The observable universe is more than 93 billion light-years wide.
Humans have traveled just 1.3 light-seconds away from Earth.
That distance—the gap between Earth and the Moon—is the farthest any human being has ever physically journeyed into space. Every astronaut who has ventured beyond our planet has remained within a region that light can cross in just over a second.
Beyond that lies a cosmos so vast that it challenges the limits of human imagination.
The observable universe stretches approximately 93 billion light-years across. Yet even this immense expanse is not the entire universe. It is only the portion from which light has had enough time to reach us since the Big Bang.
There may be vastly more space beyond that boundary. In fact, most cosmologists believe there is. But because the universe is expanding, some regions are so distant that their light may never reach Earth.
Every bright point visible in deep-space images represents far more than a single star.
Most are entire galaxies containing hundreds of billions of stars, along with countless planets, moons, and other worlds. The number of stars in the observable universe is estimated to be greater than all the grains of sand on Earth's beaches combined.
Yet everything we can see accounts for only a small fraction of reality.
According to current scientific models, ordinary matter—including every galaxy, star, planet, and living thing—makes up only about 5 percent of the universe. Roughly 27 percent is believed to be dark matter, while about 68 percent is thought to be dark energy, the mysterious phenomenon driving the accelerated expansion of space.
Even our fastest spacecraft barely dents these distances.
NASA's Parker Solar Probe can reach speeds approaching 690,000 kilometers per hour during its closest passes to the Sun. At that speed, traveling to Proxima Centauri, the nearest star beyond our Solar System, would still take roughly 6,000 years and Proxima Centauri is only 4.24 light-years away.