11.   Experts from the Marine Biological Laboratory in Woods Hole, Massachusetts, tested the Rio Tinto and were surprised to find it teeming with microscopic life.

12.   The probe could even provide information on the microscopic life that scientists announced this past summer had once existed on Mars.

13.   On Earth, most forms of microscopic life get their energy from oxygen, which is derived from sunlight.

14.   The debate over the presence of microscopic life on Mars has been reopened by two new studies of a meteorite from the Red Planet published Friday in Science magazine.

15.   The laboratories could have also provided information on the microscopic life that scientists announced this summer had once existed on Mars.

16.   The laboratories could have also provided information on the microscopic life that scientists believe may once have existed on Mars.

17.   The laboratories could have also provided information on the microscopic life that scientists announced this summer may once have existed on Mars.

18.   The presence of microscopic life on Mars is a very real possibility, according to scientists gathered here for a two-day conference.

19.   The probe could even have provided information on the microscopic life that scientists announced this past summer had once existed on Mars.