Article by – penserstudypoint

The asteroid belt is a large disc-shaped ring with large solid bodies such as asteroids (minor planets).

It divides the sequence of eight planets into two parts.

The four planets are before the asteroid belt towards the Sun are Mercury, Venus, Earth and Mars and the four planets are ahead of the asteroid belt are Jupiter, Saturn, Uranus and Neptune.

Size of asteroid belt:-

The asteroid belt is about 150 million km thick and approximately 2.2 AU from the sun.
The estimated mass of the asteroid belt is 2.39 × 10²¹ kg while only mass of the Earth is larger than the mass of the entire asteroid belt and is about 5.9×10²⁴kg .

Materials in asteroid belt:-Most of the asteroid belt material was already lost during the early 100 million years of the solar system.

It mainly consists of three types of bodies in which the first type is C-type that are rich in carbon, the second type of bodies are S-type which is silicate rich body and the third type consists of M-type bodies which contain metals like iron and nickel.

The asteroid belt consists of about 1-1.7 million asteroids in a small area of 1 km or more in diameter and this data was traced by infrared wavelengths.

The asteroid belt has large bodies whose size is about 950 km and as short as dust particles.
There is also a dwarf planet named Ceres in the asteroid belt.
There are about 200 known asteroids have a diameter of more than a hundred kilometers in size.

Facts:-Meteroids entering the Earth’s atmosphere are also mostly from the asteroid belt. Meteroids are large bodies made up of ice and dust particles.

There is also a dwarf planet named Ceres in the asteroid belt

TIME TRAVEL & WORMHOLES – myth or truth

At present, we are changing according to the time. Time not change according to us. But what if we change the time. Time travel An imaginary thought.

We don’t know if It will be future or past. It is like changing time’s direction to past or increasing time’s speed to future, but if it will be possible in the future, It may be travel to past.

According to relativity, Nothing can travel faster than light (3 × 10⁸m/sec.). At light speed, mass will be infinite (according to relativistic mass formula) . And the length of object will be zero (according to length contraction formula). But if we travel with the light speed, what can we see? Is there any color? Is there any boundary of anything? Only white light appears on moving with light speed. Everything is white.

At present, black holes are the best source to see the past. Where, light cannot even pass through. The body’s shape , space-time will be changed at light speed . 

Even if we travel with such a high-speed it will take 2000 years in reaching and coming back to Earth from a thousand light years away star(or any Terrestrial body in space). When you travel such a large distance, an atom, the smallest unit of matter also traveled to that distance, and it is amazing to imagine.


According to scientists, a wormhole is a cylindrical path between two heavy bodies in space. It is not from any science fiction movie. It is scientist’s thoughts. 

Wormhole forms by two giant bodies have very high gravity value like black holes. If a path is a thousand light years long, wormholes can make it a few million miles long. So, it may be a possibility to travel faster than light.

In 1835, Albert Einstein and Nathan Rosen called them Einstein-Rosen Bridge. Bridge that connects two, bodies that are light years far away from each others.

Worm holes are like tunnels in space connecting to distant bodies because space and time are flexible (according to Einstein). Through the wormholes we can cover very long distance in a very short period.


According to another theory we can travel with light speed. The theory proposed that, if we are stable and space can move. In this theory, a large heavy body contract the space with fast and alternately a negative mass, behind the large body, can expand that contracted space.

Negative mass is only a hypothetical Idea. It behaves just opposite of positive mass that we have.

Positive mass can contract the space while a negative mass can expand it. Due to this, we remain stable on a position and space can move.

If all this phenomena possible, we can cover large distance with speed of light by stay at a place without any change.

To be continue…

Hope u like it




There are many planetary systems like ours in the universe, with planets orbiting a host star. our planetary system is named the “solar” sytem because our sun is named Sol , after the latin word for sun, “solis”, and anything related to the sun we call “solar.”

Age 4.568 billion years

our solar system formed about 4.5 billion years ago from a dense cloud collapsed, possibly due to the shockwave of a nearby exploding star, called supernova. when this dust cloud collapsed. it formed a solar nebula – a spinning, swirling disk of material. As is typical of molecular clouds, this one consisted mostly of hydrogen, with some helium, and small amounts of heavier elements fused by previous generations of stars.

The solar system consists of the Sun, planets, dwarf planets, moons, and numerous smaller objects such as comets and asteroids. 194 moons, 3,583 comets and 796,289 asteroids have been found in the solar system. 99.86% of the solar system’s mass is found in the Sun.

The Sun is our nearest star. It is, as all stars are, a hot ball of gas made up mostly of Hydrogen. The Sun is so hot that most of the gas is actually plasma, the fourth state of matter. The sun is classified as a G-type main-sequence star, or G dwarf star, or more imprecisely, a yellow dwarf. The planets in order from the Sun based on their distance are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
Approx distance between neptune (8th) planet and sun is 4.476 billion km.
It is 143.73 billion km from the Sun, thus giving the Solar System a diameter of 287.46 billion km approx.

Based on where the planets end, you could say it’s Neptune and the Kuiper Belt. If you measure by edge of the Sun’s magnetic fields, the end is the heliosphere. If you judge by the stopping point of Sun’s gravitational influence, the solar system would end at the Oort Cloud. The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars, that is occupied by a great many solid, irregularly shaped bodies, of many sizes but much smaller than planets, called asteroids or minor planets.
The asteroid belt formed from the primordial solar nebula as a group of planetesimals.
Planetesimals are the smaller precursors of the protoplanets. Protoplanets are thought to form out of kilometer-sized planetesimals that gravitationally perturb each other’s orbits and collide, gradually coalescing into the dominant planets.

The Kuiper belt, occasionally called the Edgeworth–Kuiper belt, is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune (at 30 AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger – 20 times as wide and 20–200 times
as massive. Like the asteroid belt, it consists mainly of small bodies or remnants from when the Solar System formed.
The Kuiper belt is home to three officially recognized dwarf planets: Pluto, Haumea and Make make. Kuiper belt contain comets, mostly ice comets with black colour. When the orbit of the comet brings it close to the Sun, the ice evaporates into space, leaving some of the fine dust sitting on the surface. The dust is fine like talcum powder because comets are too small to have
enough gravity to squeeze the dust together into larger particles. The surface is very black.

The sun sends out a constant flow of charged particles called the solar wind, which ultimately travels past all the planets to some three times the distance to Pluto before being impeded by the interstellar medium. This forms a giant bubble around the sun and its planets, known as the heliosphere.

The heliosphere is the vast, bubble-like region of space which surrounds and is
created by the Sun. In plasma physics terms, this is the cavity formed by the Sun in the
surrounding interstellar medium. The “bubble” of the heliosphere is continuously “inflated”
by plasma originating from the Sun, known as the solar wind.
The heliosphere acts as a shield that protects the planets from interstellar radiation.

The Oort Cloud lies far beyond most distant edges of the Kuiper Belt. While the planets of our solar system orbit in a flat plane, the Oort Cloud is believed to be a giant spherical shell surrounding the Sun, planets and Kuiper Belt. The outer limit of the Oort cloud defines the cosmographic boundary of the Solar System and the extent of the Sun’s Hill sphere. The outer Oort cloud is only loosely bound to the Solar System, and thus is easily affected by the gravitational pull both of passing stars and of the Milky Way itself. The Oort Cloud is made up of icy pieces of space debris.
In short, gravity from the planets shoved many icy planetesimals away from the Sun, and gravity from the galaxy likely caused them to settle in the borderlands of the solar system, where the planets couldn’t perturb them anymore. And they became what we now call the Oort Cloud.
The Oort cloud is thought to occupy a vast space from somewhere between 2,000 and 5,000 au .
The outer limit of the Oort cloud defines the cosmographic boundary of the Solar System and
the extent of the Sun’s Hill sphere.



Stars are born, develop, flourish, and die over periods of millions or billions of years. The mass of the star will often determine its end as stars change and die in different ways. Their deaths leave behind different phenomena, all of which, from white dwarfs to black holes, fascinate astronomers.

Most stars are born in enormous star nurseries, known as nebulae. A nebula consists of giant clouds of gas, mostly hydrogen and helium, and dust. Gravitational pull in denser parts of the nebula, sometimes caused by nearby stars or explosions, sees matter clumping together, increasing in mass and temperature, and generating its own gravity.

As a large clump of gas shrinks and grows hotter, it is labelled a protostar. This is a potential star in the making. Eventually, most protostars get dense and hot enough to trigger off nuclear reactions deep inside them and the stars start to shine. This initial burst of energy blows away dust and gas surrounding these early stars.

The main sequence is a long period, usually lasting billions of years, in which a star generates energy through nuclear fusion, turning hydrogen into helium in its core. For stars up to three times the mass of our Sun, the main sequence comprises about 90 per cent of their life span. The Sun has been in its main sequence for more than 4 billion years.

When a star of the Sun’s size has used up most of the hydrogen fuel in its core it swells up to become a red giant. When more massive stars, eight or more times greater in mass than our Sun, start to swell, they become supergiants, Betelgeuse (also known as Alpha Orionis) is a red supergiant. It is so huge that if it replaced the Sun in our Solar System, its outer atmosphere would extend past the asteroid belt.

Some protostars do not have enough mass to trigger nuclear reactions and become stars. Instead, they generate smaller amounts of energy through continuing contraction. These failed stars are known as brown dwarfs. They will radiate their remaining heat out into space, slowly fading until they have no energy left, at which point they are known as black dwarfs.

After completing their main sequence, stars that are a similar size to the Sun start to collapse, increasing in density and temperature. The stars then swell to enormous size, before throwing off their outer layers as giant clouds of gas. The clouds cool to form a planetary nebula, surrounding the star’s remains, known as a white dwarf. Since the discovery of the Dumbbell Nebula in 1764, more than 3,000 planetary nebulae have been observed.

A white dwarf may have run out of hydrogen or helium fuel to burn in its core, but it will continue to shine for many millions of years. White dwarfs can range in colour from hot white through to cool red. Scientists estimate that a typical white dwarf is so dense that a teaspoonful of its matter would weigh about 5 tonnes. As with a brown dwarf, white dwarfs fade over time to become black dwarfs.

As some massive stars die, their cores contract sharply and temperatures rise by millions of degrees. The core absorbs more and more energy before erupting in a gigantic explosion. In the first 10 seconds of a typical supernova explosion, 100 times more energy is produced than the Sun will generate during its entire lifetime.

Some massive star deaths result in the core collapsing in on itself to form a neutron star – the smallest, densest stars known in the Universe. Neutron stars may be under 20 km (12 miles) in diameter yet contain the same mass as the Sun. Rapidly spinning neutron stars send out radio waves that we can pick up on Earth. These stars are known as pulsars.

Some stars collapse even further, into a dense point called a singularity, The space immediately around a singularity is called a black hole. It is so dense and the pull of gravity so strong that nothing, not even light, can escape from it. Astronomers cannot observe a black hole directly, only its effects on nearby objects, such as the pull of gas into the hole, which can release powerful X-rays.



Like islands in a vast sea of space, most galaxies are millions of light-years apart. However, some galaxies are close enough to be pulled by gravity into clusters. Members of galaxy clusters can pull on each other so strongly that they collide.

Stephan’s Quintet is a group of galaxies that appear to be smashing into each other. Four of them are about 280 million light-years away from Earth, but the fifth is closer to us. NGC 7318b is passing through the main group at nearly 200 million mph (320 million km/h). This creates a shock wave that causes the gas between the galaxies to heat up and give out X-rays (the light blue region in the middle).

Cluster collision
The ultimate crashes occur when several clusters of galaxies collide. The biggest collision astronomers have seen so far is a pile-up of four clusters called MACS J0717. This filament (stream) of galaxies, gas, and dark matter is 13 million light-years long. It is moving into an area already packed with matter, causing repeated collisions. When the gas in two or more clusters collides, the hot gas slows down. Galaxies don’t slow down as much, so they end up moving ahead of the gas.

A distorted view
Some galaxy clusters act as magnifying glasses in the sky. Their powerful gravity distorts the space around them. This means that light from more distant galaxies or quasars is bent on its way to us. We see multiple arcs and distorted images of the distant object, like a mirage in space.



Solar tsunamis are surges of material sent crashing across the Sun as the result of a solar flare being launched into space. They can travel at speeds up to 1.6 million km (1 million miles) per hour. These solar tsunamis are made of hot plasma and magnetic energy.

The first was observed by Gail Moreton in 1959, and since then several more studies have been conducted by the Solar and Heliospheric Observatory (SOHO) and the Solar Terrestrial Relations Observatory (STEREO) spacecraft, both of which orbit the Earth.

Solar tsunamis are formed when the Sun emits a coronal mass ejection (CME) – a massive burst of solar wind commonly associated with solar flares. Around the ejection point, a circular wave extends outwards in all directions and travels across the surface of the Sun at a super-fast rate. In February 2009, the two STEREO spacecraft watched as a billion-ton cloud of gas was hurled off the surface of the Sun from a CME.

The result of this ejection was a massive solar tsunami that towered 100,000km (60,000 miles) high and which sped across the star’s surface at about 900,000km (560,000 miles) per hour. It was estimated to contain the same energy as 2.4 million megatons of TNT.

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Solar wind streams from the Sun at a blistering 400 kilometres (250 miles) per second. The intense heat of the corona – the outermost portion of the Sun’s atmosphere – energises particles to such a level that the Sun’s gravitational field can no longer hold on to them and they escape into space.

Solar wind strength varies, creating space weather capable of disrupting technology, like global positioning system (GPS) satellites.

The movement of solar wind has a characteristic pattern that resembles a rope wobbling up and down – technically known as an Alfvén wave (after Hannes Alfvén). These magnetic strings can be observed as the greenish light that appears during the polar auroras.

Until recently scientists have struggled to understand this unusual wave behaviour, but a new set of models – based on similar waves generated by polarised light – might enable us to understand, and even predict, future fluctuations in solar wind.




Most stars are born in a huge cloud of gas and dust, called a nebula. The story starts when the nebula begins to shrink, then divides into smaller, swirling clumps. As each clump continues to collapse, the material in it becomes hotter and hotter. When it reaches about 18 million F (10 million C), nuclear reactions start and a new star is made.

Nebulas can be different colors. The color comes from the dust in the nebula, which can either absorb or reflect the radiation from newborn stars. In a blue nebula, light is reflected by small dust particles. A red nebula is caused by stars heating the dust and gas.

This is one of three huge fingers of cool hydrogen gas and dust. At the top of this finger, hot young stars shine brightly among the dark dust. Eventually these stars will blow the dust away and become clearly visible as a new star cluster.

Not all nebulas are colorful. The black Horsehead Nebula is a cloud of cold dust and gas that forms part of the Orion Nebula. The horse’s head shows up against the red nebula behind it, which is heated by stars. Many stars have formed in the Orion Nebula within the last million years.

The Pleiades cluster lies in the constellation of Taurus. It is also known as the Seven Sisters, because up to seven of its massive, white-hot stars can be seen with the naked eye. There are more than 300 young stars in the cluster, surrounded by a thin dust cloud that shows as a pale blue haze.

V838 Monocerotis is a red supergiant star, located about 20,000 light-years away from Earth. In March 2002, this star suddenly flared to 10,000 times its normal brightness. The series of images below shows how a burst of light from the star spread out into space, reflecting off the layers of dust that surround the star. This effect is called a light echo. The images make it look as if the nebula itself is growing, but it isn’t. The spectacular effect is caused by light from the stellar flash sweeping outward and lighting up more of the nebula.

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The red colour that we usually see in images of Mars is actually the result of iron rusting. Rocks and soil on the surface of Mars contained a dust composed mostly of iron and small amounts of other elements such as chlorine and sulphur. The rocks and soil were then eroded by wind and the resulting dust was blown across the planet’s surface by the activity of ancient volcanoes. Recent evidence suggests dust was also spread across Mars by water, a theory backed up by the presence of channels and ducts across the planet’s surface.

The iron contained within the dust then reacted with the oxygen in the atmosphere, producing the distinctive red rust colour, while the sky appears red because storms carried the red dust high up into the planet’s atmosphere. This dusty surface, which is between a few millimetres and two metres deep, also sits above a layer of hardened lava which is mostly composed of basalt. The concentration of iron that is found in this basalt is much higher than it is in basalt on Earth, and this also contributes to the red appearance of Mars.


If you look up into the sky on a clear night, you will see thousands of stars, but how do you know which star is which? Luckily, the stars form groups known as constellations, which can help you find your way around the heavens.

Early astronomers noticed that the stars formed groups and that these groups moved in a regular way across the heavens. They began to use characters, animals, and objects from their myths and legends to remember these groups. Most of the constellation names we use today date from Greek and Roman times, but some go back even further to the Egyptians, Babylonians, and Sumerians.

Finding the North Star
The North Star sits almost directly above the North Pole, which makes it an excellent way to find due north. It is visible all year in the northern hemisphere at the tip of a constellation called Ursa Minor (the Little Bear). To find it, you can use another constellation called Ursa Major (the Great Bear). Seven of its stars form a shape that is known as the Big Dipper. The two stars that form the front of this shape point to the North Star, which is the next bright star you see.

A group of 12 constellations can be seen in both hemispheres. The ancients called them the zodiac, from the Greek word for animals. Most of them are named after animals, but some are human and one is an object. The zodiac runs along a path in the sky called the ecliptic, which is at an angle of 23 degrees to the equator. The Sun, Moon, and planets also move on paths close to the ecliptic.