Magellan data provides new insight into tectonic processes on Venus

Date:
Sun, 25 May 2025 21:15:34 +0000

Description:
Over 30 years after its demise in the Venusian atmosphere, NASAs Magellan mission recently provided The post Magellan data provides new insight into tectonic processes on Venus appeared first on NASASpaceFlight.com .

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Over 30 years after its demise in the Venusian atmosphere, NASAs Magellan mission recently provided new insight into tectonic processes on Venus. Scientists studied large, rounded geologic features called coronae by combining gravity measurements and topography data collected by Magellan throughout its mission. Not only does the new study shed light on Venus geology, but its methods also form a basis for analyzing the data collected
by future missions to the planet.



While Venus and Earth are often considered twin planets, due to their similar sizes and compositions, the two differ vastly in many ways. One of these differences is how the planets surface is renewed. On Earth, plate tectonics drives this process, in which sections of crust, called plates, slowly drift around the planet. Venus lacks these tectonic plates, but its surface is
still affected by geologic processes, such as volcanism, which was observed
on the planet last year using Magellans data.

Coronae are not found on Earth today; however, they may have existed when our planet was young and before plate tectonics had been established, said the study lead, Gael Cascioli of the University of Maryland and NASAs Goddard Space Flight Center. By combining gravity and topography data, this research has provided a new and important insight into the possible subsurface processes currently shaping the surface of Venus. Magellans observations of four coronae. Clockwise from top left: Artemis Corona, Quetzalpetlatl Corona, Bahet Corona, and Fotla Corona. (Credit: NASA/JPL-Caltech)

Many coronae form as a plume of buoyant material in the planets mantle pushes up to the solid crust and upper mantle, together known as the lithosphere. Coronae range in size from 60 km across to as large as 2,500 km across and vary in their shapes and geological surroundings. As a result of this diversity, scientists consider coronae a valuable tool in understanding
Venuss geologic history.

The new study analyzed four ways in which these plumes and the lithosphere
can interact. Two of these scenarios recycle crust materials, driving the planets surface renewal. Lithospheric dripping recycles material as chunks of rock from the lithosphere sink, or drip into the mantle. In the subduction scenario, the plume pushes the surrounding material into the mantle.

The scientists modelled the interactions between the plume and lithosphere using 3D and compared them with the topography and gravity data collected by Magellan using an algorithm. The algorithm first selected the most likely scenarios using the topography data alone. It then compared Magellans gravity data to decide whether the corona was in an early stage, in its mid-life, or inactive.

Using this method, the team studied 75 coronae and found that plume-lithosphere interactions are happening at 52 of them, which they consider active coronae. Illustration of the tectonic processes that might be responsible for Venus coronae. (Credit: Anna Glcher, CC BY-NC)

Coronae are abundant on Venus. They are very large features, and people have proposed different theories over the years as to how they formed, said coauthor Anna Glcher of the University of Bern in Switzerland. The most exciting thing for our study is that we can now say there are most likely various and ongoing active processes driving their formation. We believe
these same processes may have occurred early in Earths history. See Also STS-30 Thread Space Science coverage NSF Store Click here to Join L2

The 75 coronae studied using Magellans observations only form a small
fraction of the 740 coronae catalogued on Venus so far. The other coronae could not be studied as a result of the low resolution of Magellans gravity data. Only coronae with a radius equal to or larger than the data resolution could be studied, which excluded all but 75 of them. Just one corona was finely resolved, meaning its radius is at least four times the resolution.

Despite the shortcomings, Magellans data proved useful over 30 years after
its mission ended. The spacecraft was launched in May 1989 by Space Shuttle Atlantis on STS-30 and arrived at Venus in August 1990. While orbiting the planet, it used its Synthetic Aperture Radar (SAR) instrument to peer below the planets thick atmosphere and map its topography. NASA commanded Magellan to dive into that atmosphere on Oct. 13, 1994, where it was destroyed under the heat of reentry. Resolvable coronae in the Magellan (A) and VERITAS (B) gravity datasets. Finely resolved coronae are marked in green. Figure C illustrates the distribution of coronae by diameter. (Credit: Cascioli et
al.)

The methods used in the new study could be applied to gravity data collected by upcoming missions to Venus. Both NASAs Venus Emissivity, Radio Science, InSAR, Topography and Spectroscopy (VERITAS) mission and the European Space Agencys EnVision mission will map the planets gravity field as part of their science objectives.

The scientists specifically analyzed VERITAS capabilities in relation to coronae and determined that it will be able to study 427 of them. Of these, VERITAS will be able to finely resolve 12. Besides the higher resolution, the data from the upcoming mission is expected to be much less noisy.

The VERITAS gravity maps of Venus will boost the resolution by at least a factor of two to four, depending on location a level of detail that could revolutionize our understanding of Venus geology and implications for early Earth, said study coauthor Suzanne Smrekar, a planetary scientist at NASAs
Jet Propulsion Laboratory (JPL) and principal investigator for VERITAS.

Cascioli et al.s study was published in the journal Science Advances on May 14th.

(Lead image: Illustration of active volcanism and volcanism and a subduction zone at the Quetzalpetlatl Corona. Credit: NASA/JPL-Caltech/Peter Rubin)

The post Magellan data provides new insight into tectonic processes on Venus appeared first on NASASpaceFlight.com .



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Link to news story: https://www.nasaspaceflight.com/2025/05/magellan-venus-coronae/


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