How to interpret this new Keck spectrum picture of Jupiter?

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Discussion Overview

The discussion revolves around the interpretation of a newly captured spectrum of Jupiter using a next-generation spectrometer. Participants express confusion regarding the apparent complexity of the spectrum, which seems to indicate the presence of many elements, despite the known composition of Jupiter being primarily hydrogen and helium. The conversation explores the implications of spectral lines and the methods used to analyze such data.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants express confusion about the spectrum showing many elements when Jupiter is primarily composed of hydrogen and helium.
  • Others clarify that while there are not hundreds of elements, there can be hundreds of spectral lines from various compounds and elements present in Jupiter's atmosphere.
  • A participant suggests that the spectrometer may be capable of measuring atmospheric components in the part-per-million range.
  • There is a discussion about the difference between qualitative and quantitative analysis in interpreting the spectrum.
  • Some participants note that each absorption line does not correspond to a single element or compound, as multiple lines can be generated by each element or compound.
  • Questions arise about the ability of scientists to extract types and concentrations of elements from the spectrum, with references to historical developments in spectroscopy.
  • One participant mentions that the spectrum is likely a reflection of sunlight modified by Jupiter's atmosphere.
  • There is a mention of the historical context of spectroscopy, including early observations and discoveries related to spectral lines.

Areas of Agreement / Disagreement

Participants generally agree that the spectrum reflects a complex interaction of various elements and compounds in Jupiter's atmosphere, but there is no consensus on the exact interpretation of the spectrum or the number of elements present. The discussion remains unresolved regarding the specifics of how to analyze and interpret the spectral data.

Contextual Notes

Some limitations in the discussion include assumptions about the nature of spectral lines and the complexity of the spectrum, as well as the dependence on the definitions of elements and compounds in the context of atmospheric analysis.

Dave Gungan
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Last night, on Wednesday, November 9, the KPF team successfully captured a first light spectrum of Jupiter with the next-generation instrument

This spectrometer picture of Jupiter has just been taken by the Keck, but I don't understand it. Wiki says Jupter is "89%±2.0% hydrogen" and
"10%±2.0% helium", but that spectrometer picture looks like Jupiter has 100s of element in it, if each of those blank bits are separate elements? Could someone please clarify my confusion.

The original atricle I found the picture from this at phys.org
 
Astronomy news on Phys.org
Dave Gungan said:
Last night, on Wednesday, November 9, the KPF team successfully captured a first light spectrum of Jupiter with the next-generation instrument

This spectrometer picture of Jupiter has just been taken by the Keck, but I don't understand it. Wiki says Jupter is "89%±2.0% hydrogen" and
"10%±2.0% helium", but that spectrometer picture looks like Jupiter has 100s of element in it, if each of those blank bits are separate elements? Could someone please clarify my confusion.

The original atricle I found the picture from this at phys.org
If I had to guess, I would say that the spectrometer design is good enough to measure atmospheric components in the part-per-million (ppm) range.
 
Dave Gungan said:
looks like Jupiter has 100s of element in it
There aren't 100's of elements. Just under 100 in nature.

There can, however, be hundreds of spectral lines.
 
OK, IDK, this is way above my pay grade. However, it seems like you are mixing qualitative analysis with quantitative analysis. Sure, there's 100's of things, but most of them may be just a few types.
 
Dave Gungan said:
This spectrometer picture of Jupiter has just been taken by the Keck, but I don't understand it. Wiki says Jupter is "89%±2.0% hydrogen" and
"10%±2.0% helium", but that spectrometer picture looks like Jupiter has 100s of element in it, if each of those blank bits are separate elements? Could someone please clarify my confusion.
Jupiter is composed of a great many things. It is mostly hydrogen and helium, but it also has other stuff. Per wiki:
Jupiter's upper atmosphere is about 90% hydrogen and 10% helium by volume. Since helium atoms are more massive than hydrogen molecules, Jupiter's atmosphere is approximately 24% helium by mass. The atmosphere contains trace amounts of methane, water vapour, ammonia, and silicon-based compounds. There are also fractional amounts of carbon, ethane, hydrogen sulfide, neon, oxygen, phosphine, and sulfur. The outermost layer of the atmosphere contains crystals of frozen ammonia. Through infrared and ultraviolet measurements, trace amounts of benzene and other hydrocarbons have also been found. The interior of Jupiter contains denser materials—by mass it is roughly 71% hydrogen, 24% helium, and 5% other elements.
All of these will show up in a spectrograph to some extent.

Also, note that each absorption line in a spectrum doesn't represent a single element or chemical compound. Each element or compound generates multiple lines, though not all of them always show up in the visible range.
 
So that's a perfectly normal spectrum for a body made of "mostly 1 or 2 elements"?

Edit: I realise they will be other elements in the planet of course, but do they really manifest as that many absorption lines?
 
Dave Gungan said:
So that's a perfectly normal spectrum for a body made of "mostly 1 or 2 elements"?

Edit: I realise they will be other elements in the planet of course, but do they really manifest as that many absorption lines?
Yep. Even the Sun's spectrum is complicated, despite also being composed of mostly hydrogen and helium and being too hot for most compounds to form:
sun_spectrum_lines_noao_900x600.jpg
 
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Wow thanks, thats changed my misconception of each atom only having 1 line as seen on tv shows, which i should have known better from warnings about sources I read here.

Can scientists actually pull out the types and concentrations of each atom from such a complicated picture? with AI learning perhaps?
 
Dave Gungan said:
Can scientists actually pull out the types and concentrations of each atom from such a complicated picture?
Sure. Been doing it for more than 150 years. See https://en.wikipedia.org/wiki/Spectroscopy

Dave Gungan said:
with AI learning perhaps?
Nope. This predates AI. This predates computers.
 
  • #10
Thanks I didnt realise it was so old.

Could anyone make a guess how many elements in the OP please? I'm curious just how good this new spectrometer is.
 
  • #12
Dave Gungan said:
Can scientists actually pull out the types and concentrations of each atom from such a complicated picture? with AI learning perhaps?

Vanadium 50 said:
Nope. This predates AI. This predates computers.
Indeed. Joseph von Fraunhofer first observed dark lines in the Sun's spectrum around 1814, which was about a decade before photography was invented. 'Proper' spectroscopy began in 1859, when Gustav Kirchhoff and Robert Bunsen (the inventor of the lab device now called a 'Bunsen Burner') discovered the cause of the dark lines in stellar spectra and then identified 16 elements in the Sun's spectrum over the next few years.

Dave Gungan said:
Wow thanks, thats changed my misconception of each atom only having 1 line as seen on tv shows, which i should have known better from warnings about sources I read here.
Each atom can have potentially a great many spectra lines, as each line corresponds to a transition between two particular electronic states, commonly described as electrons moving between energy levels. Hydrogen has 4 lines in the visible spectrum, but many more outside of that. Here's an image with many of them:
500px-Hydrogen_spectrum.svg.png

Note that this is only for a single atom with only a single electron. Atoms with multiple electrons have far more complicated spectra. Iron itself is known to have around 37,000 spectral lines (Part 7 in this paper), of which about 25,000 have been identified and categorized.

Edit: Just a piece of trivia, but did you know that the spectral lines of helium were observed in the Sun's spectrum before helium was ever discovered? The discovery of these lines spurred an investigation from the 1860's to the 1890's when helium was finally isolated in 1895. So, in effect, helium was discovered in the Sun before it was discovered on Earth. Hence its name, helium, after helios, which is the Greek word for Sun.
 
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  • #13
I maybe missing something but won't the spectrum be of reflected sun light? So it will show the solar spectrum with some modifications due to the refective properties of Jupiter's atmosphere.
Regards Andrew
 
  • #14
andrew s 1905 said:
I maybe missing something but won't the spectrum be of reflected sun light? So it will show the solar spectrum with some modifications due to the refective properties of Jupiter's atmosphere.
Regards Andrew
Yes, that makes sense to me. I'm guessing that the Sun's spectrum can be 'subtracted' from Jupiter's or something in order to get the actual spectrum of Jupiter though.
 
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