Our earth is a tiny part of the universe.Research says that the distance of our universe is 46 billion light years and there is no evidence that the universe has an edge. It means that the universe is bigger than we think.we can see only 4% of the entire universe  and 96% universe has uncountable mysteries before jumping into it. We have to know all basic things like what is lightyears,how sun creates energy etc so let explore the space.

Q : What is light-years?

Ans : To measure the distance between space objects we use lightyear. Light year is the distance that light has traveled in one earth year. Approximately one light year is equal to 6  trillion miles which is 9 trillion km. 

And one more interesting thing about lightyears is you can see the star in the past not in the present.Light travel at the speed of 300,000 km per seconds and our sun is 93 miles away from us.sun light take 8.3minute time to reach on earth it’s means you always see sun in past and this apply for all star in space.

Q : How does the sun create light and energy?

Ans : Our sun is 4.6 billion year old and it can live more than 5 billion years so ever you wonder that how sun produces energy.Sun crating a energy and light under the process of nuclear fusion in which  2 or more molecules of hydrogen are get combine together under pressure and form 

New molecules of helium.Newly formed helium molecules have less molecular weight and that little bit amount of hydrogen molecules are converted into light and energy. In the core of the sun there is a huge amount of hydrogen  that can help the sun to burn for the next 5 billion years.Per second sun releases 4.2 million metric ton energy.

Q : What is the galaxy?

Ans : A galaxy  is a huge collection of dust,gas and billions of star and  their solar system all are held 

Together by gravity.milky way is the galaxy where our solar system is located and it also has a super massive black hole in the middle.

Q : What is black Hole?

Ans : Black hole is a place where a large amount of matter is placed in a tiny place.Due to the massive dense matter black hole has super gravitational force where light can not get out from it.black hole is formed when stars are dying.

There are different types of black holes, some are big and some are small.The smallest black hole is the size of an atom but it has the mass of the largest mountain. Another type of black hole is “stellar” it has a weight upto 20 times more than the mass of the sun.Research say that there are many many stellar black holes in the earth galaxy.

Largest black hole in the universe is called “supermassive”.it has a mass of 1 million sun together and it can be fit into a large size ball.

Q : What is dark matter?

Ans : There is only 5% of the universe visible to us which includes our solar system, some galaxies and  stars which are made up of protons and neutron.remaining universe is made up of dark energy.scientist did not see the dark matter yet.Dark matter is totally different boronick matter. Boronic matter consist of neutron,electron and proton which is totally different from dark matter and it is invisible for light and electromagnetic wave.Universe has total 68% of dark matter.

Q : What is a neutron star?

Ans : When a space star dies then neutron stars are born.When stars are dying then the pressure of that star increases 20 times more than the real pressure because of that pressure a big supernova explodes and a small neutron star is born.Neutron star has 20km  diameter and because of high density it can weigh up to billions tons because of high density this neutron star spin 43 time per second. It means 4300 spins in one minute.If two neutron stars of 15km diameter bump together then catastrophic events occur and that collision can produce a massive black hole.

Q : What is supernova?

Ans : Supernova is an explosion of star.it is the largest explosion to happen in space.supernova occurs when stars died.when supernova occurs it emits more energy that sun can not emit in his entire lifespan. 

Q : What are exoplanets?

Ans : An exoplanets or extrasolar planet is a planet outside the solar system.