Space Age

Hey! Who Turned Off The Lights: Eclipses Explained

One of the most spectacular sights to behold once every 18 months, solar and lunar eclipses are fascinating to the human eye. However, a total solar or lunar eclipse would occur only once in 50-80 years. Depending on where you are located on Earth, some locations are like a diamond box in a Cricket stadium that enables you to view a total eclipse in all its glory. When people observed the Moon during an eclipse, they saw the Earth’s shadow on the Moon, which led to the discovery that the Earth was round.

Scientists still continue to discover more about the Moon from lunar eclipses. In 2011, NASA’s lunar reconnaissance orbiter obtained data of how instantly the Moon’s dayside cools during a lunar eclipse. This helped scientists understand the Moon’s surface better. Also, solar eclipses pave the way for astrophysicists to learn more about the Sun’s corona, its top layer.

Both the solar and lunar eclipses depend on the position and movement of the Earth and the Moon while orbiting the Sun. The Moon obstructs the Sun’s rays during a solar eclipse, and its shadow falls on Earth. In a lunar eclipse, the inverse happens, where the shadow of the Earth falls on the Moon, causing it to appear red. Come, let’s dive into the principle of eclipses and how they occur.

How Does the Moon Revolve Around the Earth?

To understand the cause of Eclipses, we need to understand how the Moon orbits the Earth. If you are an avid sky gazer, you might notice that the Moon keeps the same side facing our planet. This is because the Moon is tidally locked to our planet as it orbits. Most planets that are relatively close to each other in orbit are tidally locked in orbit with synchronized rotation. For instance, the planet Mercury is tidally locked to the Sun due to its close proximity and the enormous gravitational force and mass of the Sun.

The Moon orbits Earth with a 5-degree tilt; its orbit determines the portion of the Moon that is visible to the Earth. For instance, if the Moon reaches point B in the image below, then it would appear crescent-shaped when viewed from the Earth. This is because the side of the Moon exposed to the Sun is only faintly visible from Earth, thereby appearing as a crescent. The same principle applies to half-crescent, half-moon, and gibbous Moon. The whole cycle of the Moon’s orbit around Earth is 27.5 days, approximately 28 days.

What is a Solar Eclipse?

Now that we know how the Moon revolves around our Earth and how its orbit impacts our perception of it, it would be easy for us to understand how solar eclipses occur. When the Moon orbits Earth, its orbit also traverses between the Sun and our Earth. At this moment, our Moon blocks the sunlight that reaches us and results in a solar eclipse. The Moon casts a shadow onto Earth.

As the Moon obstructs the Sun’s rays, its shadow gets smaller as it reaches Earth. Umbra is the dark centre of the Moon’s shadow. People who are witnessing a total Solar Eclipse will be standing in the umbra. Penumbra is the lighter outer part of the Moon’s shadow. People who stand in the penumbra will only see a partial eclipse due to the outer shadow. A total solar eclipse is an umbral eclipse, and a partial solar eclipse is known as a penumbral eclipse. A perfect total solar eclipse will look like a ring as the Moon obstructs the Sun’s rays. Since the Moon is smaller than the Sun, the outer portion of the Sun’s rays would seep through the Moon’s edges, making it appear like a beautiful ring studded with a precious gemstone.

A total solar eclipse usually occurs in certain parts of the globe that are perfectly positioned under the umbral shadow of the Moon. They occur once in two years, and people in certain locations could be fortunate enough to see total solar eclipses more frequently than others due to their proximity to the umbra. Unlike lunar eclipses, solar eclipses last for a few minutes. If you plan to see the Sun during an eclipse, think again, as the Sun’s harmful rays could damage your retina badly, causing permanent blindness. Make sure to use solar viewing goggles or a solar viewer to enjoy the show.

What is a Lunar Eclipse?

As Earth’s natural satellite, Moon governs many aspects of our planet, from marking festivals to affecting tidal currents. When manifesting as a Full Moon, the cold, rocky body comes directly opposite to the Sun. When the Earth comes between the Sun and the Moon, it blocks sunlight from reaching the Moon. This specific alignment casts the Earth’s shadow on the Moon’s surface, causing a total lunar eclipse (the Earth eclipsing the Sun’s light from the Moon). Hence, a total lunar eclipse requires a Full Moon and the straight alignment of the Sun, Earth, and Moon.

Full Moons come around every month roughly. But why don’t we get to see the lunar eclipse every other month? Since the Moon’s orbit is inclined by 5° to the Earth’s orbit around the Sun, it usually passes above or below Earth’s shadows, totally unaffected by them. Only around two to four times a year, the Moon comes in the path of the Earth’s shadows causing either partial or total lunar eclipse (governed by the portion of the Moon affected by the Earth’s shadows).

Well, if the Earth blocks sunlight from falling on the Moon’s surface, how are we still able to see it? Thanks to the bending of light waves, sunlight passes the Earth’s atmosphere and lights up the Moon’s surface. Add to that the dynamics of light- refraction, scattering and absorption, the Moon appears deep red during the lunar eclipse. Unlike a solar eclipse, you don’t need aid to watch the Moon on a lunar eclipse. Your bare eyes will do!

Myths and Superstitions about Eclipses

Humans have always built cultural and religious myths around celestial events – eclipses are not an exception.

• Some believe that solar eclipses produce harmful rays capable of robbing one’s eyesight. But scientists disregard the notion on the grounds that the faint light crossing 150 million kilometres of space can cause, at the worst, retinal damage but not blindness.

• It is widely believed that pregnant women shouldn’t watch the eclipse as its radiation might damage the foetus. Scientists completely dismiss this myth stating that the electromagnetic radiation reaching the Earth from the Sun is perfectly safe.

• Another classic myth is that eclipses will poison any food prepared during the event. Experts suggest not to pay heed to this folklore and keep going about your life as any other normal day.

• A few religious texts strongly recommend against taking baths during the lunar eclipse. Since this is a baseless superstition, please take a bath for the sake of those around, if not for you.

• “You should not sleep during the eclipse,” Indian astrologers point out, considering the event to be a bad omen. Yet, science reaffirms, “You sleeping on your bed has nothing to do with the Moon.”

We might have come far from the ages of folktales and misinformation, but myths and superstitions continue to persist among us. Now that you know how eclipses occur keep looking forward to the numerous eclipses ahead without fear or concern, but only wonder and excitement.

Why Are Planets Round?

Have you ever wondered why planets are shaped round? Why aren’t they shaped like pyramids, cubes, or discs? Well, if they were shaped like discs, it would surely be a paradise for flat earthers. 🤣😂 Jokes apart, let’s understand the reason why planets are spherical or oblate spheroid in shape.

When the solar system was formed, planets formed from the remnants of the protoplanetary disc that comprised of asteroids. These asteroids are large space rocks that bonded together to form the planets we see today. However, you may wonder, although each planet does not constitute just rocks but also gases, why do all elements bind together in the form of a sphere?

Why a Sphere?

Well, the simple answer is gravity. Around 4.5 to 5 billion years ago, space rocks from the protoplanetary disc that orbited around the Sun were the building blocks for planets. This protoplanetary disc was formed due to the aftermath of the birth of our star, the Sun. When large space rocks or space debris and gases bump on each other, they bind together to form large planet-size objects. Over a period of time, these large rocks gather enough mass to have gravity, the key force that holds elements together in space. Once the planet is big enough, it automatically begins to clear a path around the star it orbits.

Gravity works in one way; it pulls equally from all sides, specifically from the centre to the edges. When materials of large mass bind together, gravity starts acting on them in this manner, and they clump together to form a sphere. Whether it is just space rock or high-density gas and space debris, gravity acts in the same manner and pulls materials inward, giving them a spherical shape. Gravity holds planets together, it’s the universal glue.

Are all Planets a Perfect Sphere?

Not really; most planets are slightly bulged in the middle, similar to a basketball. For instance, our Earth is slightly flat at the poles but bulged along the equator, giving it the shape of an oblate spheroid. Some planets in our solar system, like Mercury and Venus, are the roundest among all, whereas others are thicker in the middle. For instance, Saturn and Jupiter are thicker in the middle.

Try this, soak a tennis ball in water and throw it in the air by giving it a little spin. What do you observe? The water on the ball would dissipate along the outer edges in a sprinkling manner. This is the same in the case of planets too, when large planets spin, materials on the outer edge move faster than the ones on the inside to keep up. This is because things along the edge have to travel the farthest and the fastest.

Saturn and Jupiter are large planets with a fast spin; this results in a large bulge along the middle like an extra width. This width is known as the equatorial bulge. Saturn is the planet that is thickest around the middle with a 10.7% bulge and Jupiter with a 6.9% bulge in our solar system.

Gravity, the binding force in the universe, always acts inward; that’s why all materials accumulate and bind together form as a sphere and not as a pyramid, cube, or disc. This law applies to not just the planets in our solar system but to all planets in the universe.

The Journey of Life on Earth

The observable universe consists of over 200 billion galaxies that are home to trillions of star clusters. The probability of life existing in several stars is vast but rare; this is because several factors must be crossed off a long checklist in order for a planet to support life. The existence of microbial life in the universe has a higher probability compared to multicellular organisms. However, the existence of intelligent species in the universe has a much lesser probability due to the complexities in evolution regarding chromosomes and DNA.

Everything has a story to tell

Everything in this world, big or small, significant or insignificant, has a story to tell. Take, for instance, a pencil, right from the time it was manufactured until it withers away writing its last letter; it would have a wonderful story to share. If something as small as a pencil has such a beautiful story, just imagine what kind of a story would a 4.5-billion-year-old planet, our Earth, have to say. You may be wondering, who will be able to share the journey of our Earth? If you need to understand the history of our Earth and how life evolved, our genius Geologists are the ones who can explain it best.

Geologists, what would people who specialize in the study of lifeless rocks know about our Earth and the evolution of life? You may ask. Yes, it’s the layers of rock that have been sedimented over billions of years that tell us the history of our planet; it is the fossils of primitive animals like dinosaurs embedded under layers of rock that tell us about life and how it evolved. Geobiologists can tell us how life began, adapted, and evolved. Geochemists can tell us the inner workings of the Earth, the mechanisms behind the geological activity, and the constituents of minerals present in rocks.

History of our Earth

We all know that our Earth was a barren hell 4.6 million years ago, but don’t we want to know how a barren world began beaming with life? The process of the Earth cooling down took over a billion years. When our planet was first formed, it spewed out hot lava, making the surface thousands of degrees hot. Over a few million years, due to the lack of atmosphere and the vacuum of space, our planet cooled down. The hot lava that cooled down formed Basalt, the first rocks on our planet that added a layer of crust on our planet. Basalt contained some important ingredients necessary for life, minerals.

The Six Stages of formation

From an extensive study of our planet’s rocks, Geologists have theorized that our Earth has been through six stages in its formation from the beginning to the Earth we see today. These six stages are black, grey, blue, red, white, and green. The black stage was when the planet looked black due to the sedimentation of Basalt. Meteorites that formed the earth had about 250 minerals, a starter kit containing building blocks for life. Due to intense heat and pressure emitted during the planet’s early formation, many new minerals began to form, which turned the planet’s appearance from black to grey. In the Grey period, granite became the foundation of continents. One thing that baffles Geologists is that these six stages happened in quick succession over the course of 4.5 billion years, which is fast in a Geological time scale.

Water, the fundamental building block of life

The blue stage is the most important stage as this was when the first organisms began to form due to water and oxygen in the atmosphere. There has always been a never-ending debate on how water formed on Earth, with several theories floating about. Research has led experts to the discovery of hydrogen signatures in meteorites that matched the rocks found on the Earth’s mantle. With a lot of oxygen bound up with minerals, which could be liberated under certain circumstances and combined to form water. This process happens in magma, molten rock containing dissolved water that rises from the mantle to the surface in volcanos as a hot spring. As the pressure in the atmosphere fell, water vapours evaporated into the atmosphere as steam condenses and falls back on Earth as rain filling our oceans and rivers.

Geologists discovered Zircon, an essential mineral present 4.3 billion years ago, which could have formed only in the presence of liquid water. Experts debate whether microscopic life could have existed 4.3 billion years ago as the first forms of life were discovered in stromatolites, the earliest fossils of life that existed 3.5 billion years ago.

Proterozoic era, the formation of single-celled organisms

In the red stage of the Earth’s evolution, the atmosphere was rich in nitrogen and carbon dioxide but lacked oxygen. Microbes that were floating in water or stromatolites began changing everything, turning the Earth red. The first single-celled organisms were cyanobacteria that thrived in trillions. These microbes began living off the sun’s energy through photosynthesis, which led to a rise in oxygen levels in the atmosphere. Oxygen was a new gas to our planet back then; with the early oceans filled with dissolved iron, the new oxygen reacted with iron and began to rust, which gave Earth a red appearance.

With Earth’s new continents forming and breaking apart, there was dramatic extremes in the climate. Our planet froze into ice and snow, thereby making it appear white. In the white stage, most life was nearly wiped out with only a hand full of single-celled microbes living near dying volcanoes where there was warmth. These volcanoes spewed out carbon dioxide that heated up the Earth, and over the course of a few million years, ice began melting due to a natural greenhouse effect.

Paleozoic era, the formation of complex multi-cellular organisms

For nearly 2.5 to 3 billion years, single-celled organisms were the only complex life on Earth. Once all the ice melted, oxygen levels in the atmosphere skyrocketed and paved the way for cells to multiply and evolve to form complex life. Five hundred forty million years ago, our planet became a paradise beaming with life. The first multicellular organisms were invertebrates, algae, and small plants. Trilobites were one of the first invertebrate creatures that thrived in the seabed during the early Paleozoic era. They were arthropods, had hard shells, and survived on worms and small plants.

The Paleozoic era was known to be the kingdom of sea creatures, as primitive fish, corals, sea scorpions, amphibians, and aquatic plants evolved and thrived in this period. Around 359 to 299 million years ago, amphibians slowly began ruling the land and began evolving to adapt to living on land. This evolution happened throughout a few tens of millions of years. The end of the Paleozoic era was known as the Permian period when continents joined together to form a supercontinent known as Pangea. During this period, the first non-mammalian synapsids like Dimetrodon and Edaphosaurus and therapsids such as Gorgonopsids and Scutosaurus walked the Earth.

Pangea was relatively dry with harsh seasons as large water bodies did not regulate it. These conditions resulted in 95% of life on the planet becoming extinct. This event, known as the Permian extinction, occurred around 250 million years ago, which marked the end of the Paleozoic era. Although the adverse climate is one of the widely accepted theories that caused the Permian extension, other theories include extreme volcanic activity, hydrogen sulphide emissions, and perhaps even an asteroid impact.

Mesozoic era, the reign of the dinosaurs

As the famous saying by Ian Malcolm (Jeff Goldblum) in the Jurassic Park movie goes, “One thing the history of evolution has taught us is that life cannot be contained. It breaks free, expands to new territories, and crashes through barriers painfully, maybe even dangerously. Life will always find a way.”

After the great Permian extinction, the supercontinent Pangea began breaking free due to the movement of Earth’s tectonic plates and forming smaller continents. The movement of oceanic and land plates paved the way for rivers to form and diverse climatic conditions favourable for life.

The Mesozoic era is the period where Dinosaurs and small mammals thrived. This period of 190 million years is further divided into Triassic, Jurassic, and cretaceous periods respectively. Dinosaurs, birds, and small mammals co-existed in this era along with gymnosperms, angiosperms, and flowering plants. Sauropods, Theropods, and Ornithischians were the three main species of dinosaurs that existed with flying and aquatic dinosaurs. Sauropod dinosaurs had long necks, long tails, small heads and walked on all fours. They were herbivores and existed during the Jurassic period measuring nearly 25 to 30 meters in length. Some Sauropod dinosaurs are Brachiosaurus and Apatosaurus.

Theropod dinosaurs were bipedal, had three-toed limbs, and were either carnivorous or omnivorous. They existed during all three periods and hunted in packs. The infamous Tyrannosaurus Rex (T-rex), Carnotaurus, Allosaurus, and Spinosaurus are theropods. Ornithischian dinosaurs were herbivorous dinosaurs with pelvic structures similar to birds. They were quadrupedal, with some of them being omnivores too. They existed during the Jurassic and Cretaceous periods. Triceratops, Ornithopoda, Thyreophora, and Stegosauria are some examples of Ornithischians.

Dinosaurs coexisted with small mammals in the Mesozoic era that were quite small and weighed less than 15 kg. Mammals back then were cynodonts, with some fossil records stating that they lived during the late Permian period. Believe it or not, these small mammals were our ancestors, as they survived the great extinction that occurred when a large meteor hit the earth. A large meteor hit Earth during the end of the cretaceous period 66 million years ago, ending 75% of life. This mass extinction event marked the end of the Mesozoic era. Evidence of this meteor strike can be found in the Chicxulub crater impact crater buried underneath the Yucatán Peninsula in Mexico.

Cenozoic era, the reign of mammals

After the giant meteor hit Earth and wiped out the dinosaurs 65 million years ago, mammals, certain birds, and some sea creatures were left alive. Most mammals could survive the meteor impact as they were small, agile, and could easily dig deep holes and go into hibernation. The extinction of dinosaurs is one of the main reasons why mammals could evolve and thrive on Earth. If the dinosaurs continued to exist, most of the mammal species would have been wiped out as they were easy prey and might not have adapted well with the dinosaurs in the long run as it would have prevented them from evolving.

Mammals like rhinoceros, cats, dogs, hippos, gorillas, mammoths and other creatures evolved to adapt to the new climate. Prosimians, the ancestors of the first apes, existed over 50-55 million years ago. With millions of years of evolution, they became monkeys, which resulted in many prosimian species becoming extinct. During the Miocene geological period, 20-5 million years ago, apes evolved from monkeys and were displaced from many environments. Their evolutionary line led to hominins, chimpanzees who were connected to homo-habilis and Neanderthals. However, it took another few million years for homo-habilis to evolve to homo-sapiens, modern humans, whose fossil records date back to 100,000 years. Humans have also been through their fair share of challenges and survived an ice age that occurred 13,000 years ago.

The history of how life evolved on our planet is truly fascinating. Regardless of two major extinctions that wiped out nearly all life on Earth, there is always a way for survival if creatures can adapt and evolve to thrive in different environments. As Charles Darwin said, “it is not the strongest of species that survives nor the most intelligent that survives. It is the one that is most adaptable to change.”

The Moon, A Perfect Soulmate for Earth

Thousands of poems, millions of admirers, an object that lights up the lives of star-crossed lovers, the Moon. Have you ever wondered how this thing of beauty has had a profound impact on our lives? Oh, I am sure that a 4-billion-year-old relationship between our Earth and the Moon would redefine true love. Here is a wonderful story of how two planets that were meant to be, collided with each other and became entangled in the web of love. This collision was one reasons why our Earth transformed from a barren Hell into a paradise beaming with life.

Proto Earth, a barren planet

4.5 billion years ago, proto-Earth, which formed from the remnants of swirling gas and dust, revolved around infant Sun. The planet was a barren hell filled with lava due to the rise of hot magma from the planet’s mantle. The atmosphere comprised harmful gases erupting from volcanos, and there was no protection from asteroids and space debris. Several asteroids and debris hit young proto-Earth as they revolved around the newly formed Sun. For millions of years, our planet, which we now call home, remained lifeless and uninhabitable.

The collision that was meant to be

Around 4.5 to 4.6 billion years ago, a planet named Thea revolved around the young Sun, its orbit nearly along Proto-Earth. It was a planet the size of Mars and travelled at the speed of 4 km/second. Due to the gravitational influence of either Venus or Jupiter, it headed towards a collision with Proto-Earth. Thea struck Earth at a 45-degree angle, at the speed of 8,900 miles per hour. The collision resulted in the ejection of pieces of Proto-Earth and Thea. The Earth’s gravity slowly drew some particles. A huge chunk of rocks began slowly forming into a small planet by accumulating the remnants of the proto-planetary disc that had formed due to the collision. This small planet, the Moon, got tidally locked to the Earth and began revolving around it. This whole process would have taken a hundred million years to happen.

The collision between Thea and Proto-Earth had slightly tilted Earth’s position and stabilized its orbit around the Sun, thereby forming a perfect orbit in the habitable zone of the star. Before the collision, Earth was spinning faster with no probability of a stable atmosphere forming. The collision slowed down the Earth’s rotation and stabilized it further. If Thea had struck Earth head-on, it would have resulted in both planets being destroyed instantly, creating a short-lived asteroid belt between Venus and Mars. In January 2016, there was evidence that confirmed the presence of the same materials, which turned out to be Thea’s remains, found on both the Earth and the Moon.

The formation of the Moon and Alternate hypothesis

Lunar rock samples, retrieved from Apollo astronauts, had a startlingly similar composition to Earth’s crust. This confirms that the formation of the Moon was likely due to a violent event. The Moon’s formation from the resulting collision between Thea and the Earth is known as the Giant-Impact hypothesis, which is widely accepted by scientists today. However, let us look into three other hypotheses that existed from the beginning.

The first hypothesis describes that a single planet body split into Earth and Moon. The second one speculates that the Moon was captured by the Earth’s gravity, which was the case for most outer planets. The third hypothesis describes that the Moon’s origin formed from the remanets of the protoplanetary disk that accreted.

An inseparable bond that binds our life force

The Moon helps the Earth rotate in its axis and keep it in perfect orbit. Although most asteroids that are aimed close to the Earth’s orbit usually get caught by Jupiter’s massive gravity, some smaller asteroids land on the Moon. Without the Moon, there would be no environment for many coastal animals to survive as our oceans would have smaller tides, thereby preventing crabs, starfish, turtles, and snails from reproducing and surviving. The temperatures on Earth could vary erratically as the Earth’s axis would tilt by 45 degrees or more. There could be no tilt that could result in no seasons or a major tilt that could result in extreme seasons, perhaps an eternal ice age.

Without the Moon, the Earth’s rotation could slow down further, resulting in far shorter days and more days in a year. We must always celebrate the inseparable bond between the Moon and our Earth. Their strong relationship helps humans thrive. That fortunate collision has helped the Earth stay in perfect orbit and given birth to the evolution of the life we see today. Many scientists theorize that without the Moon, life on Earth may not have evolved as we know it. This is because the Earth would have had a far different orbit around the Sun, leaving it either too hot or far too cold for life to exist. Thea was a planet that sacrificed itself to give us life. It is this 4-billion-year-old relationship between these two lovebirds that helps us evolve and thrive on this planet.

Into Interstellar Space with Voyager

Have you ever imagined yourself leaving the Earth, travelling into outer space, visiting other planets, and eventually leaving the solar system to view the universe in all its glory? Well, Voyagers did just that! Come, let’s take a journey into interstellar space with Voyager.

Voyager the Journey and Beyond

In the early 1970s, NASA had a stellar plan to study outer planets of the solar system and gain a deeper knowledge of them. They were wondering how to build a space probe that could hover through space. With the information gathered from the Pioneer 10 spacecraft, scientists at NASA’s Jet Propulsion Laboratory were able to design the probe such that it could take immense radiation from Jupiter with enhanced radiation shielding. On July 1st 1972, the project to launch Voyager 1 and Voyager 2 for the purpose of deep space exploration began.

Equipped with 16 hydrazine thrusters referencing instruments and gyroscopes, the two Voyagers had instruments to study objects in space and bring to light the best pictures of the cosmos through its cameras.

Take off… the beginning of an awesome journey

On September 5th 1977, Voyager 1 took off from NASA’s Kennedy Space Centre in Florida. Although Voyager 2 probe was launched a month before, Voyager 1 would be the first to reach Jupiter and Saturn due to its trajectory. Scientists at the Kennedy Space Centre and employees of NASA’s jet propulsion laboratory watched the rocket break through the stratosphere and reach outer space. Voyager 1 sent the first picture of the Earth and the Moon on September 6th 1977, a trickle of tear rolled down the eyes of scientists and engineers as they saw the image.

Flyby of planets in the solar system

Travelling at the speed of 17 kilometres per second, Voyager 1 reached Jupiter on March 5th 1979. It was a sight to behold; it captured images that helped scientists decipher the giant red spot and conclude that it is the eye of a huge storm. It also uncovered other strange phenomena that inflated Jupiter’s magnetic field due to ions stripping from the planet’s surface and creating a torus around it. This acts as an electric generator in Jupiter’s magnetic field.

Voyager encountered Saturn, the ringed planet, on November 9th 1980 and captured its rings in the most magnificent picture. It also flew by Titan, one of Saturn’s moons, and discovered the possibility of seas of liquid methane and ethane on its surface. Voyager 2, on the other hand, reached Saturn nearly a year later in August 1981 and made it to Uranus in January 1986. It made a phenomenal discovery of 11 new moons orbiting Uranus and took pictures of them.

In August 1987, NASA’s deep space network completed expanding the three big dishes that enabled engineers and scientists at the laboratory to better communicate with the two Voyagers. Voyager 2 made yet another startling discovery of six new moons when it encountered Neptune in August 1989. In the meantime, Voyager 1 was on its way towards the end of the solar system. You may ask, why didn’t the Voyagers encounter Pluto? That’s because the primary objective of the Voyager mission was focused on exploring Jupiter and Saturn for Voyager 1 and Uranus and Neptune for Voyager 2.

Are we just a speck? The Pale Blue Dot

On valentine’s day 1990, NASA’s engineers turned the camera of Voyager 1 towards Earth just before disabling the camera to conserve energy. The camera captured the image of a pale blue dot with its size hardly a fragment of a pixel. This image shook the whole of humankind as it was a clear depiction that the human race is just a speck of merely irrelevant species in this vast humongous universe that spans to a diameter of 93 billion lightyears (observable). (nine thousand three hundred crore lightyears).

First man-made object to enter interstellar space

On February 17th 1998, Voyager 1 became the farthest ever human-made object from the Earth, beating the Pioneer 10. The termination shock is a boundary that separates the solar wind and the Heleosheath; it is the outermost region of the solar system. At this point, the solar wind slows down and heats up abruptly. Scientists and engineers at NASA could not communicate with Voyager 1 as ground antennas were not scheduled to capture the data that the spacecraft was listening to. However, after a while, NASA’s experts were able to connect back to the Voyager as it entered the Heleosheath. They were able to measure the analyze the measurements and nature of the spacecraft only when Voyager 2 crossed the termination shock three years later.

The Heliosphere is the region outside the solar system that resembles a bubble that is inflated by plasma emitted by the Sun. This region ends at a point known as the Heliopause, which is exposed to the particles and ions of deep interstellar space. Picture this, you are visiting another country and are going through two different checkpoints, the security checkpoint and the immigration and customs checkpoint. This concept is somewhat similar and also applies to both Voyagers that left the solar system.

On August 25th 2012, the Voyager 1 becomes the first human-made object in the history of mankind to leave the solar system and enter interstellar space, followed by Voyager 2 on November 5th 2018. The Voyagers collect detect the intensity of the cosmic space and the interstellar magnetic field around the heliosheath and send data back for our scientists to rack their brains about. Scientists understand the nature of the coronal mass ejection thrown out by the Sun, causing the Voyagers to ring.

For the universe to see… The Golden Record

Where would the two Voyagers go? You may ask, well, their trajectory is not pointed to any nebula, specific star or a planet, but it travels aimlessly through interstellar space at the speed of 62,140 km/hour. Oh! You might think that is fast, but it is nothing compared to the speed of light, which is 300,000 kilometres per second. Since most starts in our neighbourhood are around 4-8 light-years away, it would take the Voyager a whopping 73,000 years to reach Proxima Centauri at its current speed of 17 km/second. That is if its trajectory is aimed towards Proxima Centauri.

The odds that one of the Voyagers would come in contact with intelligent life in this colossal universe is highly minuscule. Scientists at NASA, along with Carl Sagan, decided to add a Golden phonographic record for any intelligent life to decipher. This golden record contains a message from the human race that includes greetings in various languages, sounds, music, thoughts, and images of Earth and life. Jimmy Carter, the US president at that time, also shared a small message, “We are attempting to survive our time and may live into yours, having solved the problems we face, to join a community of galactic civilizations.”

Placing the Golden record on both the Voyagers was truly a remarkable idea. Experts at NASA have included some simple ways how the record can be played and accessed through pictorial representations. Also, the record is built in such a way that data could be extracted from it even after a billion years (100 crore years). The record also includes an hour-long brain wave of Carl Sagan’s wife.

A Tribute to Carl Sagan

Although he lived a relatively short life, Carl Sagan was one of the most influential and brilliant astrophysicists. He was also a cosmologist, astrobiologist, and science communicator. He has written several books that continue to influence students and young scientists to pursue their dreams in the field of Scientology. His inquisitiveness, scientific thinking, and advocacy has propelled several kinds of research and built a platform for young scientists to emulate.

Here is the link to the speech by Carl Sagan in Cornell lecture 1994 regarding the pale blue dot.

A Tribute to Stephen Hawking

Meet the man who gave a new definition to the universe, a cosmologist, a passionate physicist, and a genius who was born to mesmerize the world with his voracious intellect. Stephen William Hawking was one of the world’s greatest theoretical physicists and an indispensable asset in the field of cosmology and particle physics.

A Legend is born

Stephen Hawking was born on 8th January 1942 to a relatively well to do family in Oxford, England. In his initial years, he was not academically successful but eventually showed excellence in scientific subjects and mathematics. He was also known as Einstein during his school days. He studied at Oxford university college, which was an utter cakewalk for him as he found most subjects ridiculously easy. However, he went into depression when he was diagnosed with motor neuron disease, Amyotrophic Lateral Sclerosis (ALS), during his graduate years, and doctors gave him only two years to live. Despite this severe blow in his life that rendered him speech impaired and physically challenged, Hawking cheated death and soared to great heights with his thoughts pervading in every young astrophysicist well past his demise.

New Beginnings

Hawking came to Cambridge to study with one of the world’s famous cosmologists back in the 1960s, Sir Fred Hoyle.

Hoyle strongly believed in the steady-state theory, which inferred that the universe has no beginning or end. This theory stated that matter would continuously be created as the universe expands, in utter disagreement with the big bang notion of an indefinitely dense initial state. The steady-state theory was widely accepted among the most renowned astrophysicists at that time.

Young Hawking was eager to flex his neurons and genius intellect; he called his doctoral thesis properties of expanding universes. During his first months at Cambridge, he was interested in Narlikar’s calculations and began hanging around his office opening discussions and sharing ideas. He became more engrossed with Narlikar’s difficulties with the project Hoyle assigned.

In a talk at the prestigious royal society, Hoyle discussed the latest ideas based on Narlikar’s calculations. After his speech, he asked the crowd whether they had any questions, flaunting his appreciation with a sheepish grin filled with pride. Much to his dismay, Hawking stood up and said, “the quality you talk about diverges.” Filled with ego, Hoyle says, “How do you know?” Hawking replies, “Because I worked it out.” Hawking goes on to showcase his paper summarizing mathematical methods he had used and proved the divergence of Hoyle’s equations.

Hoyle was furious as an embarrassed laugh passed through the audience. He had his work refereed openly by an unknown post-graduate student.

Limitless Intellect

One of the Oxford tutors supervising Hawking’s work in statistical physics assigned several problems from a textbook. Only to be greeted with a list of mistakes in the textbook marked clearly with a valid explanation. His mind knew no bounds as he harnessed extreme intellect that enabled him to decipher even the most complex calculations and postulates into simple yet understandable concepts.

As Hawking was nearing his end of term at Oxford, he met with a terrible fall in the staircase due to the beginning effect of ALS, which resulted in a temporary memory loss. However, even ALS stood no match, as Hawking passed with flying colours!

A New Perspective of the Universe

Albert Einstein predicted the existence of black holes through his theory of relativity. Black holes stemmed from massive stars that collapsed. However, this black hole theory was not well understood by scientists due to the lack of exploration and complex nature of the concept.

Hawking took it a step further and notched it down for easier understanding. He christened a new definition to the black hole theory that established the existence of black holes as reality and not just a theory that could be debunked. With his remarkable brain, he proved certain rigorous mathematical theorems of Einstein’s equations for gravity. Under general circumstances, he showed that there were places where equations broke down and coined them singularities. The region inside a black hole, in which even light cannot escape, is known as a singularity.

Yes, Black holes Shrink, Hawking Radiation

In his initial research, Hawking was of the strong impression that the size of a black hole remains constant and never changes. However, after some vigorous research and rethinking, he proved that black holes could shrink as they radiate energy, thereby reducing mass. This energy that radiates is known as Hawking radiation.

Hawking theorized that this radiation from virtual particles was constantly popping into and out of existence in the bizarre quantum realm. This happens in matter-anti-matter pairs, where one has positive energy and the other with a negative. Hawking also emphasized that black holes have tendencies of evaporating or boiling themselves away in a brilliant burst of energy equal to a million 1 megaton hydrogen bombs, astounding, isn’t it?

Gracefully Dealing with Criticism

A successful person is always prone to criticism; Stephen Hawking was not new to that. He faced criticism from other scientists who coined the black hole information paradox. This paradox was a puzzle with the combination of quantum mechanics and general relativity.

Hawking proved that once a star dies, all its mass would collapse into a single point of infinite density that results in a singularity. The information paradox stated that once the black hole collapsed, all information is lost, thereby violating the principle of quantum physics that information cannot be destroyed as it stays constant. Hawking debunked the paradox with his witty argument that information is not lost but is encoded in particles emitted by the radiation.

Hawking’s contributions to physics are a force to be reckoned with. His level of intellect was beyond comprehension and blew the minds of renowned cosmologists and scientists. He established a strong foundation for scientists in the future by bridging several gaps in quantum cosmology, black holes, thermodynamics, and various riddles in the universe. His contributions would pave the way for future research and reshape our understanding of the universe.

My Trip to Mars- Part 2 [Story]

As the doors of the Alien spacecraft open, four humanoid shaped living beings step out. Lisa and I couldn’t quite make out their physical appearance as they seemed to be wearing a very large spacesuit which concealed their bodies. At this point, we stood petrified at the sight of them and couldn’t book it from there immediately as our space pod was at a significant distance from us. I signaled to Lisa that it is time to make it to the pod with a simple head gesture, she nodded. However, just as we were about to break into a run, the Alien creature gestured for us to come aboard just like how we would ask a little child to come forward. We were astounded, as these extra-terrestrials could establish a simple communication with us just by observing the head gesture I made.

We stood rooted to the ground as we didn’t know what their intentions were. After a bit of thought, I told Lisa that I am going to go to them and you make it back to the ship. This is NASA‘s backup plan, as under unforeseen circumstances one member of the crew must make it back to tell the tale.

As I inched my way towards these strange extra-terrestrial creatures, my heart was throbbing uncontrollably. I mustered up the courage to step onto their spacecraft, they signaled me to come in. As I stepped inside, I was dumbfound by the amazing infrastructure of their space craft. It was huge and had the capacity to carry over 500 astronauts. They sealed the airlock and pressurized the chamber. And then came the moment of truth, they removed their helmets to reveal themselves. They looked just like humans except that their skin color was blue and they had a pointy nose. One of them came to me and asked me to remove the helmet of my spacesuit, I was reluctant to do so at first but figured if they were going to be hostile to me, they could have destroyed my spaceship easily given that their technology is far advance. Soon as I removed my helmet, I found the air around me to be very heavy and I started feeling immense pressure on my chest. They observed this and handed me a small mask which helped me breathe better. I later figured that these aliens are used to living in a planet with a far higher oxygen density than that of Earth’s, which is why the oxygen saturation was making it harder for the cells in my lungs to adapt to a different atmospheric condition.

These strange beings took me to a large room which had different types of gadgets and holographic control systems that I have never seen before. They played a video clip which was voiced over in English. They explained to me that they were the first ever living beings to roam the universe. They existed 3 Billion years before the solar system was formed, and had had foreseen the conditions on Earth well before our existence, and studied us thoroughly over the years. They had also honestly admitted that they were very hesitant to approach us as we were so technologically far behind that we would leave them no choice but to attack if we see them as hostiles. They had mastered every aspect of travel, inter-planetary combat and warfare, time jumps, and things which we only read in science fiction books.

The video clip also had content for how to develop a space habitat, how to mine asteroids, colonize planets which are near the habitable zone, deflect a large asteroid approaching Earth, as well as some basics of building space defense systems. This was way too much information to process. They gave me a small Tablet like device which contained this video, asked me to share it with the concerned person and also wished me good luck. The alien space craft landed near the coast of California. I used an inflatable boat to get to the coast.

I immediately radioed to my colleagues Lisa and Sam, telling them that I have safely landed on Earth. They would never believe me as they were on their way back to Earth but had covered just about a quarter of the distance. I went to NASA headquarters and shared this information. Believe it or not, this information had cut down the construction cost of our space habitat significantly and we finished the project well before hand. The World Space Organization had raised its stakes in the field of space research and development and we were on a whole different route. With this information, I am sure that we would have mastered interstellar travel and colonized many planets before the 23^rd century. Thanks to the unknown Alien benefactor, we will never forget your small contribution which has paved a new way to Humanities’ greatest achievements, yet to come.

My Trip to Mars [Story]

It’s the year 2085, things are really bright for NASA as this is the 17^th time they are embarking on a manned space mission to Mars. Since NASA have had a bitter experience in the past, they have redesigned the old space suit to better adapt to the atmospheric pressure and temperature of the red planet. Our team is sure that this will work just as planned as the spacesuit has been tested in the large planetary simulation chamber multiple times. In this mission, we are going to conduct the final inspection and plot the coordinates for constructing the space habitat.

If everything goes as planned, we would be able to colonize Mars by the beginning of the 22^nd century. Ever since all the countries in the world realized that there is no point in fighting with each other and spent all their resources for the development of their society, things have taken a wild turn and we are heading for the betterment of the future. The world space organization has postponed its 8^th interstellar mission until our project is done as it involves a lot of expenditure.

This image has an empty alt attribute; its file name is habitat.png

Things are going just as planned, its 24 hours to launch, not just my family, but the whole world is excited to watch this event unfold as we will be back with the good news. 4.2 billion people have already booked their reservations for becoming permanent residents of the Martian world encompassed by a space habitat. Sadly, most of the bookings are wait-listed as only 2.5 billion people can be accommodated in the structure. The remaining people will have to wait until the year 2125 for the next habitat to be constructed.

The day of the launch has arrived, the fuel lines of the rocket are fully secure, me and my team of 2 astronauts Sam, and Lisa have boarded the spacecraft equipped with all the gear and resources for our 300 day long journey. As we are waiting to ride on, I look into the sky and think to myself, “This is it, we are going be a part of something mankind is going to be proud of for years to come. “ 10, 9, 8, 7, 6, 5, 4, 3, 2, 1 and we are off into space. Our spacecraft has now reached space and we are about to slingshot our way to Mars. My team are anxious about whether they will make it. I assure them that everything is perfect as I check my console for any fuel leaks, pressure variance and change in direction. We cross our planet’s gravitational field and are on our way to the red planet.

Just 50 days left to reach. I toggle through the cameras and happen to stumble upon a relatively small blue globular thing, turns out is our Earth. I radio back to headquarters and tell them that I am on track and need some assistance with the landing gear. I also share the remainder of my schedule, they verify it and then give me a thumbs up.

We reach Mars, Lisa and I gear up as Sam is going to hang back and assist us with the landing from the spacecraft. We hop into the pod and detach ourselves from the craft. We steer our way towards the red planet.

As I approach Mars, I see a glimmer of sunlight reflecting off its surface and boy oh boy, it was a truly amazing sight. I was mesmerized by that beautiful red desert sand glistening off the surface. Lisa preps the landing gear and we are ready to land. I reduce the speed of the engine and reverse the throttle to counter the gravitational force of the Martian world. As the spacecraft makes its way to the surface, I see that the atmosphere is much different than that of Earth’s. Looks like a huge amount of reddish brown dust lingers around. We make a smooth landing at the spot as planned and radio back to NASA headquarters.

Lisa and I inspect the surrounds for any large debris and get out of the spacecraft. As I set my foot on the ground, I tell her, “This is our first step to into a new world, we are going to start what humanity has dreamed of for many years.” We inspect the land for a couple of days and plant the markers at the optimum location. That’s it, our job is done, we radio back and tell the world that the construction of the Martian space habitat has begun. Just as we are about to make our way back to the space pod, we see an unidentified spacecraft hovering over the planet just a couple of yards away from our pod. From the looks of it, we can tell that this is some Alien spacecraft far ahead of our technological achievements. This unidentified spacecraft makes a soft landing and the doors open.

[To be Continued]

Aliens Where Are You?

While your looking at the stars in the clear night sky, have you ever wondered that out of billions of galaxies in the universe, why is it that no one has ever contacted us? There are several probabilities as to why our extra-terrestrial friends haven’t got in touch with us yet. Let’s look into some common theories which give us something to ponder about.

Hello! Is Anyone there?

The distance between stars and galaxies is too much that it would take a considerable about of time to travel to them even if you are going at 60% the speed of light. We all know that no object of mass can travel at the speed of light as it would simply disintegrate. However, there could be alien civilizations that can construct spacecrafts which can travel half the speed of light. Even if they do, it would take them generations to find for a planet which can sustain life. So why would they waste their precious resources for an expedition which is doomed.

Life, It Doesn’t Happen In The Blink Of An Eye

Yes, we are biological multicellular beings who have evolved into humans. But in order for us to exist, several things need to fall in place in order for life to thrive. Firstly, the planet needs to remain in the habitable zone of its parent star. A little too far, we will freeze to death, a little too close, we will be burned to a crisp. Secondly, the atmospheric pressure and the air mixture needs to be in perfect consistency in order for single cell organisms to thrive. Finally, the environmental conditions need to support the evolution of microorganisms which in turn gives rise to intelligent beings.

Maybe We Aren’t Worth Their Time

What if aliens are too smart for us? What if they don’t find the need to contact us as we are still in the infant stage of development? Yes, they would be so technologically advanced that they wouldn’t want to waste their energy to visit us if they knew that they wouldn’t be benefitted in any way.

The Great Filter

An Italian-American physicist Enrico Fermi was asked: If the universe is so vast, why are we still unable to contact aliens? He then responded by giving his theory known as the Fermi Paradox. This states that even if there is life out there, the probability of it being intelligent is a far cry. The paradox also gives us an insight as to how communication between extra-terrestrials can be close to impossible as they might not be using radio frequencies. Instead they could be using different systems to communicate. Systems which are far more advance that it would take close to a million years for us to figure out what they are. If advance civilizations have access to immense power which is capable of destroying planets larger than Mars, the odds are that they could easily get into territorial disputes, desire for more power and end up destroying themselves in the process. This point is known as the great filter. In order for civilizations to get through the great filter, they need to work together and use their resources for their betterment wisely, instead of getting overwhelmed by their differences and aspiring for more power.

Can You See Us?

Let us picture an alien civilization which is capable of using a very power telescope that can zoom in to view each detail clearly. Assuming that this civilization is about 60 million light years away from earth. While they are seeing us with their powerful telescope, they will be able to see dinosaurs. You know why? Cause they will be viewing our planet as how it was 60 million years ago, when the dinosaurs existed. This is because light will take so long to reach them that they cannot see the present. So they would assume that there is no intelligent life on that planet.

These are some reasons why aliens haven’t contacted us yet.

Betelgeuse: The Amazing Red Giant

Betelgeuse is the only star that glows red in the night sky. The average lifespan of a star is about 13.5 billion years (1,300 crore). Our sun is around 5.3 billion years old, halfway through its life. Betelgeuse on the other hand is a giant star, much bigger than that of our sun. It has exhausted almost all of its fuel and is nearing the end of its life.

Size Comparison With Our Sun

Our sun is a medium sized star that will turn into a red giant in another 5 billion years ( 500 crore). At that time, as a red giant, it will encompass the orbits of Mercury and Venus. Our earth will be uninhabitable as it will be stripped off its atmosphere and left burnt. Hey don’t worry, this won’t happen even in your great great grandson’s lifetime. The sun will remain a red giant for a million years. In this phase, it will burn its reserve fuel. After a million years, the outer layer of our star will fade away as a gaseous shell, thereby exposing its core. This event is known as a planetary nebula. The exposed core will appear as a glowing white dot known as a white dwarf.

However, Betelgeuse is a massive star which is more than 15 times the mass of our sun. Which means that the mass of the core will collapse and the star will explode into a supernova instead of forming a planetary nebula.

So When Will it Go Supernova?

Betelgeuse is currently a red giant that could go supernova any time. Astronomers are studying the star closely, however, they are not able to determine when it will explode. When it does, the people of earth will experience a breathtaking view of the explosion. The sky will light up and for a brief period it will seem like there are two suns present. The light emitted by the explosion will be so bright that it will engulf a part of the sky.

You may wonder whether we might get destroyed by the explosion. You need not give it a thought as the star is 642 light years away.

Where is it?

On a clear night sky, Betelgeuse will appear as a red star. In fact, it is the only star that appears as a red dot. You can spot it easily as it is a part of the Orion constellation. Refer to the image below.