Astronomy Rewind: October 2020

Exploring the exquisite Dark matter, water on the moon and much more...

There are truths which one can see only when it’s dark.

– Isaac Bashevis Singer

Developments in space exploration have been on a substantial rise even though most of 2020 was spent in our homes. Over the past months, we saw several exciting breakthroughs: like the discovery of Moon’s magnetic crust, another step towards unraveling the Dark Matter mystery, and even substantial development in the Gravitational Waves Research.

This edition of Rewind covers a multitude of topics from the novel experiment proposed for detecting dark matter to the Nobel prize in Physics, 2020. Read along to appreciate the enthralling episode of astrophysics development over the past month of October.

Top News

Water on the sunlit areas of the Moon? NASA says yes!

We’ve known for over a decade now that the Moon has water. From the Chandrayaan — 1 mission to Deep Impact, Kaguya, and Cassini, numerous independent studies have estimated or confirmed the presence of water on the lunar surface. What they all have in common is that this water is located chiefly in the craters and cold, shadowed areas, far from the presence of any sunlight.

Credits: NASA/Daniel Rutter

However, the latest observations by NASA’s SOFIA observatory disagree with the above idea. In October 2020, the Stratospheric Observatory for Infrared Astronomy (SOFIA) detected water molecules on the Southern hemisphere of the Moon. H2O molecules have been found in the Clavius crater, which happens to be one of the largest craters on the lunar surface. The report published by NASA states that around 340 ml of water is present in a cubic meter of lunar soil — roughly a small bottle’s worth.

This discovery is even more significant because the water present on the sunlit side of the Moon. With the lack of atmosphere and the presence of sunlight, you’d expect this water to evaporate, but the evidence points to the contrary. What could be the processes behind the water cycle on the Moon?
It’s worth noting that the Sahara, one of Earth’s driest places, has over 100 times water than that, but the mere presence of a significant amount of water on the Moon marks massive progress for space enthusiasts further studies. Of course, it also raises substantial questions: whether anyone, government or private player, can claim rights to the water, or whether this will lead to exploitation and depletion of the Moon’s natural resources. Food for thought!

Billion tiny pendulums will try to detect Dark matter!

From questioning what dark matter and dark energy was to now moving towards if we could create dark matter, we have come a long way!

If our current model of physics is right, billions of sub-atomic dark matter particles are passing through the Earth every second. Up until now, experiments conducted to detect dark matter involved in seeking non-gravitational signs of interactions. Researchers at National Institute of Standards and Technology (NIST) on the contrary, came up with a great experiment that purely relies on the gravitational coupling, i.e. look for dark matter solely through its gravitational interactions with luminous matter. Here, a billion millimetre-sized pendulums would act as dark matter sensors. When a dark matter particle is suspended near a pendulum, it will deflect slightly due to attraction between both the masses. But this small force is overwhelmed by other noises and electrical signals, and it becomes as hard to detect it as to hear a pin drop on a busy road.

Hence, they formulated an array of about a billion tiny mechanical sensors distributed over a cubic meter that differentiates an actual dark matter particle from an ordinary particle or fallacious random electrical signals or “noise” which might trigger a false alarm in the sensors. Additionally, we could even detect its direction on the due course. This procedure to jump into the experimental stage, researchers felt it accountable to endure techniques that the smartphone and automotive industries already have to produce large numbers of mechanical detectors. This can also be implemented on a small scale to know about other weak forces and sub-atomic particles.

As we continue to evolve new technologies and increase detector sensitivity, we can close in on where dark matter is hiding, and we’ll finally be able to bring the universe’s darkest secrets into the light.

Head into the link given below to know more about this experiment and unbox the enigma of darkness, Sic Mundus Creatus Est!

The mystery behind the Moon’s magnetic crust!

Ever since the beginning of human curiosity, the moon has been a continuing wonder. We were fascinated by the giant impact hypothesis, which revealed that the moon could have evolved from our earth.

Credit: Science Advances, doi: 10.1126/sciadv.abb1475

Researches unveiled many similarities between our earth and the moon in terms of its composition. Hence scientists still believe that the moon should be colonized first. Thus science continues to resolve the mysteries of the moon. One such mystery is the moon’s magnetic crust. Fifty years ago NASA’S APOLLO 11 landed humans on the moon and brought the lunar rocks and dust. Researches on those findings reveal that the moon’s magnetic field was perhaps more robust than the earth’s magnetic field close to 4 billion years ago. But between 4–2 billion years ago the magnetic field of the moon was diminished by the power of 10. And between 2–1 billion years ago it dropped down by a factor of 100. Scientists do believe that the moon would have been closer to the earth when it possessed a greater magnetic field and later as they drifted apart the magnetic field started decreasing, as the liquid core started crystallizing. The liquid core is needed to create the electromagnetic field, that’s the lunar dynamo. Also, scientists do believe that the impacts from the meteorites generated the moon’s magnetic field. However, the moon’s magnetic field takes the role to shield its surface from the solar wind and the supersonic plasma emitted by the sun.

To learn more, please read the news article given below —

Hexagonal storm on Saturn!

In the ongoing attempt to unveil the mysteries of the cosmos, cosmologists stumble upon weird yet awe-inspiring phenomena. Working on it may seem like a blind alley, but may turn to be rewarding. This has turned to be true for Jeremy Bloxham, Professor of Geophysics at Harvard University, and his research associate Rakesh K. Yadav. They have been meticulously working on the grounds behind the persistent hexagonal-shaped storm in the North pole of Saturn.

Credit: NASA/JPL-Caltech/Space Science Institute — Public Domain

First spotted in the year 1981 by Voyager 2, this visually spectacular feature in the murky and turbulent atmosphere of the gas giant self-sustained even when observed during the Cassini-Huygens mission in 2006. This six-sided storm vortex, estimated to be 29,000 km wide with sides extending up to 2,000 km, is a perfect example of ‘turbulent self-organization’. While one set of researchers believe that the hexagon is shallow and only extends hundreds of kilometers deep, another school of thought alleges that the zonal jets are thousands of kilometers deep.

In the paper published in Proceedings of the National Academy of Sciences, the scientists assert that this stellar rarity is the result of interactions between a tremendous hurricane with smaller vortices, analogous to a broad rubber band forming finite edges with the aid of smaller ones around it that elastically stretches from outside. Though they weren’t successful in creating a hexagonal-shaped hurricane in their month-long simulation, rather a nonagon moving faster than usual, they believe that this reasoning could help understand the dynamics of the Saturnian atmosphere. In a broader perspective, the duo believes that further refinement in the findings will be a key to yield more insights about the universe itself.

Cosmology bags another Nobel Prize!

Ten years after the death of Albert Einstein, in 1965, Penrose finally demonstrated the formation and existence of black holes, when even Einstein himself was skeptical of their existence. The groundbreaking paper described the physical properties of black holes and went on to be the most critical contribution to relativity since Einstein. It took the academy almost 55 years to recognize the greatness of Sir Roger Penrose. Still, we are glad they finally paid attention to the math-wizard, who inspired a generation of astrophysicists!

The Royal Swedish Academy of Sciences conferred the Nobel Prize in Physics 2020 to Roger Penrose for “The discovery that black hole formation is a robust prediction of the general theory of relativity” and to Reinhard Genzel and Andrea Ghez for “The discovery of a supermassive compact object at the centre of our galaxy.”

Roger Penrose used Mathematics to prove that black holes are a direct consequence of Albert Einstein’s general relativity theory. And this paved the way for considerable strides in Blackhole physics. Building upon the idea that Black holes exist, Genzel and Ghez used some of the world’s largest telescopes to observe the orbits of the stars closest to the center of the Milky Way, which led them to conclude the presence of an invisible, massive black hole. The physicists think that the black hole could most likely be hiding in Sagitarrius A*. With that, Ghez became the fourth woman to win the Nobel Prize in Physics, inspiring girls all over the world to aim not just for stars but the mysteries beyond them!

Last year, we were able to capture the first photo of a black hole, which would not have been possible if it weren’t for the winners of the Nobel this year. They set out on a path to unveil the workings of the cosmos and got us where we are today, but we still have a long way to go, and their contributions will surely be the foundation blocks of the future!

An Eye Candy!

The Ghoul of IC2118

The Ghoul of IC 2118

Inspired by the Halloween season, this telescopic portrait captures a cosmic cloud with a scary visage. The interstellar scene lies within the dusty expanse of reflection nebula IC 2118 in the constellation Orion.

That’s all folks! Stay tuned and excited for Nakshatra Rewind November 2020 that is all set to reveal equally if not more compelling discoveries. To experience the joy of exploring the intricacies of the universe, keep looking beyond the stars and follow Nakshatra to join this exciting journey of exploring the cosmos together.

Until then, Adieu from the Nakshatra team.

Looking beyond the stars!

This article was compiled in collaboration with VEYINI RAMAMOORTHY, Harshinee Murali, Atotmyr, Ayush Pathak, Mridhula Venkatanarayanan and Shiddhartha Ramprakash.



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