The Universe Today

What happened

Some 13.8 billion years after it began, the observable universe contains an estimated two trillion galaxies, each with billions of stars, woven into a vast web of filaments and voids. It is still expanding — and, driven by dark energy, expanding ever faster. Everything we can see is made of ordinary matter that accounts for only about 5% of the whole; the rest is invisible dark matter and dark energy.

Why it matters

From a hot, formless beginning the cosmos has built the galaxies, stars, and worlds we see today — and given rise, on at least one small planet, to beings able to look back and reconstruct its history.

Sources

• NASA Science. Hubble Reveals Observable Universe Contains 10 Times More Galaxies Than Previously Thought · Reputable source
• NASA Goddard Space Flight Center. WMAP — Content of the Universe · Reputable source