Oceans on Mars

We were recently reading this story from NASA that says Mars used to have large oceans. It includes a tantalizing picture reminiscent of Google Earth. So we decided to see if we could simulate oceans in Google Mars.

We have looked at a number of stories in the past where people have used KML to simulate sea level rise:

However, it turns out this technique doesn’t work over large areas. KML polygons set to fixed altitude do not curve with the earth’s surface.

So, instead, we found a digital elevation model (DEM) map of Mars provided by NASA that can be obtained from here. We then used an image editing program to colour the lower elevations blue and make higher elevations transparent. We then took the resulting image and made an image overlay and you can see the result below:

Mars Ocean

For an even more realistic effect, we combined our ocean with this Mars map also from NASA. Then we used it in an image overlay on the Earth, instead of Mars, which enables us to turn on the ‘Clouds’ layer, giving the result seen below:

Mars Ocean and Clouds

The NASA image did not have clouds, but the picture on this Wikipedia page does. Without plants, the land would not have been green like much of the Earth is.

To try these out for yourselves, download these KML files: Mars Ocean
Mars Ocean and Land. The second one is best viewed with all layers turned off except the ‘Clouds’ layer (found in the ‘Weather’ layer).

The maps may not be scientifically accurate, as we don’t know whether the elevation data in the NASA maps takes into account the equatorial bulge that is created due to rotation. On Earth we usually calculate elevation above or below Sea Level, but that doesn’t work on Mars as it doesn’t have a sea.

About Timothy Whitehead

Timothy has been using Google Earth since 2004 when it was still called Keyhole before it was renamed Google Earth in 2005 and has been a huge fan ever since. He is a programmer working for Red Wing Aerobatx and lives in Cape Town, South Africa.

PLEASE NOTE: Google Earth Blog is no longer writing regular posts. As a result, we are not accepting new comments or questions about Google Earth. If you have a question, use the official Google Earth and Maps Forums or the Google Earth Community Forums.


  1. Equatorial Bulge does NOT occur due to rotation, but due to Moon’s Attraction! Compare with Venus (NO Moon, no bulge), and Jupiter (Maximum Moons, Maximum Bulge).

    • Timothy Whitehead says:
      • Wikipedia sometimes has it Wrong, since it depends upon the Contributor! Scanning the EQUATOR, the “Bulge” occurs at the TOP of the Owens Stanley Snowy Peaks to the Depths of the Pacific! Further, the South Pacific Islands are RISING (Vulcanism), while the Challenger Deep (-10 km, near Marianas) is SINKING!

    • Venus has no equatorial bulge because its rotation is so slow – it rotates once in 243 days. Jupiter, with an equatorial radius 11.2 times that of Earth, has the fastest rotation of any planet in the solar system – 9.841 hours, so naturally it has the largest equatorial bulge in the solar system. Jupiter’s moons total a tiny fraction of their planet’s mass and while the four Galilean moons might have some appropriately tiny effect on Jupiter, its equatorial bulge is, like Earth and Mars – and the other gas giant planets with their rapid spins – due to rotation.
      The Moon raises a water bulge on Earth – we all know that – but its gravitation effect on Earth’s crust is far less that the centrifugal force of the planet’s rotation.

      • Larger PATTERN reveals Ignored Information! Diurnal, Mixed, and Semiurnal TIDES occur with BULGE Categorization, where Simplest (Gulf of Mexico Diurnal) produces 2x {E-W}/(N-S)= Sun/Moon Tides! Coasts with CONVEX (facing East) Semidiurnal Tides exhibit KARST TOPIGRAPHY, such as China, Florida, and Yucatan. Karst produces a BULGE, interspersed with DEEP VALLEYS! This Emphasizes that the Moon- working with the Sun produces an IRREGULAR BULGE, and Not just at the Equator! My Analysis finds that Greenland’s Height/Width = 2.14, which is near the 2.16 found for other 6 cases for Moon/Sun TIDAL RATIOS! Greenland has Expanded in ALL DIRECTIONS, creating an INLAND LAKE (geophysics found)! Centripetal Firce is an EASY ANSWER for Mathematicians, but NOT for Earth Scientists!

        • What can I say in the face of such knowledge? You have turned on its head everything I thought I ever knew about planetary structure. You are amazing, sir.

          • Thanks, KINDLY! Outstanding Feature to be Solved: Moon has 5.145 degrees Inclination to the Ecliptic; Sun has 7.2 TILT- yielding 2.055 degrees, where SUN is Orthogonal (90 degrees) to Moon! Both are MEASURED CORRECTLY; How Possible?

  2. If the bulge had anything to do with the moons or suns gravity pull, then it would bulge more at the point where it is closest to the moon or sun. Also, the sun being so much bigger than the earth, pulls on the earth as a whole equally and not more at the equator because of more mass. Not to mention seasonal tilt. The moon while being equatorially tied… Is too small to have that much pull to distort the shape of the earth on it’s own. The moon might have a (small) contributing effect but rotational spin was more likely the main reason. Also the bulk of this bulging effect probably took place long ago when the earth was much hotter and pliable. Like shortly after the planetary collide that is theorized to be how the moon was made.

  3. Andrew Okulitch says:

    While the moon does create a small bulge in the earth’s crust, because of the moon’s orbital tilt, it is not coincident with the much larger equatorial bulge produced by the earth’s rotation. Moreover, the eqiatorial bulge exists all around the eath’s circumference while the moon’s tidal bulge move around the earth in a combination of the earth’s rotation and the moon’s orbital path. Both bulges can be accurately measured and the upper case rantings of Harold Overton can be safely ignored.

    • Another word for Mr Overton’s rantings might be “gibberish”. I haven’t understood a word he’s said and I’ve been fluent in Internet for a long time.

      • Me neither, but I am deeply impressed with the ALGORITHM he uses that makes SEEMINGLY random WORDS capitalized. If his reasoning wasn’t so FLAWLESS, I would have assumed it’s the regular PATTERN of speech of the YELLING lunatic. As it is, I have to ASSUME it is a sign of his genius and eventually it will all make sense, even for us lesser beings.

  4. The elevation data everyone has used for Mars since 2001 is that from MOLA (Mars Orbiter Laser Altimeter) which *is* with respect to an equipotential surface that takes into account bulging from the rotation. See this paper for the definition of zero elevation: http://dx.doi.org/10.1029%2F2000JE001364

    • Apologies, I just realised that your elevation model is based on Viking data from the 70s which was still defining zero elevation based on atmospheric pressure and I would guess is so imprecise that worrying about equatorial bulging doesn’t even make sense l. MOLA elevation data is much more accurate (up to 30cm). You can get it from here: http://www.mars.asu.edu/data/mola_color/

  5. I am Slowly working it out, so I ignore those who exhibit : “for every Work of Man, there is a Vandal WATCHING for his CHANCE!” (So long as there is no violence)! Bulge Creation, including Continents is found by Scrolling:

    • Andrew Okulitch says:

      “Vandalism” is an integral part of the scientific process, refining and debunking erroneous theories. Those poor, paranoid people, working outside the scientific community in the mistaken belief that they alone have the answers and that the community is trying to supppress them, forget that the lone genius who revolutionizes scientific thought and understanding is a very rare beast indeed, and that it is highly unlikely that they are one of them. Here we will have mutual “ig-norance”. He will ignore me and I will quite happily ignore him. He is certainly not the first nor last of well meaning, hard working and dedicated scientific misfits that I have encountered.

  6. What a load of *****, who are you trying to impress ; obviously, yourselves. ROTFL

    • Andrew Okulitch says:

      There, there, Ken. It’s okay if you can’t understand scientific facts and debates. Nobody is trying to impress anyone and contributions with obscure internet abbreviations add nothing. The saying goes “It is better to remain silent so no one suspects your ignorance than say something and remove all doubt.”

    • Timothy Whitehead says:

      Wow! Great find. My guess is its an Easter Egg (joke of some sort). I’ll do a post on it.

PLEASE NOTE: Google Earth Blog is no longer writing regular posts. As a result, we are not accepting new comments or questions about Google Earth. If you have a question, use the official Google Earth and Maps Forums or the Google Earth Community Forums.