# Could there be caves/underground tunnels in Venus?

If so, would they have the same pressure/temperature than of the surface of Venus? How could we "scan" the surface to gather that kind of information?

For reference, there are several images of lava tube "entrances" on the moon, (where they are much more visible due to almost no atmosphere) in the question Is there a map or list of all the lava tube skylights the LRO has detected on the Moon? as well as the answer there.

However, looking on Venus might be more of a challenge.

From what we know, Venus is still a geologically and volcanically active planet. Because of this volcanic activity, Lava tubes exist on the Venus.

A study published in 2020 states, it ...

identified 37 recently active volcanic structures on Venus. The study provides some of the best evidence yet that Venus is still a geologically active planet. A research paper on the work, which was conducted by researchers at the University of Maryland and the Institute of Geophysics at ETH Zurich, Switzerland, was published in the journal Nature Geoscience on July 20, 2020.

A lava tube is a type of lava cave formed when a low-viscosity lava flow develops a continuous and hard crust, which thickens and forms a roof above the still-flowing lava stream. Tubes form in one of two ways: either by the crusting over of lava channels, or from pāhoehoe flows where the lava is moving under the surface.

Additionally, there is evidence of lava tubes on the Moon and plenty of examples of lava tubes on Earth. The longest known lava tubes are in the Undara Volcanic National Park in Queensland Australia, where there are tubes up to 100 km in length.

Two planetary astronomers from the University of Wollongong in Australia, Dr Graeme Melville and Prof. Bill Zealey, researched these lava tubes, using data supplied by NASA, over a number of years and concluded that they were widespread and up to ten times the size of those on the Earth. Melville and Zealey said that the gigantic size of the Venusian lava tubes (tens of meters wide and hundreds of kilometers long) may be explained by the very fluid lava flows together with the high temperatures on Venus, allowing the lava to cool slowly.

Edit:

Thanks to @uhoh, the question How livable would a lunar lava tube be? may be of interest.

• Venus might be too hot for lava tubes to form and sustain. Stone on Earth may behave plastic over a very long time. But at much higher temperatures plastic behaviour might take less time. – Uwe Mar 22 '18 at 14:19
• +1 again if I could. A further discussion of lava tubes on the Moon (as seen from MRO) as well as those of Undara on Earth can be found in the Earth Science SE question What conditions could produce 50 km long lava tubes? and its extensive answer. – uhoh Mar 22 '18 at 22:36
• There are lava tubes on Venus, so you could update your answer ! articles.adsabs.harvard.edu/full/1993PASAu..10..200Z/… and en.wikipedia.com/wiki/Geology_of_Venus#Lava_flows_and_channels – Cornelis Aug 1 '20 at 9:54
• @Cornelisinspace: thanks for the information. I've updated the answer – Fred Aug 1 '20 at 22:03
• – uhoh Aug 2 '20 at 3:06