Now Mars is pulsing 3 times per night in the UV, can anyone explain these waves in simple terms? Do these waves happen on Earth?

I link below to questions on another kind of Mars pulse) Phys.org's NASA's Maven observes Martian night sky pulsing in ultraviolet light links to the new paper Imaging of Martian Circulation Patterns and Atmospheric Tides Through MAVEN/IUVS Nightglow Observations in Journal of Geophysical Research: Space Physics.

This seems to be related to long period of waves in Mars' atmosphere.

Question:

1. Is it possible to explain in simple terms what makes these waves happen?
2. Is a similar or at least related wave phenomenon detectable in Earth's atmosphere?

A different (and currently unanswered) question about a different periodic behavior in Mars' atmosphere:

• I haven't found anything about pulsations in UV, but the night glow also occurs on Earth & Venus. The night glow was first discovered on Mars by ESA's Mars Express probe in 2003. – Fred Aug 7 '20 at 3:19
• @Fred thanks! Whatever these waves are, all that's necessary to address item 2) is some evidence that similar waves are seen on Earth. – uhoh Aug 7 '20 at 4:31
• A Wikipedia artciel on airglow may partly explain part 1 of the question: en.wikipedia.org/wiki/Airglow – user20217 Aug 7 '20 at 9:25

The Martian nightglow comes from molecules in the atmosphere that react with solar radiation, carry it over to the night side, and give off the energy they gained as ultraviolet light as they free-form stable compounds. From https://www.nasa.gov/press-release/goddard/2020/mars-nightglow:

The diagram explains the cause of Mars’ glowing nightside atmosphere. On Mars’ dayside, molecules are torn apart by energetic solar photons. Global circulation patterns carry the atomic fragments to the nightside, where downward winds increase the reaction rate for the atoms to reform molecules. The downwards winds occur near the poles at some seasons and in the equatorial regions at others. The new molecules hold extra energy which they emit as ultraviolet light. Credits: NASA/MAVEN/Goddard Space Flight Center/CU/LASP

The Martian nightglow has been used to trace atmospheric circulation on Mars.

As for a similar phenomenon on Earth, and for that matter on planets generally, the above NASA reference goes on to say:

Many planets including Earth have nightglow, but MAVEN is the first mission to collect so many images of another planet’s nightglow.

• I've broken the question up into two parts; 1) Is it possible to explain in simple terms what makes these waves happen? and 2) Is a similar or at least related phenomenon detectable in Earth's atmosphere? I don't see anything yet that addresses this wave phenomenon on Mars or on Earth. Is it possible to at least find something that Earth's night glow also pulses due to a related wave phenomenon? That would at least address 2). – uhoh Aug 7 '20 at 1:56

I will try to keep it a simple and short answer.

1. Is it possible to explain in simple terms what makes these waves happen?

The combination of solar activity (solar wind), Mars atmosphere and what is left of Mars magnetosphere.

1. Is a similar or at least related phenomenon detectable in Earth's atmosphere?

Yes actually there is one called Aurora Borealis or Northern lights.

In addition ask yourself another question since the Mars effect is in the UV zone thus above the visible (by humans) EM spectrum.

How would Earth look like under the "eyes" of an Ultraviolet Imaging Spectrograph?

I have not found any images related to that question, so i would say that i would expect to see something in the UV zone in Earth also.

Furthermore i think you will find interesting that there is also a similar effect in Saturn. One of the many findings of Cassini's mission.

EDIT

Trying to answer the following question that became for me more clear after a relative comment.

Why Mars has this behavior and is pulsing 3 exactly times per night?

I have a theory for that phenomenon which i don't know if you will find it accepted as an answer. So here goes...

I think the atmosphere in Mars acts like a giant capacitor that discharges at regular times at the UV spectrum area. How is this possible? Some facts to base the theory:

Mars atmosphere is thin.

The atmosphere of Mars is about 100 times thinner than Earth's (source: space.com), and it is 95 percent carbon dioxide. Here's a breakdown of its composition, according to a NASA fact sheet:

• Carbon dioxide: 95.32 percent
• Nitrogen: 2.7 percent
• Argon: 1.6 percent
• Oxygen: 0.13 percent
• Carbon monoxide: 0.08 percent
• Also, minor amounts of: water, nitrogen oxide, neon, hydrogen-deuterium-oxygen, krypton and xenon

At this point we have to insert into our logic the term Dynamic Equilibrium. The most common example of a Dynamic Equilibrium is something that happens in a closed can of soda. What is that? The balance between the following reactions per second:

• H2CO3 → CO2 + H2O
• CO2 + H2O → H2CO3

The above facts indicate that there is not much material to recycle in the chain presented in the image below:

And in order to keep the Dynamic Equilibrium between the gases in the Martian atmosphere there must be a reaction of NO becoming back to NO2, that occurs at the same time in some other part of the planet, such as this one:

2 NO + O2 → 2 NO2

(just remember 0.13% O2, 2.7% N2 exist in Martian atmosphere, Oxygen found in Martian Fe2O3 AKA rust is not counted - but it is a good clue that Mars had once Oxygen and Iron at surface levels)

Last but not least Mars magnetosphere could be one of the reasons. Why? First of all a Geographical map of the Martian crustal magnetic fields based on the spherical harmonics model by Morschhauser et al. [2014] at 200 km altitude, created from MGS MAG/ER data. The map is centered on the antimeridian with labels showing east longitude for a uniformly spaced 30 • grid. Contours show zero altitude relative the areoid

Despite the fact that Mars no longer has an internal dynamo capable of generating a large global magnetic field as on Earth, there is evidence to suggest that Mars may once have had such a dynamo. This is mainly supported by observations from the American satellite mission MGS (Mars Global Surveyor), which from 1997 to 2006 measured the magnetic field of Mars using a small magnetometer from an altitude of 100-400 km above the planet’s surface. These measurements showed the existence of powerful magnetic crustal fields on the planet’s surface, far more powerful than those found on Earth.

The presence of these crustal fields gives rise to local mini-magnetospheres, i.e. small areas where the lines of the magnetic field locally protect the planet surface from electrically charged particles. Mini-magnetospheres occur when a magnetic field line is connected to two different points on the Martian surface, thus creating a kind of bubble. Between these ‘bubbles’, one end of the magnetic field lines can be connected to the planet and the other to the interplanetary magnetic field (IMF). (source: Mars’ magnetic field)

If all off the above are correct (i hope i did not forget to mention anything more) then this phenomenon could occur periodically (3 times per night) and at certain geographical regions, simply because it is following a cycle of events

• +1 but I'm afraid this post is so "simple and short" that it does not rise to the level of an answer. I haven't asked what makes UV light, I've asked how the waves that modulate the light are produced. It's the "pulsing 3 times per night" behavior that is so curious, and is what I've asked about. – uhoh Aug 11 '20 at 21:46
• @uhoh i think now is more clear :). I am not able to provide a solid answer on that meaning of having some sort of reference to it. I like to check out an idea/theory that could be the origin but i need to read and search first, and come back to edit my answer. The idea has to do with a question, among others, is Mars atmosphere thin? In addition i see in the image provided in the above answer that the UV lights are a product of a "cycle" of certain gases. Mars has magnetic field only in the Southern hemisphere. Last but not least the term "Dynamic Equilibrium" rings a bell also. – user19169 Aug 11 '20 at 22:15
• Okay thank you for looking into this! – uhoh Aug 11 '20 at 23:31
• Thanks for all of your work! At first I was concerned by the phrase "Last but not least Mars magnetosphere could be one of the reasons..." because I'd thought that except for the small, local multipole fields near the surface there was no large-scale field. But it turns out that Mars has a weak induced field: Mars Does Have a Magnetic Field of Sorts – And We've Finally Got Data to Map It – uhoh Aug 21 '20 at 3:47
• – uhoh Aug 21 '20 at 3:49