How big and mysterious is space? Here's what a NASA expert says

How Big Is Space? Astronomers Still Don’t Know for Sure (Image: Canva)

Occasionally, gazing up at the night sky inspires awe. Those little pinpricks of light contain secrets beyond our imagination. It's not hard to feel insignificant under the stars, and they are right to make us feel so—space is unimaginably huge.

A Journey Far Beyond Pluto

Even in our own solar system, distances seem infinite. Think of driving continuously at highway speed to Pluto. It would take about 6,000 years—more than recorded history. But Pluto is only the beginning. When astronomers look outside our solar system, they measure space in something larger than miles. They use light-years, a measurement that considers the vastness of space.

Light travels quickly—about 186,000 miles per second. In one year, that is approximately six trillion miles. The closest star to our Sun is four light-years away. That is to say, its light travels to Earth for four years, always at fantastic speed.

The Milky Way and Beyond

Our own Milky Way galaxy is huge by itself. It reaches from one edge of near 100,000 light-years to the other edge. But it's just one among billions. Pictures from strong telescopes such as James Webb reveal us tens of billions more. They consist of galaxies so far away that their light left them more than 13.5 billion years ago.

Since the universe is expanding, they are even farther away now. That implies they are not only 13.5 billion light-years away in our time frame. Actually, scientists estimate the observable universe reaches 92 billion light-years. But that's only the part that we can observe.

What Lies Beyond the Edge?

Here's where the intrigue thickens. Nobody knows whether the universe ends at all. Scientists have no definitive proof to say for certain whether it is infinite or finite. All our discoveries notwithstanding, we can't actually measure space's actual size. The universe might just extend endlessly—or it could be larger than any telescope can see.

Even with the finest equipment and smartest brains, space remains mysterious. For the time being, all we have to go on is this: space is huge beyond comprehension, and its real size is one of science's biggest mysteries.