Sun is white and not yellow, confirms former NASA astronaut!


Most people believe the Sun is yellow since it appears yellow from the ground, but after reading this tweet, we may have to rethink our views.

This space truth was recently confirmed by NASA astronaut Scott Kelly in a widely shared tweet. The Sun's true colour is actually white, and the explanation the dwarf star typically seems yellow is due to an odd interaction between light physics that causes the sun to look yellow the majority of the time.

Our atmosphere causes the sun to appear yellow. But once you are outside of the atmosphere of the Earth, the Sun appears to be all white. NASA claims that this is because of way our eyes see colour.

Sunsets and sunrises seem red, yellow, or orange because the sun's light must traverse through all of Earth's atmosphere to reach the surface when it is lower in the sky than when it is directly overhead.

According to NASA, shorter light wavelengths, like blue, are more likely to be scattered through the atmosphere as time goes on, whereas longer light wavelengths, like red, can go considerably farther.

Since the amount of sunshine merely inundates the photoreceptor cells in our eyes, blending all the colours together, we are unable to distinguish a single colour from the sun. White is the result of combining all colours of light. As a result, the sun appears white in space and yellow on Earth. DailyBangladesh/RAH, Source: https://www.daily-bangladesh.com/
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Mars rover sees hints of past life in latest rock samples

NASA's Perseverance Mars rover has detected its highest concentrations yet of organic molecules, in a potential signal of ancient microbes that scientists are eager to confirm when the rock samples are eventually brought to Earth.

While organic matter has been found on the Red Planet before, the new discovery is seen as especially promising because it came from an area where sediment and salts were deposited into a lake -- conditions where life could have arisen.

"It is very fair to say that these are going to be, these already are, the most valuable rock samples that have ever been collected," David Shuster, a Perseverance return sample scientist, told reporters during a briefing.

Organic molecules -- compounds made primarily of carbon that usually include hydrogen and oxygen, but also at times other elements -- are not always created by biological processes.

Further analysis and conclusions will have to wait for the Mars Sample Return mission -- a collaboration between NASA and the European Space Agency (ESA) to bring back the rocks that is set for 2033.

Nicknamed Percy, the rover landed on Mars' Jezero Crater in February 2021, tasked with caching samples that may contain signs of ancient life, as well as characterizing the planet's geology and past climate.

The delta it is exploring formed 3.5 billion years ago. The rover is currently there investigating sedimentary rocks, which came about from particles of various sizes settling in the then watery environment.

Percy cored two samples from a rock called "Wildcat Ridge," which is about three feet (one meter) wide, and on July 20 abraded some of its surface so it could be analyzed with an instrument called SHERLOC that uses ultraviolet light.

The results showed a class of organic molecules called aromatics, which play a key role in biochemistry.

"This is a treasure hunt for potential signs of life on another planet," NASA astrobiologist Sunanda Sharma said.

"Organic matter is a clue and we're getting stronger and stronger clues...I personally find these results so moving because it feels like we're in the right place, with the right tools, at a very pivotal moment."

There have been other tantalizing clues about the possibility of life on Mars before, including repeated detections of methane by Perseverance's predecessor, Curiosity.

While methane is a digestive byproduct of microbes here on Earth, it can also be generated by geothermal reactions where no biology is at play.DailyBangladesh/SA, Mars rover sees hints of past life in latest roc
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