41.  That would show changes happening too rapidly to be caused by anything but liquid water.

42.  The calculations assumed a liquid water content of roughly between a third and one gram per cubic meter of water vapor, he said.

43.  The contemporary Mars is a rugged desert, frigid and with an atmosphere much too thin for liquid water to flow or pool on the surface.

44.  The leap to amino acids is said to take only the addition of liquid water.

45.  The prevailing thinking about Mars is that its thin atmosphere and dearth of liquid water would quickly extinguish any stowaways.

46.  The orbits of the planets are so close to the host stars that scorching temperatures there rule out the existence of life or liquid water.

47.  The three essential ingredients for life to begin are organic building blocks, energy and liquid water.

48.  The tidal ebb and flow would be especially pronounced on a body of liquid water.

49.  There is growing evidence that Europa has an ocean of liquid water beneath its icy crust.

50.  There is no liquid water on the Martian surface now, but scientists figure that the planet is water-rich.