Lyrid meteor shower is happening now

Yes, the Lyrid meteor shower is indeed happening today! The Lyrids are an annual meteor shower that occurs from about April 16 to April 25 each year, with the peak usually around April 22 or 23. The best time to observe them is typically during the predawn hours, when the sky is darkest and the shower's radiant point, the constellation Lyra, is high in the sky. 

These meteors are caused by the Earth passing through the debris left behind by the comet C/1861 G1 Thatcher. If you have clear skies and minimal light pollution, it's a wonderful celestial event to witness. Under a perfectly dark sky, you may be lucky enough to catch a glimpse of 10 to 15 Lyrids per hour.

So why wait!! Just go outside and look upwards. You might just get lucky and witness a heavenly show. 

All the best!!

Prabir Rudra

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Fermi Paradox: Where are all the Aliens!??

 

The intriguing idea known as the Fermi Paradox poses the question of why, despite the likelihood that there is extraterrestrial life out there, we have not yet found any proof of these civilizations. The paradox draws attention to the apparent contradiction between the likelihood that extraterrestrial civilizations exist and the paucity of evidence or communication with them. It is named after the Nobel prize-winning physicist Enrico Fermi, who famously raised the question during a discussion about the viability of space travel and the existence of intelligent alien life.

The Fermi Paradox has several proposed solutions and explanations.

The rare earth hypothesis lowers the possibility of the existence of additional intelligent civilizations by suggesting that the conditions required for complex life to arise are exceedingly rare.

The Great Filter Hypothesis postulates that life, whether it be microbiological, complex multicellular, or technological civilizations, may be stuck at some point in its evolutionary process due to an impenetrable barrier.

The theory of technological singularity postulates that sophisticated civilizations will ultimately reach a point at which their technology advances to the point that they are undetectable and uninterested in communicating with other civilizations.

Self-destruction: The theory suggests that civilizations may eventually wipe themselves out through conflict, deterioration of the environment, or other ways before they have an opportunity to colonize other planets or extend into space.

Transcendence: This theory postulates that advanced civilizations may evolve into entities that live outside the realm of human comprehension, such as energy- or digital-based beings, rendering conventional means of communication obsolete.

The Zoo Hypothesis postulates that extraterrestrial civilizations exist and are aware of us, but they have decided not to contact us, either so they may observe us in peace or so they can let us evolve naturally.

Though each of these theories provides a unique viewpoint on why we haven't yet found any evidence of extraterrestrial intelligence, the real reason is still one of the greatest mysteries of science. These days, several studies from various research groups are published annually on the subject of extraterrestrial intelligence. The current exoplanet revolution has bolstered the hypothesis that advanced civilizations might exist outside of Earth.

More instruments are available for researchers to use in this kind of investigation. In April 2018, for instance, NASA's Transiting Exoplanet Survey Satellite (TESS) successfully launched and quickly took over from Kepler, which was retired later that year. Among many other things, the highly anticipated $10 billion James Webb Space Telescope of the agency was launched in December 2021 and is currently searching for possible biosignature chemicals in the atmosphere of neighboring exoplanets. The PLATO (Planetary Transits and Oscillations of Stars) mission of the European Space Agency is scheduled to launch in 2026. Later this decade, three massive ground-based observatories with adequate power to detect exoplanet air are expected to go online: the Extremely Large Telescope, the Giant Magellan Telescope, and the Thirty-Meter Telescope. Furthermore, a very ambitious initiative called Breakthrough Starshot intends to use swarms of small, laser-sailing nanoprobes to conduct up-close studies of Proxima b (The exoplanet Proxima Centauri b, also known as Alpha Centauri Cb, is a member of the larger triple star system Alpha Centauri and is circling the red dwarf star Proxima Centauri, which is the nearest star to the Sun.) and other adjacent worlds. Around 2050, if technology development proceeds as planned, the first of these robotic interplanetary vehicles may take off.

These kinds of missions and tools will aid scientists in expanding their knowledge of astrobiology, which is still in its infancy. For example, we have no idea whether our backyard contains worlds that support life. Since bacteria can endure in harsh conditions, studies conducted on Earth have led to the possibility that microbial life exists on Mars, Europa, Enceladus, and/or Titan, the massive satellite of Saturn. However, none of those planets have been investigated quite well enough for us to be certain.

But the Fermi Paradox is thinking much beyond microorganisms. In order to find a solution, we must ascertain the frequency with which extraterrestrial life emerges as well as the frequency with which it acquires the capacity and inclination to interact with other sentient beings or travel among the stars.

Perhaps the most prevalent life-supporting habitats in the Milky Way galaxy are subterranean waters, like those found on Europa and Enceladus. It appears improbable that organisms evolving in such environments will create spacecraft; in fact, a large number of them might not even be aware that there are other planets to discover. 

Another possibility is alien psychology. Perhaps there are many advanced extraterrestrial civilizations, but the majority don't seem to want to interact with humans or come to Earth. Maybe Earth and its people are just too boring for them to play around with, and they won't until mankind proves intelligent and deserving enough to be accepted into the "galactic club."

Or perhaps the majority of sentient aliens generally remain silent out of fear that communicating with their galactic neighbors will result in their own captivity or destruction. Such possibilities have been mentioned by some researchers, including the late Stephen Hawking, to support their contention that mankind shouldn't actively promote itself.

Then there are the practical challenges associated with the search for sentient aliens. The cosmos is vast and extraordinarily old. Only 200,000 years have passed since the beginning of human history, and only since 1960 have we been searching for potential E.T. radio transmissions. Thus, the likelihood that we coincide with a detectable alien civilization in space and time doesn't appear very high.

Most academics believe that there is most likely no single answer to the Fermi Paradox. The "great silence" that faces us now is probably the result of several circumstances, some of which may have been mentioned above. And it could not be too long until the characteristics of those things become more apparent. 

Prabir Rudra

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Will Pluto ever regain its status as a planet? Does it matter?

 

The general public was furious. Textbooks needed revision. On August 24, 2006, scientists at the International Astronomical Union (IAU) decided to reclassify Pluto, reducing its status from a planet to a dwarf planet. This decision was widely viewed as a demotion and has had a lasting impact on our understanding of the solar system. 

The whole Pluto controversy is based on the problems with the definition of a "planet." According to the International Astronomical Union, a planet is a celestial entity that 

1)  orbits the sun,    

2)  appears almost spherical    

3)  has largely cleared its orbital vicinity of debris. 

However, opinions on even this collection of measures differ. Despite their massive size, few asteroids have been removed from Earth's and even Jupiter's orbits. Ceres is one example of a small, circular globe that orbits the sun but is not regarded as a planet.

A lot of confusion indeed

The purported downgrade of Pluto from planetary classification presents more significant questions regarding the definition of any object in the solar system, or perhaps in space in general. It demonstrates how science isn't always able to classify objects into neat categories. Because it is not clear how to evaluate the many non-circular objects that round our sun if the definition of a planet is expanded once more. This might potentially cast doubt on the asteroid belt—the vast swath of tiny asteroids that lies between Mars and Jupiter. Or what would happen if a planet were to mysteriously fragment?

Nevertheless, many people are still confused about the controversy surrounding Pluto and the reasons behind its removal from the planetary orbit, even after the argument began nearly 20 years ago. However, the evolution of the solar system from nine planets to eight (at least according to the IAU definition) took a long time and illustrates one of science's greatest assets: the capacity to modify concepts that appear unchanging in the face of new information.

Peculiarity of Pluto

When astronomer Clyde Tombaugh of the Lowell Observatory in Arizona studied photographic plates of the sky on several nights, he saw a tiny dot that floated back and forth against the backdrop of stars. This led to the discovery and classification of Pluto as a planet in 1930 (note the IAU was created in 1919). However, the newest possibility in the solar system was immediately seen as a peculiarity. For 20 of its 248-year journey, it actually approaches the sun closer than Neptune due to its extremely eccentric, or non-circular, orbit. In addition, it is inclined toward the ecliptic, the plane that the other planets in the solar system revolve.

The first object in the Kuiper Belt was identified by scientists in 1992 as 1992 QB1, a small body orbiting beyond Neptune's orbit and out in Pluto's neighborhood. Soon, a large number of these objects were discovered, and they revealed a belt of tiny, frozen worlds like the asteroid belt between Mars and Jupiter. Though first believed to be even larger than Pluto, the faraway body Eris was discovered by astronomers in July 2005, upending Pluto's reign as the ruler of this region.

Confusion all around

The following queries required to be posed to researchers: Did this imply that Eris was a planet as well if Pluto was? What about the smaller things in the asteroid belt or all those other icy objects out in the Kuiper belt? What was the precise threshold for designating a body as a planet? A phrase that had appeared clear-cut and uncomplicated was now revealed to be strangely equivocal.

Following a heated discussion, numerous new definitions for planets were put forth.

Astronomers were no closer to finding a solution a year later, and the problem cast a shadowy pall over the 2006 IAU General Assembly meeting in Prague. Four proposals were put forth throughout the eight days of intense debate that the researchers had to sit through at the meeting. A contentious proposition proposed increasing the number of planets in the solar system to 12, incorporating the largest asteroid, Ceres, and Pluto's moon, Charon. 

By the end of the Prague conference, three new categories for solar system objects were decided upon by the 424 astronomers. Only the planets Mercury through Neptune would be regarded as planets after that. From then on, Pluto and its relatives, which were spherical objects that orbited alongside other objects, were referred regarded as dwarf planets. Small solar system bodies would be the name given to all other objects in orbit around the sun.  

The planet discussion underwent a major sea change as the New Horizon spacecraft flew across Pluto, revealing a world far more active than anyone had previously thought. Big mountains, beaten craters, and evidence of liquid moving across the surface all indicate that the world has experienced significant geological change since it formed. Based solely on this, some, like Stern, have argued that Pluto ought to be classified as a planet because it is a dynamic location that is not so static that the only things that perturb its surface are micrometeorites.

Observations of Charon, the moon of Pluto, reveal a very dynamic planet with a red cap on its pole that seems to change color in response to the gradual seasonal changes that occur so far out in the solar system. Notably, Mercury and Venus, two well-known planets, do not have as many moons as Pluto. (Most asteroids and dwarf planets have moons as well, which further complicates the definition of a planet.)

There are always new classification schemes emerging. As per a suggestion from 2017, a planet is characterized as "a round object in space that's smaller than a star." This would reclassify Pluto as a planet, but it would also reclassify the moon of Earth and many other moons in the solar system, bringing the total number of planets recognized by the scientific community to 110. A year later, Alan Stern, a leader of NASA's New Horizons mission coauthored an editorial piece in The Washington Post with planetary scientist David Grinspoon, claiming that astronomers ought to reevaluate their theories since the IAU's definition was "flawed" and "hurriedly drawn." 

Will Pluto ever regain its planetary status?

So far, these requests have been ignored, and it doesn't appear probable that the IAU will take up the issue again anytime soon. As of now, it is thought that Pluto was misclassified when it was first discovered; it was never on the same footing as the other eight worlds. So Pluto is still not a planet. It was never, in fact. Scientists think that we have misinterpreted it for fifty years. Maybe we are wiser now. Nostalgia for Pluto indeed makes for a weak planet argument, but that's all there is to it. Probably we should move on to reality now.

Does it really matter?

This abundance of planet-forming possibilities suggests that every solar system might be a different ecosystem. Although it is generally true that stars can create planets through the collapse of gas and dust in their surroundings, the specific dynamics involved in planet formation are much more intricate. Are several stars involved, for instance? What is the amount of dust that is available? Is a supernova or a black hole stealing the essential gas and dust that planets require to expand?

All of this suggests that in order to account for the variety of ways that a globe could emerge, our definition of a planet might need to change. Planets might be associated with specific zones or creation conditions. It appears that the only certainty is that planethood and the controversy surrounding Pluto will remain hotly contested for some time to come as data continue to be gathered.

But when modern-day kids (who were not born when Pluto was a planet) raise a question about the necessity of the definition of a planet, it is very difficult to give an answer, and one generally avoids such a situation by saying that it's complicated!!

Prabir Rudra

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If Earth suddenly has the atmosphere of Venus

 

At a distance of 108 million kilometers (67 million miles) from the Sun, Venus is the second closest planet to the Sun in our solar system. So it is expected that the planet of love is a broiling hot inferno.

The conditions on Earth would drastically change if it had the atmosphere of Venus, making it incredibly inhospitable to life as we know it. Once the clear blue sky would now be a thick oppressive canvas of yellow with massive clouds of sulfuric acid. Though they would block out most of the Sun, this would not be enough to mitigate the extremely hot temperatures on the ground. How would that transform the Earth? Will that ring the death bell for all life on Earth? This is what would probably occur:

• Extreme Heat: Venus has a thick atmosphere primarily made up of carbon dioxide, with some clouds containing sulfuric acid. The runaway greenhouse effect produced by this dense atmosphere traps heat and raises temperatures to extremely high levels. Earth's average temperature would soar to around 460°C (860°F), hot enough to melt lead. 

• Crushing Pressure: The pressure in Venus's atmosphere is roughly 92 times higher than that of Earth. It is like living approximately 900 meters underwater. Human beings would be crushed and structures would be flattened by this pressure. 

• Toxic Atmosphere: Venus's atmosphere would be incredibly corrosive due to the sulfuric acid clouds. When they combine with water vapor in the Earth's atmosphere, they would produce acid rain, which is deadly to living things and capable of dissolving most materials. 
  

• No Oxygen: In the atmosphere of Venus, oxygen is scarce. Breathing would be impossible for most species, including humans, as a result. Asphyxia and death would result from a shortage of oxygen.

• No Liquid Water: Any water on the surface of the Earth would either boil away or exist as vapor high in the atmosphere due to the extremely high temperatures and pressure. There wouldn't be any liquid water left on the planet's surface, which is necessary for life as it exists now.

• No Protection from Radiation: Right now, the atmosphere of Earth acts as a barrier to keep dangerous solar radiation from reaching humans. This shield would be compromised in the presence of an atmosphere like Venus, leaving life on Earth vulnerable to hazardous solar radiation levels. 

But astronomers suggest that things were not always so drastic as it is today in Venus. A long time ago Venus might have had a climate similar to that of Earth. There might even have been oceans of water. But those times are long gone. With time the planet's atmosphere built up an excessive amount of carbon dioxide and other gases trapping heat from the Sun paving the way for a runaway greenhouse effect. Now the planet is basically an apocalyptic wasteland.

If Earth today had a similar atmosphere, all the gardens, trees, and forests would burn out leaving out their blackened skeletons. Birds will fall out of the sky. Animals would gasp their last breaths and even the fishes would bubble out of the sea. Water bodies across the planet will be at their boiling point. With time all the water will boil out and the surface of the Earth will become absolutely dry leaving behind the skeletons of the marine life. With enough time even the things that used to symbolize humanity's achievements would become grotesque sculptures of what they once were. Due to the extreme pressure, the buildings would collapse, and so would the bridges. Roads will develop cracks and become completely undrivable. This will present a devastating image. Overall, if Earth had the atmosphere of Venus, it would become an uninhabitable, hellish world devoid of life as we know it.

The only way to survive these extreme conditions is probably to take shelter underground. Subterranean shelters in the planet's crust will protect us from the extreme heat and pressure. With the right design, these shelters can recreate the favorable atmosphere that we need to stay alive. Geothermal energy can be harnessed and used in these shelters to power them. Another way of survival is to leave Earth and inhabit another planet that has favorable conditions for life. 

Maybe this transformation of Earth as we know it today into a Venus-like planet will not happen overnight as we tried to imagine in the above note, but conditions show that probably we are on course towards reaching such a situation. Global warming, melting of polar caps, pollution, and deforestation are all pointing towards such a catastrophic end to life on Earth.

It's a stark reminder of how delicate and crucial Earth's atmosphere is to sustaining life and preservation of this atmosphere should be our priority.

Prabir Rudra

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Total Solar Eclipse in April 2024

 

The total solar eclipse that will occur on Monday, April 8, 2024, will cross North America, going over Canada, the United States, and Mexico. When the moon moves between the sun and the Earth and briefly obscures the sun's face, this is known as a total solar eclipse. The term "path of totality" refers to the lunar shadow's trajectory across the surface of Earth. Thirty-one million Americans already reside inside the path of totality, making the celestial marvel accessible to them. The South Pacific Ocean will be the starting point of the total solar eclipse. The Pacific coast of Mexico will witness totality first in continental North America, weather permitting, at approximately 11:07 a.m. PDT.

Following its journey from Mexico, the eclipse will pass across Oklahoma, Arkansas, Missouri, Illinois, Kentucky, Indiana, Ohio, Pennsylvania, New York, Vermont, New Hampshire, and Maine before entering the United States in Texas. The complete solar eclipse will also be visible in a few isolated areas of Tennessee and Michigan. After crossing Southern Ontario into Canada, the eclipse will pass over Quebec, New Brunswick, Prince Edward Island, and Cape Breton. At 5:16 p.m. NDT, the eclipse will leave continental North America and cross the Atlantic coast of Newfoundland, Canada.

The total solar eclipse on April 8 is expected to be the largest mass travel event in U.S. history, drawing together eclipse professionals and amateur skywatchers alike.

Various things should be avoided during a solar eclipse. Following is a list of such things:

1) Do not look directly at the sun.

2) Avoid using optical devices.

3) Don't drive wearing eclipse glasses.

4) It is better to avoid travel.

5) Do not drive while trying to watch the eclipse.

6) Use proper eye protection.

7) Don't use optical devices without proper filters.

8) Supervise children while watching the event.

Prabir Rudra

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The Devil Comet is approaching us

Over the next few days, skywatchers will be able to see more than just the bright planet Mercury and April's total solar eclipse. Comet 12P/Pons-Brooks, sometimes known as the "devil comet," will be visible in the night sky for the next few days and might emerge during the April 8th total solar eclipse. Since Pons-Brooks only completes one orbit around the sun every 71 years, observing it is usually an opportunity that comes only once in a lifetime.

Pons-Brooks is a ball of ice and rock that is 10.5 miles wide. In comparison, it will be twice as large as the Mount Everest. It is currently traveling towards our sun with an extremely elliptical or stretched-out orbit. It features a frozen shell, or nucleus, encircling a core composed of solid ice, gas, and dust. A coma, or a cloud of frozen material, progressively seeps out of the comet's center and covers the nucleus. 

Pons-Brooks is cryovolcanic, unlike most other comets. It frequently erupts when the nucleus's fractures are opened by sun radiation. As a result, frozen cryomagma under extreme pressure erupts into space. The surrounding cloud of frozen particles enlarges and seems brighter than usual when this happens.

For the first time in 69 years, Pons-Brooks erupted violently in July 2023, leaving behind two separate gas and ice trails that resemble a pair of devil horns. It has persisted in erupting rather regularly.

When will it be visible?

Pons-Brooks may become visible to the unaided eye during the next few weeks as it passes through the inner solar system. It will stay that way until April 2 when it moves closer to the sun and disappears from view in the pitch-black night sky. The evenings of 30th and 31st March are considered to be the best time to see the comet as it will be nearest to the Earth at that time. On June 2, when it moves away from the sun, it will be at its closest to Earth. It will be roughly 139.4 million miles away and presents no known hazard to Earth. 

It is expected to become even more active in the upcoming weeks and be visible to the unaided eye with a maximum brightness magnitude of about 4.0, according to SETI Institute postdoctoral scholar Ariel Graykowski. The appearance appears brighter the lower the magnitude. It won't be very noticeable in the sky because "the limit for naked eye objects in dark, moonless skies is around 6 magnitudes," according to Graykowski.

Where should we look?

It is most seen in the early evening in the Northern Hemisphere toward the west-northwest horizon. Pons-Brooks is located low in the northwest sky, close to the Pisces constellation. It should look like a blazing ball of ice, trailed by the forks of its horns.

An hour or so after sunset, the comet should be visible to the unaided eye low in the west. As it approaches the sun, it will become somewhat brighter. You want to find a place where you can see the western horizon unhindered and where there are no city lights. Using binoculars might be a good idea as the comet might be difficult to find without them.

The brightest planet Venus will become visible on one side of the sun as the sky grows darker. Jupiter, the second-brightest planet in the solar system, is located on the other side. Furthermore, you should be able to see Comet Pons-Brooks closer to Jupiter but between Jupiter and the sun if it is sufficiently bright.

Remember this is your only chance to see it because it won't be seen again until 2097. 

Prabir Rudra

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Big Bang: The beginning of the Universe

The Big Bang theory is the prevailing cosmological model for the observable universe's earliest known periods and its subsequent large-scale evolution. It proposes that the universe began as a hot, dense state approximately 13.8 billion years ago and has been expanding and cooling ever since.

Here's a brief overview:

1. Initial Singularity: The Big Bang theory proposes that the universe began as a hot, dense point known as a singularity. At this moment, all the matter, energy, space, and time were contained within this infinitesimally small point. As a result, certain qualities became infinite or undefined at the Big Bang, hence the name singularity.

2. Rapid Expansion: Approximately 13.8 billion years ago, the singularity underwent a rapid expansion known as cosmic inflation. This expansion caused the universe to cool down and expand, leading to the formation of subatomic particles and eventually atoms.

3. Formation of Elements: As the universe expanded and cooled, subatomic particles such as protons, neutrons, and electrons combined to form the first hydrogen and helium nuclei. This process, known as Big Bang nucleosynthesis, occurred within the first few minutes after the Big Bang.

4. Formation of Stars and Galaxies: Over millions to billions of years, gravity caused regions of higher density in the early universe to collapse, forming stars and galaxies. Within galaxies, stars formed from clouds of gas and dust, and many stars went on to form planetary systems.

5. Cosmic Microwave Background Radiation (CMB): About 380,000 years after the Big Bang, the universe cooled enough for neutral atoms to form. This event, known as recombination, led to the release of photons that continue to travel through the universe today as the cosmic microwave background radiation. The CMB provides a snapshot of the universe at that early stage.

6. Observable Universe: The expansion of the universe continues to this day. The observable universe, the part of the universe we can see, includes galaxies, clusters of galaxies, and cosmic structures, all moving away from each other due to the ongoing expansion.

The Big Bang theory is supported by a wealth of observational evidence, including the cosmic microwave background radiation, the observed distribution of galaxies, the abundance of light elements, and the large-scale structure of the universe. However, it's important to note that there are still unanswered questions and areas of active research within cosmology, such as the nature of dark matter and dark energy, and the conditions of the universe before the Big Bang. This is probably the reason why various competing theories like the steady state theory, cyclic universe model, multiverse hypothesis, quantum cosmology, etc. find their place in the literature.

Prabir Rudra

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The explosion of Corona Borealis: Once in a lifetime sight in the sky

According to NASA, astronomers anticipate that a "new star" will emerge in the night sky at any moment between now and September, 2024. This celestial spectacle is expected to be once in a lifetime.

The Milky Way's Corona Borealis, or Northern Crown constellation, which is situated between the Boötes and Hercules constellations, is where the anticipated brightening event, known as a nova, will occur.

A nova is the quick, brief explosion from a collapsing star known as a white dwarf, whereas a supernova is the catastrophic death of a large star.

The "Blaze Star," or T Coronae Borealis, is a binary system in the Corona Borealis that consists of an aged red giant star and a dead white dwarf star. When stars run out of hydrogen for nuclear fusion and start to fade, red giants are created. NASA estimates that in roughly 5 or 6 billion years, our sun will turn into a red giant, sputtering and growing as it releases layers of material and probably vaporizing the inner planets of the solar system. In this context, Earth's future is yet unknown.

An explosive event occurs in T Coronae Borealis approximately every 79 years.

Because of their close proximity, the stars in the orbital pair interact furiously with one another. As the red giant heats up, it becomes more unstable, shedding its outer layers that fall as matter onto the white dwarf star.

According to the space agency, the interchange of stuff leads the white dwarf's atmosphere to steadily heat up until it undergoes a "runaway thermonuclear reaction," which results in a nova.

How to keep an eye on the event?

Astronomers are closely monitoring T Coronae Borealis once more after it last had a spectacular outburst in 1946.

In an email, NASA Meteoroid Environments Office lead William J. Cooke stated that "most novae happen unexpectedly, without warning." Nonetheless, T Coronae Borealis is among the galaxy's ten recurrent novae. From the last eruption in 1946, we know that the star will darken for a little more than a year before brightening up quickly. T Coronae Borealis started to dim in March of last year, and between now and September, some researchers anticipate that it may go nova. We are unable to predict with greater accuracy than the few months it will take for this to occur, given the current state of knowledge.

It is anticipated that the star system, which is 3,000 light-years away from Earth and usually too faint to be seen with the unaided eye, would become as bright as Polaris, or the North Star.

When the nova reaches its maximum brightness, it will appear as if a new star has emerged. It can be seen with binoculars for a little over a week and without any equipment for a few days, after which it will fade and be lost from view for another 80 years or more.

The nova will be visible from the Northern Hemisphere, appearing in a little arc between the constellations Hercules and Boötes.

The Neil Gehrels Swift Observatory, located in space, will be used by astronomers to analyze the celestial event through ultraviolet and X-ray light, while the Hubble Space Telescope will be used to observe the nova.

Cooke stated, "Repeated novae like T Coronae Borealis provide us insights into the thermonuclear runaway that occurs on the surface of the white dwarf when the star goes nova and help us understand the mass transfer between the stars in these systems."

Updates regarding the eruption and its appearance will be available from the NASAUniverse account on X, formerly known as Twitter.

Cooke remarked that the brightness of Nova Cygni, which he saw last in 1975, was comparable to that of T Coronae Borealis. It is not anticipated that Nova Cygni will encounter another explosion.

"On August 29, I was outside as a teenage astronomy geek who was about to start college," Cooke recalled. "Looking up at the sky, I saw that there was a star that shouldn't have been there in the Cygnus constellation. We discovered that we were staring at a nova after I persuaded some pals who thought I was insane to look at it! It was a really memorable event that confirmed my professional decision to pursue astronomy. I used to make jokes about how undergraduate physics had to blow out a star for me to have to endure it.

Prabir Rudra

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Wormhole: The missing link between us and our future home

 

The term "wormhole" usually describes a theoretical spacetime tunnel-like structure that may link two different points in space or time, possibly enabling instantaneous or faster-than-light travel between far-off places. The idea comes from theoretical physics, specifically from the perspective of general relativity.

Wormholes are frequently discussed as solutions to Einstein's field equations in astrophysics and cosmology. These equations control the gravitational effects of matter and energy on the curvature of spacetime. Although the equations of general relativity make wormholes theoretically viable, they have not been detected or verified to exist in reality, hence they are still considered speculative.

Scientists, authors, and filmmakers have all been captivated by wormholes, which are often depicted in science fiction as a way to travel through space or journey back in time. Wormhole stability, traversability, and the exotic stuff needed to stabilize them are only a few of the many unresolved concerns in the nascent scientific field of wormhole research.

More recently, the word "wormhole" has been used metaphorically to refer to systems or procedures that allow for unusually fast data transfer, financial transactions, or communication between distant sites or systems in domains like computer science and finance. A "wormhole" in the context of blockchain technology, for instance, might be a bridge that permits token transfers between several blockchain networks.

Given the challenges and uncertainties like existence, stability, need for exotic matter, traversability, time dilation, and paradoxes, interstellar travel via wormholes remains highly speculative at this point. While it's an intriguing concept that has captured the imagination of scientists and science fiction enthusiasts alike, practical implementation would require significant advancements in our understanding of fundamental physics and the development of technologies far beyond our current capabilities. But if this turns out to be a success then humanity can seriously think in terms of colonizing other habitable planets in the future, when the resources of our planet get completely depleted. 

It is said that the future of humanity lies in space and wormholes might just be the missing link between us and our destination (future home). But we have a long way to go!!

Prabir Rudra

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Mysterious radio signals from space indicate that we may have contacted the Alien world

 

China's five hundred meter aperture spherical radio telescope (FAST) has recorded some strange signals coming from a faraway galaxy (3 billion light-years from Earth). The cosmic source from which these signals are coming is identified as Fast radio burst (FRB) and the source is named FRB 20201124A. 

This is in fact the second time that such repeated signals have been received after its discovery in 2019. FRBs are intense but brief flashes of radio frequency emissions. They last just a few milliseconds, and so detection of these signals requires high-end instruments and proper knowledge.

Chinese astronomers who have studied these signals say that the signals are coming from a magnetar or neutron star residing in that galaxy, having an extremely high magnetic field. The scientists continuously monitored these signals coming from the same direction for 91 hours. Out of these 91 hours, 1863 signals have been received for 82 hours.

                                     Magnetar

Scientists from China and America are now collaborating in studying these strange signals and trying to derive meaning from them. They say that radio signals of different wavelengths have been received from time to time coming from this same direction. Moreover, the object is said to emit smaller and weaker radio bursts between the fast radio bursts. Observations from FAST, Guizhou, China have been localized by the US National Science Foundation's Karl G. Jansky Very Large Array (VLA). 

                                       Signals

They speculate that there is a hidden code in these signals and probably some alien species is trying to communicate with us via these signals. The trouble is however the decryption of this code and understanding the message hidden in it (if at all there is any).

Fast radio bursts are not new to us, in fact, they have been discovered 15 years ago. These radio bursts are associated with the energy release equal to millions of suns. Generally, most FRBs explode once and the corresponding radio signals are received once during a particular time. But there have been exceptions to this. Many FRBs have been found to emit signals continuously over a period of time which is quite baffling indeed. In 2020 a fast radio burst was discovered inside its galaxy, which is again a very rare and strange incident.

Since then the study of FRB has gained interest and scientists have continuously monitored FRB 20201124A. It has been found that the source is not only sending the signals but also polarizing them simultaneously. More polarization would mean stronger magnetic fields of the source. 

Carefully studying these signals would help us to know more about the atmosphere of the source magnetar. The study has been published in the prestigious journal Nature. These signals are continuously reaching us for the past few years, but we are yet to derive any meaning from them. If we finally do succeed in doing that, probably it will be a new dawn in the scientific prowess of humans.

By

Prabir Rudra

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The rings of Neptune captured by James Webb Space Telescope after three decades

                         Rings of Neptune

Rings of Neptune!! Yes, you heard it correctly. We are all so familiar with the rings of Saturn, the countless small particles of different shapes and sizes that orbit around Saturn, giving a ring-like look. But very rarely do we find anybody speaking about the rings of Neptune. This is exactly what the James Webb space telescope has spotted. 

But this is not the first time that these rings have been visible to us. We knew about these rings earlier, but this is the first time we have received such a clear and crisp image of the rings of Neptune and this spotting has been possible after 30 years. 

                     James Webb Space Telescope

Neptune has always fascinated researchers since its discovery on 23rd September 1846 by Johann Galle. It is the only planet in the solar system which was discovered on the basis of mathematical prediction rather than by empirical observation. 

Alexis Bouvard observed that there were unexpected changes in the orbit of Uranus. From this, he hypothesized that the orbit of Uranus was subject to gravitational perturbations of an unknown planet, which was later found to be Neptune.

In 1989 Nasa's Voyager II spacecraft did a flyby past Neptune and during this time it captured the planet's rings. After that Voyager II continued its journey in interstellar space beyond the solar system, so no more images of these rings could be captured. 

The recent images captured by the Webb show Neptune's fainter dust bands in addition to several bright, narrow rings. It should be noted that Neptune is located 30 times farther from the Sun than Earth and its orbits are located in the remote darker regions of the solar system. Moreover, due to its chemical composition, it is generally referred to as an ice giant, in contrast to the gas giants like Jupiter and Saturn.

           

                    Hubble Space Telescope

The images of Neptune captured by the Hubble space telescope (images at visible wavelength) have a bluish tinge due to the presence of small amounts of gaseous methane. But the James Webb space telescope captured Neptune in its near-infrared range which gave the planet a purple tinge instead of blue. 

Apart from these, Webb has also captured 7 out of 14 moons of Neptune. There is a very bright point seen in the image captured by the Webb, which is Neptune's large and unusual moon Triton (it orbits Neptune in a strange backward orbit). Triton reflects more than 70% of the sunlight that is incident on it. Moreover, due to methane absorption, the planet's atmosphere is darkened at near-infrared wavelengths. The combined effect is that Triton quite easily outshines Neptune in the image. The image from Webb has also revealed a continuous band of high-latitude clouds surrounding the planet, which was never seen before.

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Prabir Rudra

 

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TOI-1452b: An Earth-like planet with deeper oceans and two suns.

 

Recently NASA discovered an exoplanet orbiting around two suns outside our solar system in the Draco constellation. It is named TOI-1452b and is 70% larger in size compared to Earth. The most striking feature of the planet is that it is covered with oceans considered to be deeper than those on Earth. But the feature that arouses the greatest interest is that the planet is situated in the habitable region of the parent stars and water on it remains in a liquid form unlike many moons in our solar system.

This super-earth was discovered two years ago by the TESS space telescope. The planet orbits a binary star system that has currently collapsed to its dwarf stage. So they are around four times smaller than the sun. The revolution speed of the planet is extremely high and so a year on this planet lasts for only 11 days. The orbit of the exoplanet is smaller compared to Earth separated by only 97 astronomical units. Moreover, it is cooler but receives enough light to sustain life.

Researchers have estimated a total ocean presence of around 30% of the total mass. This is huge compared to that of Earth because Earth's 70% water regions only make up about 1% of the total mass. The massiveness of the planet suggests that the depths of the oceans will be far greater than those on Earth. So from this, we can understand the huge reservoir of water that this planet holds. To add to this, all the water present on this planet is in liquid form, which is a real advantage. We know that Jupiter's two moons Ganymede and Callisto contain deep oceans, but they are buried deep beneath thick sheets of ice. The same applies to Saturn's moons Titan and Enceladus.

                 Jupiter and its moon Ganymede

                        Titan: Saturn's moon

To draw some concrete inferences, scientists need to get more observations from powerful telescopes like the James Webb. It is theorized that life originated under the oceans near the hydrothermal vents. Considering this, presence of such a huge amount of water are really positive signs for us. Although scientists are of the idea that the planet does not have an atmosphere, we know that the planet can be brimming with life. This is because some of the branches of the oldest bacteria can live in extreme environments. So in all, the exoplanet is of great interest to us and can be significant in shaping the future of humanity.

                       Bacteria

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Prabir Rudra

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What if we can experience multiple sunrises and sunsets in a single day!!

 

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Prabir Rudra

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The curious case of Pluto

 

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Prabir Rudra

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How the stars and the planets influenced the date of India's Independence

 

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Prabir Rudra

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White dwarf: The death bed of a star telling the story of its glorious past (Meme)

 

Read the full article at:  https://www.spacetimerecipe.com/2022/08/white-dwarf-death-bed-of-star.html

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Prabir Rudra

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White dwarf: The death-bed of a star telling the story of its glorious past

 

A white dwarf is a compact stellar core remnant resulting from gravitational collapse. Dense electron degenerate matter fills up such astronomical objects. Since nuclear fusion ceases to take place in a white dwarf, it almost has no light of its own. But still, a white dwarf may appear faintly lit in the sky, due to the residual thermal energy that it carries forward from the fusion reaction during the star's lifetime. Sirius B at a distance of 8.6 lightyears is the nearest known white dwarf. Around 8 white dwarfs are known to us in the vicinity of our solar system.

Formation

When a star is on the verge of completing its life cycle, its thermonuclear fuel is completely depleted from the core. This results in the halt of the nuclear fusion occurring in its core and there is an imbalance of outward and inward forces in the star with the inward gravitational force dominating the outward thermonuclear force. So the star collapses due to its own mass, with its volume becoming smaller and smaller. This makes the inside material denser and denser. Now if the original star does not have enough mass (> 25 solar masses) to form a neutron star, the remnant generally goes on to form a white dwarf, which is the final evolutionary stage of such stars.

In the main sequence, a star fuses hydrogen to form helium, releasing an enormous amount of energy that counterbalances the inward gravitational attraction. But when all the hydrogen gets burned up, the star expands into a red giant phase, when it fuses helium into carbon and oxygen (true for low and medium mass stars). Now if the red giant cannot produce the necessary temperature (around 1 billion K) to fuse carbon, then the core will be filled with inert carbon and oxygen. After shedding off the outer layers, forming a planetary nebula, the final remnant core rich in inert carbon and oxygen will be the white dwarf. This is the most general scenario and most abundantly found in the universe. But in the case of some small stars, they are not able to fuse helium into carbon and oxygen, and so they form helium-rich white dwarfs.

Stellar Equilibrium

At the white dwarf stage, the further collapse of the star is hindered by the electron degeneracy pressure. But there is a maximum mass limit that can be supported by this degeneracy pressure. This limit is called the Chandrasekhar limit which is approximately equal to 1.44 solar masses. So if a white dwarf accumulates enough matter from its companion star to go past the Chandrasekhar limit, then the electron degeneracy pressure can no longer hinder further gravitational collapse. The resulting white dwarf explodes into a very violent and bright event known as a supernova and the core further collapses towards the formation of a neutron star.

Transformation into a black dwarf and the final fate

Since there is no nuclear fusion going on in a white dwarf, it slowly radiates out whatever remnant heat it has over time and cools down. So initially white dwarfs are bluish-white (hot) due to the radiations emanating from them, but with time they become redder due to cooling. Finally, these dwarf stars are supposed to totally stop radiating and turn into black dwarfs. But the time taken for a white dwarf to turn into a black dwarf is calculated to be greater than the age of the universe, and hence it is thought that there are no such black dwarfs existing in the universe today. The oldest white dwarfs exiting today still radiate out the heat of a few thousand kelvins, which is such a mind-blowing fact!! Even if a black dwarf forms, it will be a really challenging task to locate it due to its non-radiating nature. 

No matter how dark, cool or insignificant they are, such entities will continue to roam around in the eternal space and tell the stories of their glorious past!! Such death beds of once fierce and powerful stars will keep whispering through the ages!!

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Prabir Rudra

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