Sir: Space exploration is a ceaseless story of overcoming problems. And as we all know, water is unique. The simple combination of hydrogen and oxygen is crucial for life. So, NASA’s latest discovery that water may flow on the red planet Mars, at least in the warmer months of summer, is indeed a major and exciting discovery. Even Google could not help but celebrate the incredible news. The Google Doodle for September 29 featured an animation celebrating the news about water on Mars. The liquid water on the surface of Mars is not in the form of rivers or lakes, instead the water is found soaking Martian hillsides, appearing as dark streaks called recurring slope lineae (RSL). It could be that salts in the Martian soil absorb water from the planet’s thin atmosphere. As it is extremely cold on Mars, so the water freezes until summer, then melts and oozes out as salty brine. It can also be that an underground aquifer or a reserve of ice beneath the soil is responsible for the flow. It can be any or all of these. Finding that out is the most important thing of all for NASA scientists. Merely concluding that there is water on Mars is a great milestone for studying the planet. But it is not worth all of the NASA’s hype. NASA did not even get into the origins of the water, which is the most important part of the whole discovery. If NASA has started their search for water in the solar system, then they should also think about exploring Jupiter’s moon Europa and Saturn’s moon Enceladus. Scientists think these worlds hide warm, habitable tons of water beneath their icy shells. SADIA KHALID Karachi