<p>I have data of a Jupiter's image and the spectra of each pixel in the image, and I am playing around to see what I can do with it.</p>
<p>I have managed to find Jupiter's rotational velocity by finding the difference between the wavelengths of H-<span class="math-container">$\alpha$</span> line of two pixels one at the centre and another at the edge of Jupiter's data cube.</p>
<p>I have also managed to identify a few spectral emission lines of Jupiter's red spot.</p>
<p>Is it possible to do something similar and find the orbital velocity, or the distance between Earth and Jupiter?  Or is there anything else that a spectrum of Jupiter can tell us?</p>

CC BY-SA 4.0
2020-10-05T06:03:02.760Z
Whatever you extract has to be an intrinsic property of Jupiter, so forget anything "relative" such as orbital velocity. Of course the collected light can be put in relation to distance to the source, but for this one must know or postulate the brightness of the source. It is not the case, at least without mixing various previous knowledge. In general, absolute intensity is not a real spectroscopical feature.
Alchimista
CC BY-SA 4.0
2020-10-05T07:42:07.227Z
There might be some sort of dispersive effect that can tell you something about the Earth's atmosphere, or vice versa. In fact, unless I'm mistaken, theoretically you could infer the distance based on the dispersion, but I'm not sure how accurately based on the resolution of your data!
Dagelf
CC BY-SA 4.0
2020-10-06T09:57:45.747Z
@Dagelf If there *was* some hypothetical "dispersive effect" from the Earth's atmosphere (leaving aside what that's supposed to mean), the most you could learn would be "Jupiter is somewhere beyond the Earth's atmsophere".
Peter Erwin
CC BY-SA 4.0
2020-10-06T10:00:36.900Z
Depending on the absolute accuracy of your wavelength calibration, you could measure the radial velocity of Jupiter relative to the Earth from the Doppler shift of Jupiter's emission line, but that's only part of the full orbital velocity vector.
Peter Erwin
CC BY-SA 4.0
2020-10-21T04:46:00.700Z
@PeterErwin Why do you say "hypothetical"? Doesn't light always disperse when it enters a medium with a different density, because the different wavelengths are slowed down at different rates? Are you saying that it has only to do with the angle, and nothing to do with the distance?
Dagelf
<jupiter><spectra>
What can Jupiter's spectrograph tell us other than its rotational velocity?
Blue Man
# What can Jupiter's spectrograph tell us other than its rotational velocity?

(Asked by: username_0 on 2020-10-05)

I have data of a Jupiter's image and the spectra of each pixel in the image, and I am playing around to see what I can do with it.

I have managed to find Jupiter's rotational velocity by finding the difference between the wavelengths of H-$\alpha$ line of two pixels one at the centre and another at the edge of Jupiter's data cube.

I have also managed to identify a few spectral emission lines of Jupiter's red spot.

Is it possible to do something similar and find the orbital velocity, or the distance between Earth and Jupiter? Or is there anything else that a spectrum of Jupiter can tell us?

**Tags:** jupiter, spectra

> **Comments:**
> **username_1**: Whatever you extract has to be an intrinsic property of Jupiter, so forget anything "relative" such as orbital velocity. Of course the collected light can be put in relation to distance to the source, but for this one must know or postulate the brightness of the source. It is not the case, at least without mixing various previous knowledge. In general, absolute intensity is not a real spectroscopical feature.  
> **username_2**: There might be some sort of dispersive effect that can tell you something about the Earth's atmosphere, or vice versa. In fact, unless I'm mistaken, theoretically you could infer the distance based on the dispersion, but I'm not sure how accurately based on the resolution of your data!  
> **username_3**: @username_2 If there *was* some hypothetical "dispersive effect" from the Earth's atmosphere (leaving aside what that's supposed to mean), the most you could learn would be "Jupiter is somewhere beyond the Earth's atmsophere".  
> **username_3**: Depending on the absolute accuracy of your wavelength calibration, you could measure the radial velocity of Jupiter relative to the Earth from the Doppler shift of Jupiter's emission line, but that's only part of the full orbital velocity vector.  
> **username_2**: @PeterErwin Why do you say "hypothetical"? Doesn't light always disperse when it enters a medium with a different density, because the different wavelengths are slowed down at different rates? Are you saying that it has only to do with the angle, and nothing to do with the distance?  

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