Talk:Earth's magnetic field

Request removal of outdated passage about Mars's atmosphere

The sentence "Calculations of the loss of carbon dioxide from the atmosphere of Mars, resulting from scavenging of ions by the solar wind, indicate that the dissipation of the magnetic field of Mars caused a near total loss of its atmosphere." from the "Significance" section is obsolete (from 1992).

This article Atmospheric Escape states that the vast majority of atmospheric stripping on Mars is/was caused by other processes not related to the magnetic field at all. This is properly supported by the MAVEN mission to Mars the paper to which is cited in reference 15 https://doi.org/10.1016%2Fj.icarus.2018.05.030. — Preceding unsigned comment added by 2003:E5:F10:FE05:F556:C879:F05D:D6E (talk) 16:57, 29 December 2021 (UTC)

As this change has been reverted a second time I want to explain this more verbosely. The second source supposedly confirming this sentence has literally nothing to do with mars' magnetic field at all. The first source is very old and only describes an assumption that has been disproven by the MAVEN mission.

The graph on page 8 of the paper I've mentioned above clearly shows that sputtering, which is the only process of atmospheric loss that is mitigated by the magnetic field, only represents an insignificant fraction of the total loss. DOI : 10.1016/j.icarus.2018.05.030

The idea that the solar wind strips away planets' atmospheres with too little magnetic field is outdated but is still stubbornly clinging on in many places. Here is a lecture explaining the current state of the art of our understanding of magnetic field interactions with solar wind https://www.youtube.com/watch?v=s7yGeWUyMkg 2003:E5:F02:1CD5:CC50:2B1:F735:FEFB (talk) 21:54, 5 January 2022 (UTC)

I agree that there seems to be something missing in the most common explanation. Wikipedia articles are intended to be based mostly on paraphrasing reliable secondary sources. The sources that you propose seem to be mainly primary sources. Wikipedia editors do not have the competence to say that it is time to discard the old explanation and take up the new explanation. If the new explanation takes hold and filters down to reliable secondary sources, then we can paraphrase those sources. It does not belong in the introductory section of the article. However, I would have no objection to adding a section about recent new explanations. Constant314 (talk) 00:09, 6 January 2022 (UTC)

I can understand that reasoning, however, this information isn't new. The MAVEN mission was in 2016. This particular source has already been incorporated into other Wikipedia articles like Atmospheric Escape which correctly presents the information from said paper.
And this is by far not the only paper correcting this general misconception.
It is very easy to find lots of articles about this somewhat recent shift in perception.

https://eos.org/research-spotlights/how-marss-magnetic-field-let-its-atmosphere-slip-away
https://www.aeronomie.be/en/annual-report/does-earths-magnetic-field-protect-our-atmosphere
https://web.ua.es/docivis/magnet/earths_magnetic_field2.html
https://www.space.com/11187-earth-magnetic-field-solar-wind.html
https://earthscience.stackexchange.com/questions/14915/does-the-magnetic-field-really-protect-earth-from-anything

I think this misconception is partly also due to another confusion. The earth's magnetic field indeed indirectly protects us from harmful UV radiation. Without the magnetosphere, the solar wind would dismantle the ozone layer. So it protects stuff on the planet but not the atmosphere itself.

The only sources I can find that still confirm this old concept of mars losing its atmosphere because of its lost magnetic field actually cite Wikipedia as their source.

Furthermore, the article is about "Earth's magnetic field", so that section is just off-topic at best anyway.
2003:E5:F02:1CD5:CC50:2B1:F735:FEFB (talk) 01:31, 6 January 2022 (UTC)

Earth's magnetic field magnitude

Hi, the second paragraph states: The magnitude of Earth's magnetic field at its surface ranges from 25 to 65 μT (0.25 to 0.65 G) [3]

This seems to be outdated or incorrect, as the magnetic magnitude in South Atlantic can be as low as 22μT. Source 1: https://en.wikipedia.org/wiki/South_Atlantic_Anomaly Source 2: http://www.geomag.bgs.ac.uk/education/earthmag.html#_Toc2075549

Perhaps a specialist can review... THX.. Shaberer-en (talk) 13:10, 14 February 2024 (UTC)

Wikipedia is not a reliable source, and I was not able to find the value 22μT in the second source. Can you point out where it is in the second source? Constant314 (talk) 19:18, 14 February 2024 (UTC)

Hi Constant314,

Thx for your response, sorry for the delay in replying.

the second source states 22,000 nT (=22μT)

http://www.geomag.bgs.ac.uk/education/earthmag.html#_Toc2075549

same this one (approx middle):

https://www.esa.int/Applications/Observing_the_Earth/FutureEO/Swarm/Swarm_probes_weakening_of_Earth_s_magnetic_field

While this one states 22,500 nT:

https://www.frontiersin.org/articles/10.3389/feart.2016.00040/full

(this is reference #1 in https://en.wikipedia.org/wiki/South_Atlantic_Anomaly)

THX! Shaberer-en (talk) 10:43, 25 February 2024 (UTC)

I saw it this time in the bgs ref. Looks good. Make the change if you wish, Constant314 (talk) 15:20, 25 February 2024 (UTC)

thanx - my first update! Shaberer-en (talk) 13:49, 2 March 2024 (UTC)

GA concerns

I am concerned that this article no longer meets the good article criteria. Some of my concerns are listed below:

• There are uncited statements, including entire paragraphs.
• There are many sources listed in "Further reading". These should be considered for inclusion in the article or removed.

Is anyone interested in fixing up this article, or should it go to WP:GAR? Z1720 (talk) 08:31, 7 October 2024 (UTC)

GA Reassessment

Earth's magnetic field

Article (edit | visual edit | history) · Article talk (edit | history) · Watch • Watch article reassessment page • Most recent review

Result pending

There are a lot of uncited passages, including entire paragraphs. The sources listed in "Further reading" might be helpful for adding inline citations. Z1720 (talk) 15:28, 14 October 2024 (UTC)