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View Full Version : Dry Heiligenschein



01101001
2004-May-21, 11:47 PM
In another forum, I saw this link (http://www.engl.paraselene.de/html/opposition_effect.html) to an explanation of the enhanced retroreflection near the shadow of the rovers' mast head, as demonstrated in thumbnail:

http://marsrovers.jpl.nasa.gov/gallery/all/2/n/133/2N138183651EFF5300P1827L0M1-THM.JPG
Larger Image (http://marsrovers.jpl.nasa.gov/gallery/all/2/n/133/2N138183651EFF5300P1827L0M1.HTML)

They call it an opposition effect or "dry heiligenschein" -- which is just so fun to say.

In my own experience, I was familiar with such an effect viewing dew on grass, but, of course, dew was pretty much off my list for an explanation of similar on Mars, so I was glad to read about this.

ToSeek
2004-May-22, 12:45 AM
I think I'll start using it as a cuss word: Oh, heiligenschein!" ;)

The Bad Astronomer
2004-May-22, 08:03 PM
The strongest I have ever seen it in was in the very dry dust (no rain for months) in a baseball field across the street from my house.