I'm on the Tenerife island and (in the mountains above the clouds - 2300) the day before yesterday, I could clearly see the Milky Way and stars (1 am). So I went to the same place yesterday and the quality was much worse (at midnight).

I'm curious why there was such a difference and what parameters could cause this difference.

  • bigger moon?
  • different moon position?
  • sand from Sahara?

It's El Teide park cerca 2300 meters above the sea.

Is it worth to try again today? What parameters should I look up? It's like 2 hours of driving so I would like to be able to estimate the results in advance.

  • 7
    $\begingroup$ Hi. La Palma dweller here. There was another swell of dust laden Calima air yesterday, also a strong windshear at ~2000m at least where i live (Cumbre Vieja in my back). Though i could see the galactic centre clearly when I were out (550m asl), it was much more diffuse and flickering than the day before. Today, I can't even see the horizon from the dust. If you can, find a place that's in laminar air flow. And yes, the moon is beast. Wait till it's low. $\endgroup$ – user34599 Jul 28 '20 at 19:41
  • $\begingroup$ Just to echo what @a_donda said, the Calima is a big factor in the Canary Islands. If there's fine dust rising up from the Sahara, that will be a big influence on visibility. $\endgroup$ – Ben Hillier Jul 29 '20 at 8:04
  • $\begingroup$ Just curious - are you doing naked eye observation? $\endgroup$ – rinspy Jul 31 '20 at 10:28
  • $\begingroup$ @rinspy yes, but I want to take some photos (just with a mobile) $\endgroup$ – Milano Aug 1 '20 at 12:22

If you want to see the milky way, you really need the moon to have set. The moon sets about 50 minutes later each day, so you will need to go later. On the 28th of July, the moon sets at about 2 am and on the 29th it sets at about nearly 3am. If the moon is up that will significantly affect the background sky brightness. But when the moon is down, Tenerife has dark enough skies to see not only the milky way, but also the zodiacal light.

The other parameter is high cloud. Although you are above low lying stratus, High cirrus or cirrostratus cloud can still obscure your view. Sand might also have an effect, but the reason that you can't see the milky way is primarily because the moon is up. So go back at 2am or later, until dawn at about 6am.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.