Venus Might Still Have Active Volcanoes, as Recent Lava Flows Suggest ‘Ongoing’ Eruptions

Astronomers have again discovered evidence of recent volcanic activity on Earth’s sister planet in data from the 1990s

Scientists have uncovered evidence of recent volcanic activity on the surface of Venus in archival data from the 1990s, suggesting eruptions may be “ongoing.” The findings support the theory that Earth’s so-called sister planet is still geologically active—and indicate it might be more active than previously thought, according to a paper published Monday in the journal Nature Astronomy.

“This paper does strengthen the case for current volcanic activity,” Philippa Mason, a planetary geologist at Imperial College London who did not contribute to the findings, tells New Scientist’s Alex Wilkins

“This definitely is another step in the path to understanding Venus as a living, breathing world,” Paul Byrne, a planetary scientist at Washington University in St. Louis who was not involved in the research, says to Science News’ Adam Mann.

Volcanic activity has significantly changed Venus’ surface throughout its history. According to one theory, past eruptions set off a runaway greenhouse effect that converted the planet from a wet and temperate world into a super-hot and dry hellscape. But researchers thought this volcanism stopped 2.5 million years ago.

Last year, however, astronomers discovered the first direct evidence of recent volcanic activity on Venus. A reanalysis of data collected in the 1990s by the NASA spacecraft Magellan revealed that a volcanic vent had changed shape and increased in size in less than a year.

For the new study, researchers again turned to Magellan data. Between 1990 and 1992, the spacecraft mapped 98 percent of the planet’s surface. Its images are the most detailed ever taken of Venus, according to NASA. The mission found that at least 85 percent of the planet’s surface is covered with volcanic flows. But since Venus has no water, such features would not be eroded easily, and they could be from as long as hundreds of millions of years ago.

As it orbited Venus, Magellan shot radio waves at the planet’s surface that boomeranged back to the spacecraft. Based on the characteristics of the returning waves, researchers can infer properties of the rocks on the surface.

In the new paper, the team focused on data collected from the Sif Mons volcano and the Niobe Planitia region in both 1990 and 1992. The strength of the returning radio waves increased over that time, suggesting that new rock had formed since 1990, per NASA.

The researchers considered that these changes were not related to volcanism—for instance, windblown sand could have formed dunes, or the planet’s atmosphere could have interfered with the measurements. But ultimately, the team determined the most likely explanation was that Magellan had detected solidified lava from volcanic activity.

“They were able to show, I think convincingly, that in these two instances the changes in how the surface looks in radar is best explained by there being lava flows,” Byrne tells Science News.

“Magellan is the gift that keeps on giving,” Stephen Kane, a planetary scientist at the University of California, Riverside, who did not contribute to the findings, says to the New York Times’ Robin George Andrews.

The analysis determined the Sif Mons and Niobe Planitia eruptions produced about 12 and 17 square miles of rock, respectively, per NASA.

“Our findings allowed us to estimate the flow rate, and it turned out that Venus is actually much more active than expected, and the level of activity is comparable, or similar, to Earth,” Davide Sulcanese, a co-author of the study and planetary scientist at the Università d’Annunzio in Italy, tells Gizmodo’s Passant Rabie.

Researchers will be able to learn more about Venus’ volcanoes in the coming years. NASA’s Veritas mission, which will launch no earlier than 2031, will map the planet’s surface and study its makeup, as well as its volcanic activity. The European Space Agency is also targeting an early 2030s launch for its Envision mission, which will aim to improve our understanding of Venus’ surface, interior, atmosphere and tectonic activity.