Writing and Reading

     [1] Controversy still surrounds the origin, abundance, and history of water on Mars. [2] Recently, NASA and an international team of planetary scientists have found evidence in meteorites on Earth that indicates Mars has a distinct and global reservoir of water or ice near its surface. [3] They reached this conclusion by ascertaining that water in the meteorites contained hydrogen atoms with a ratio of isotopes distinct from that found in water in the Red Planet’s mantle and current atmosphere. [4] This discovery helps resolve the question of where the “missing Martian water” may have gone. [5] Scientists continue to study the planet’s historical record, trying to understand the apparent shift from an early wet and warm climate to today’s dry and cool surface conditions.
The writer wants to add the following sentence.