செவ்வாய் கிரகம் - Mars
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இன்றைக்கு ஐஐடி பேராசிரியர் திரு.மணி அவர்களுடன் பேசிகொண்டிருக்கும் பொழுது செவ்வாய் கிரகத்தில் நீர் வடிகிறது என்றும் , பனி கட்டி உருகிய நிலையில் இருப்பதாகவும் குறிப்பிட்டார் . இதை NASA வும் உறுதிபடுத்தியுள்ளது. அங்கு நீர்நிலைகள் இருந்தால் அங்கு உயிரினங்கள், முன்பு வாழ்ந்து தற்பொழுதும் வாழ்ந்து கொண்டிருக்கலாம். இன்னும் இது குறித்து ஆய்வுகள் செய்தால் பல உண்மைகள் வெளிப்படும் என்று குறிப்பிட்டார். லண்டனில் இருந்து Malini Shravan இதே கருத்தை , இதில் இணைக்கப்பட்ட படத்தோடு சொல்லியுள்ளார் .
-கே.எஸ்.இராதாகிருஷ்ணன்.
14-10-2015
14-10-2015
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செவ்வாய் கிரகத்தில் உருகிய நிலையிலுள்ள நீர் ஓடுகின்றது என்று சான்றுகளோடு NASA நேற்று உறுதிப்படுத்தியுள்ளது. இக் கிரகத்தின் துருவங்களில் உறைந்த நிலையில் நீர் உள்ளது என்று எப்போதோ கண்டு பிடிக்கப்பட்டிருந்தாலும் உருகிய நிலையிலுள்ள நீர் ஓடுகின்றது என்ற புதிய கண்டுபிடிப்பு செவ்வாயில் உயிரினங்கள் வசித்திருக்கலாம் அல்லது இப்போதும் வசித்துக் கொண்டிருக்கலாம் என்ற ஐயப்பாட்டை மேலும் அதிகரித்துள்ளது.
செவ்வாய் கிரகத்தில் உருகிய நிலையிலுள்ள நீர் ஓடுகின்றது என்று சான்றுகளோடு NASA நேற்று உறுதிப்படுத்தியுள்ளது. இக் கிரகத்தின் துருவங்களில் உறைந்த நிலையில் நீர் உள்ளது என்று எப்போதோ கண்டு பிடிக்கப்பட்டிருந்தாலும் உருகிய நிலையிலுள்ள நீர் ஓடுகின்றது என்ற புதிய கண்டுபிடிப்பு செவ்வாயில் உயிரினங்கள் வசித்திருக்கலாம் அல்லது இப்போதும் வசித்துக் கொண்டிருக்கலாம் என்ற ஐயப்பாட்டை மேலும் அதிகரித்துள்ளது.
NASA CONFIRMS THAT LIQUID WATER FLOWS ON PRESENT-DAY MARS:
New findings from NASA's Mars Reconnaissance Orbiter (MRO) provide the strongest evidence yet that liquid water flows intermittently on present-day Mars. Using an imaging spectrometer on MRO, researchers detected signatures of hydrated minerals on slopes where streaks are seen on the Red Planet. They darken and appear to flow down steep slopes during warm seasons, and then fade in cooler seasons. These downhill flows, known as recurring slope lineae (RSL), often have been described as possibly related to liquid water. The streaks absorb light at specific wavelengths associated with chemicals known to pull water from the Martian atmosphere in a process known as deliquescence.
PURE WATER vs BRINE:
Pure water would rapidly evaporate and/or freeze on the present-day surface of Mars at most times and places; however brines are far less volatile compared to pure water due to their lower freezing points and evaporation rates. Various hydrated salts have been detected on the surface of Mars and they would lower the freezing point of a liquid brine, just as salt on roads here on Earth causes ice and snow to melt more rapidly. They allow the water to remain liquid at lower temperatures but also help keep it from boiling off in the thin atmosphere of Mars. It remains unclear where the water comes from. Theories include deliquescence, melting subsurface ice or even a liquid-water aquifer that feeds the process.
Pure water would rapidly evaporate and/or freeze on the present-day surface of Mars at most times and places; however brines are far less volatile compared to pure water due to their lower freezing points and evaporation rates. Various hydrated salts have been detected on the surface of Mars and they would lower the freezing point of a liquid brine, just as salt on roads here on Earth causes ice and snow to melt more rapidly. They allow the water to remain liquid at lower temperatures but also help keep it from boiling off in the thin atmosphere of Mars. It remains unclear where the water comes from. Theories include deliquescence, melting subsurface ice or even a liquid-water aquifer that feeds the process.
WATER ON MARS:
This is not the first discovery of water on Mars. Polar ice caps were discovered on the planet four decades ago, and erosion patterns on the surface strongly suggest rivers and oceans may have existed there in its early years. However, with low gravity and a thin atmosphere, it is thought that this water largely evaporated out into space, instead of falling back down, as it would have done on Earth. Evidence of flowing water today changes what experts know about the planet and its ability to house life. While the discovery doesn't by itself offer evidence of life on Mars, either past or present, it does boost hopes that the harsh landscape still offers some refuge for microbes to cling to existence. It is not the first potential clue that Mars could have once (or may still) host life. The Mars Curiosity rover, for instance, has detected methane on the surface of Mars suggesting the possibility of past or present life.
This is not the first discovery of water on Mars. Polar ice caps were discovered on the planet four decades ago, and erosion patterns on the surface strongly suggest rivers and oceans may have existed there in its early years. However, with low gravity and a thin atmosphere, it is thought that this water largely evaporated out into space, instead of falling back down, as it would have done on Earth. Evidence of flowing water today changes what experts know about the planet and its ability to house life. While the discovery doesn't by itself offer evidence of life on Mars, either past or present, it does boost hopes that the harsh landscape still offers some refuge for microbes to cling to existence. It is not the first potential clue that Mars could have once (or may still) host life. The Mars Curiosity rover, for instance, has detected methane on the surface of Mars suggesting the possibility of past or present life.
28th Sep 2015 News conference at NASA headquarters:
https://www.youtube.com/watch?v=vWRr0msp2n4
https://www.youtube.com/watch?v=vWRr0msp2n4
Main photo by NASA:
The blue colour seen upslope of the dark streaks are thought not to be related to their formation, but instead are from the presence of the mineral pyroxene. The image is produced by draping an orthorectified (Infrared-Red-Blue/Green(IRB)) false colour image on a Digital Terrain Model (DTM) of the same site produced by High Resolution Imaging Science Experiment.
The blue colour seen upslope of the dark streaks are thought not to be related to their formation, but instead are from the presence of the mineral pyroxene. The image is produced by draping an orthorectified (Infrared-Red-Blue/Green(IRB)) false colour image on a Digital Terrain Model (DTM) of the same site produced by High Resolution Imaging Science Experiment.
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