New Telescope Helps Us Imagine Another World Like Ours
Opinion Advocates for ideas and draws conclusions based on the author/producer’s interpretation of facts and data.
By Scott Levine
On July 11, NASA released the first photos from the James Webb Space Telescope (JWST), which launched at the end of last year and now studies the universe from a point in space about a million miles from Earth.
While this telescope works quite differently, many people see this observatory as an upgrade. It fills the very big shoes of the Hubble Space Telescope, which has fundamentally changed our understanding of our universe since its launch in the early 1990s.
One photo is of a corner of the sky about the size a single grain of sand would appear to us if we held it at arm’s length. It highlights a cluster of galaxies about four billion light years away called SMACS 0723. A light year is the distance light travels in a year: about six trillion miles (or about 9.5 trillion kilometers). Scattered across that photo, we see galaxy upon galaxy, some like our Milky Way, as we look deeper and deeper into space.
Each of SMACS 0723’s galaxies have countless stars, some like our sun.
Even though light is the fastest thing there is, it’s frustratingly slow at the scale of the universe. It takes incredible amounts of time for those stars’ and galaxies’ light to reach us. As the line from the telescope stretches off, perfectly straight, across millions and billions of light years of unimaginable emptiness, we’re looking farther and farther back in time. The SMAC 0723 we see in the photo today is the
SMAC 0723 of four billion years ago.
But we’ve learned how light works, and how to use that frustration to our advantage. We can tell what direction those galaxies are moving relative to us and each other and figure out how far away they are. We can learn how long ago those objects formed.
Some of the light we see in that photo is behind the cluster and is so far away that it’s been traveling to us, from our point of view, for about 13 billion years. That’s 98 percent of the time since the big bang.
We’ve learned enough about the nature of the light to know that if there’s nitrogen, hydrogen, oxygen or even water on those worlds. It’s here, why not there?
We’ve learned.
The beauty JWST has shown us so far is undeniable, but so is the voyage it can send us on. As I stare at that photo, I wonder not just what’s out there, but who. There must be at least one world hidden in that photo, orbiting a star and bathed, like we are, in warmth and light. For me it’s harder to imagine that there isn’t. Could there be at least one world where critters, creatures or people live and die, love and struggle, but somehow find their way through?
Even when things are bleak, I remember all we’ve learned, all we’ve taught each other, all we’ve discovered and the path we’ve all followed so we can see photos like that one. These, and all the photos that come next, show us where we’ve been and where we’re going.
Tonight, let’s head outside, pick out any grain-of-sand-sized patch of sky, look up and imagine what we’ll learn tomorrow – or imagine who might be staring back at us with hope.
Scott Levine (astroscott@yahoo.com) is an astronomy writer and speaker from Croton-on-Hudson. He is also a member of the Westchester Amateur Astronomers, who are dedicated to astronomy outreach in our area. For information about the club including membership, newsletters, upcoming meetings and lectures at Pace University and star parties at Ward Pound Ridge Reservation, visit westchesterastronomers.org.
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