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Indian origin scientist tells why aliens can’t contact us

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Sydney: If the search for an alien life has not yielded any conclusive results in the last 50 years, it is probably because life on other planets was brief and has gone extinct soon after its origin owing to runaway heating or cooling on their planets, say astrobiologists led by an Indian origin scientist.

“The universe is probably filled with habitable planets, so many scientists think it should be teeming with aliens,” said Aditya Chopra from Australian National University (ANU).

“Early life is fragile so we believe it rarely evolves quickly enough to survive,” he added in a paper published in the journal Astrobiology.

“Most early planetary environments are unstable. To produce a habitable planet, life forms need to regulate greenhouse gases such as water and carbon dioxide to keep surface temperatures stable,” Dr Chopra added.

About four billion years ago the Earth, Venus and Mars may have all been habitable. However, a billion years or so after formation, Venus turned into a hothouse and Mars froze into an icebox.

“Early microbial life on Venus and Mars, if there was any, failed to stabilise the rapidly changing environment,” said co-author associate professor Charley Lineweaver.

“Life on Earth probably played a leading role in stabilising the planet’s climate,” he noted.

According to Dr Chopra, their theory has solved a puzzle.

“The mystery of why we haven’t yet found signs of aliens may have less to do with the likelihood of the origin of life or intelligence and have more to do with the rarity of the rapid emergence of biological regulation of feedback cycles on planetary surfaces,” he explained.

Wet and rocky planets, with the ingredients and energy sources required for life seem to, be ubiquitous. However, as physicist Enrico Fermi pointed out in 1950, no signs of surviving extra-terrestrial life have been found.

A solution to Fermi’s paradox, say the researchers, is near universal early extinction which they have named the “Gaian Bottleneck”.

“One intriguing prediction of the ‘Gaian Bottleneck’ model is that the vast majority of fossils in the universe will be from extinct microbial life, not from multicellular species such as dinosaurs or humanoids that take billions of years to evolve,” Lineweaver pointed out.(IANS)(image-wired.com)

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NASA Plans To Install An Instrument To Monitor Plant Water Use

The instrument, called ECOSTRESS, or ECOsystem Spaceborne Thermal Radiometre Experiment on Space Station

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NASA Plans To Install An Instrument To Monitor Plant Water Use
NASA Plans To Install An Instrument To Monitor Plant Water Use, Flickr

NASA plans to install on the International Space Station (ISS) an instrument that will measure the temperature of plants from space, enabling researchers to determine plant water use and to study how drought conditions affect plant health.

The instrument, called ECOSTRESS, or ECOsystem Spaceborne Thermal Radiometre Experiment on Space Station, will hitch a ride to the space station on a SpaceX cargo resupply mission scheduled to launch from Cape Canaveral Air Force Station in Florida on June 29, NASA said on Tuesday.

Plants draw in water from the soil, and as they are heated by the Sun, the water is released through pores on the plants’ leaves through a process called transpiration.

This cools the plant down, much as sweating does in humans. However, if there is not enough water available to the plants, they close their pores to conserve water, causing their temperatures to rise.

Plants use those same pores to take up carbon dioxide from the atmosphere for photosynthesis — the process they use to turn carbon dioxide and water into the sugar they use as food.

If they continue to experience insufficient water availability, or “water stress,” they eventually starve or overheat, and die.

The data from ECOSTRESS will show these changes in plants’ temperatures, providing insight into their health and water use while there is still time for water managers to correct agricultural water imbalances.

“When a plant is so stressed that it turns brown, its often too late for it to recover,” said Simon Hook, ECOSTRESS principal investigator at NASA’s Jet Propulsion Laboratory in Pasadena, California.

“But measuring the temperature of the plant lets you see that a plant is stressed before it reaches that point,” Hook said.

Space
Space, Pixabay

These temperature measurements are also considered an early indicator of potential droughts.

When plants in a given area start showing signs of water stress through elevated temperature, an agricultural drought is likely underway.

Having these data in advance gives the agricultural community a chance to prepare and/or respond accordingly, NASA said.

Also read: Woman Sues NASA Over Keeping Moon Dust Gifted to Her by Neil Armstrong

“ECOSTRESS will allow us to monitor rapid changes in crop stress at the field level, enabling earlier and more accurate estimates of how yields will be impacted,” said Martha Anderson, an ECOSTRESS science team member with the US Department of Agriculture in Beltsville, Maryland. (IANS)