In childhood when we look up in to the sky at night wondering the shining stars often some questions arises ‘’What is above the sky? Why sky is blue at morning and black at night? How far are these stars from us?’’ and other these types of questions. These questions brings a never ending curiosity out of us and this never ending curiosity led us to find out the answer to these mysteries. And to answer these types of mysteries there is a special field of science ‘’SPACE SCIENCE”. Space science is a discipline which encompasses all of the scientific disciplines that involve space exploration and study natural phenomena and physical bodies occurring in outer space. At first we will talk about space exploration

Space exploration is the area of space science which uses astronomy and space technology to explore outer space. While the exploration of space is mainly carried out by astronomers with the help of telescopes, Its physical aspect of exploration though is conducted both by unmanned robotic space probes and human spaceflight. Space exploration, like its classical form astronomy, is one of the main pillars on which space science heavily relies. The observation of objects in space, known as astronomy, predates reliable recorded history, it was due to the development of large and relatively efficient rockets and space crafts during the mid-twentieth century that the dream of physical space exploration become a reality.


But for the exploration of outer space we needed some powerful and useful combination of lenses that is why Telescope came in to being. It is said that the first telescope was invented in 1608 in the Netherlands by an eyeglass maker named Hans Lippershey. The Orbiting Astronomical Observatory 2 is famoused as the first space telescope launched on December 7, 1968. As of February 2, 2019, it is recorded that 3,891 confirmed exoplanets have been discovered. Our home galaxy Milky Way is estimated to contain nearly 100–400 billion stars and more than 100 billion planets. There are at least 2 trillion galaxies in the observable universe. GN-z11 is the most distant known object from Earth, which is reported to be 32 billion light-years away. All these remarkable achievements and space knowledge is because of the invention of telescope.


Now it was the time to go for exploration of space so there was a need for a spacecraft or a rocket and to fulfill this need the Bumper-WAC( a sounding rocket made by United States) become the first human made object to enter the folds of space In 1949, which reached an altitude of 393 kilometers (244 mi), according to NASA, although V-2 Rocket MW 18014 crossed the Kármán line earlier, in 1944. The very first and the successful orbital launch was of the Soviet Sputnik 1 (“Satellite 1”) mission on 4 October 1957. It is known that it has orbited Earth at a height of about almost 250 km . Two radio transmitters (20 and 40 MHz) were used, which emitted “beeps” that could easily be heard by radios all over the globe To gather information about the electron density of the ionosphere, analysis of the radio signals was used while temperature and pressure data was encoded during the interval of radio beeps. And from the results of these signals it was concluded that the satellite was not punctured by a meteoroid


Salyut 1 was the first ever space station of any kind, launched into low Earth orbit by the Soviet Union in the year 1971. The International Space Station is currently the only and fully functional space station, with continuous inhabitance since the year 2000.


Since the quest to explore the space has started and man has expand his vision to see broader and dive in to the sea of space astronomers, scientists and engineers have made exceptional records in the world of space science. Due to their efforts we all know that we live in a galaxy named ‘’MILKYWAY’’ but do you know there are millions of stars in a single galaxy and each star has its own solar system. Below is an image of position of our solar system in our home galaxy

Now after looking in to that picture one can wonder how vast is our galaxy, but wait there are millions of galaxies in the known universe. Our solar system consists of 8 planets and one dwarf planet. Every single planet has its own natural satellites often called Moon of that planet

Starting in the mid-20th century many probes and then human missions were sent into Earth orbit, and then on to the Moon for the purpose of space exploration. Also, probes were sent throughout the known Solar system, and into our Solar orbit. Unmanned spacecraft have been sent into orbit around Saturn, Jupiter, Mars, Venus, and Mercury by the 21st century, and the most distance active spacecraft, Voyager 1 and 2 traveled beyond 100 times the Earth-Sun distance.

The sun of our solar system had always been a major concern and focus of solar exploration. It is the sun around which every planet of every solar system revolves. But in fact even sun of every solar system revolves around the center of galaxy and which is also called the Galactic Center. The galactic center is an intense radio source known as Sagittarius A*, a supermassive black hole .

A supermassive black hole is the largest type of black hole, which contains a mass of the order of nearly hundreds of thousands to billions of times the mass of the Sun. Black hole is a special class of celestial body that have undergone gravitational collapse, leaving behind spheroidal regions of spacetime from which nothing can escape, not even light. Some Observational cosmological evidence indicates that nearly all large galaxies contain a supermassive black hole, at the galaxy’s center. And recently In April 2019, the EHT collaboration revealed the first-ever image of a black hole, which captured the behemoth at the heart of the galaxy M87.

All the information and references have been taken from Wikipedia,space%20probes%20and%20human%20spaceflight.



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