Scientists could one day float an aerial robot over Venus


Seismology is about waves. The epicenter of the earthquake is like a rock falling into a pond. The disturbance spreads along the earth’s crust. This movement translates into pressure changes in the air above the ground. This produces infrasound waves (long and slow sound waves so low that humans cannot hear them) that travel directly upward from the epicenter (epicenter waves) and travel above the seismic waves as they travel along the earth (surface waves).

On earth, a network of seismological ground stations uses sensors to detect these waves and determine the epicenter and intensity of the earthquake. This new study shows how a balloon equipped with sensors can do the same thing from the air. Balloon barometers that capture only the epicenter or ground infrasound can help understand the location and intensity of the earthquake. Those who have captured both may tell us what the planet’s crust looks like. This may help to observe the surfaces of planets that we can’t actually see.

(Seismic data also applies to us were able Look.The Martian seismic readings from the InSight lander are in Draw the crust of Mars.)

To prove that it is possible to study the seismology of Venus from the air, the team plans to conduct a flight activity in Oklahoma where earthquakes are frequent, possibly due to hydraulic fracturing, to test whether they can hear from high places in the atmosphere. The infrasound of the earth’s rumble. However, when the 2019 Ridgecrest series of earthquakes hit near the JPL’s Los Angeles base, it caused thousands of small aftershocks. Senior project manager James Cutts, research technologist Siddharth Krishnamoorthy and The rest of the team felt the opportunity. “This must be done as soon as possible, because the later it happens, the weaker the aftershocks and the fewer the number,” Krishnamurti said.

Question: They don’t have balloons yet. In 16 crazy days, they scrambled to build four ultralights”Heliotrope“Simple balloons are about 20 feet in diameter and 12 feet high. They are made of plastic sheeting and tape. When the sun heats the air in their charcoal-covered plastic balloon “envelope”, heliotrope-named tortoise, hare, Hare 2 and Crazy Cat-Ascend into the stratosphere. They float freely with the wind, and everyone has an air pressure sensor bag hanging on the tether below, listening to the faint sound of aftershocks.

On July 22, 2019, the ground was shaken by the aftershock. As it passed under the balloon, it produced a surface infrasonic disturbance of the barometer that traveled 4.8 kilometers upwards and hit the turtle, recorded as a series of tiny pressure changes. These changes were so small that it took Krishnamurti several months of data analysis to see them after the flight. But they are there: the tiny wave profile perfectly matches the seismic readings of the four ground seismometer stations in the area near the balloon. They also matched a computer model of the infrasound propagation of aftershocks. The tortoise heard the earthquake.

But can the balloon capture seismic infrasound while floating in the atmosphere? Venus? There, the balloon will fly higher, about 50 kilometers instead of 5 kilometers.At that height, the acid cloud of Venus May attenuate infrasound waves, Making them more difficult to detect. (What does Venus sound like? This is the voice of Bach On Earth, Titan, Venus and Mars, due to different sound wave attenuation factors. )

However, other factors can be beneficial to the balloon. Although the Venusian wind is blowing steadily at a speed of more than 200 miles per hour, a balloon at a stable altitude should remain relatively “quiet” when the breeze is blowing. (Imagine the calmness of a hot air balloon. Its speed is the same as the wind speed.) Because of the thick atmosphere of Venus, Byrne writes, the coupling efficiency between the surface of Venus and the atmosphere is 60 times that of it. The Earth is-this means that energy from earthquakes will be more easily transmitted into the atmosphere of Venus, making it the main location for floating seismographs.


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