Tuanze hapa chini kabisa. We’re in the solar system - our sun, 8 planets with their several moons and a planetoid(pluto). Since distance in space is measured in light years(LY) we should get some orientation and perspective. It takes 4.15 hours for light to travel to Neptune (takes about 8.3 minutes to reach the Earth). The farthest (and fastest) man-made craft is Voyager I launched in 1977. It went past pluto and is now almost 18B kilometres away from earth. It takes light 16hrs to reach it. Though scientist have ‘buried’ it, they continue to get faint pings from it. I hope hadi hapo you’re not dazed with the figures.
Voyager I
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Now to the topic at hand. The sun in solar system is one of the stars in the Milky Way Galaxy. The nearest other ‘sun’ is Proxima Centaur. Taking into consideration the Voyager I’s speed, it’ll take 72,600yrs to get to this star.
Na hapo hatujafika kwa mungu. Imagine the distance maombi huenda. MW galaxy isn’t that big if you compare it to the other galaxies in the observable universe. It’s only 100,000 LYs in diameter and about 1,100 LYs thick.
MW Galaxy
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Again, for some perspective, it’ll take Voyager 1 14,000 years to travel one LY.
From the dawn of humankind to a mere 400 years ago, all that we knew about our universe came through observations with the naked eye. Then Galileo turned his telescope toward the heavens in 1610. The world was in for an awakening. Saturn, we learned, had rings. Jupiter had moons. That nebulous patch across the center of the sky called the Milky Way was not a cloud but a collection of countless stars. Within but a few years, our notion of the natural world would be forever changed. A scientific and societal revolution quickly ensued. In the centuries that followed, telescopes grew in size and complexity and, of course, power. They were placed far from city lights and as far above the haze of the atmosphere as possible. Edwin Hubble, for whom the Hubble Telescope is named, used the largest telescope of his day in the 1920s at the Mt. Wilson Observatory near Pasadena, Calif., to discover galaxies beyond our own.
Hubble, the observatory, is the first major optical telescope to be placed in space, the ultimate mountaintop. Above the distortion of the atmosphere, far far above rain clouds and light pollution, Hubble has an unobstructed view of the universe. Scientists have used Hubble to observe the most distant stars and galaxies as well as the planets in our solar system.
Hubble’s launch and deployment in April 1990 marked the most significant advance in astronomy since Galileo’s telescope. Thanks to five servicing missions and more than 25 years of operation, our view of the universe and our place within it has never been the same.
Hubble Space Observatory
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Though hubble observation is LOS(line of sight), many galaxies have been observed in deep space. Through it we’ve come to know of black holes, quasars, pulsars etc etc.
Henway, back to my point. There are over 250 BILLION stars in our milky way galaxy. The probability of having an earth-like planet is 250,000,000,000/1. Ngoja kwanza. In that line of sight that hubble is pointed, there are over 100 TRILLION (yes, trillion) galaxies! Yaani our sun is like on grain of sand among all other grains of sands on earth. The probability of having another earth is 250B x100T x 360/1. Tafakari hayo. [ATTACH=full]239967[/ATTACH]
Juzi tu, it was discovered that the universe is expanding at a speed exceeding the speed of light, meaning you’d never see some galaxies coz they’re moving away at more than the sped of light! Again they’ve just seen a galaxy hurtling towards the Milky Way! Time to liquidate assets na kuingia SJ. Asande
[SIZE=1]The Earth is flat. Period![/SIZE]