Nasa’s announcement that Curiosity did not detect methane in Mars’ atmosphere may disappoint India’s space scientists, say reports. Hunting for methane is a prime focus of India’s first interplanetary mission: the Mars Orbiter Mission (MOM), scheduled to be launched later this month. Methane is a by-product of living organisms and spotting traces of the gas would have increased the likelihood of the Red Planet harbouring some form of life.
ISRO scientists, however, deny any such concerns. “It would be naïve to believe that Curiosity’s findings confirm the absence of methane in the Martian atmosphere,” MOM project director S Arunan said. “The presence of methane is probably localised and not to be found homogenously distributed. It is likely present only in certain regions of the atmosphere.”
Moreover, the detection of methane in the alien atmosphere also depends on other factors such as solar activity. A Methane Sensor for Mars (MSM) payload is one of five scientific experiments on board the MOM spacecraft and it will seek to detect methane in a different region of the planet’s atmosphere.
The latest data sent back by Curiosity merely underlines the ‘now you see it, now you don’t’ aspect of Mars. Tell-tale signs of conditions essential for life on Mars have so often turned out to be false alarms — since the 1890s, when Percival Lowell mistook an optical illusion for Martian ‘canals’, to recent ‘discoveries’ by robotic probes that hint at the presence of water or even microorganisms.
Scientists have used terrestrial telescopes to remotely analyse Mars’ atmospheric chemistry and concluded that methane is indeed present there. And the ESA’s Mars Express Orbiter mission recorded anomalous methane readings there in 2004. Since the MOM is designed to emulate the European orbiter’s observations, the Indian probe may well resolve one of the most enduring mysteries in this solar system.
The MOM is scheduled for launch on October 28 (with a window that extends till November 19). Every two years, a narrow window opens up, which allows an optimal trajectory to be achieved for a Mars mission by combining the least amount of fuel with the shortest journey time.
Orbital mechanics of both Earth and Mars dictate this. Indeed, another mission is also gearing up to use the new launch window: Nasa’s Mars Atmosphere and Volatile EvolutioN (MAVEN) mission will launch on November 18. MAVEN will study key aspects of Martian history such as the effects of the solar wind that interacts with the atmosphere, and how the atmosphere lost its water, nitrogen and carbon dioxide over time.
If nothing goes wrong, MOM will swing into Mars orbit in August 2014 while MAVEN will reach a month later. Suddenly the Martian orbit looks set to become quite crowded with the two spacecraft expected to join Nasa’s Mars Odyssey and the Mars Reconnaissance Orbiter, apart from the Mars Express Orbiter.
Thanks to these missions, within the next few years, we may have mineralogical maps of Mars that would be even better than those of Earth. MOM carries a thermal infrared imaging spectrometer to map Mars’ surface composition and mineralogy. That would mean a better understanding of Mars’s geologic and meteorological features — invaluable for the first human visitors on the planet.
By then, mankind would probably have definitive or at least plausible answers to questions like what makes the Martian sky pink; or whether Marsquakes occur; or how the surface has been scarred by sheared rocks and polygonal gouges in the ground. Or, indeed, if life forms – even if they are microbes – define the biochemistry of this intriguing planet.
Prakash Chandra is a science writer
The views expressed by the author are personal