New Evidence for Large Ancient Ocean on Mars
2022-11-07
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1Researchers say they have discovered new evidence that Mars once had a large northern ocean.
2The finding adds to existing evidence that ancient Mars had the right conditions to possibly support some form of life.
3Today, Mars has a cold, desert climate.
4Any water is believed to be in the form of ice because of the planet's extremely cold temperatures.
5But there is a rich amount of evidence suggesting that rivers, lakes and even oceans once existed on Mars.
6For example, a 2015 study by the American space agency NASA suggested that 4.3 billion years ago, Mars likely had an ocean that covered nearly half of Mars' northern hemisphere.
7Another NASA-supported study, published in January, estimated that three billion years ago, the climate in much of the planet's northern hemisphere was very similar to present day Earth.
8The study noted that at the time, Mars likely had a much thicker atmosphere than today and had an active, northern ocean.
9Now, two American researchers have released a set of maps they say provides new environmental evidence of a large ancient ocean on Mars' low-lying northern hemisphere.
10The team collected data from satellite images of Mars.
11They then combined these images to create topography maps of the planet's northern hemisphere.
12Using these maps, the researchers said they were able to piece together evidence of shorelines that sat at the edge of a huge body of water about three-and-a-half billion years ago.
13The scientists recently published their findings in the Journal of Geophysical Research: Planets.
14The team said it used software developed by the United States Geological Survey to map data collected by spacecraft operated by NASA.
15The research uncovered more than 6,500 kilometers of ridges that are believed to have been formed by flowing water.
16The scientists say the ridges likely represent the leftover evidence of eroded river systems and an ancient ocean floor.
17The team said its research also suggested large levels of sediment, providing further evidence of a large ocean.
18Benjamin Cardenas was a co-writer of the study.
19He is a professor of geosciences at Penn State University in Pennsylvania.
20He said in a statement the area of Mars studied - now known as Aeolis Dorsa - contains "the densest collection" of water-formed ridges on the planet.
21Cardenas said the study's findings demonstrate the possible ocean in that area of Mars was very active and interesting.
22"It was dynamic. The sea level rose significantly," he said.
23"Rocks were being deposited along its basins at a fast rate. There was a lot of change happening here."
24Cardenas added that areas on our own planet containing water-formed ridges and sediment provide researchers with much useful information about an area's climate and life forms.
25"If scientists want to find a record of life on Mars, an ocean as big as the one that once covered Aeolis Dorsa would be the most logical place to start," he said.
26The team noted that the major goal of NASA's Mars explorer, Curiosity, is to look for signs of ancient life on the planet.
27Currently, Curiosity is operating within the planet's Gale Crater, which is in the southern hemisphere of Mars.
28In the past, researchers have also found evidence of past water systems around Gale Crater.
29In addition to providing more evidence of a large ocean, Cardenas suggested the new study also provides useful information on Mars' ancient climate and developmental history.
30"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.
31I'm Bryan Lynn.
1Researchers say they have discovered new evidence that Mars once had a large northern ocean. The finding adds to existing evidence that ancient Mars had the right conditions to possibly support some form of life. 2Today, Mars has a cold, desert climate. Any water is believed to be in the form of ice because of the planet's extremely cold temperatures. But there is a rich amount of evidence suggesting that rivers, lakes and even oceans once existed on Mars. 3For example, a 2015 study by the American space agency NASA suggested that 4.3 billion years ago, Mars likely had an ocean that covered nearly half of Mars' northern hemisphere. 4Another NASA-supported study, published in January, estimated that three billion years ago, the climate in much of the planet's northern hemisphere was very similar to present day Earth. The study noted that at the time, Mars likely had a much thicker atmosphere than today and had an active, northern ocean. 5Now, two American researchers have released a set of maps they say provides new environmental evidence of a large ancient ocean on Mars' low-lying northern hemisphere. 6The team collected data from satellite images of Mars. They then combined these images to create topography maps of the planet's northern hemisphere. 7Using these maps, the researchers said they were able to piece together evidence of shorelines that sat at the edge of a huge body of water about three-and-a-half billion years ago. 8The scientists recently published their findings in the Journal of Geophysical Research: Planets. 9The team said it used software developed by the United States Geological Survey to map data collected by spacecraft operated by NASA. The research uncovered more than 6,500 kilometers of ridges that are believed to have been formed by flowing water. 10The scientists say the ridges likely represent the leftover evidence of eroded river systems and an ancient ocean floor. The team said its research also suggested large levels of sediment, providing further evidence of a large ocean. 11Benjamin Cardenas was a co-writer of the study. He is a professor of geosciences at Penn State University in Pennsylvania. He said in a statement the area of Mars studied - now known as Aeolis Dorsa - contains "the densest collection" of water-formed ridges on the planet. 12Cardenas said the study's findings demonstrate the possible ocean in that area of Mars was very active and interesting. "It was dynamic. The sea level rose significantly," he said. "Rocks were being deposited along its basins at a fast rate. There was a lot of change happening here." 13Cardenas added that areas on our own planet containing water-formed ridges and sediment provide researchers with much useful information about an area's climate and life forms. "If scientists want to find a record of life on Mars, an ocean as big as the one that once covered Aeolis Dorsa would be the most logical place to start," he said. 14The team noted that the major goal of NASA's Mars explorer, Curiosity, is to look for signs of ancient life on the planet. Currently, Curiosity is operating within the planet's Gale Crater, which is in the southern hemisphere of Mars. In the past, researchers have also found evidence of past water systems around Gale Crater. 15In addition to providing more evidence of a large ocean, Cardenas suggested the new study also provides 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. 16I'm Bryan Lynn. 17Bryan Lynn wrote this story for VOA Learning English, based on reports from Penn State, NASA the Journal of Geophysical Research: Planets and Arizona State University. 18___________________________________________________________________ 19Words in This Story 20topography - n. the shape and other physical characteristics of a piece of land 21shoreline - n. the edge of a sea, lake or wide river 22ridge - n. a long, narrow piece of land 23erode - v. to rub away over time 24sediment - n. the material that sinks to the bottom of a liquid 25dynamic - adj. continuously changing or developing 26deposit - v. to leave something somewhere 27logical - adj. reasonable and based on good judgment 28______________________________________________________________________ 29What do you think of this story? We want to hear from you. We have a new comment system. Here is how it works: