed by a spectrometer to find out the composition.

While the laser-induced breakdown spectroscopy in ChemCam has been successfully used for determining the composition of objects in difficult to reach or extreme environments like nuclear reactors and sea floor, this is the first time it is sent to another planet.

Curiosity also has the ability to drill and scoop samples from the Mars surface and conduct analysis using spectroscopy inside the spacecraft.

Apart from the chemical composition, the Mars Science Laboratory is equipped to find out the mineralogy of samples.

The Chemistry and Mineralogy (ChemMin) instrument uses X-ray diffraction to determine the mineralogy of the samples, a standard tool used by scientists. This is the first time that this instrument is ever being sent to another planet.

But any scientists would vouch that the success of studying samples taken for analysis depends on how well the sampling is done. Random selection of sampling sites or samples will have no meaning, as it may not reveal everything, and at times be completely misleading.

Field geologists often rely on visual inspection of the study area for different parameters like rock types, layering and possible minerals before deciding on the area to be sampled and the kind and number of samples to be taken.

If the samples to be studied are loose sand or soil, the texture, grain size etc are looked at before collecting the samples.

This is where Curiosity scores over its predecessors. The ChemCam is equipped with a telescope to image the small craters that the laser has made by vapourising the selected area.

The message relayed to scientists here will help them in determining the next target areas in the near vicinity to be sampled next.

Once the area has been chosen based on the image provided by ChemCam, MAHLI (Mars Hand Lens Imager) comes into the picture. MAHLI is the best instrument that mimics a handheld lens carried by field geologists.

Scientists will be able to have a close-up view of the structures and textures of both rocks and minerals. While this will provide ample information about Mars, it will greatly help in deciding if samples need to taken for further analysis.

According to R. Aileen Yingst, Planetary Science Institute researcher, MAHLI, with its high resolution camera, will be able to show a magnified view of the Martian surface.

As the American Astronomical Society states, Curiosity is both a Mars Science Laboratory and a geologist married into one.