Did you know that there is a giant spacecraft that has been hovering around the Earth’s orbit since November 1998? This magnificent spacecraft is home to the best crew of astronauts and astrophysicists from around the world. It is a unique laboratory equipped with the best-in-class equipment built to study the nature of space, analyze the behavior of the human body when exposed to prolonged stays in space, and research various phenomena occurring in and around our planet. It orbits the Earth at a whopping speed of 17,500 mph, at that speed, it takes only 90 minutes to orbit the entire planet.
Origins
In November 1998, the first component of ISS was launched from a Russian Proton rocket from Bikonur Cosmodrome in Kazakhstan. With the combined efforts of the best astrophysicists and scientists from around the globe, the ISS was assembled over the next two years with increased precision and attention to detail. The first crew made it to the space station on November 2, 2000, and the initial stages of the research began in full swing. Eventually, NASA continued to add different sections to the space station with the help of Russia, Japan, and Europe, thereby completing the construction in 2011.
What Is In The ISS?
Weighing close to one million pounds under the Earth’s gravity, ISS can support a crew of six astronauts and a few visitors from Earth. It is a large facility that covers the size of a football field with five separate sectors for astronauts from Russia, Japan, United States, and Europe.
ISS consists of labs that enable astronauts to conduct scientific research, modules that are home to systems that enable the space station to function, living areas for the crew, and nodes (modules) that connect parts of the space station with each other. It also consists of solar arrays or solar panels on its sides that collect energy from the sun in order to enable optimal functioning.
Also, robotic arms are mounted outside the space station enabling radiators to control the temperature. These arms also aid astronauts to perform routine maintenance procedures of the space station in hard-to-reach areas. They also move astronauts around when they are out for spacewalks outside.
ISS is also equipped with an airlock sector that is open to the outside enabling astronauts to go on spacewalks with ease. It is an airtight room with two entrances that opens without letting air out of the spacecraft. It also acts as a docking port for new visitors to enter and receive supplies for the crew from Earth.
Why Is ISS Important?
ISS has enabled humans to live in space and explore various aspects of how the human body behaves when exposed to microgravity (the condition of being weightless). For over 20 years, astronauts have been living in space laboratories and performing in-depth research on aspects that cannot be done on Earth. The behavior of liquids, and gases under microgravity, have been clearly analyzed. It allows scientists to understand the mechanism of spacecraft when on a long-term space journey. This station has provided a perfect platform to prepare astronauts for long-term space travel and is currently being used to study the travel from Earth to Mars. It enables humans to reach the farthest points in space than ever before.
Have you ever wondered how the continents in our world took shape? Did you know that over 250 million years ago, the world was comprised of only one large landmass surrounded by a massive ocean? The first-ever landmasses took hundreds of millions of years to form. This was after the Earth cooled and the atmosphere was formed, over 3 billion years ago.
Our Earth has been through hell, taken a severe beating from various external forces, and sacrificed a lot to make life possible for millions of species that thrive today! The movement of tectonic plates is the reason why we see the continents that are present today. Tectonic plates comprise the Earth’s uppermost mantle and comprise oceanic and continental crusts. Earthquakes typically occur around mid-ocean ridges and large faults that mark the edge of plates.
Tectonic plates constantly move even today; that’s the reason why tsunamis and earthquakes occur. The continents which we see today are the result of a 250-million-year-old journey of plate movement. Come, let’s dive into understanding how the movement of plate tectonics have shaped the continents we see today.
Super Continent Pangea
Around 300 to 275 million years ago, a supercontinent called Pangea existed, which was known to be the first-ever landmass to exist. This amazing supercontinent was surrounded by a massive ocean called Panthalassa. Pangea existed during early the Permian period when the first multi-cellular organisms thrived on Earth. Plants, insects, vertebrate animals and early marine life lived during the Permian period.
After studying the geological composition of Earth in 1912, Alfred Wegner, a German meteorologist, proposed the existence of Pangea as a part of his theory of continental drift. Later, geologists further delved into this theory, studied the composition of the Earth’s crust and the movement of plates to confirm the existence of this supercontinent. Pangea in Greek means “all the Earth.”
Continental Plates
The continents we see today are the product of over 250 million years of tectonic plate activity. Pangea began to break apart around 200 years ago during the Early Jurassic Epoch. This supercontinent broke and drifted apart in different directions. Each continent is placed on a specific plate. Some important plates include South American Plate, Eurasian Plate, Indo-Australian plate, North American Plate, Caribbean plate, and Antarctica plate.
Formation of Continents
When Pangea first broke apart, each continental plate broke apart, and the respective plates began moving in different directions according to the movement of the tectonic plates. Another important point to note is that in some cases, the movement of the tectonic plates were accelerated by strong oceanic currents.
The North American plate was the first to break apart and moved in the north-western direction. Another large chunk of landmass at the bottom of Pangea broke off and moved southwards to form Antarctica. The Indo-Australian Plate, stuck to the Antarctic plate, broke apart and moved eastwards with a slight tilt towards the north. The Eurasian plate began moving in the North-East direction. The South American plate began moving towards the west, and the African Plate began moving towards northwards, eventually touching the Eurasian Plate. All these continents moved to their current location over 200 million years.
Formation of the Himalayas
Now that we have seen how the movement of plate tectonics has shaped the continents we see today. You might be wondering, isn’t there something that I have missed out on? Yes, how could one forget about the Indian sub-continent? Well, the best has been saved for the last.
Around 200 million years ago, the tectonic plate that holds the Indian Subcontinent was located in the southernmost region of Pangea right above Antarctica. This plate was sandwiched between the African plate and the Indo-Australian plate. Initially, the African and the Indo-Australian plates broke apart. After another 10 million years, the Indian Subcontinent broke away from the Antarctic Subcontinent and began moving northwards towards Asia.
The plate that held the Indian Subcontinent moved relatively fast. Most of the crust below the Indian Subcontinent came off due to the movement of the oceanic plate, thereby making the landmass much lighter. With excess weight shed off, the Indian Subcontinent travelled relatively faster over millions of years from the region close to Antarctica to Asia. During the initial stage of the journey, a small landmass in the western side of the Indian Subcontinent broke apart and moved along the African plate. This landmass is what is now known as Madagascar.
The Indian Subcontinent made contact with the Eurasian plate around 50 million years ago. The impact of this collision is what caused the formation of the Himalayas. When the Subcontinent collided, the oceanic plate that was attached to the North-East portion of the landmass made contact with the Eurasian plate. This collision lifted the plates to form the Himalayas. Even today, the Indian Subcontinent continues to move Northward by a small margin, causing earthquakes in Nepal and parts of Tibet.
Conclusion
Tectonic plates are constantly moving, and in a few million years into the future, the continents we see today will eventually drift further away. Who knows?? Maybe 200 million years into the future, all continents may even converge together and form a new landmass.
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.
Trilobites
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.
Gorgonopsids
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.
Types of dinosaurs
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.
Time scale for reference
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.”
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.
Earth day is celebrated all over the world as it is a day to spread environmental awareness about our home planet. It was first celebrated on April 22nd 1970 and has had a word-wide reach ever since. This day is considered to be of great importance as people from different culture, religions, and race come together and spread love. Let us dig into some fun facts about our home planet.
Our Earth Was Once a Barren Hell
About 4.5 billion years ago, just after our sun was formed, there were a set of planets which formed due to space debris that deposited during the aftermath of the star formation. This deposit of debris was the leading cause for the formation of the solar system.
Our Earth is also a product of space debris. It was situated inside a solar protoplanetary disc which posed a hellish atmosphere on earth. The earth was prone to constant volcanic activity which lead to scorching temperatures at its surface. It was like a molten hell with flowing rivers of pipping hot larva. Over the course of the next two billion years, the earth’s atmosphere changed drastically as it was present in the habitable zone of the sun. That is what made life possible for us.
Staying Comfy With Plate Tectonics
Did you know that plate tectonics exist only on earth and not on any other planet. The outer crust of earth comprises of plate tectonics which float on hot magma. They are in constant motion due to the magnetic field of the earth. When these plates rub against each other, they break free from the wrath of the hot magma and resurface. This constant geological activity leads to the formation of mountains, and steep ridges. This is why plate tectonics play an important role in keeping our planet at bay and providing the best scenery which serves as a visual treat.
Is the Earth a Perfect Sphere? Hmm Maybe Not
Hey you may be thinking, yes it isn’t a perfect sphere cause it has mountainous regions and huge canyons. Well the truth is that our earth is flat at the poles and slightly bulged in the region of the equator. It is shaped like an oblate spheroid. The reason why there is a bulge near the equator is due to the rotation of the planet and the effect of the magnetic field.
Molten Iron Core: Our Earth’s Magneto
You need to be ever grateful to the molten iron core which is at the center of our planet which is enclosed by an outer core. This arch angel creates a magnetic field (Magnetosphere) which is powerful enough to encompass our whole planet. This field protects us from the fury of solar winds from the sun. So without the iron core, we would have burned to a crisp years ago.
Earth’s atmosphere extends to a distance of a Whooping 10,000 km
Yes, you read it right, the atmosphere of our home planet is really dense for the first 50 km from the surface and reaches to about 10,000 km into outer space. The layer of atmospheres include the Troposphere, Stratosphere, Mesosphere, Thermosphere, and the Exosphere.
The reason why the density of the atmosphere reduces as you reach outer space is because due to the gravity of the planet. 75% of the Earth’s atmosphere is near the earth. This region is rich in gases like oxygen and nitrogen. The earth’s atmosphere is also our savior as it protects us from small asteroids and space debris by burning them to smothers before they reach the earth’s surface.
Co-orbital satellites: Hey where did they come from?
3753 Cruithne and 2002 AA29 are two asteroids which are locked into a co-orbit with earth. These two spacefarers orbit our sun in a synchronized manner. The image below will give you a better perspective.
Space Age 