History of space exploration and achievements

HISTORY OF SPACE EXPLORATION AND ACHIEVEMENTS:


Exploration is always in the genes of human but space exploration became much popular in the early 21st century due to the commercialization of space industry.

       The beginning of space exploration Was in 1957 when Soviet Union sent the first unmanned mission into space. They launched a satellite called "Sputnik 1".Later in

•  Sputnik 1

that year, they again launched another satellite known as "Sputnik 2" which carried a dog into orbit. After experimenting with animals, the first manned mission took place when Russia on April 12, 1961 carried a young man named Yuri Gagarin into the orbit. Followed by that couple of more mission took place.

     With development   of technology it was the time to take human to the moon which turned into reality in 1969 when Neil Armstrong and his crew made a safe landing on moon in Apollo 11. Neil Armstrong became the first human to step foot on the moon.

• Neil Armstrong on the moon

 After triumphing the moon it was the time to give their attention to Mars. In 1971 "Mariner 9" became the first space probe to orbit the red planet. In so many Mars missions organizations around the world faced lot of failures but nothing stop them to exploring the unknown. As a result of constant hard work NASA became the first space organization to land their "Viking Landers" on

• Viking lander on Mars

Martian soil. It just create a whole new enthusiasm among the industry. Later so many Mars missions took place, many succeeded and many didn't. The latest successful mission was taken by India on 24th September 2014. With this India became the first Asian country to successfully send an orbiter to Mars. It was completed in a record budget of $71 million, making it the least expensive Mars mission to date.

        Due to remarkable achievements of mankind, space exploration has now become more popular in 21th century mainly because of the commercialization of space industry. Companies like Space x, Blue origin made space exploration more cheaper than ever.

• Space x

 Space exploration is also done by astronomers with telescopes. Telescopes like Hubble Space Telescope, James Webb Telescope also plays an important part in astronomy. In 2019 Swiss scientists Michel Mayor and Didier Queloz received half of the Nobel Prize award for their ground breaking discovery of an exoplanet orbiting a solar type star. This will disclose a whole new chapter for the space lovers and explorers.

• Hubble Space Telescope

       It's just little more than 60 years of human space explorations and there's a whole bunch of things to be discovered. Hopefully it all will be possible in the near future.

Celestial Sphere

CELESTIAL SPHERE:

                     If you look at the night sky, you will see that all stars always appear fixed relative to each other and the entire pattern of stars rigidly orbit the sun throughout the year in the same manner. We employ this artificial, earth-based view of the heavens to make celestial maps by pretending that the stars are attached to the inside of an enormous hollow shell which is basically the "Celestial Sphere" and the Earth is at the center of the sphere.

THE NIGHT SHY:

                  In day time we can't see the stars due to the sunlight. But at night we can watch the stars quite clearly. The pattern of stars is visible in the dark which is called "Constellation". But the same view is invisible in the big cities due to the light pollution. You can clearly see the difference of the night sky with and without the light pollution in the following picture. In this photograph you can clearly see the difference of the night sky with and without light in Goodwood, Ontario, Canada.[copyright Todd Carlson /skynews Magazine]

CELESTIAL SPHERE IN NAVIGATING THE SKY:

                In celestial sphere stars are seemed fixed because they are too far away. In reality they do move relative to each other. But we neither see their motion nor perceive their relative distances because they are so far from us. Astronomers use celestial sphere in finding stars, but the condition is the stars must be fixed on it, just as cities are fixed on maps of the Earth. They applied a coordinate system to it to locate this quickly.

• CELESTIAL EQUATOR: If we expand the Earth's equator onto the celestial sphere we obtain the "celestial equator",which divides the sky into northern and southern hemispheres same as the Earth's equator divides the Earth into two hemispheres. Now if we stretch the Earth's north and south poles out into space along the Earth's axis of rotation to the celestial sphere, it will give us "north celestial pole' and "south celestial pole"

• DECLINATION AND RIGHT ASCENSION: Using the same conditions as the celestial equator, astronomers divide up the surface of the celestial sphere in precisely the same way that latitude and longitude grid divides the Earth. The equivalent to latitude on Earth is called "declination" on the celestial sphere. It is measured from 0 degree to 90 degree north or south of the celestial equator. The  equivalent of longitude on Earth is called "right ascension" on the celestial sphere, measured from 0 h to 245 h around the celestial equator.

• VERNAL EQUINOX: The Sun also orbit around the our galaxy (Milky Way Galaxy) through out the year.So we can say the Sun also has an orbit in the celestial sphere.Just as the    location of Greenwich, England, defines the prime meridian, or zero of longitude on Earth, we need to establish a zero of right ascension. It is defined as one of the places where the Sun's annual path across the celestial sphere intersects the celestial equator. The celestial equator and the Sun's path intersect at two points. The equivalent on the celestial sphere of the Earth's prime meridian is where the Sun crosses the celestial equator moving northward. Angles of right ascension are measured from this point, called the "vernal equinox".