Exploring our Solar System

OUR SUN

The Sun is the closest star to Earth and is the center of our solar system. A giant, spinning ball of very hot gas, the Sun is fueled by nuclear fusion reactions. The light from the Sun heats our world and makes life possible. The Sun is also an active star that displays sunspots, solar flares, etc.. These phenomena impact our near-Earth space environment and determine our "space weather." Someday, the hydrogen in the Sun will run out. A long time from now. Our star will puff up. It will eat some planets. Even the Earth! Eventually our Sun will end up as a white dwarf.
The highly rarefied area around the sun, called the corona, extends millions of kilometers into space but is visible only during a total solar eclipse (left). Temperatures in the corona are over 1,000,000 K.


What goes around the Sun:
The first thing to notice is that the solar system is mostly empty space. The planets are very small compared to the space between them. Even the dots on the diagrams above are too big to be in proper scale with respect to the sizes of the orbits.
The orbits of the planets are ellipses with the Sun at one focus, though all except Mercury are very nearly circular.
Mercury, Venus, Earth and Mars are all Rocky planets, inner planets and small planets
Jupiter, Saturn, Uranus and Neptune are gas , outer, giant planets.
The asteroid belt between Mars and Jupiter forms the boundary between the inner solar system and the outer solar system.

Mercury
Very tiny planet, only slightly bigger than Earth’s moon, has a very elliptical orbit. Has no moons.
Venus
It is the brightest object in the sky except for the Sun and the Moon. Venus is sometimes regarded as Earth's sister planet. Venus is only slightly smaller than Earth and their densities and chemical compositions are similar. But it is radically different from Earth. It may be the least hospitable place for life in the solar system.
The pressure of Venus' atmosphere at the surface is very high, composed mostly of carbon dioxide. This dense atmosphere raises Venus' surface temperature by about 400 degrees to over 740 K (hot enough to melt lead). Venus' surface is actually hotter than Mercury's despite being nearly twice as far from the Sun.
Earth
Earth, our home planet, is a beautiful blue and white ball when seen from space. The third planet from the Sun, it is the largest of the inner planets. Earth is the only planet known to support life and to have liquid water at the surface.
Mars
Mars, Earth's outer neighbor, is the fourth planet from the Sun. Mars' bright appearance and reddish color stand out in the night sky. Impressive surface features such as enormous volcanoes and valleys are frequently obscured by huge dust storms. The planet probably got this name due to its red color; Mars is sometimes referred to as the Red Planet. Olympus Mons: the largest mountain in the Solar System rising 24 km (78,000 ft.) above the surrounding plain. Early telescopic observations revealed that Mars has permanent ice caps at both poles.
Jupiter
It is the largest planet in the solar system. When approached from afar, its fantastic striped atmosphere gradually reveals intriguing clouds that move around the planet.
Saturn
Saturn, the sixth planet from the Sun, has the most spectacular set of rings in the solar system.
Uranus
Uranus, the seventh planet from the Sun, has its spin axis almost in the plane of its orbit about the Sun. This produces unusual seasons and also causes unique magnetic and electric field structures.
Neptune
Neptune, the eighth and furthest planet from the Sun, is a very cold place. Its bluish color is caused by small amounts of methane gas in its atmosphere.
Moon
The Moon was first visited by the Soviet spacecraft Luna 2 in 1959. It is the only extraterrestrial body to have been visited by humans. The first landing was on July 20, 1969. The gravitational forces between the Earth and the Moon cause some interesting effects. The most obvious is the tides.


Space Exploration:


In 1942 the German V2 was the first rocket to reach 100km from the Earth’s surface (the boundary of space).The rocket was designed by Wernher Von Braun, who later worked with NASA as the creator of the rockets that went to the moon.

In 1947, the first animals were launched into space. Fruit flies were used to study the effects of space travel on animals, and were chosen because they are more similar to humans than you might imagine!The flies travelled with a supply of corn to eat on the flight.

Albert II, was the first monkey in space. He was a Rhesus monkey, a type of monkey that originally comes from Asia. Albert went into space on 14th June, 1949 in a specially adapted American V2 rocket, that flew to a height of 83 miles from earth.

On 4th October 1957, Russia launched the first satellite into space; Sputnik 1, and the space age had properly begun!Sputnik was the first satellite in orbit around the earth. Today there are over 500 working satellites in space. Sputnik means "Satellite" in Russian.

In November 1957, the Russian space dog Laika became the first animal to orbit the earth.Laika travelled in a spacecraft known as Sputnik 2. Laika means "Barker" in Russian, and her mission helped scientists understand whether people could survive in space.

By 1959 Both American and Russian scientists were in a race to get a spacecraft to the Moon; the Russians made it first.Space-probe Luna 2 crash-landed into the moon at a speed that would kill an astronaut if one had been travelling in it! It was ten more years until a human visited the moon's surface.

On 12th April 1961, Russian Cosmonaut Yuri Gagarin became the first man in space. Gagarin's spacecraft, Vostok 1, completed one orbit of the earth, and landed about two hours after launch.Gagarin had to bail out and land using his parachute, because the Vostok 1 was designed to crash land!

In 1963 US President John F. Kennedy promised the world that the US would land men on the moon before 1970. Before they could risk people's lives, NASA sent a robot spaceship to the moon, to make sure they could land without crashing. It was called Surveyor 1, and it made the first soft landing on the Moon on 30th May 1966.

On 20th July 1969, Neil Armstrong, and then Buzz Aldrin took "one small step" and became the first men on the moon. The first words said on the moon were "the Eagle has landed". Their spaceship, Apollo 11 worked perfectly, flying them 250,000 miles to the moon, and bringing them all the way back safely to earth. Buzz was a childhood nickname - his real name was Edwin!

Two days into its journey to the moon, on 13th April 1970, Apollo 13 suffered an explosion caused by a wiring fault. Using only whatever was on board, NASA scientists and the astronauts on board improvised repairs to bring the crippled spaceship home.The mission was a successful failure: although the crew never walked on the moon at least they made it home alive!

In 1973, Russian space probe Mars 2 explored Mars, the fourth planet of the solar system.The probe was made of two parts. One part stayed in orbit for a year, sending pictures of Mars back to earth. The other was to land and explore the surface of Mars, but it was destroyed when its parachute failed to open.

Until 12th April 1981 all spacecraft were designed to be used only once. The Space Shuttle, was designed to be reused for up to 100 visits to space, in an attempt to make space travel less expensive.With five hugely powerful rocket motors, it can fly at more than 17,000 miles per hour. Six have been built.

On January 28th 1986, tragedy struck. Space Shuttle Challenger exploded shortly after launch, because of a fuel system failure. All seven astronauts on board were killed, and all shuttles were grounded for nearly three years.This shocking accident reminded the world of the dangers of space travel, and the incredible bravery of all astronauts.

In 2003, Space shutter Columbia burst into flames on its return journey, and all its’ crew members were killed. On boars was Kalpana Chawla among others.

In 2000 the first permanent crew moved into the International Space Station (ISS), where crews of astronauts have been living ever since. The ISS is a huge space station for research and space exploration that began construction in 1986 and will not be finished until 2010.

On the 28th April 2001 American millionaire Dennis Tito became the first space tourist when he paid around 20 million dollars for a ride in a Russian Soyuz spacecraft.Dennis spent a week in orbit, most of the time visiting the International Space Station. He had to train for 900 hours just to be a passenger!


Why does an astronaut wear a spacesuit?
Space is a very challenging place to explore. There is no air in space, so there is nothing to breathe. It is very cold, unless the sun is shining onto you - and then, without air to protect you, the rays of the sun would soon burn you!To survive in space you need a suit that protects your body from the heat and cold, and surrounds you with air to breathe. Space suits are pressurised, meaning they are full of air to support your body, which is why they look puffed up. A space suit is like a tiny spaceship for one. It is a very complicated machine, with air conditioning, heating, air to breathe and water to drink. It even has a built in toilet!Some space suits attach to a rocket powered backpack, which allows the astronaut wearing it to fly around in space.

II Ramayana II

Ramayana, the greatest epic of all times, was written by Maharishi Valmiki over 2000 years ago.

Ramayana tells us the Story of Lord Rama, who came on the Earth as an incarnation of Vishnu. He was born as the son of king Dashratha and Queen Kaushalya. He was the eldest among his brothers- Bharat, Lashman and Shatrughan. He married the daughter of king Janak- Sita and was living happily in Ayodhyaya. It was then when his stepmother, Queen Kaikayi asked Dashrath to make Bharat the king and banish Rama in the forest for 14 years. Rama, being an obedient son, agreed.

His loving wife , Sita and loyal brother , Lakshman followed hin in the jungle. They lived there peacefully untill one day Suparnakha, sister of the demon king Ravana spotted them. She instantly liked the handsome Rama, and approached him. Rama rejected her. Furious, she charged towards Sita, where in Lakshman cut off her nose.

Agitated, Suparnakha went to her brother Ravana, and told him of Sita's extraordinary beauty and the brother's atrocities on her. Ravana kidnapped Sita and brought her to Lanka.

Rama and Lakshman enlisted the help of the monkey king, Sugriva and his general, Hanuman to trace Sita. Hanuman was able to locate Sita in Lanka. Soon, Rama and his monkey army invaded Lanka.

A fierce battle raged. Ravana was helped by his able son, Indrajit and mostrous brother , Kumbhkaran. His another brother Vibhishana , was good at heart, and so he changed sides to be with Rama. In the end , Rama won the battle and rescued Sita.

Rama and Sita were noble rulers of their land and ruled wisely.

We celebrate Dasahara on the day of Rama's victory over Ravana and Diwali on the day Rama returned back to Ayodhyaya.

Marvels of Medicine

All of us fall sick sometimes. Medicines cure us and get us back on our feet quickly. But there are many different systems of medicines prevelant in the world today:
Allopathy : also known as the Modern medicine.
Ayurveda : The classic Indian approach to the art of healing.
Homeopathy : propagated by a German Dr. Samuel Hahnemann

Modern Medicine:
Hippocrates is known as the father of medicine. He was the first to suggest that diseases are not divine interventions but natural problems, curable by nature itself.

Steps of a treatment:
When we fall sick, a doctor can cure us. First he needs to ascertain the disease. This is called Diagnosis. He may take help of some tests to accurately diagnose the disease.
Then he will prescribe some medicines in a Prescription.
We must always follow the doctors’ advice.
At times, doctors need to operate on a patient. This is called Surgery

What makes us sick?.
Diseases can be caused due to many reasons. Microorganisms like bacteria and Virus are the main culprits. Some diseases like malaria spread through mosquitoes. Some, like Typhoid are spread by eating dirty food and water. Infectious diseases are diseases that spread from one person to another.
The best way to stay healthy is to eat a balanced diet, personal hygiene and regular exercise. Remember, Prevention is better than cure.

Important types of medicines.
Vaccine: is given to improve the body’s immunity to a particular disease.
Antiseptic: is a substance that is applied to a living tissue or skin to reduce the possibility of infection.
Antibiotic: are substances that kill or inhibit the growth of bacteria. Antibiotics are given to a patient if he has bacterial infection. One must always complete the full course of an antibiotic medicine.

First Aid:
The immediate care given to someone in emergency is called First Aid.
Always keep a first aid box ready in home. A typical First Aid box will contain
1. Bandaid 2. AntiSeptic 3. Cotton wool and bandage 4.Ointment 5. Scissors 6. Common medicines.



Ayurveda, which means "science of life" in Sanskrit, is based on the premise that everything in the universe, including the human body, is comprised of five basic elements: earth, wind, fire, water and space
Ayurveda prescribes natural remedies to cure the diseases. Yoga plays a big part in ancient Indian system of healthcare.
Charaka was a prominent Rishi and the first important physician of India. His book, Charak Samhita, is an important source of Ayurvedic remedies.
Sushruta was an important surgeon of ancient India and his book Sushruta Samhita is an important document on early surgery .


Homeopathy: Homeopathy is a form of alternative medicine , first expounded by german Dr. Samuel Hahnemann. He put forth the idea of “like destroys like” , and created this branch of medicine. Homeopathy is characterised by highly diluted doses of medicine given typically in sugar balls.

Other alternate forms as acupuncture, Siddha medicine etc. also exist throughout the world.

Hibernation

Energy is needed all the time.
We all need energy – all the time. Every living animal on Earth is burning energy all the time. Physical activities like walking and breathing burn energy. Pumping blood and digesting food burns energy. Even thinking burns energy. For warm-blooded animals, a lot of energy is burned just keeping our body temperature where we need it. Even when we're sleeping, we're burning energy.

What happens in Winters?
That's the whole reason animals eat -- to gain enough energy to fuel all those processes. The system works fine when there's plenty of fruit on the trees or rabbits to catch and eat . But what happens when winter comes and it becomes very difficult to find food? How do animals survive with few energy sources available?
Winters can be very harsh in many places. Human beings find warmth in heaters, woollen clothes etc., but what do animals do? Where do they get their food from when all the land is covered in snow ?
Animals have different, wonderful strategies to cope with winters. Some migrate, Some Adapt, and yet some hibernate. Smaller animals tend to be more likely to hibernate, because migration would require an enormous amount of energy relative to their body size. Larger animals are less apt to hibernate because of the additional energy required to warm up a large body.

What is Hibernation?
Some animals "hibernate" for part or all of the winter. This is a special, very deep sleep. The animal's body temperature drops, and its heartbeat and breathing slow down. It uses very little energy. In the fall, these animals get ready for winter by eating extra food and storing it as body fat. They use this fat for energy while hibernating. Some also store food like nuts or acorns to eat later in the winter. Bears, skunks, chipmunks, and some bats hibernate. Cold-blooded animals like fish, frogs, snakes and turtles have no way to keep warm during the winter. Snakes and many other reptiles find shelter in holes or burrows, and spend the winter inactive, or dormant. This is similar to hibernation.
Water makes a good shelter for many animals. When the weather gets cold, they move to the bottom of lakes and ponds. There, frogs, turtles and many fish hide under rocks, logs or fallen leaves. They may even bury themselves in the mud. They become dormant. Cold water holds more oxygen than warm water, and the frogs and turtles can breath by absorbing it through their skin.
When an animal enters a hibernationlike state during the summer, it's known as estivation. It's much less common than hibernation. Estivation is like hibernation in hot weather. Animals that live in deserts or tropical climates practice estivation. It may not occur solely because of food supply issues, as with hibernation, but because the conditions become too hot and dry for the animal to survive. The process typically involves burrowing into the ground, where the temperature stays cool, and reducing metabolic activity in a similar manner to hibernation.

How does hibernation work ?
Hibernating animals have a special substance in the blood called hibernationinducement trigger, or HIT. This substance becomes active in the fall, when the days becomecooler and shorter. When HIT becomes active, the animals start preparing for winter. Someanimals store food so that they can eat when they wake up, and some animals eat a lot in latesummer and fall to add excess fat to their bodies. This fat keeps them warmer and acts as asource of energy while they are sleeping. Some animals also make changes to the placeswhere they will sleep (dens). They add leaves and grasses to keep them warm.

Preparing for Hibernation
Preparation is required to hibernate successfully. Some animals prepare a den (also known as a hibernacula) and line it with insulating material, just as leaves or mud. Ground squirrels and lemurs do this. Polar bears dig tunnels in the snow. Other bears might spend the winter in a hollow beside a tree or a shallow cave, leaving them partly exposed to the weather. Bats are well-known for wintering in caves or attics.
Next comes food storage. Food can be kept in the den if it's nonperishable, but this requires the animal to wake up briefly during the winter to eat. Another option is to eat a large amount of food starting in late summer, building up a reserve of internal fat.
Several other things occur when an animal is hibernating:Heart rate drops to as little as 2.5 percent of its usual level. A chipmunk's heart rate slows to five beats per minute from the usual 200.Breathing rate drops by 50 percent to 100 percent. Yes, 100 percent. Some animals stop breathing entirely. A few reptiles go their entire hibernation period without breathing, and even mammals have shown the ability to survive with drastically reduced oxygen supplies. Consciousness is greatly diminished. This varies by species, but many hibernating animals are completely oblivious to their surroundings and are nearly impossible to wake up.
If you were to wake up a hibernating animal midwinter, you would be effectively killing it. It would use up so much energy warming itself up in order to awaken that it would have no chance of making it to spring even if it could re-enter hibernation.