Planets and stars...

[Anubis]

I'm begining to get comoftable recognising planets in the night sky. Some advice I got the other day was stars twinkle and planets don't. I thought the twinkling was caused by atmospheric turbulence, and therefore planets would be affected by it too.

Is it true, or an old wives tale?

Thanks!

[Ant]

Hi Anubis,

Twinkling is caused by the atmosphere and affects both planets and stars.

Ant

[lunator]

Hi Anubis

The reason Planets don't twinkle is they are not 'point sources' Even though they look like it to the naked eye.

Stars are so far away they are point sources so their light gets spread out by the atmosphere hence the twinkling.

I hope this is clear.

Cheers

Ian

[Anubis]

That makes sense, thanks!

[The Warthog]

To take this a little further, when the stars are twinkling furiously, the planets won't be, but it will be harder to see detail on the planets because of the turbulence.