27 Jan 2019

Mercury: world of ice and fire

Mercury: world of ice and fire


Our solar system how beautiful it is, it consists of Sun, Planets, natural satellites, asteroids, and many more. If we talk about planets then they are eight right now, because Pluto is no more considered as a planet. As we know life is only possible on Earth among them all. If we talk in respect to the distance from the sun then mercury is the closest planet to the Sun.

Physical characteristics of mercury

As we know Mercury is innermost planet, so it’s surface temperature range between 100k to 700k (-172℃  to 427℃  ), a temperature swing of more than 1,100 degrees F (600 degree C), the greatest in the solar system.

Mercury is orbiting the sun at an average distance of 58 million kilometres. Because mercury is closest planet to sun, it moves faster than any other planet at an average 48 kilometres per second.
Solar system

If we talk about its size it is slightly bigger than Earths moon. Its equilateral radius is 2439.7km which is even smaller than the biggest moon of our solar system, Titan and Ganymede.

If we compare on the basis of density Mercury is second densest planet after Earth. Planet Mercury has huge metallic core of about 2,200 to 2,400 miles (3,600 to 3,800 km) wide, or about 75 percent of the planet's diameter.

If we talk about its atmospheric, then according to NASA atmosphere of Mercury is surface bounded exosphere almost vacuum. Its atmosphere generally consists of Helium, Hydrogen, Oxygen, potassium, Sodium, with possible trace amount of argon, carbon dioxide, water, nitrogen, xenon, krypton and neon.
Gas composition of Mercury atmosphere

As our Earth takes 365 days to complete one revolution around the sun but in the case of Mercury it takes just 88 days. But, if we see rotation time then it is 59 Earth days.

Some interesting facts about Mercury

1. As we know temperature of Mercury is very high, so we can never think about presence of ice on Mercury. But, it is true that ice is present on the Mercury, on that portion which never face the sun and never got sunlight.
Mercury: the planet of ice

2. As like as presence of ice, Organics the building blocks of life is also present. But even though we cant think about life there because Mercury has not enough atmosphere for life.

3. Mercury has atmosphere that changes with its distance to the sun. Yes, it is true that its atmosphere changes. Mercury has very thin atmosphere known as exosphere. Scientists have detected calcium, sodium and magnesium in it—all elements that appear to change in concentration as the planet gets closer and further from the Sun in its orbit.
Crust of Mercury
The changes appear to be linked to how much solar radiation pressure falls on the planet.

4. As similar to change in temperature at different distances from sun, Mercury’s magnetic field is different at both poles. Yes, even the magnetic field is different. And the magnetic field is just 1% weaker than of the earth.

5. As we all know that maximum of planets in our solar system have moons or rings. But, Mercury and Venus are the exceptions which have no moons or rings.

20 Jan 2019

Why do we need to find another home?

Why do we need an another home?

 Habitable planet
Today we are living happily with our families and friends. But, does we know how longer things will continue.
Today we must know that at one day we must have to leave our beautiful planet and this is going to be happen because of our own mistakes.

   How life from earth is going to be end


We all know the fact that the population of humans on earth is increasing. Because of increase in population humans are overusing natural resources and start making their own artificial resources which is damaging the planet. Industrialisation, urbanization indreased pollution and also leads to decreased the quality of environment that damaged and still damaging the planet.
Humans are killing the forests brutally and making their own houses by snatching their home from animals and other organisms of the forests.
This whole thing is creating a great disbalance in planet's environment.
Today we can feel the rise in temperature because of greenhouse effect which is also our creation. If humans will continue then earth is no longer going to be a planet where humans can survive. Which means we need any other planet, any other home.

This may become our next home

In search for life, we are searching every planet in our solar system but until now we don't get any signs of life on any planet of our solar system. This is the reason, we are trying to look outer from our solar system.

At December 1689 we have found a solar system which is nearest for us and we named that solar system,  Alpha century star system.
Habitable planet

Alpha century is actually a binary star system and both the Stars are very closed to each other. The bigger star in this star system named as alpha century A and other is named as alpha century B. The bigger one, alpha century A is bigger than our own sun, it's radius is nearly equal to 9 lakh km. Alpha century B is smaller than our Sun and its luminosity is less than our sun and it's radius is almost 6 lakh km.

Alpha century star system is nearly 4.37 light years from us. Predictions are, both the stars of alpha century star system is older than our sun.  In 1915 a Scottish astronomer Robert T. A. Innes, saw a blinking in his photographic plate during study of alpha century star system. He rechecked those plates on different times but the blinking was same on every plate.

This is a object which is really big in size and after study we get that the size of its parallax and diameter is similar to alpha century A and B. The interesting fact about that star is, it was showing a proper motion than alpha century A and B. That object was named as alpha century C or Proxima centuri.
Proxima centuri

 Proxima centuri is nearly 4.24 light years away from our solar system which is the nearest star from us. So after this discovery the alpha century star system is now a triple star system. Proxima centuri is the smallest and coolest star in that system. Proxima centuri complete one orbit of alpha century A and B nearly in 5.5 lakh years.

According to calculation, Proxima centuri is not only very older star than our sun but it's life in future is also pretty long. Because of its long life in future we are thinking that, can we use this long life of this star. In 2016, finally we confirmed a planet rotating Proxima century and we named it Proxima century B. Proxima century B is 0.05AU from its star Proxima century.

The exciting fact about this planet is, it was under habitable zone. No, the question is, is the life on Proxima century B is possible and if it is then how we reached there. It means again, the barrier for our next home is, it's distance from us. But, it is possible to solve it in future and to rescue human life from earth.

Nebula "The birth place of stars"!

Nebula "The birth place of stars"


The night sky ,how beautiful it looks and has also too many mysteries in it. If we talk about it's beauty, then stars are the objects that makes it so beautiful by forming such a beautiful arrangements called constellations and have different colours and are at different distances. And also stars are the only energy source of universe. As we know that everything that are in the universe born and has to die. In the case of stars the place where they born called Nebula. But, nebula is not a only place where they born but we can say stars mostly born in nebula.
Lets know more about Nebula........

What is Nebula?

As we know many bodies are present in space like stars, planets, black holes and Nebula is like one of them. Nebula are giant cloud of dust, hydrogen, helium and other ionized gasses in space.

How big is Nebula?

If we talk about size of nebula then most of nebulae are of vast size and some are hundreds of light years in diameter. A nebula that is barely visible to the human eye from Earth would appear larger, but not brighter. The Orion Nebula is the brightest nebula in the sky and occupying an area twice the diameter of the full Moon and can be viewed with the naked eye.

Where are Nebula present?

Nebulae are present in the space between the stars which is also known as interstellar space. And the closest known nebula to the Earth is called the Helix Nebula, which is remnant of a dying star possibly one like the Sun. It is approximately 700 light-years away from the Earth.

Types of Nebulae

1. Diffuse Nebulae

As we all know that word diffuse means spread out. 

Now guess how does diffuse nebulae appears?

If you guess that they are very large in size and spread out then you are absolutely right. Actually the dust and gas of diffuse nebulae are often so spread out that it’s hard to tell where the nebulae start and where it ends. That means diffuse nebula has no well defined boundaries.

Diffuse Nebulae can also be divided into :-

i. Emission Nebulae

As it is a type of diffuse nebulae so are very large and are often birthplace of stars. One of the well known is the Orion Nebula.
Emission Nebulae

Emission nebulae usually glow red or pink in colour. This is because they contain lots and lots of hydrogen gas. Hydrogen gives off red light when it’s energized! Hey guys if you don’t like red or pink colour, lets see next nebula that we are going to talk about.

ii. Reflection Nebulae

Sometime nebulae don’t have stars with enough energy to excite the gas of nebula. At this stage they reflects light of nearby stars.
Reflection Nebulae

As you notice small particles of dust floating in the air. And we all know this happen because dust particles reflects the light. This is what pretty much happens in reflection nebula.
As i told you about colour reflection nebula often appears blue as we look it from telescope.

iii. Dark nebulae and Bok Globules

As you can probably guess, Dark nebula don't emit or reflect any light because gas and dust in dark nebula is very thick.
Dark nebulae

Astronomers can see dark nebulae when they’re in front of something bright. Dark nebulae block out light from emission nebulae and stars behind them.

Bok globules are small dark nebulae. Like in emission nebulae, stars can form in Bok globules! Because the gas is already so dense, gravity pulls harder on it until it collapses to form stars.

12 Jan 2019

"Time travel" a possible phenomenon!

"Time travel" a possible phenomenon

Time travel

Whenever we made any mistake in our life, we think that, if I have another chance to do this thing from better way then the world will be better from now.
Time travel is only thing/phenomenon which can give us a chance to go in past and change the past for a better future and time travel also gives a chance to go in future and see what’s going to happen in the future. In other words time travel is a miracle which can change this world into a perfect world, time travel give rise of every possibility. 
Lots of questions rises in our mind which is related to time travel like, is time travel possible? And if it is then why we are still unable to do that?
If time travel is possible then why future humans didn't came to us by travelling in past.? Let's try to find answers of some of these questions.

Why people think time travel is just hypothesis

Time travel

Everyone is excited about time travel but some of us thinks that, time travel is only possible in movies and cartoons. Every man who stands against time travel has some questions about it, some of them are:

 1.    If time travel is possible then why we still doesn't meet with future's humans? It means if time travel is possible then why future's humans didn't came to us by travelling in past.
 2. According to Einstein, any body which have any mass, can't travel with the speed of light and without travelling with the speed of light we can't do any time travel.

 3. Grandfather paradox: it means if a person travel back in past and kill his grandfather before his marriage and return to his original time then a question arises. If his grandfather was killed then how his father born and also how he born. This is known as grandfather paradox.

Ways by which time travel should be possible

1. Travelling at speed of light

Time travel
you must have heard that, if we travel with the speed of light then time will slows down for us. Let's understand with a example. Let's assume two man ‘A’ and ‘B’ ,where ‘A’ is an astronaut and ‘B’ is doctor. After some time, ‘A' have to go in a space mission with a advance spaceship which can travel near speed of light. ‘A' moved for his mission in space with almost speed of light for 1 long year. After a year when ‘A’ backs to earth and meet ‘B’ then he finds that his ‘B’ is almost 60 year older than before.

It means when ‘A' is travelling in space for a year with nearer to the speed of light then his one year is nearly equal to 60 years of earth, this concept is called time dilation. Hence, we can say that ‘A’ travels in future, almost 60 years.
Here the problem with this technique is, we are still unable to make any ships or aircraft which can travel nearly at the speed of light.

2. By black holes

Time travel
we must know, time is not absolute ( which is said by Newton) but it is relative. It means time is not moving with the equal speed in this universe it is effected by mass and gravity exerted by mass. Hence, we can say that, the time slows down near the heavy mass which exerts great gravitational force.

It means, time on Jupiter moves slower than the time of earth, but this difference is very small so we need a object which is more than 100,000 times the mass of Jupiter. These objects are known as black hole. Black holes are the object with the ultimate gravity and mass which warp space-time more than any other body do in the universe. There are two ways by which we can do time travel with the help of black holes.

The first one is, we have to live on a planet near to black holes for some years. For example, if a person live 10 years on a planet near to black hole and return to earth then 20 years passes on earth which means that person is in 10 years future.

In Second method, we have to rotate at the outer edge of event horizon of a black hole. Here we must know, event horizon is on out zone of a black hole so we have to rotate near the event horizon for 10 years and return to earth. Again, it is 20 years for earth and we feel time travel.
But the problem in this theory is, the nearest black hole from us is 1600 light years away from us, which means light will take 1600 years to reach there.
Here the question is, will we ever be able to do time travel or not, will we able to make a spacecraft which can travel nearly at the speed of light or will we able to reach a black hole.

Here are many more methods of time travel that we will discuss later in detail.

Now answer of the above asked questions, if time travel is possible then why future humans didn't came to us by travelling in past?

Answer is, if future humans are able to make any spacecraft which can travel with the speed of light which means they are very developed and we should know that the percentage of destruction of a developed society is very high so may be they destroy themselves and should be more another reasons than we normally think about.

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6 Jan 2019

Our closest friend "The Andromeda "


Andromeda galaxy

At night when we look at sky we see the real beauty with trillions of stars, constellations, galaxies, shooting stars, planets. If we talk about galaxies, then milky-way is our native Galaxy and our neighbour and closest Galaxy is Andromeda. It is really bigger and larger than our milky way. It is really interesting to know about this giant Galaxy. So, let begin..................

History of discovery

Not from now, but from very long decades humans were very curious to know about mysterious and exciting things and among one of them is our sky. From very long time people have observed the night sky and found many interesting things about it. And when astrologers see the Andromeda galaxy many of them say different about it.

History of early observations on Andromeda

First image of Andromeda

Around the year 964, the Persian astronomer Abd-al-Rahman al-Sufi described the Andromeda Galaxy as little cloud. When Charles Messier labelled it as M31 in 1764, he incorrectly credited the discovery of what was then called a nebula to the German astronomer, Simon Marius, who provided the first telescopic observation of the object.

In 1850, William Parsons, saw and made the first drawing of Andromeda’s spiral structure. And the first photographs of Andromeda were taken in 1887, by Isaac Roberts.
Roberts mistook Andromeda and similar spiral nebulae as solar systems being formed.
In the 1920s, the Andromeda galaxy became part of the Great Debate between American astronomers Harlow Shapley and Heber Curtis.

At the time, astronomers thought the Milky Way composed the whole universe, and the strange patches known as nebulae lay inside of them. Curtis had spotted various novae in Andromeda, and argued instead that it was a separate galaxy.

In 1925, Edwin Hubble settled the debate by identifying Cepheid variable (a kind of star characterises to precise measurements of distance) for the first time on astronomical photos of Andromeda. Because Shapley had previously determined that the Milky Way was only 100,000 light-years across, but Hubble's calculations revealed that the fuzzy patch was too far away to lie within the Milky Way.

In the 1940s, calculated distance to Andromeda doubled  when Walter Baade was the first to observe individual stars in the central region of the galaxy, and found two different types of Cepheid variables. And the first radio maps of Andromeda was captured in the 1950s by John Baldwin.

Recent discoveries about Andromeda

Our understanding of the size of the Andromeda galaxy has grown bigger in recent years. In 2015, observations from the Hubble Space Telescope found that a halo of material surrounding Andromeda is six times larger and 1,000 times more massive than what was previously measured.

In 2015, scientists released the most detailed photo of Andromeda ever, using a mosaic of images from the Hubble Space Telescope. The image included 7,398 exposures taken over 411 pointing’s of the telescope. The image revealed more than 100 million stars within the galaxy, as well as dust structures and other features.

In late 2017, scientists unexpectedly found two supermassive black holes closely orbiting each other. At the time, the research team said these black holes were likely the "most tightly coupled" of any supermassive ones known.

Here we know all about the discoveries and observations did by the astrologers and their excitement about Andromeda galaxy.

But, now the question is about its formation. How does Andromeda formed? How much time taken in its formation?

Let’s try to answer these question......

Formation of Andromeda

Collision of galaxy

The Andromeda Galaxy was formed roughly 10 billion years ago from the collision and subsequent merger of smaller protogalaxies.
The violent collision formed most of the galaxy's (metal-rich), galactic halo and extended disk. During this epoch, its rate of star formation would have been very high, to the point of becoming a luminous infrared galaxy for roughly 100 million years.

Andromeda and the Triangulum Galaxy had a very close passage 2–4 billion years ago. This event produced high rates of star formation across the Andromeda Galaxy's disk—even some globular clusters—and disturbed M33's outer disk.

Over the past 2 billion years, star formation throughout Andromeda's disk is thought to have decreased to the point of near-inactivity. There have been interactions with satellite galaxies like M32, M110, or others that have already been absorbed by Andromeda Galaxy. These interactions have formed structures like Andromeda's Giant Stellar Stream.

A galactic merger roughly 100 million years ago is believed to be responsible for a counter-rotating disk of gas found in the centre of Andromeda as well as the presence there of a relatively young (100 million years old) stellar population.

Structure and future of Andromeda Galaxy

Collision of galaxy

If we talk about shape of Andromeda so, it is is actually a barred spiral galaxy, like the Milky Way. And the galaxy is inclined an estimated 77° relative to Earth (where an angle of 90° would be viewed directly from the side).
Analysis of the cross-sectional shape of the galaxy appears to demonstrate a pronounced, S-shaped warp, rather than just a flat disk. A possible cause of such a warp could be gravitational interaction with the satellite galaxies near the Andromeda Galaxy.

The Andromeda Galaxy is approaching the Milky Way at about 110 kilometres per second (68 miles per second). This makes the Andromeda Galaxy one of about 100 observable blueshifted galaxies and therefore it is expected to collide directly with the Milky Way in about 4 billion years.

The home of 200 billion stars"The Milky Way"

The milky way 

Milkyway galaxy

The universe is full of surprises and mysteries and humans are curious. This interesting relationship between humans and universe is the reason behind such a huge number of unsolved mysteries.
Today we know that, we are living in a planet named as earth, this planet is in our solar system and this solar system is present at outer edge of our galaxy " the milky way ".

Here the question is, how much we really know about our own galaxy?

Let's try to get answer of the question.

 Facts of milky way

The size of milky way is 100,000 light years, which means light will take 100,000 year to travel from one end of the galaxy to another end.
Milky way is the home of more than 200 billion stars.

Until 1920s astronomers thought, all the stars and everything is inside milky way galaxy. Our milky way is considered in a spiral galaxy.

The study of galaxy helps in understanding, how our universe and their stars forms.

The place where stars born in called nebula. It is a complex mixture cloud of gasses and clouds which emits light. Our galaxy also contains many of nebulas where stars born’s.

Most interesting facts of milky way:-

 1. All naked-eye stars contained in milky way :- it isn't that long ago that we use to think of the stars as light leak in a black curtain, just a little further than we could reach, and heaven was on the other side. 
In actual fact, all the stars that we can see in the night sky with the naked eye, which is around 9,096 or 4,548 from each hemisphere, are contained within our own galaxy.

 2. Milky way is classified as barred spiral galaxy:- the milky way is a spiral armed galaxy, and as is typical for about 67% of those, ours is barred. It is suspected that such bars are the consequences of a galaxy drawing gas from its spirals into its heart, but as the density of the bars increase over the millennia their own gravity destroys them resulting in spirals without bars.

 3. A black hole is located at its centre:- after such a long discussion and debate in scientific world now we can say that, a super massive black hole is present at the centre of milky way. That black hole is named as Sagittarius A and it is situated at 26,000 light years from us and it's weight is equal to 4.1 million solar mass which is a source of intense radio waves.

Nebula in milky way

Nebula in milkyway galaxy

Study of nebula in a particular galaxy is the best way to understand that galaxy.
When lots of gasses and dust collected a place in a galaxy then that could make the light of stars dim. With the observation by the Hubble telescope, now we also know that the nebula doesn't only make star's light but the clouds of nebula also Emit light. The colours in a nebula also tells about the elements by which the nebula formed.

Orion nebula:- It is situated at 14 light years from us. It is a shining cloud of gasses and dust. With the help of this nebula, we could know that how our Sun or any other star originated. Study tells that, some stars in Orion nebula is to much new some of them are lakh year old only. It is one of the brightest nebula and visible to the naked eye in night sky. It is also known as messier 42/ m42/ NGC 1976. The nebula is part of a much larger nebula that is known as the Orion molecular cloud.

Formation of stars

Formation of star

Observation of the nebula have revealed approximately 700 stars in various stages of formation within the nebula. Stars form when clumps of hydrogen and other gasses in an H|| region contract under their own gravity. As the gas collapses, the central clumps becomes stronger and the gas heats to extreme temperatures by converting gravitational potential energy to thermal energy.

If the temperature gets high enough, nuclear fusion will ignite and form a protostar. The protostar will born when it begins to emit enough radiative energy to balance out its gravity and halt gravitational collapse.

Star formation is the process by which dense regions within molecular cloud in interstellar space sometimes referred to as "Steller nurseries" or "star-forming regions", collapse and form stars.

As a branch of astronomy, star formation includes the study of the interstellar medium and giant molecular clouds as precursors to the star formation process, and the study of protostars and young Steller objects as its immediate products. It is closely related to, planet formation, another branch of astronomy.

Star formation theory as well as accounting for the formation of a single star, must also account for the statistics of binary stars and the initial mass function. Most stars do not form in isolation but as part of a group of stars refers as star clusters or Steller association.