The sky has always been an object of human interest from the beginning to the present. When life on earth is difficult, sometimes I lift my head and look at the sky. I like the sky during the day, but I also get comfort from the night sky. When I think of the infinite universe, countless stars, and the passing time, the pain and anguish that befell me will not feel so great.
The author, widely known as the host of the 2014 television documentary ‘Cosmos: A Spacetime Odyssey’, is an astrophysicist regarded as the ‘successor of Carl Sagan’. This book presents the great discoveries of mankind up to recently in an easy yet profound way.
Recently, people’s interest in space-related articles is increasing as they meet as news every day. In particular, as the James Webb (JWST) space telescope floating in space began to observe in earnest, the mysteries of the universe are being revealed one by one.
There is only one star in the solar system. In other words, a star is a celestial body that emits energy by burning itself. The rest, including Earth, are called planets. Earth orbits the sun at a speed of 30 km/s.
The origin of our moon can be traced back to an incident where a protoplanetary body the size of Mars accidentally collided with the Earth at an angle. Part of the crust and mantle ejected from the impact orbits around the primordial Earth, forming a moon made of less dense matter from these fragments. This is the conclusion that astronauts came to by analyzing moon rocks brought from the moon.
The closest to the spiral-shaped Milky Way to which the Sun belongs is the Andromeda Galaxy. It is the terminal station of the animated film ‘Galaxy Railroad 999’. It is about 2.5 million light years from Earth. Advances in astrophysics are revealing that dwarf galaxies, fine gases, cosmic rays, and vacuum quantum energy fill the vast space between the two galaxies.
about 13.8 billion years ago. The entire space-time, matter, and energy of the universe as we know it were packed into one point, that is, less than a trillionth of a volume. It is not yet known how it came into existence, but it expanded and exploded rapidly. The explosion was called the Big Bang. After the Big Bang, the universe is still expanding, and no one knows how long it will continue.
It takes time for light from distant celestial bodies to reach us. To observe spatially distant places is to bring events from the distant past into the present. To see the deep abyss of the universe brings events from billions of years ago into the present.
An image of the deep universe, taken by the James Webb Space Telescope, was released on July 12. The oldest galaxy in the picture is about 13.1 billion years old. This is why it is evaluated that it is one step closer to the beginning of the universe as it was created approximately 700 million years after the Big Bang.
Until now, the space between the stars was considered empty. However, it is revealed that matter and energy exist in that vast darkness. Of the total mass of the universe, 68% of dark energy, 27% of dark matter, and only 5% of the remaining visible matter are normal visible matter. There is nothing in the elevator, but it appears to be full of something.
Korea is also going into space. Following the successful launch of the lunar orbiter Danuri, which was launched on August 5, the plan to plant the Taegeukgi on the moon in 2030 is in progress. The human challenge to reveal the fascinating reality of the universe continues today.