The first hints of the development of life emerged on our planet about 3.7 billion years ago, when the most ancient and primitive tidbits of self-replicating nucleic acid formed on our primordial Earth–most likely originating from ribonucleic acid (RNA) molecules. The replication of these very ancient tidbits required energy, sufficient space to evolve, and even smaller and more elementary constituent building blocks. Life evolved on Earth because our planet possessed a rocky surface; an abundance of life-sustaining liquid water sloshing around in ancient seas; and a nurturing, blanketing atmosphere. In March 2016 astronomers announced their research findings suggesting that life was able to thrive on our primordial planet thanks to yet another necessary ingredient: the presence of a protective magnetic field. The new observations of the youthful, Sun-like star Kappa Ceti reveal that a magnetic field plays a starring role in making a planet a nurturing abode for the emergence of life.
“To be habitable, a planet needs warmth, water, and it needs to be sheltered from a young, violent Sun,” commented study lead author Dr. Jose-Dias Do Nascimento in a March 6, 2016 Harvard-Smithsonian Center for Astrophysics (CfA) Press Release. Dr. Nascimento is of the CfA in Cambridge, Massachusetts, and the University of Rio G. do Norte (UFRN), Brazil. 바카라사이트
Kappa Ceti is located 30 light-years from Earth in the equatorial constellation of Cetus (The Whale), and it is very similar to our own Sun–but much younger. The team of astronomers calculates an age of a mere 400-600 million years for Kappa Ceti, and this is in agreement with the age estimated from its rotation period. This age roughly corresponds to the era when life first appeared on Earth. As a result, studying Kappa Ceti can provide astronomers with important information about the early history of our own Solar System.
Our Star And Kappa Ceti
Kappa Ceti is a yellow dwarf star that has a rapid rotation of approximately once every nine days. Even though no confirmed exoplanets have been observed in orbit around the star, Kappa Ceti is considered to be a promising candidate to host terrestrial planets, which are rocky planets similar to Earth–such as Mercury, Venus, and Mars in our Sun’s own family. The Kappa Ceti system is considered to be a potential binary star, but this has not been confirmed.
Since 1943, the spectrum of this star has provided one of the most stable anchor points by which other stars are classified. Kappa Ceti has approximately the same mass as our Sun, sporting 95% of its radius–but only 85% its luminosity. It is not clear whether Kappa Ceti has an equal amount–or more–of atomic elements heavier than hydrogen, when compared to that of our own Sun. However, it has been determined that this distant star possesses between 98% and 240% of our Star’s abundance of iron. All atomic elements heavier than helium, called metals by astronomers, are forged in the searing-hot nuclear fusing furnaces of our Universe’s myriad of fiery stars. Only hydrogen, helium, and trace quantities of lithium and beryllium were manufactured in the Big Bang birth of our Cosmos almost 14 billion years ago. The most ancient stars are more depleted of these heavy metals than younger generations of stars, because younger stars have benefited from the older stellar generations’ production of heavier atomic elements (stellar nucleosynthesis). The older stars scattered their newly forged metals into interstellar space when they perished, after having used up their necessary amount of hydrogen fuel. The freshly forged metals were then available to be incorporated into the material of baby stars. Small stars, like our Sun or Kappa Ceti, die with relative peace, tossing their outer gaseous layers into the space between stars. However, more massive stars blast themselves to smithereens in supernova explosions, hurling their metals much more violently into space.
Astronomers think that Kappa Ceti is a relatively young star. This is because its rapid rotation rate is indicative of a youthful star, only several hundred million years of age. The magnetic properties of this star make it an excellent match for our Sun at the important point when life first emerged on Earth.
Our Solar System’s Late Heavy Bombardment occurred almost 4 billion years ago. This marks the time when the greatest number of rampaging objects crashed into the quartet of rocky, terrestrial planets: Mercury, Venus, our Earth, and Mars. It is thought that these invading objects were probably comets, forced out of their cold, dark, and remote home located beyond the outermost planet, the gaseous ice giant Neptune. This invading horde of icy comets stormed their way into the golden light and melting warmth of the inner Solar System, causing immense damage. The invading comets of the Late Heavy Bombardment are thought to have been rudely evicted from their distant home as a result of a strange dance performed by the quartet of giant gaseous planets of our Solar System’s outer limits: Jupiter, Saturn, Uranus, and Neptune. The ancient gymnastics engaged in by these four enormous worlds hurled the comets closer to our Star. This relentless invasion of thundering, highly destructive chunks of ice and rock, possibly destroyed any life that may have already emerged on Earth, as the frothing, sloshing, life-loving ancient oceans evaporated.
Sometime between the Late Heavy Bombardment and 2.5 billion years ago, the very first precious tidbits of fragile life appeared on our planet. These very delicate cells used carbon dioxide as their source of carbon, and they were also quite adept at oxidizing inorganic materials in order to obtain the necessary energy. At long last, these fragile cells evolved the ability to engage in glycolysis, which is the chemical process that frees the energy of organic molecules such as glucose, and it generates Adenosine-5′-triphosphate (ATP) molecules as short-term sources of energy. To this day, ATP continues to be used by almost all life-forms on our planet, and it is virtually unchanged from its primordial beginnings.
