Tag Archives: climate change

‘Black Beauty’ zircons record ancient Mars climate

Was Mars — now a cold, dry place — once a warm, wet planet that sustained life? And if so, how long has it been cold and dry? … By analyzing the chemical clues locked inside an ancient Martian meteorite … Continue reading

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HiRISE: Blockfall on north polar layered deposits

The north polar layered deposits (NPLD) are a stack of layers of ice and dust at the North Pole of Mars. The layers are thought to have been deposited over millions of years, as the atmosphere changed in response to … Continue reading

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Debris aprons and valley fill hold ancient ice several hundred million years old

Along the edge of the crustal dichotomy, where the southern highlands step down onto the northern plains, lies a landscape of mesas, buttes, and valleys. Valleys appear choked with linear streams of debris, and on the flanks of many mesas … Continue reading

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Was nitrogen in the early Mars atmosphere a key to ancient habitability?

Scientists have long suspected that ancient Mars had a thicker atmosphere and temperatures warmer and far more habitable than at present. But modelers have difficulties making the numbers come out right,

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Well-rounded pebbles in Gale Crater’s rocks point to longtime stream flow

Mars Science Laboratory rover Curiosity landed in Gale Crater at a feature called Bradbury Rise, which lies near the far end of the Peace Vallis alluvial fan. The fan is a broad, flat deposit of sand, gravel, and pebbles washed … Continue reading

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Most deltas on Mars created by short, catastrophic floods

Rivers that run into lakes and other standing bodies of water drop sediment where the flow slackens as it enters the body of water. Over time, the accumulating material builds a delta — a wedge of sediment whose form can … Continue reading

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Are brines actually needed to make recurring slope lineae flow?

Recurring slope lineae (RSL) are finger-like dark lines on steep slopes that appear and grow longer during the warmest time of year, then fade and disappear over winter. They repeat the following Mars year in the same places. While scientists … Continue reading

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‘Faint young Sun paradox’ a problem for Mars (and Earth, too)

Astronomers say that billions of years ago when the Sun was young, it shone with only 70 percent its current brightness, notes Robert Craddock (Smithsonian Institution). If that were true of today’s Sun,

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Gale’s winds sculpted the Mt. Sharp mound as they built it

The major reason for sending the Mars Science Laboratory rover Curiosity to Gale Crater is the five-kilometer (three-mile) high layered mound, dubbed Mt. Sharp, that looms at the crater’s center. The lowest layers have been altered by water

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Gale Crater’s Lake District

Mars rover Curiosity landed on, or just beyond, the far end of an alluvial fan — rocks, gravel, and sand washed down by the Peace River from the north rim of Gale Crater. The rover has driven for 200 sols … Continue reading

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