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Mars Rover Spots Clouds Shaped By Gravity Waves (sciencemag.org)

Posted by BeauHD on from the ripples-in-spacetime dept.

sciencehabit writes from a report via Science Magazine: NASA's Curiosity rover has shot more than 500 movies of the clouds above Mars, including the first ground-based view of martian clouds shaped by gravity waves, researchers reported this week at the Lunar and Planetary Science Conference. The shots are the best record made so far of a mysterious recurring belt of equatorial clouds known to influence the martian climate. Understanding these clouds will help inform estimates of ground ice depth and perhaps recurring slope lineae, potential flows of salty water on the surface, says John Moores, a planetary scientist at York University in Toronto, Canada, who led the study with his graduate student, Jake Kloos. "If we wish to understand the water story of Mars's past," Moores says, "we first need to [separate out] contributions from the present-day water cycle." Using Curiosity's navigation camera, Moores and Kloos recorded eight-frame movies of this wispy cloud belt for two martian years. They've used two angles to capture the clouds: one pointed directly up, to see wind direction and speed, and another that keeps the rover's horizon in the frame, allowing a view into the clouds' depth. Given the limited water vapor, solar energy, and atmosphere, the martian clouds lack the variety of shapes seen on Earth. But during one day of cloud gazing -- Curiosity's 1302th martian day, to be precise -- the team got lucky and saw something unusual. That day, when Curiosity looked to the horizon, it saw a sequence of straight, parallel rows of clouds flowing in the same direction: the first ground-based view of a gravity wave cloud. Similar to the waves that follow a pebble tossed into a pond, gravity waves are created when some unknown feature of the martian landscape causes a ripple in the atmosphere that is then seen in clouds. Such waves are common at the edge of the martian ice caps, but thought to be less frequent over its equator.

56 comments

  1. Gravity waves, really? by dschiptsov · · Score: 1

    And the reason why we do not have those gravity waves here on Earth is?

    1. Re:Gravity waves, really? by Calydor · · Score: 4, Insightful

      We probably do, but our atmosphere is so many times more active than that of Mars that any effect by gravity waves is drowned out (heh) by all the other things happening at the same time - air pressure, air humidity, wind etc.

      --
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    2. Re:Gravity waves, really? by Anonymous Coward · · Score: -1

      N1ggers will steal anything.

    3. Re:Gravity waves, really? by Wytter · · Score: 5, Informative

      The gravity wave phenomena as used in meterology have very different length scales than gravity waves in general relativity. It's a different phenomena, same name. And these type of gravity waves also shape the clouds on earth. https://en.m.wikipedia.org/wik...

    4. Re:Gravity waves, really? by Anonymous Coward · · Score: 1

      We do, undular bores for example.

      Note that fluid dynamics' gravity waves (what's discussed here) and relativity's gravitational waves (e.g. as detected by LIGO) are two entirely different things.

    5. Re:Gravity waves, really? by michelcolman · · Score: 5, Informative

      This is not the cosmological kind of gravity waves (the ones we are building complex detectors for that have been in the news during the last few years) but a much more down to earth, I mean Mars, weather phenomenon. Happens on earth all the time, not really that special. Probably only made the news because of confusion with the other kind of GW,

    6. Re:Gravity waves, really? by Anonymous Coward · · Score: -1

      They are *gravitational* waves (as they are known in fluid dynamics).
      We have clouds that do that here on earth too.
      Not *gravity* waves.
      The author of the original article appearantly didn't know the difference or didn't care, but they are indeed very different things.

    7. Re: Gravity waves, really? by oobayly · · Score: 1

      We do - do an image search for gravity waves satellite photo.

      Admittedly, the only reason I know is from a Rogue NASA tweet. I couldn't understand how you could see them until I realised I was getting them confused with gravitational waves.

    8. Re:Gravity waves, really? by Anonymous Coward · · Score: 0

      You got it wrong, but don't worry because it means that the author got it wrong twice. What a loser!

    9. Re: Gravity waves, really? by Anonymous Coward · · Score: 0

      It's further away from the Sun and we only have one moon. Lots of ocean to affect weather conditions too. So, we wouldn't get anything like that unless the poles shifted instantaneously or the moon stopped orbiting.

    10. Re:Gravity waves, really? by Chrisq · · Score: 1

      We do. All you need to do to see them is go to the ocean or a reasonably large lake. These are not gravitational waves, simply waves in a fluid surface under gravity.

    11. Re: Gravity waves, really? by Anonymous Coward · · Score: 1

      This is more like cloudy tidal waves, nothing to do with gravitons.

    12. Re:Gravity waves, really? by arobatino · · Score: 4, Informative

      They are easily detectable on earth - for example see here (picture here). They've also been detected in the atmosphere of Venus, which has winds over 200 miles per hour.

    13. Re:Gravity waves, really? by logpoacher · · Score: 4, Informative
      Gravity_wave - fluid dynamics phenomenon

      Gravitational_wave - General Relativity

      Wikipedia does not constitute proof, but it's probably right in this case.

    14. Re:Gravity waves, really? by BitZtream · · Score: -1

      We do.

      The difference is we refer to them by their actual name:

      Compression waves

      Gravity has absolutely 0 to do with them and calling them gravity waves just makes you look stupid.

      --
      Persistent Volume manager for Kubernetes - https://github.com/dwimsey/openshift-pvmanager
    15. Re:Gravity waves, really? by pscottdv · · Score: 1

      "Gravity Wave", here, means a wave wherein the restoring force is gravity, such as waves on the ocean. It is not the same as the cosmological gravity waves caused by coalescing black holes sought by the LIGO experiment.

      --

      this signature has been removed due to a DMCA takedown notice

    16. Re:Gravity waves, really? by Tim+the+Gecko · · Score: 2

      It's a different phenomena, same name.

      It's not even the same name. To quote the same article

      This article is about the movement of fluids. For the phenomenon of general relativity, see gravitational wave.

    17. Re: Gravity waves, really? by Anonymous Coward · · Score: 1

      You're pretty much completely wrong. Gravity waves is a name that has been around for nearly a century in multiple fields for cases where gravity is the dominant restoring force for the wave, including large oscillations in flow without compression in air and in incompressible liquids. That has nothing to do with compression, hence why they are not called compression waves...

    18. Re:Gravity waves, really? by Falconhell · · Score: 1

      Lee waves are used by gliders to reach great heights, they result from mountain ranges (forming lenticular clouds) , and at the edges of different air masses..

      Standing waves ocour too, the Morning Glory wave is caused by the collision of two airmass.

      The cloud streets, form when the wind aligns rows of Cumulus clouds, which then form the "mountain" that triggers a wave in the atmosphere above. This is known as thermal wave, and can at times be seen in the form of a Pilious cloud.

      Strong wind shears can induce waves too, often of higher frequency. (Think high altitude Herring bone cloud) Increasing wind speed with altitude also helps the waves form and propagate, in some cases the wave is over 3 wavelengths long before dissipating.

      The Perlan project has been trying for some time to reach very high altitudes on Earth, using the polar vortex, to reach a pressure zone similar to Mars atmosphere.

    19. Re:Gravity waves, really? by dbIII · · Score: 1

      We do. It turns out that the term is used for two different things and this is the atmospheric physics use of the term instead of the gravitational physics use.

    20. Re:Gravity waves, really? by Anonymous Coward · · Score: 0

      WE do have them, you just dont pay attention.

    21. Re: Gravity waves, really? by Anonymous Coward · · Score: 0

      cloudy tsunamis?

  2. Ruling out all magnetic anomalies? by Anonymous Coward · · Score: -1

    They captured a ripple in the clouds. Inferring that it was caused entirely by "gravity" from "some unseen anomaly" sounds like there might be other possibilities.

    1. Re:Ruling out all magnetic anomalies? by Anonymous Coward · · Score: 0

      It is caused by gravity, and the source of the gravity is Mars. "Gravity Waves" are what we old-schoolers used to call "Waves". Air goes over a mountain or ridge, and oscillates up and down for a while.

      The "unseen anomaly" is a hill or valley. Not that anomalous, really.

      It's a bit like dropping a glass and calling it a "gravity fall".

  3. Gravity waves != gravitational waves by Anonymous Coward · · Score: 5, Informative

    Just a reminder: the gravity waves (waves resulting from gravity restoring an equilibrium) discussed in the article are different from gravitational waves (wave functions describing gravity itself).

    1. Re:Gravity waves != gravitational waves by dmgxmichael · · Score: 1

      Just a reminder: the gravity waves (waves resulting from gravity restoring an equilibrium) discussed in the article are different from gravitational waves (wave functions describing gravity itself).

      In layman's terms it's the difference between waving at someone, and having a seizure. One is an external phenomena caused by gravity, the other is an internal (sorta) phenomena of gravity.

    2. Re:Gravity waves != gravitational waves by Zorpheus · · Score: 1

      So it is just the same as waves on water? Very interesting story then.

    3. Re: Gravity waves != gravitational waves by Anonymous Coward · · Score: 0

      Worst analogy ever ?

    4. Re: Gravity waves != gravitational waves by Tablizer · · Score: 0

      Let's see if I got this straight:

      Cloud particles gravitationally pull on each other such that if there is a disturbance in their movement, ripples form in the attraction movement pattern somewhat similar to ripples on a pond after tossing in a pebble: the particles bunch up and then some other force (???) pushes them back apart after a period of time. What's this other force? (On a pond, the weight of the peak of the wave pushes it back down.)

      It seems we normally don't see these on Earth because our thicker atmosphere and magnetosphere overwhelm gravity's direct influence.

      If this is the case, I'm surprised Mars cloud particles (mostly dust and ice) would have enough gravitational influence on each other. It's really a small amount of mass, and rather defused. Thus, I think I am missing a piece of the puzzle.

      --
      Table-ized A.I.
    5. Re: Gravity waves != gravitational waves by Obfuscant · · Score: 1

      Let's see if I got this straight: Cloud particles gravitationally pull on each other

      No. At least not to any significant amount.

      It seems we normally don't see these on Earth because our thicker atmosphere and magnetosphere overwhelm gravity's direct influence.

      What is it you think that keeps our "thicker atmosphere" where it is if it isn't "gravity's direct influence"?

      Gravity waves are waves in something that are moderated by the force of gravity. E.g. regular waves at the beach are gravity waves. The properties depend directly on the difference in densities between the two layers in contact. For surface waves this is air/water. For subaqueous (or "internal") waves, it is a water/water interface.

      There are also infragravity waves. Those are waves created by wave-wave interactions that occur at frequencies very much below those of gravity waves. A surface gravity wave may have a period of 10-15 seconds. An infragravity wave may be 100-200 seconds in period. Think "sneaker".

      And while you might think that the ripples on the surface caused by wind are called "ultragravity" waves, they are actually called "capillary waves".

    6. Re: Gravity waves != gravitational waves by Tablizer · · Score: 1

      "Gravity waves" seems misleading or confusing. Maybe it stuck for historical reasons?

      Pond and sea waves involve multiple forces interacting in a rhythmic way. Labeling their cause as one force among multiple is problematic communication.

      --
      Table-ized A.I.
    7. Re: Gravity waves != gravitational waves by Obfuscant · · Score: 1

      "Gravity waves" seems misleading or confusing. Maybe it stuck for historical reasons?

      It stuck because it is accurate.

      Labeling their cause as one force among multiple is problematic communication.

      All scientific communities have their terminologies, and "gravity waves" is an accurate use of the words for fluid dynamics. It is not gravity that CAUSES the waves, it is gravity that moderates them.

    8. Re:Gravity waves != gravitational waves by Anonymous Coward · · Score: 0

      It's unfortunately that this distinct has to bespoke every time there's an articulate about gravitas waves. Gravity waves are a classy science topical, gravitational waves are a relatively tropic. This could be fixated if people acceptance that diffident words have diffeological meanings even if they have the same rutabaga.

  4. Gravity waves, eh? by Anonymous Coward · · Score: -1

    There is more bullshit coming from the astrophysics community than almost any other field of science. It's embarrassing.

    1. Re: Gravity waves, eh? by Anonymous Coward · · Score: 0

      I agree that astrophysicists tend to spout a lot of bullshit, but please see some of the above comments about the difference between gravity waves and gravitational waves.

  5. Who is making these small brown clouds? by Anonymous Coward · · Score: 0

    Who is making these clouds these days?

  6. Last time. by Anonymous Coward · · Score: -1

    The last time I heard of gravity waves shaping clouds was when your mum managed to fit in an Antanov and took her maiden voyage.

  7. No no no by Anonymous Coward · · Score: 0

    "It’s far from certain those are gravity waves, though, Heavens says. They could also be “cloud streets,” a similar looking pattern that’s potentially associated with strong winds striking heated air parcels as they near the top of the lower atmosphere."

    Occams razor says it's strong winds.

    They're seeing gravity waves everywhere now, even where they're not.

  8. TRUMP SHOULD HALVE NASA'S BUDGET by Anonymous Coward · · Score: -1

    Restore $5M to Meals-On-Wheels and increase military budget by $9,995B! The chinks and the rooskies are on the offensive, we have to sink them now not go prance in space!

    1. Re:TRUMP SHOULD HALVE NASA'S BUDGET by sTERNKERN · · Score: 1

      Just crawl back into your swamp where you came from.

    2. Re:TRUMP SHOULD HALVE NASA'S BUDGET by Anonymous Coward · · Score: 0

      How are we going to reach out to muslim nations?

  9. fu3k'er by Anonymous Coward · · Score: -1

    in

  10. Score:-5, Pwned by Anonymous Coward · · Score: 1

    Witness BitZtream getting pwned!

  11. OUCH! by Anonymous Coward · · Score: 1

    Damn, that's embarrassing!

    1. Re:OUCH! by Wulf2k · · Score: 1

      Would a properly maintained hosts file have helped prevent this from happening to him?

  12. Possibly... by hwk_br · · Score: 1

    FTFA: "It’s far from certain those are gravity waves, though."

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    \m/
  13. I am confused by 140Mandak262Jamuna · · Score: 0
    Don't we call these things tidal forces? When large masses (like our Moon) moves, its gravitational influence also moves along with it. That changes the graviatational effects on other bodies near by. The general term used for this is Tidal forces. Because the ocean tides are the most common and observed phenomena due to this.

    Gravitational waves on the other hand are extremely hard to observe, and they do not involve moving large massive bodies locally.

    --
    sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
  14. "Curiosity's 1302th martian day, to be precise" by Anonymous Coward · · Score: 0

    "Curiosity's 1302th martian day, to be precise" is the best example of precision versus accuracy I've ever read on Slashdot.

  15. It's bitztream by Anonymous Coward · · Score: 0, Insightful

    The autism-hating, custom EpiPen-hating, Musk-hating Slashdot troll!

  16. Fake Science by frovingslosh · · Score: -1, Troll

    I doubt that anyone here reading this (except maybe the snowflakes) believes the "clouds shaped by gravity waves"claim. No wonder they are losing funding, and NASA has no one to blame except themselves.

    --
    I'm an American. I love this country and the freedoms that we used to have.
    1. Re:Fake Science by Tablizer · · Score: 0

      Mars is a yuuuge commie plot funded by the UK secret police and Hollywood gangsters, who film all the fake rovers in Lena Dunham's basement.

      --
      Table-ized A.I.
    2. Re:Fake Science by wonkey_monkey · · Score: 1

      Why is it so unlikely?

      --
      systemd is Roko's Basilisk.
  17. Gravy ... not gravity waves by Anonymous Coward · · Score: 0

    More likely the Martian head-chef was brewing some Venusian sulfur-stew when a Romulian-fly pricked his ladle-hand. Oops go the striations ... but unknown? Dick + Jane = grant

  18. Time crystals and now gravity waves?! by edi_guy · · Score: 0

    What's the next research to get super-excited about only to find out it's "Not what you thought it was." ?

  19. So by BitztreamNotARealNam · · Score: 1

    How's life in the hypocrite lane?

  20. Second not twooth by Anonymous Coward · · Score: 0

    1302th

    1302nd