Scientists have been facing a vexing problem when it comes to gas giants around other stars similar to Jupiter: why can’t they find any water? Now, they think they might have an answer.

Using the Hubble and Spitzer telescopes, scientists have found that the water is there, it’s just been blocked by thick clouds in the atmosphere of these massive planets, according to a Los Angeles Times report.

The discovery could help scientists better understand the atmosphere of these mysterious worlds, and perhaps the evolution and composition of gas giants like Jupiter in general.

It’s difficult to peer underneath the surface of a gas giant, and we have had a tough time learning about the composition of even Jupiter in our nearby solar system, let alone the similar exoplanets discovery in other solar systems. Perhaps it may be time to send another probe to take a look, as the last time NASA did so was 20 years ago with Galileo.

Gas giants have no solid surface, but it had always been assumed that they would have plenty of water since oxygen is one of the most abundant elements in the universe — behind only helium and its partner in water, hydrogen.

But as it turns out, it’s not so easy to look beneath Jupiter’s violent atmosphere, where the water is trapped deep within. And sending a probe isn’t such an easy solution — Galileo got destroyed by the incredible pressures and blistering temperatures before it could get much of a reading from the atmosphere.

What’s next to further unravel this mystery? Scientists will be using the data they’ve been able to gather to get greater precision on how much water is in the atmospheres on these planets, and compare it to parent stars to see if there is a connection between the chemical makeups of these planets. Such a connection could help planet hunters narrow down their search for worlds that are likely to support life.