Search found 7 matches

by RADDAD
Tue Feb 21, 2012 4:00 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Anticrepuscular Rays Over Wyoming (2012 Feb 21)
Replies: 20
Views: 4080

Re: APOD: Anticrepuscular Rays Over Wyoming (2012 Feb 21)

I am sorry, but the APOD explanation is erroneous. It has nothing to do with Great Circles. Great Circles are curves around a sphere - these rays are parallel straight lines. I found a better explanation a few years ago: Parallel straight lines appear to converge looking in either direction. If you ...
by RADDAD
Mon Jun 06, 2011 5:06 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Geometers Playground Over Wyoming (2011 Jun 06)
Replies: 65
Views: 44070

Re: APOD: Geometers Playground Over Wyoming (2011 Jun 06)

You get to see yourself coming and going on Monument Rd!
by RADDAD
Wed Jun 01, 2011 3:52 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Jets from Unusual Galaxy Centaurus A (2011 May 31)
Replies: 16
Views: 3841

Re: APOD: Jets from Unusual Galaxy Centaurus A (2011 May 31)

I found the term "light" quite off-putting since nothing in the image was visible light. Electromagnetic radiation I believe is the best term. It is not the light spectrum, but the electromagnetic spectrum. If you were writing this for fourth graders "light" would be fine. I have...
by RADDAD
Mon Feb 28, 2011 1:38 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Saturns Hyperion: A Moon with Odd... (2011 Feb 27)
Replies: 32
Views: 5217

Re: APOD: Saturns Hyperion: A Moon with Odd... (2011 Feb 27)

Looks more like honeycomb than sponge or coral to me. Maybe the honeycomb structure is an artifact of Hyperion's formation and not impacts. Some form of outgassing, or???
by RADDAD
Fri Dec 10, 2010 3:04 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: A Twilight Occultation (2010 Dec 10)
Replies: 18
Views: 3155

Re: APOD: A Twilight Occultation (2010 Dec 10)

Great photo! Brings back fond memories of an occultation of Saturn I observed shortly after I had made my first six inch Newtonian (circa 1961/62) back in Indiana. I was able to see the whole show - entrance and exit. My favorite part was the emergence (or disappearance) from the dark limb of the mo...
by RADDAD
Sun Dec 05, 2010 5:01 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Anticrepuscular Rays Over Colorado (2010 Nov 28)
Replies: 42
Views: 4978

Re: APOD: Anticrepuscular Rays Over Colorado (2010 Nov 28)

Interesting discussions. Sometimes it is good just to ENJOY the photo or the phenomenon. I first noticed this display while driving in eastern Oregon with my stepson. I stopped the car and we stood there wondering why the rays were reconverging toward the opposite horizon ... They should keep diverg...
by RADDAD
Fri Dec 03, 2010 6:07 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Dark Belt Reappearing on Jupiter (2010 Nov 29)
Replies: 34
Views: 3920

Re: APOD: Dark Belt Reappearing on Jupiter (2010 Nov 29)

Chris, you mentioned cyclic but without regular periodicity. It would be interesting to know how often this phenomenon has occurred. Someone must be keeping recent records. I checked my old log and I saw a one-band Jupiter on January 18, 1990. I am not a regular observer - You get out of the habit l...