Researchers concerned with space exploration say they have discovered new evidence that Mars once had a large northern ocean. The discovery adds to existing evidence that the ancient Mars had the right conditions to possibly support some form of life.
Today, any water on Mars is believed to be in the form of ice because of the planet's extremely cold desert temperatures. But there is a rich amount of evidence suggesting that rivers, lakes and even oceans once existed on Mars. A study by the American space agency NASA suggested that billions of years ago, Mars likely had an ocean that covered nearly half of Mars' northern hemisphere(半球). Another NASA-supported study estimated that about several billion years ago, the climate in much of the planet's northern hemisphere was very similar to today's Earth. The study noted that at that time, Mars likely had a much thicker atmosphere than today and had an active northern ocean.
Two American researchers recently released a set of maps to provide new environmental evidence of a large ancient ocean on Mars' low-lying northern hemisphere. The team collected data from satellite images and photos of Mars. They then combined them to create maps of the planet's northern hemisphere. Using the maps, the researchers were able to piece together evidence of shorelines that sat at the edge of a huge body of water about 3.5 billion years ago.
The researchers published their findings in the Journal of Geophysical Research：Planets. Benjamin Cardenas, a professor at The Penn State University, was a co-writer of the study. He said the study's findings showed the possible ocean in that area of Mars was changeable and interesting. "It was dynamic(动态). The sea level rose significantly," he said. "Rocks were being deposited(沉积) along its basins at a fast rate. There was a lot of change happening here." Besides, Cardenas suggested the new study also provided useful information on Mars' ancient climate and developmental history. "Based on these findings, we know there had to have been a period when it was warm enough and the atmosphere was thick enough to support this much liquid water at one time," he said.
