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NASA’s Webb finds carbon source on surface of Jupiter’s moon Europa

webbtelescope.org

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Re: NASA’s Webb finds carbon source on surface of Jupiter’s moon Europa

#31

Post by Auracle »

sgt wrote: post #26
abracadaniel wrote: post #24

Earlier quoted context omitted.

For comparison, the furthest we've dug down is about 8 miles, and Europa's ice crust is estimated to be 10-15 miles. So, yeah that would be like us getting discovered by mole people from nearly twice the depth we're capable of reaching. It's fun to think about what a civilization on Europa would think about their world. You can go up, but it gets colder and the pressure gets lower. It'd be like trying to go to space,…

No need to dig, you just melt yourself downwards. It's not exactly like digging through rocks on Earth.

Of course, barring collapse, the rocks won’t reform right above you as you go.

Re: NASA’s Webb finds carbon source on surface of Jupiter’s moon Europa

#32

Post by TaylorAlexander »

SoftTalker wrote: post #9
icapybara wrote: post #7

Earlier quoted context omitted.

There’s an image of Europa from Webb in the article.

It's less clear than I'd expected. Is that image deliberately downscaled so as to not reveal the true capabilities of the telescope optics?

Webb has two main instruments and one of them is not very high resolution (but I think it’s the one that gets good spectral data). When you browse the raw Webb images on the nasa website you see a mix of high res and low res images and they are each attributed to one of the two instruments.

Re: NASA’s Webb finds carbon source on surface of Jupiter’s moon Europa

#36

Post by finite_depth »

jl6 wrote: post #28
slg wrote: post #14

This is obviously a ginormous leap from this announcement and just a tangent sparked by it. The possibility of intelligent life developing on a world like Europa encrusted with what is effectively a miles think solid atmosphere has always been one of my favorite feasible sci-fi hypotheticals. Could you imagine how that would impact their culture? Would they even know there is anything on the other side of the ice? Th…

The relevant sci-fi is the planet of Krikkit from the 3rd Hitch-Hikers book, Life, the Universe, and Everything . On that world, life evolved under a permanent blanket of cloud. At no point did they ever see the stars, or think that there might be something of interest above them. Until one day they sent up a rocket which penetrated the dust cloud, and for the first time they became aware of the rest of the universe.…

[dead]

Re: NASA’s Webb finds carbon source on surface of Jupiter’s moon Europa

#37

Post by spookie »

whoisthemachine wrote: post #27
micromacrofoot wrote: post #23

An aside, but hovering over the image only to have it obscured... and then smaller on click, is a little comical.

And then if you click on "Expand" (after clicking on the click which makes it smaller), it is restored to its original size.

We might have discovered carbon below 10km of ice on another celestial body, but we still cannot make sense of magic smoke.

Re: NASA’s Webb finds carbon source on surface of Jupiter’s moon Europa

#38

Post by dotnet00 »

SoftTalker wrote: post #9
icapybara wrote: post #7

Earlier quoted context omitted.

There’s an image of Europa from Webb in the article.

It's less clear than I'd expected. Is that image deliberately downscaled so as to not reveal the true capabilities of the telescope optics?

You can probably even find the raw data for the image on one of NASA's sites soon if not already available. This isn't a spy satellite where there's a strategic need to hide the capabilities of the optics. If anything, it's more valuable to show off the capabilities because of how it's somewhat of a prestige project.

Re: NASA’s Webb finds carbon source on surface of Jupiter’s moon Europa

#39

Post by LeifCarrotson »

SoftTalker wrote: post #9
icapybara wrote: post #7

Earlier quoted context omitted.

There’s an image of Europa from Webb in the article.

It's less clear than I'd expected. Is that image deliberately downscaled so as to not reveal the true capabilities of the telescope optics?

No, they're quite open about the capabilities of the optics (see https://webb.nasa.gov/content/forScientists/faqScientists.ht...). It's just that Europa is very far away.

Webb's mirror system has an angular resolution of about 0.1 arcseconds. Earth is currently about 630 million km from Europa (Webb is only 1.5 million km away from earth). Because the sine of theta is approximately equal to theta for values of theta near zero, you can get the diameter of a 0.1 arcsecond cone at x km from Earth by multiplying by 0.00000485 = sin(2pi/3603600).

0.1 0.00000485 * 630000000 = 305 km

The article says the pixels are about 320 km, so the math works out pretty close (for astronomy).

Those magnificent images of black holes and galaxies that are way more distant, but also way way bigger. This isn't downscaled when you compare it to gorgeous, sharper images like those at [1], a 340 light-year wide multi-image mosaic of the Tarantula Nebula, which is "only" 161000 light years away, that width is 1/500th the distance and Europa's width is 1/20,000th the distance.

In space, intuition about distances that you've built up from using your eyeballs on human-scale terrestrial objects just doesn't work, you've got to do the math.

[1]: https://www.nasa.gov/feature/goddard/2022/a-cosmic-tarantula...

Re: NASA’s Webb finds carbon source on surface of Jupiter’s moon Europa

#40

Post by dotnet00 »

sph wrote: post #25
steve1977 wrote: post #2

“All these worlds are yours - except Europa. Attempt no landing there.” You have been warned guys… ;)

Honestly, the only thing I wish to see before I die is a submarine mission to Europa or Ganymede. It would be even more mind blowing and an amazing achievement for humanity, and the search for extraterrestrial life. That, and the dragonfly-helicopter-thing on Titan. Have you ever seen the Sun set on a methane lake? It's time for a rewatch of Europa Report (2013).

It's such a shame that the lander component of Europa Clipper got cancelled.
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