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NASA’s InSight detects Phobos using its seismometer during solar eclipses

ethz.ch

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Re: NASA’s InSight detects Phobos using its seismometer during solar eclipses

#4

Post by sambroner »

Very neat article. Nasa and ETH Zurich noticed the Martian moon Phobos during the eclipse using a seismometer. The effect is tiny, but their hypothesis is that this is caused by the top level of ground rapidly cooling. The effect can be used to determine the material of the ground. Separately, this can help determine Phobos' orbit more accurately.

> “This tilt is incredibly small,” Stähler notes. “Imagine a 5- franc coin; now, push two silver atoms under one edge. That’s the incline we’re talking about: 10-8.” As slight as this effect was, it was still unmistakable.

Re: NASA’s InSight detects Phobos using its seismometer during solar eclipses

#6

Post by natcombs »

sambroner wrote: post #4

Very neat article. Nasa and ETH Zurich noticed the Martian moon Phobos during the eclipse using a seismometer. The effect is tiny, but their hypothesis is that this is caused by the top level of ground rapidly cooling. The effect can be used to determine the material of the ground. Separately, this can help determine Phobos' orbit more accurately. > “This tilt is incredibly small,” Stähler notes. “Imagine a 5- franc…

That is incredible sensitivity. How does one calibrate something, or also not suspect the instrument is affected by other environmental variables?

Re: NASA’s InSight detects Phobos using its seismometer during solar eclipses

#7

Post by sambroner »

dreen wrote: post #5

Considering the Moon could have a similar (but stronger due to totality) effect on Earth during a Solar eclipse, could the Moon cause an earthquake?

This seems to be caused by heat, not the gravity. The article includes a story about a lamp being left on in a mine that caused enough thermal expansion to be measured by a seismometer.

Presumably the solar eclipse could be measured as well.

Re: NASA’s InSight detects Phobos using its seismometer during solar eclipses

#8

Post by dreen »

sambroner wrote: post #7
dreen wrote: post #5

Considering the Moon could have a similar (but stronger due to totality) effect on Earth during a Solar eclipse, could the Moon cause an earthquake?

This seems to be caused by heat, not the gravity. The article includes a story about a lamp being left on in a mine that caused enough thermal expansion to be measured by a seismometer. Presumably the solar eclipse could be measured as well.

I did mean the heat, not gravity. A Solar eclipse on Earth blocks all direct sunlight for about 10 minutes. My question is would that be enough to cause an earthquake, by suddenly cooling an area of the planet.

I also realise the night blocks sunlight for way longer, but maybe this is different because the effect is spread out. During eclipse we have the planet all around the area of eclipse heated up and a comparatively small area not being heated in the middle.

Re: NASA’s InSight detects Phobos using its seismometer during solar eclipses

#9

Post by macintux »

dreen wrote: post #8
sambroner wrote: post #7

Earlier quoted context omitted.

This seems to be caused by heat, not the gravity. The article includes a story about a lamp being left on in a mine that caused enough thermal expansion to be measured by a seismometer. Presumably the solar eclipse could be measured as well.

I did mean the heat, not gravity. A Solar eclipse on Earth blocks all direct sunlight for about 10 minutes. My question is would that be enough to cause an earthquake, by suddenly cooling an area of the planet. I also realise the night blocks sunlight for way longer, but maybe this is different because the effect is spread out. During eclipse we have the planet all around the area of eclipse heated up and a comparati…

I suspect, without having any real clue, that you’d see greater localized extremes in temperature with a pop—up thunderstorm.

I’d have a hard time believing earthquakes could result from that (although the science & engineering in this article are enough to make me believe just about anything is possible).

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