From: Lammlein, D. Lunar seismicity and tectonics. The lunar seismic network: Mission update. Further analysis of lunar seismic data revealed that shallow moonquakes were the most high-energy seismic events on the moon. Shallow moonquakes lasted a long time, and compared to deep moonquakes or thermal quakes, they generated much more powerful vibrations.
Consider the following map created by Weber and colleagues showing the magnitudes of shallow moonquakes observed by the seismic network. In , researchers reported new, more precise estimates about where shallow moonquakes were coming from. All quakes, on Earth and on the moon, usually start at a single location, called an epicenter.
Look at the map that the researchers generated and highlight areas where shallow moonquakes seem more common. What areas of the moon using latitude and longitude areas would you tell future missions to avoid if they wanted to avoid shallow moonquakes? Based on this map, do you think it is likely that shallow moonquakes are caused by lunar plate tectonics, similar to how earthquakes are caused by plate tectonics on earth? The gravity of the Earth pulls on the moon, and the gravity of the moon pulls on the Earth.
That means that instead of being the same distance from the Earth all the time, the moon moves between being close to the Earth and far away from it.
The position of the moon in its orbit where it is closest to the Earth is called the perigee , the position farthest away is called the apogee. Look at the following chart of shallow moonquakes plotted against how far away the moon was from the Earth EMD, which means Earth-moon distance.
Dots mark shallow moonquakes, the x-axis shows when the quakes occurred, and the y-axis shows how far away the moon was from Earth when each quake occurred. Dots closer to the top of the graph farthest from Earth occurred when the moon was near its apogee , dots closer to the bottom of the graph nearest to Earth occurred when the moon was near its perigee.
The surface of the moon is covered by silt, mountains, valleys, and of course, craters. Fresh, reflective regolith can be exposed by meteor impacts, faults that have thrust up to form ridges called fault scarps , and moonquakes that shake up old regolith.
There is a global community of thousands OK, more like tens of thousands! What do they think about the risk that moonquakes might pose to future manned missions to the moon? Could moonquakes pose a threat to future manned missions to the surface of the moon, and if so, how could missions be planned to minimize those risks? Make sure your recommendation describes the severity of moonquakes as well as where and when a mission should land in order to best avoid them, citing evidence from your research.
B: Earth and the Solar System The solar system consists of the sun and a collection of objects, including planets, their moons, and asteroids that are held in orbit around the sun by its gravitational pull on them. Science and Engineering Practices Analyzing and Interpreting Data Analyzing data in 6—8 builds on K—5 experiences and progresses to extending quantitative analysis to investigations, distinguishing between correlation and causation, and basic statistical techniques of data and error analysis.
The first three were generally mild and harmless. Shallow moonquakes on the other hand were doozies. Between and , the Apollo seismic network saw twenty-eight of them; a few "registered up to 5. A magnitude 5 quake on Earth is energetic enough to move heavy furniture and crack plaster.
Furthermore, shallow moonquakes lasted a remarkably long time. Once they got going, all continued more than 10 minutes. On Earth, vibrations from quakes usually die away in only half a minute. The reason has to do with chemical weathering, Neal explains: "Water weakens stone, expanding the structure of different minerals. When energy propagates across such a compressible structure, it acts like a foam sponge—it deadens the vibrations.
The moon, however, is dry, cool and mostly rigid, like a chunk of stone or iron. Follow Charles Q. Choi on Twitter cqchoi. Follow us on Twitter Spacedotcom or Facebook. Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at: community space.
Charles Q. When the moon is at apogee, the unit area the Earth is acting on is actually greater. Mapping out which faults are active could be key to any future plans for a longer-term presence on the moon. And the reduced gravity could produce significant shaking from even a weak moonquake.
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