how did life began? are we alone in the universe?
Answers
Answer:Microbial life forms have been discovered on Earth that can survive and even thrive at extremes of high and low temperature and pressure, and in conditions of acidity, salinity, alkalinity, and concentrations of heavy metals that would have been regarded as lethal just a few years ago. These discoveries include the wide diversity of life near sea–floor hydrothermal vent systems, where some organisms live essentially on chemical energy in the absence of sunlight. Similar environments may be present elsewhere in the solar system.
For millennia, people have turned their eyes to the stars and wondered if there are others like themselves out there. Does life, be it similar to our own or not, exist elsewhere in our Solar System? Our Galaxy? Until 1992, when the first exoplanet was confirmed, it was uncertain whether there were even any planets outside those in our own Solar System. Today we know of over 3850 planets around other stars and thousands of planet candidates. Do any of these planets have conditions that would support life? What conditions favor the formation of terrestrial-class planets in developing planetary systems? NASA can help address these questions by developing missions designed to find and characterize extrasolar planetary systems.
Before we can determine if there are other planetary systems capable of supporting life, we must first find them. NASA Science pursues this goal by supporting a focused suite of ground-based observations through the Kepler mission, a now retired space-based observatory which studied the prevalence (how many there are per star) of extrasolar planets, and through the operation of TESS (Transiting Exoplanet Survey Satellite) which is performing an all-sky survey to discover transiting exoplanet ranging from Earth-sized to gas giants.
Explanation:
universe was made by big bang before 4 billion years tthe temperature was very hot at that time.but after certain amount of time hillium and hydrogen developed and oxygen also came at that same time ozone layer developed and after that universe became cold.then 3 billion years ago one cellular animal such as amiba paramisium and so on came on earth after that many cellular animals born. before 350 million years ago some fishes born which had not a jaw.after that frogs developed and before 200 million years ago snakes came on earth. before 65 million years birds developed and just after that dinosaurs born and after some time they were destroyed by asteroids and after that animals like cows cats dogs also born.and just before 15million years Ramapithecks types of gorrilas developed and after that homo habilus born and after that homo erects born and before 1 million year ago Nianderthal manav also born thy were also called as ‘adimanav' and after that humans born and developed many religions.