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Reduced Gravity Levels Linked to Astronauts’ Weight

Relationship between Gravity and Astronauts' weight

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Reduced gravity linked to astronauts' weight
Reduced Gravity Levels Linked to Astronauts' Weight. Pixabay
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The study, led by Jay C. Buckey at Dartmouth College in New Hampshire, US, showed that reduced gravity levels (microgravity) in space can lead to spaceflight-associated neuro-ocular syndrome (SANS) in some astronauts.

SANS refers to structural changes in the eye that may impair vision, including swelling of the optic nerve (optic disc edema) and coloured indentations (choroidal folds) in the blood vessel network at the back of the eye.

“Pre-flight weight, waist circumference and chest circumference were all significantly greater in those who developed either disc edema or choroidal folds,” Buckey said.

On Earth, the weight of the body’s tissues presses against other bodily structures (e.g., bones, muscles, organs, veins) creating compressive forces, which can affect pressures in blood vessels and in organs throughout the body.

These compressive forces increase as body weight increases. In microgravity, body tissue is weightless, so compressive forces against the rest of the body are absent, the researchers said.

People with more body tissue — and therefore a higher body weight — are proportionately more likely to experience physiological changes in a low-gravity environment because they experience a greater change in these compressive forces, Buckey hypothesised.

For the study, published in the American Journal of Physiology, the team examined data collected by NASA from astronauts who had made long-duration space flights (averaging 165 days).

Reduced gravity levels linked to astronauts' weight
Representational image. Pixabay

Also Read: Video: Gravity Could be Sustainable Source of Energy

“The results from this study show a strong relationship between body weight and the development of ocular changes in space,” he added.

The team also found that none of the female astronauts analysed — who weighed less than the males — returned to Earth with symptoms of SANS. (IANS)

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New Gamma-Ray Collection Named After Hulk, Godzilla: NASA

Since 2008, Fermi's Large Area Telescope (LAT) has been scanning the entire sky each day, mapping and measuring sources of gamma rays, the highest-energy light in the universe.

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NASA names new gamma-ray constellations after Godzilla, Hulk. Pixabay

NASA has used certain characters from modern myths such as the “Hulk” and “Godzilla” to name its new set of 21 gamma-ray constellations constructed in celebration of its Fermi Gamma-ray Space Telescope’s 10th year of operations.

Fermi has mapped about 3,000 gamma-ray sources — 10 times the number known before its launch and comparable to the number of bright stars in the traditional constellations.

“For the first time ever, the number of known gamma-ray sources was comparable to the number of bright stars, so we thought a new set of constellations was a great way to illustrate the point,” NASA’s Goddard Space Flight Center’s Elizabeth Ferrara who led the constellation project said in a statement.

Gamma-ray constellation
The background shows the gamma-ray sky as mapped by Fermi. The prominent reddish band is the plane of our own galaxy, the Milky Way; brighter colors indicate brighter gamma-ray sources. NASA

 

“Developing these unofficial constellations was a fun way to highlight a decade of Fermi’s accomplishments,” Julie McEnery, the Fermi project scientist at NASA’s Goddard Space Flight Center said.

Comic book fans who know the backstory of Hulk, the big, green, angry alter ego of Bruce Banner, whose experiments with gamma rays went terribly wrong, could easily appreciate NASA’s pick in naming one of its constellations.

Gamma rays are the strongest form of light. They pack enough punch to convert into matter under the right circumstances, a transformation both Banner and the Hulk would certainly appreciate.

NASA’s choice of Godzilla constellation is linked to its trademark weapon “heat ray,” a fiery jet. This bears at least a passing resemblance to gamma-ray jets associated with black holes and neutron stars.

Gamma-ray constellation
NASA names new gamma-ray constellations after Godzilla, Hulk

 

Godzilla ranks as one of cinema’s most famous monsters and is among the most recognisable symbols of Japanese popular culture.

In the original 1954 movie, nuclear weapons tests disturb the creature’s deep ocean habitat, and it emerges from the sea to wreak havoc in Japan.

The 21 gamma-ray constellations also include famous landmarks — such as Sweden’s recovered warship, Vasa, the Washington Monument and Mount Fuji in Japan — in countries contributing to Fermi science.

Since 2008, Fermi’s Large Area Telescope (LAT) has been scanning the entire sky each day, mapping and measuring sources of gamma rays, the highest-energy light in the universe.

Also Read: NASA Plans For Science Payloads For Delivery To Moon

The emission may come from pulsars, nova outbursts, the debris of supernova explosions and giant gamma-ray bubbles located in our own galaxy, or supermassive black holes and gamma-ray bursts — the most powerful explosions in the cosmos — in others.

“Fermi is still going strong, and we are now preparing a new all-sky LAT catalog,” said Jean Ballet, a Fermi team member at the French Atomic Energy Commission in Saclay.

“This will add about 2,000 sources, many varying greatly in brightness, further enriching these constellations and enlivening the high-energy sky!” (IANS)

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