Life on the Planet Mercury? ‘It’s Not Completely Nuts’

Trilobites A new explanation for the rocky world’s jumbled landscape opens a possibility that it could have had ingredients for habitability. Mercury — a planet with a surface hot enough to melt lead — might once have contained ingredients needed for life. Though that’s a pretty big might. The new theory, published last week in the journal Scientific Reports, is based on a particularly muddled feature on the planet orbiting closest to the sun, known as “chaotic terrain.

” Here, the cracked, uneven and jumbled landscape consists of fractured rock, mismatched peaks and collapsed craters. “Think of a kid throwing up a bunch of building blocks and how they land,” said Deborah Domingue, a co-author of the study from the Planetary Science Institute, headquartered in Tucson, Ariz. “Some are up, some are down, some are tilted — that’s chaotic terrain. ” For nearly 50 years, scientists have thought the chaos on Mercury was caused by earthquakes that raced throughout the planet when a massive asteroid struck the planet’s far side.

But the new study, led by Dr. Domingue’s colleague Alexis Rodriguez, upends that notion. It suggests the terrain could not possibly have formed in response to the collision because it occurred 2 billion years after the impact crater formed. In addition, Dr.

Rodriguez and his colleagues discovered that areas within the chaotic terrain appear to have dropped. It’s as though the layer of crust just below the surface had simply disappeared. The easiest explanation is that subsurface volatiles — elements that can easily switch from a solid to a liquid or a gas — heated up as a result of the intrusion of magma below. That caused those elements to transform into a gas, forcing the terrain above them to collapse into a jumbled mess.

“Let’s say I have a house on stilts, and I kick one out,” Dr. Domingue said. “My house is going to tilt right?

“That’s what’s going on here.”

” Paul Hayne, a planetary scientist at the University of Colorado Boulder who was not involved in the study, agrees that the prevailing explanation for Mercury’s mishmash — which has long been unchallenged — is likely wrong. He also notes that the new story is consistent with what scientists have observed on Mars, where similar terrain was likely caused by the release of volatiles. It’s a thrilling prospect given that volatiles — particularly water — are needed to kick-start life. Though the team cannot say which volatiles were present, there is reason to hope that water might be one of them, Dr.