The universe formed how many years ago

Explaining it may require entirely new concepts of space and time. When astronomers look through a telescope, they are looking back in time. Other galaxies are much farther away in space and time. The Hubble Space Telescope can see galaxies that are more than 13 billion years old and formed not long after the Big Bang. Observations have been made of the cosmic microwave background, the faint glow left over from the Big Bang, that help to get a picture of what the early universe was like, especially before those first stars formed.

Andromeda Galaxy—our nearest neighbor. Astronomers are now planning a suite of new space- and ground-based telescopes and smaller-scale equipment and research. With these tools, they plan to study dark matter and dark energy, the black holes at the center of galaxies, the formation of planets like Earth around other stars, and many other aspects of our astonishing universe.

When it launches in , it will use powerful infrared vision to peer into the deep universe. Ready for the specifics? The Big Bang theory accounts for all of the following except:.

How did the universe begin? How will it end? Ready to take the quiz? Wait, start at the beginning. Of everything. Learn More. Why stand behind this theory?

Recombination dramatically changed the look of the universe; it had been an opaque fog, and now it became transparent. The cosmic microwave background radiation we observe today dates from this era. But still, the universe was pretty dark for a long time after recombination, only truly lighting up when the first stars began shining about million years after the Big Bang. They helped undo much of what recombination had accomplished.

These early stars — and perhaps some other mystery sources — threw off enough radiation to split most of the universe's hydrogen back into its constituent protons and electrons. This process, known as reionization , seems to have run its course by around 1 billion years after the Big Bang. The universe is not opaque today, as it was before recombination, because it has expanded so much.

The universe's matter is very dilute, and photon scattering interactions are thus relatively rare, scientists say. Over time, stars gravitated together to form galaxies, leading to more and more large-scale structure in the universe. Planets coalesced around some newly forming stars, including our own sun. And 3. While much about the universe's first few moments remains speculative, the question of what preceded the Big Bang is even more mysterious and hard to tackle. For starters, the question itself may be nonsensical.

If the universe came from nothing, as some theorists believe, the Big Bang marks the instant when time itself began. In that case, there would be no such thing as "before," Carroll said. But some conceptions of the universe's birth can propose possible answers. The cyclic model, for example, suggests that a contracting universe preceded our expanding one.

Carroll, as well, can imagine something existing before the Big Bang. Cosmologists and physicists are working hard to refine their theories and bring the universe's earliest moments into sharper and sharper focus. But will they ever truly know what happened at the Big Bang? It's a daunting challenge, especially since researchers are working at a To do so would require one of the greatest pieces of fortune in science.

In the mids Astronomers Arno Penzias and Robert Wilson were having a tough time trying to tune into the microwave signals transmitted from the Milky Way. The radio antenna they were using kept picking up a persistent weak hiss of radio noise. Nor could clearing the pigeons that had roosted in there, or their mess. If the Big Bang theory is true, how did it lead to all the planets, stars and galaxies we can see today?

Thanks to a series of calculations, observations from telescopes on Earth and probes in space, our best explanation is this. Around A preliminary announcement about finding these waves in was quickly retracted, after astronomers found the signal detected could be explained by dust in the Milky Way.

According to NASA, after inflation the growth of the universe continued, but at a slower rate. As space expanded, the universe cooled and matter formed. One second after the Big Bang , the universe was filled with neutrons, protons, electrons, anti-electrons, photons and neutrinos.

During the first three minutes of the universe, the light elements were born during a process known as Big Bang nucleosynthesis. Temperatures cooled from nonillion 10 32 Kelvin to 1 billion 10 9 Kelvin, and protons and neutrons collided to make deuterium, an isotope of hydrogen. Most of the deuterium combined to make helium , and trace amounts of lithium were also generated. The heat of creation smashed atoms together with enough force to break them up into a dense plasma, an opaque soup of protons, neutrons and electrons that scattered light like fog.

Roughly , years after the Big Bang, matter cooled enough for atoms to form during the era of recombination, resulting in a transparent, electrically neutral gas , according to NASA. This set loose the initial flash of light created during the Big Bang, which is detectable today as cosmic microwave background radiation.

However, after this point, the universe was plunged into darkness, since no stars or any other bright objects had formed yet. About million years after the Big Bang, the universe began to emerge from the cosmic dark ages during the epoch of reionization. During this time, which lasted more than a half-billion years, clumps of gas collapsed enough to form the first stars and galaxies, whose energetic ultraviolet light ionized and destroyed most of the neutral hydrogen.

Although the expansion of the universe gradually slowed down as the matter in the universe pulled on itself via gravity, about 5 or 6 billion years after the Big Bang , according to NASA, a mysterious force now called dark energy began speeding up the expansion of the universe again, a phenomenon that continues today.

A little after 9 billion years after the Big Bang, our solar system was born. The Big Bang did not occur as an explosion in the usual way one think about such things, despite one might gather from its name.