Several years into the mission, MARSIS scientists began to see small, bright echoes under the south polar ice cap—so bright that the reflection could indicate not just rock underlying the ice, but liquid water. The researchers doubted the signal was real, however, because it appeared in some orbital passes but not others.
Liquid water spied deep below polar ice cap on Mars | Science | AAAS
（適当訳：南極の氷の下に液体の水らしき反応があった。まだ確実かどうかは分からない）
で、色々と他のデータを調査して、どうも水はあるようだという結論になり、今回の発表。
High levels of salt and temperatures dozens of degrees below zero do not bode well for any microbes trying to live there, Stillman says. “If martian life is like Earth life, this is too cold and too salty.” But he says researchers will want to look for other lakes under the ice and find out whether they are connected—and whether they point to an even deeper water table.
Liquid water spied deep below polar ice cap on Mars | Science | AAAS
Lakes might even turn up at lower, warmer latitudes—a location more suitable for a martian microbe, says Valèrie Ciarletti of the University of Paris-Saclay, who is developing a radar instrument for Europe’s ExoMars rover, due to launch in 2020. “The big, big finding would be water at depth outside the polar cap.”
（適当訳：塩分が濃く、温度も低い。地球の基準で言えば、寒すぎで濃すぎ。ただ、他にもあるかもしれない。
低緯度に微生物が生存できるもう少し温度の高い水もあるかもしれない。）
地球にも極限環境生物はいるから、寒くて濃厚な場所だって調べてみたくなるよね。
