Giant liquid mirrors could revolutionize the hunt for habitable worlds

A Giant Mirror Made of Liquid—Floating in Space? Meet the Future of Telescopes

Imagine a telescope so massive its mirror stretches 50 meters across—wider than a U.K. soccer field and nearly eight times the size of James Webb’s iconic eye on the cosmos. But here’s the twist: this mirror isn’t solid glass. It’s a delicate film of liquid, suspended in space.

Welcome to FLUTE—the Fluidic Telescope—a bold concept developed by NASA and Technion that could redefine how we explore the universe.

🚀 Why We Need Bigger Telescopes

To directly image Earth-like exoplanets, we need telescopes far larger than anything we’ve launched before. Even the James Webb Space Telescope, with its foldable 6.5-meter mirror, maxed out current engineering. Traditional methods just can’t scale to the enormous sizes we need.

But in the weightlessness of space, liquids form perfect curved surfaces, ideal for reflecting light. That’s the genius of FLUTE: use physics, not machinery, to shape the mirror.

🌊 The Challenge: What Happens When It Moves?

One big question loomed: what happens to a giant liquid mirror when the telescope turns to look at a new target? Would it slosh around like soup in a bowl?

New research by Israel Gabay and colleagues at Technion dives into this problem. Using advanced math and clever lab experiments, they built the first detailed model of how such mirrors behave during telescope movements—or “slewing maneuvers.”

📉 The Surprising Results

When a 50-meter liquid mirror slews, ripples form—especially at the edges. But they spread inward slowly, and even after 10 years of daily movements, the central 80% of the mirror remains nearly perfect. That’s more than enough for high-quality imaging.

Even cooler: small, well-planned maneuvers in different directions can cause more balanced ripples, making it easier to correct them with optics.

🧪 Lab Tests Confirm the Theory

To test their math, the team used electromagnetic forces on microscopic liquid films in the lab. The tiny ripples they observed matched predictions—proving the physics holds up, even at vastly different scales.

🔮 Why This Matters

This is more than a clever trick—it’s a game-changer. Liquid mirrors could allow space telescopes that:

  • Change shape for different tasks
  • Auto-correct optical errors
  • Even self-heal after micrometeorite strikes

As we design the telescopes of the 2030s and beyond, FLUTE offers a radically different path: one that trades rigid engineering for elegant physics.


📖 More info:
Israel Gabay et al. “Fluid dynamics of a liquid mirror space telescope,” arXiv, 2025.
DOI: 10.48550/arxiv.2507.02812