Before stars ignited and galaxies took shape, before time as we understand it even began, the universe underwent something almost unimaginable—an event called cosmic inflation. In less than a blink of an eye, the fabric of space stretched faster than the speed of light, transforming a microscopic point into an enormous cosmic expanse.
But here’s the problem: we still don’t know why it happened. While physicists are convinced that inflation shaped the universe, the driving force behind it remains a mystery. That’s where NASA’s SPHEREx mission comes in.
Launching tomorrow, March 4th, 2025 aboard a SpaceX Falcon 9 rocket, this groundbreaking mission is designed to uncover direct evidence of inflation’s fingerprints—data that could rewrite our understanding of reality itself.
A Telescope Unlike Any Other
Most space telescopes, like the James Webb Space Telescope, focus on capturing detailed images of galaxies and exoplanets. SPHEREx has a completely different goal—it will scan the entire sky in infrared light, creating the most detailed 3D map of the cosmos ever made.
By analyzing the large-scale structure of the universe, SPHEREx could provide the strongest proof yet that quantum ripples—tiny fluctuations at the dawn of time—stretched into cosmic structures we see today.
The theory of inflation is widely accepted, but not everyone is convinced. Critics argue that for inflation to occur, it would require an extraordinarily precise set of conditions—so precise that it seems almost too convenient.
And here’s the real kicker: scientists have never directly detected the exotic particles that would have driven inflation. Everything we think we know about it is based on indirect clues. SPHEREx might finally change that.
By studying the way galaxies are distributed across space, the mission could determine whether inflation was triggered by one energy field or multiple interacting forces—a distinction that could either validate or dismantle decades of theoretical physics.
During inflation, the universe wasn’t filled with stars or planets—it was a seething ocean of unknown energy. This energy created tiny fluctuations, which later grew into the cosmic web of galaxies we see today.
SPHEREx will study whether these structures align with a single, uniform field—or if multiple forces were at play. If the data suggests inflation was driven by more than one energy field, it could completely overturn our current models of the universe’s origin.
Why SPHEREx Must Go to Space
Unlike visible light, infrared radiation can reveal signals from the very first moments of the universe. But there’s a problem—Earth itself glows in infrared, making it impossible to detect these faint signals from the ground.
That’s why SPHEREx will operate in space, cooled to minus 350 degrees Fahrenheit, using specialized shielding to block out unwanted heat. From orbit, it will have a clear, unobstructed view of the entire sky.
Beyond solving one of the greatest mysteries in cosmology, SPHEREx will also:
- Trace how water and organic molecules spread across the galaxy, helping us understand the conditions for life.
- Study the formation of the first galaxies, shedding light on how the universe evolved over time.
NASA classifies SPHEREx as a medium-scale mission under its Explorers Program, meaning it’s designed to deliver high-impact science at a fraction of the cost of massive projects like James Webb.
Sharing its ride to orbit will be PUNCH, a separate mission dedicated to studying the solar wind and its impact on Earth.
If SPHEREx finds evidence that inflation’s fingerprints match predictions, it will stand as one of the most significant confirmations in the history of physics. But if it uncovers something unexpected, it could force scientists to rethink everything about how the universe began.
