Early, energetic collisions could have driven volcanism on Venus

A new study has found that Earth's sister planet Venus likely experienced higher-speed, higher-energy impacts, creating a superheated core that fuelled volcanism and resurfaced the planet.

A team led by Southwest Research Institute compared the early impact histories of Earth and Venus to explain how the latter has maintained a youthful surface despite lacking plate tectonics.

Both Earth and Venus formed around the same time but have evolved differently over the course of billions of years. Unlike Earth, Venus has only one continuous plate for its surface, but has more volcanoes than any other planet in the solar system, approximately 60 times more than Earth. These volcanoes have played a crucial role in rejuvenating its surface through torrents of lava, a process that may continue to this day.

Professor Jun Korenaga, a co-author from Yale University, stated, "Our latest models show that long-lived volcanism driven by early, energetic collisions on Venus offer a compelling explanation for its young surface age. This massive volcanic activity is fueled by a superheated core, resulting in vigorous internal melting."

The subtle differences in Earth and Venus' distance from the Sun led to variations in their impact histories, particularly the number and outcome of these collisions. The closer proximity of Venus to the Sun and its higher orbital velocity energized the impact conditions. Additionally, the collisions that contributed to Venus' growth were predominantly from objects originating beyond Earth's orbit that required higher orbital eccentricities to collide with Venus instead of Earth.

Dr. Simone Marchi, the lead author of the new paper about these findings in Nature Astronomy, said, "Interest in Venus is high right now. These findings will have synergy with the upcoming missions, and the mission data could help confirm the findings."  

NASA's upcoming VERITAS mission (short for Venus Emissivity, Radio science, InSAR, Topography, And Spectroscopy) will study the surface and interior of Venus. It will be followed by the agency's DAVINCI mission and the European Space Agency's EnVision mission.