Milestones in Astronomy: 1927 to 1971

In astronomy, there are a lot of terms you may come across that you are unfamiliar with. Throughout the 1900s, theories and other classifications emerged with every technological advancement. You will learn about the Big Bang theory, quasars. Pulsars, and the black hole.

1927 , The Big Bang theory emerges. This model is the one widely embraced by the astronomy community as explaining the early start of the universe. One of the major points of the theory is that the universe was once in a very hot and dense state that started to expand quite rapidly , which is where the name ‘Big Bang’ came from. This rapid expansion caused the universe to cool. Scientists have used recent measurements and other observations to date the original state of the universe as occurring around 13.7 billion years ago.

1930 , Clyde Tombaugh discovers the dwarf planet Pluto. The astronomer from America also discovered many asteroids. He is known for calling for scientific research to be made on the subject of unidentified flying objects.  

1959 , The first photographs of the far side of the Moon is revealed, thanks to the Soviet satellite Luna 3. Up until this time, no one knew what this part of the Moon looked like because it never faces the Earth.

1961 , The first quasars are discovered. A quasar is the shortened term used to refer to a quasi-stellar radio source. Packed with a lot of energy, quasars possess a distant active galatic nucleus. Possessing a great deal of light, quasars were initially identified as being high sources of electromagnetic energy, which includes visible light and radio waves. They were described as being pointy and quite similar to stars.

1967 , The first pulsars are identified. They are described as a highly magnetized, rotating neutron star that sends out a beam of electromagnetic radiation. The beam of emission must point towards the Earth in order for one to observe the radiation, which is called the ‘lighthouse effect.’

1971 , The first black hole is detected. It is described as a region in space that nothing (not even light) can escape because the strength of its gravity is so powerful. Black holes give off x-ray radiation. They decrease in size and continue to get smaller and smaller until they eventually disappear or ‘evaporate.’ The majority of black holes form when the death of a large star takes place. This star is larger than the sun and has ran out of the energy that sustains its nuclear reaction. The star loses the force pushing itself outward and is bested by the force of its own gravity pulling inward. Over time, the star has so much gravity and is so compressed that it consumes itself until there is nothing left but a hole in the space-time due to the gravity left over from the star.