Earth Matters

September Puzzler

September 26th, 2022 by Kathryn Hansen

Update on October 26, 2022: This puzzler image shows Lake Retba along the coast of Senegal. The lake’s water’s are often rosy, but had darkened by the time this image was acquired in September 2022 after bouts of heavy rainfall and flooding. Congratulations to Keith Trinity, who was the first to correctly identify the lake and its location. Special mention goes to Rakhee Ranjan for pointing out the intense monsoon season in 2022 and other facts about the region. Read more in the related Image of the Day.

Every month on Earth Matters, we offer a puzzling satellite image. The September 2022 puzzler is shown above. Your challenge is to use the comments section to tell us where it is, what we are looking at, and why it is interesting.

How to answer. You can use a few words or several paragraphs. You might simply tell us the location, or you can dig deeper and offer details about what satellite and instrument produced the image, what spectral bands were used to create it, or what is compelling about some obscure feature. If you think something is interesting or noteworthy, tell us about it.

The prize. We cannot offer prize money or a trip on the International Space Station, but we can promise you credit and glory. Well, maybe just credit. Within a week after a puzzler image appears on this blog, we will post an annotated and captioned version as our Image of the Day. After we post the answer, we will acknowledge the first person to correctly identify the image at the bottom of this blog post. We also may recognize readers who offer the most interesting tidbits of information. Please include your preferred name or alias with your comment. If you work for or attend an institution that you would like to recognize, please mention that as well.

Recent winners. If you have won the puzzler in the past few months, or if you work in geospatial imaging, please hold your answer for at least a day to give less experienced readers a chance.

Releasing Comments. Savvy readers have solved some puzzlers after a few minutes. To give more people a chance, we may wait 24 to 48 hours before posting comments. Good luck!

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44 Responses to “September Puzzler”

  1. Nadeem Siddiqui says:

    East Harbor, comprising “Pilgrim Lake”, shown in image, the original back-barrier lagoon, Moon Pond and Salt Meadow, both back-barrier salt marshes. Also shown are the position of the original inlet, filled in 1868, and the current four-foot diameter culvert connecting the system to Cape Cod Bay. Maybe I Guess???

  2. Prasenjit Chowdhury says:

    Chilika Lake, odisha

  3. Keith Trinity says:

    Lac Rose Senegal Latitude; 14.840276° Longitude -17.225446°

  4. Tom Bemis says:

    Indiana Dunes National Park?

  5. Chris Sykes says:

    The pic looks like the Kennedy space centre in Florida

  6. Alberto Pereira says:

    Brazil, Rio de Janeiro

  7. Fritz Goebel says:

    Lake Retba, Senegal, near Dakar. Floods washed away salt mounds. The lake may lose its pink color due to the flooding.

  8. Simon Erceg says:

    Looks like Lake Retba in Senegal. Just down the road from Dakar.
    A highly salty lake with a pink colour from algae.
    Would probably be a great swimming location, until you get salt in your eyes!


  9. Nagareddy says:

    It’s like great wall of China, got hole through

  10. John Barbieri says:

    Link Lake , British Columbia

  11. John Harrington says:

    it is the Atlantic coast of Senegal northeast of Dakar
    and the image includes Lake Retba

  12. Tirthankar Ghosh says:

    Place where Earth and water mixedup , the river is make intresting.

  13. Corbin Greco says:

    The camera that was used was a normal camera, and may be sensitive to inferred light, and the scale of the image looks to be very large, so those green rectangles are probably very big, and it is on a remote beach somewhere.

  14. Harun Ula says:

    This is the lake in Senegal known as “Lac Rose” (Pink lake ). It is pink in a season of the year. It was the end point of the Paris-Dakar Rally!

  15. lucas liu says:

    this picture is token at Lake Retba in north of the Cap Vert peninsula of Senega and the date should be between June to September because of the Local rainfall and dry season and the lake itself is always changing

    ( this could be identify from the city near by )

  16. Nikhil says:

    Heart ❤️ shape pond that interesting
    Location : earth

  17. Darren Hawkins says:

    Lake Retba, Sénégal. (The Rose Lake) this image was probably captured recently in the rainy season when the algae has less sunlight, therefore not producing the red pigment that aids this process.

  18. Luc Van de Moortel says:

    lac Retba Senegal

  19. chinmohan ghosh says:

    Dear sir/ Mam,
    Respected all,
    I thing this picture was shown a interesting picture of a Sea,
    and it is look like a Big Hole, so this things will make it to so interesting.

    i don’t know that am i right or not? But i just try to give answer of puzzle and want to test my luck.

    Thanking you,
    Regards- Chinmohan Ghosh.

  20. MANIMARAN S says:

    Land and sea Face-off.

  21. MANIMARAN S says:

    Image of Earth and Sea Face On

  22. Paolo De Martin says:

    Maybe it could be our Sardinia in Italy!

  23. Rakhee Ranjan says:

    Lake Retba

    Also known as pink lake, it is located in north-west Africa in Senegal. Locally, it is called Lac Rose.

    Depending on the time of the day, the lake changes its colour from a light purple to a deep scarlet pink.The pink color of the water is due to a type of algae (Dunaliella salina) that is found in the lake.They produce a red pigment that absorbs and uses the energy of the sunlight turning the water pink.

    Its salinity content is nearly equal to the Dead Sea and even higher (as much as approximately 40%) during the dry season months. 

    Since the 1970s, local residents have been mining Lake Retba for its salt, which they use mainly to preserve fish. Waist-deep in water, the men scrape the bottom of the lake to harvest this universally useful mineral.The salt is then taken back to the shore where it is sectioned into small mounds. Dotted along the lake’s shore, these pristine white hills of salt create an arresting contrast against the pink of the lake.

    This monsoon season,Senegal, like other countries in the West and Central Africa region, recorded above-normal rainfall.As a result, drainage systems and retention reservoirs were quickly overwhelmed and channelled flood waters towards the lake which ultimately lead to rise in water level, washing away dozens of salt mounds. Due to all this, the thriving ecosystem of the lake is threatened. The salinity level and colour also gets affected with the gushing of freshwater. This peculiar change in the character of the lake is visible in the photograph captured from the satellite.

  24. Alex von Hildebrand says:

    Looks like a somewhat dry place. Some infrastruxture has been built to probably protect the coast from erosion. Expensive initiative, I guess. So is it in Australia?

  25. suman kumar bhagat says:

    Lake rebta..may be u gonna land capsule on that lake ..or gonna land any space shuttle

  26. Giacomo Losi says:

    Hello, it is a coastal area, it is not clear if of a lake or of a sea. It could be a sea and it is present a kind of a lagoon. There are some rectangular shapes along the coast, most probably human made of human conditioned. Also some probable crops in the more inland area and it seems to be present towns or an agglomerations of buildings and roads inland of the lagoon.

  27. Oscar says:

    The dark blue spots are ocean water meaning that there’s a leak of ocean water eating up the coast of the beach.

  28. Sivasurya says:

    the above given image is the satellite image of Caspian sea.
    It is the lake which is called by the name of sea.

    The Caspian Sea is situated about 500 km east of the Black Sea, between southeastern Europe and Western Asia, east of the Caucasus Mountains, south of the vast Eurasian Steppe, and west of the Karakum and Kyzylkum Deserts of Central Asia.

  29. Ivan Kordač says:

    Lac Rose (or Retba) near Dakar – Senegal on Cap-Vert peninsula with high salt content water…

    Not easy for me – it is old picture from satelite…. I tried to find it near by Alexandria or somewhere near Egypt…

  30. MUNIRAJ.N. says:

    Looks like Caspian sea…

  31. MUNIRAJ.N. says:

    Looks like Caspian sea

  32. Deborah says:

    Lake Retba, Senegal

  33. Tanishq says:

    Senegal :- International Charter activated due to floods in Dakar

  34. Olivier Marcil says:

    We are looking at Lac Rose, Sénégal or Pink Lake, Senegal


  35. Didac says:

    This is the Lake Retba, Lac Rose or Pink Lake in Senegal, close to Dakar.
    It is interesting due to the special pink color of the lake, given by salty algae Dunaliella.

  36. Mital Patel says:

    Its lake retba, also know as rose lake because it changes color depending on environmental factor. I guess the water level is not what it look like in the picture.


  37. Smriti Singh says:

    The Answer for September Puzzle – Misaquamicut Beech, Rhode Island

  38. Harvey Hartman II says:

    Looks like Padre Island.

  39. George Munga says:

    Looks like vehicles moving over a bridge on a Dyke. I guess people escaping from Russia to avoid conscription into the army

  40. Kurt Gubrud says:

    Lake Pontchartrain?

  41. Andy says:

    Pink lake, no idea why it’s significant – however I can’t assure you I search the costal regions for 45 minutes and found it the proper way.

  42. Aladin jafar mousa says:

    Lac Rose Senegal 14°50’33″N 17°13’34” W

  43. Pradip Kumar Routray says:

    Lake Retba Senegal?? Interest: the various natural & climatic threats affecting the Lake and environment (rainfall, drought conditions, deforestation, erosion).