Hunga Tonga: New Volcanic Pacific Island Gives NASA a Glimpse of Life on Mars

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Hunga Tonga's crater lake pictured from the summit rim, June 4-5. Damien Grouille/Cecile Sabau/NASA

NASA has been watching the birth of a new volcanic island in the Pacific Ocean. The first to persist in the age of the modern satellite, the emerging rock offers scientists a laboratory to map rarely seen geological processes. These rapid changes, researchers believe, could be used to model the mysterious terrain of Mars.

High-resolution optical and radar satellite observations by NASA were presented at the American Geophysical Union Fall Meeting in New Orleans on December 11.

New Volcanic Island

The new island, Hunga Tonga-Hunga Ha'apai, emerged from a violent underwater eruption in late December 2014. Scientists expected the island in Tonga to survive just a few months. Now, they believe it could last up to 30 years.

Most volcanic islands disappear quickly after they are beaten down and drowned by waves. This island is one of only three in the past 150 years to survive beyond its initial bruising, and the first to be observed by modern satellites.

The last island to withstand the violent waves of the ocean was Surtsey, off the coast of Iceland, which emerged in 1963 and still exists today.

"Volcanic islands are some of the simplest landforms to make," said first author Jim Garvin, chief scientist of NASA's Goddard Space Flight Center in Greenbelt, Maryland, in a press release. "Our interest is to calculate how much the 3-D landscape changes over time, particularly its volume, which has only been measured a few times at other such islands. It's the first step to understand erosion rates and processes and to decipher why it has persisted longer than most people expected."

Evolution of the Island

The island's shape has changed drastically over its short life span, as NASA's time-lapse video above shows.

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Digital elevation model derived from stereo satellite images shows the topography of the new island. Left: April 21, 2015. Right: September 19, 2017. NASA

At birth, Hunga Tonga clung to a neighboring island to the West. Soon, waves eroded Hunga Tonga's sediment, forming a land bridge to another neighbor to its east. By 2016, a sandbar had closed off the volcanic crater from the sea, which stopped the island from melting into the ocean. Researchers believe the underlying rock beneath the tiny group of islands might be helping to support its newest member.

"The two islands that surround this new land mass have some pretty tough substrate, so there's something happening to help make this solidify and stay in place, chemically," said co-author Vicki Ferrini, a geologist at the Lamont-Doherty Earth Observatory in Palisades, New York, in the press release.

Window Into Life on Mars

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The evolution of the Hunga Tonga's terrain can teach scientists about Mars. Coastal erosion is pictured, June 4-5. Damien Grouille/Cecile Sabau/NASA

Watching new terrain appear and evolve here on Earth can help scientists interpret Martian evidence better, the researchers note. "Everything we learn about what we see on Mars is based on the experience of interpreting Earth phenomena," Garvin said.

Satellite data from Mars has been misunderstood in the past. In 2015, NASA announced the discovery of running water on the surface of Mars. Earlier this year, scientists from the United States Geological Survey showed that this water was really just slopes of dust and sand.

Hunga Tonga is valuable because its volcanic features mirror those of Mars. The opportunity to watch them evolve and change is "unprecedented," according to the press release.

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Mars water flows re-identified as dust and sand. NASA/JPL/University of Arizona

The new island could even teach researchers about the Red Planet's past—specifically, if Mars has a history of volcanic oceans that could harbor life.

"We think there were eruptions on Mars at a time when there were areas of persistent surface water. We may be able to use this new Tongan island and its evolution as a way of testing whether any of those represented an oceanic environment or ephemeral lake environment," Garvin said.

Those wet, hot sites, Garvin said, could be the perfect place to search for evidence of past alien life.