Seismology has been ubiquitous on Earth for decades, and missions like InSight have recently provided similar data for the interior of Mars. Understanding the inner workings of the planet is key to understanding its geology and climate. But the inner workings of Venus, perhaps our closest sister planet, remain a mystery.

The sulfuric acid cloud and the scorching surface temperatures are probably not working. But Siddharth Krishnamurthy of NASA’s Jet Propulsion Laboratory and Daniel Bowman of Sandia National Laboratory think they have found a solution using seismometers suspended in balloons. As we mentioned earlier, this idea has been around for a while. However, this may seem counterintuitive; Don’t seismometers normally need to be on the ground to detect anything?

Conventional seismometers, yes. But another type of seismometer is only now becoming more acceptable. An infrasonic seismometer monitors infrasonic pressure waves created by seismic activity transmitted from an extraterrestrial medium such as the atmosphere.

Venus has a lot of atmosphere, so it seems like an ideal place to use this technology. Better still, the upper reaches of the cloud layer are one of the most similar places in the solar system to the Earth’s environment; therefore many ideas have arisen to create “cloud cities” on Venus.

There’s no need to build an entire city to house sensors that only collect infrared data, so a high-altitude balloon would serve this purpose perfectly. This solves one of the most difficult problems of Venus exploration: the development of materials that can survive on its surface.

NASA has spent millions of dollars developing radiation-shielded sensors that can withstand extreme pressures and temperatures at the surface. But since even these are relatively simple, it would not require any additional effort to develop a sensor held in air at acceptable temperature and pressure for this particular use case.

An obvious question arises in this context: How will the signal reach the sensors floating in the atmosphere from the ground? Earthquakes (or Venus earthquakes as in this case) cause deafening sounds that are then transmitted at low frequencies throughout the atmosphere. Sensitive microphones, such as those in a balloon, can read these signals.

One such experiment was recently performed on Earth, where an infrared microphone was able to pick up signals from two earthquakes with a magnitude of 7.3 and 7.5, despite being 3,000 km away from the epicenter of earthquakes in the stratosphere. Using this experiment as a template, researchers can develop a similar system for use on Venus, with the appropriate modifications necessary for that planet’s environment.

In addition, this was much more advanced than previous experiments with infrared seismometers, and much closer to the actual distance such a sensor could be from the epicenter of an earthquake on Venus. Venus is becoming an increasingly interesting option for exploration; Fraser explains why. However, there are still many problems.

First, we failed to successfully launch a balloon at Venus, let alone a mission with sensitive seismometers.

Second, there was “ground truth” in the Earth experiment; this meant that the researchers knew from other sources that an earthquake had occurred when they received the signal.

Since there are no other sensors on Venus that could provide such control, researchers will have to speculate as to what is causing the particular pattern in the data; There may have been an earthquake on Venus or the balloon may have been shaken in some way. . Also, earthquakes over seven magnitudes on Earth are considered powerful, and it’s unclear whether seismometers can detect smaller earthquakes even on our own planet.

Venus may have the same range of seismic activity or even be more active, but at a lower intensity, making the detection of less powerful earthquakes a priority. The JPL team recorded a 4.2-magnitude jolt, but the balloon was less than a few thousand kilometers away.

It’s always a good idea to use technology developed on Earth to explore space, and this seems like a new way to use seismometers in a new way. However, despite nearly a dozen missions planned to Venus in the near future, there are currently no mission plans that use these features. For now, we will have to wait to understand the inner workings of our nearest sister planet. Source