Where does water come from.
A new clue has been discovered from distant and foreign worlds.
A group of researchers found that planets that formed dry can become water rich worlds.
This challenges the existing view in the field.
The research shows that even planets that formed without water and began as dry and rocky worlds can produce water deep inside them.
Water is essential for life on Earth but where did it come from in the first place.
Scientists long believed that water was brought to Earth from far away in the solar system.
Giant frozen planets like Uranus and Neptune are in the outer solar system where it is cold enough for water to freeze.
According to this idea water rich objects formed far from the sun and later were delivered to Earth.
In a series of laboratory experiments and computational models a research team showed that many water rich planets did not form far from their stars or require a supply of ice as previously thought.
Instead they may have created their own water from the inside out.
The findings blur the line between types of planets.
Dry worlds with a hydrogen envelope and water covered planets were once thought to be two separate types.
The new research shows they may actually be stages in the evolution of a planet.
Thanks to space missions and telescopes for finding planets researchers have discovered thousands of exoplanets.
Two common types are rocky super Earths slightly larger than Earth and sub Neptune planets which are larger and have a thick atmosphere.
The fact that such types do not exist in our solar system makes them especially mysterious.
Recent observations indicate that some sub Neptune planets are water worlds planets with lots of water while other sub Neptune planets are dry rocky planets with a hydrogen atmosphere.
The surprise is that many of the water worlds are located very close to their stars where it should be too hot for water to condense or survive.
In a series of laboratory experiments the researchers used powerful lasers and a diamond anvil cell to create the extreme heat and pressure found inside sub Neptune planets.
Then they tracked what happened when hydrogen gas came into contact with hot rocky materials using X rays.
Their results show that water can form through chemical reactions from dry material.
Hydrogen from the atmosphere reacted with oxygen released from the rocks creating water.
Even planets that formed without water that began as dry and rocky worlds with thick hydrogen blankets could produce water deep inside them.
Computer simulations found that the water created spreads efficiently inside the planet allowing continuous water production.
This discovery suggests that many water rich planets did not form far from their stars or need a supply of ice as previously believed.
The findings show that planets can produce one of the main key ingredients for life water even in extream environments close to stars.
The conclusion is that water may be much more common in the universe than previously thought.