Izay Ayesha describes a fascinating phenomenon
The Remarkable universe inhabited by the human race (or is it?) is a fascinating evolving story that has kept scientists entranced since decades. It is usually accepted that the Big Bang, the most widely-accepted theory for the origin of the Universe, took place 13.7 billion years ago. In one instant the Cosmos were created and with this countless unsolved mysteries came to fore that have puzzled scientists for centuries.
It is described that around 13.7 billion years ago, everything in the entire Universe was condensed in an infinitesimally small singularity, a point of infinite denseness and heat. Suddenly, from this mere dot, a huge explosion expanded space like a balloon. From a single atom, the Universe grew to bigger than a galaxy. It is still expanding today. Now scientists have the first all-sky microwave image of the Universe soon after the Big Bang published by a team of astronomers from NASA and Princeton University. The time frame describing this unique phenomenon is known as light year and while describing most space objects light year is used to describe their distance. A light-year is the distance light travels in one Earth year with one light-year is about nine trillion km (six trillion miles).
Incredibly, the numerous planets, stars, galaxies, and everything else one can see make up less than 5% of the total Universe. The odd thing is that 26.8 % is a substance scientists label as dark matter. It does not interact with light or visible matter but can be detected through its gravitational influence on the movements and appearances of other objects in the Universe, for example stars or galaxies. The rest of 68% of the Universe is called dark energy, the mystery force that rules the Universe. This phenomenon overwhelmed gravity and gained control of the Universe about five billion years ago. It is invisible, fills all of space and its repulsive gravity is speeding up the expansion of the Cosmos.
The phenomenon of Universe has given way to any discoveries such as the Crab Nebula that is a six-light-year-wide remnant of a supernova explosion. First observed by Chinese and other astronomers in the year 1054, it is 6,500 light-years from Earth. Supernova is violent stellar explosion that litter the Cosmos. One of the brightest, named by scientists as LMC N49 is approximately 160,000 light-years from Earth. Spiral galaxies consist of a flat, rotating disk containing stars, gas, and dust. These galaxy forms were originally described by American astronomer Edwin Hubble (1889–1953). Suitably, this image of Spiral Galaxy M81 is viewed from the Hubble Space Telescope.
The galaxy inhabited by the human race (really?), the Milky Way, is a barred spiral-shaped galaxy and includes Earth’s own solar system. The oldest stars in the Milky Way are nearly as ancient as the Universe itself, probably formed after the Big Bang. And there are thousands of galaxies out there. Even the small dots seen are entire galaxies and are about 13 billion light-years away. Stellar jets are beams of ironised matter ejected from some astronomical objects but usually produced by young stars still in the process of forming.
A black hole is a place in space where gravity is so strong that even light cannot get out. This is because matter has been squeezed into a hugely compressed area. This happens, for example, when a star is dying. Scientists reckon there are millions of these cosmic bodies in our galaxy but no one knows what they contain. An exoplanet is a planet beyond Earth’s solar system. Most exoplanets orbit stars but free-floating exoplanets, called rogue planets, orbit the galactic center in permanent darkness and are untethered to any star.
Kepler-186f is the first exoplanet discovered in what scientists call the habitable zone—the region around the host star where the temperature is right for liquid water. Kepler-452b (sometimes nicknamed Earth 2.0 or Earth’s Cousin) is an exoplanet orbiting the Sun-like star Kepler-452, about 1,400 light-years from Earth in the constellation Cygnus. It is the first potentially rocky super-Earth planet discovered orbiting within the habitable zone of a star very similar to the Sun. TW