Voyager 1 entered interstellar space on August 25 2012 heading toward the northwest of the center of the Milky Way Although traveling at over 38,600 mph 62,100 km h the probe will take 40,000 years to fly by the nearest star in the constellation Camelopardalis Gliese 445
INTRODUCTION Beyond our Solar System lie 300 billion stars in our home galaxy the Milky Way Yet the Milky Way is only one among hundreds of billions of galaxies in the known Universe The nearest star to our Sun is over 24 trillion miles 38 trillion kilometers away and reaching it is far beyond our current technology But the 21st century is bringing amazing advances in our exploration of deep space We have found alien planets studied black holes and gained insights into the origins of the Universe itself What incredible events will the coming years bring Planets beyond our Solar System range from rare gas giants several times larger than Jupiter to more common Neptune-sized planets to less numerous smaller planets or Super-Earths These last kinds like those orbiting in the triple star system of Gliese 667 are the best candidates for supporting life
THE BIG BANG In the 1920s US astronomer Edwin Hubble discovered that the Universe is expanding very fast This meant back in time galaxies were much closer together In fact go back far enough and all matter and energy must have been in one tiny place NASA Wilkinson Microwave Anisotropy Probe WMAP Reflectors Optics Solar array Launched in 2001 WMAP measured traces of microwave background radiation left from the Big Bang The cooler blue areas are where gravity first caused matter to collapse and form stars EPIC EXPANSION Imagine the future entire Universe within one original particle smaller than a single atom Then 13 8 billion years ago it erupted in the Big Bang In a tiny fraction of a second it became the size of a grapefruit with two of the Universe’s basic forces gravity and the strong nuclear force A microsecond later this expanded as a fizzing cauldron of energy and particles trillions of degrees hot with the two other basic forces weak nuclear and electromagnetic The European Space Agency’s Planck spacecraft recently produced an even more detailed heat map of the Universe The denser areas probably came from tiny fluctuations within the original particle before it inflated after the Big Bang A visual timeline of the Universe from its origin 13 8 billion years ago Inflation Quantum fluctuations in original particle Afterglow light pattern 375,000 years First stars 400 million years Development of galaxies solar systems and planets Dark energy accelerated expansion WMAP Dark ages THE FIRST MATTER Still after less than one second the Universe cooled enough for fundamental particles called quarks to combine They formed atomic particles such as protons and electrons as a vast dark fog of hydrogen After three minutes it was cool enough for protons to link with neutrons and electrons forming atoms of helium gas By 400,000 years the Universe now cool at 4,900 ºF 2,700 ºC glowed with the first light 06
The WMAP result confirms that our Cosmos is much much stranger than we ever imagined Science Magazine 2003 Breakthrough of the Year At one billion years old the early Universe resembled a gigantic nebula space cloud dotted with newly forming galaxies lit from within by the massed ignition of trillions of stars COSMIC STUFF As confirmed by the WMAPand Planckprobes ordinary matter atoms and molecules accounts for less than 5 of the Universe The rest is made up of 27 dark matter and 68 dark energy As the Universe expands ordinary matter energy and dark matter lose density while dark energy which is evenly distributed everywhere stays the same Over the last six billion years the Universe has been flying apart at an increasing speed as dark energy becomes more and more dominant This is just one small section of the Hubble Ultra Deep Field View The light from galaxies took so long to get here we see them as they existed a just few hundred thousand years after the Big Bang 07 The UNIVERSE is expanding FASTER than ever propelled by mysterious DARK ENERGY PEERING INTO THE PAST Studying starlight shows that chemical elements like helium leave markers in the light spectrum from red to violet The longer starlight takes to travel to us the more these markers shift into the spectrum’s red end known as Red Shift The most distant stars we can see with the Hubble Space Telescope are estimated to be 12 billion light years away So we see them as they were just after the Universe began The farthest galaxies are also moving away the fastest Probably in 11 billion years the Universe will have vanished
