Search found 4 matches

by barakn
Tue Oct 15, 2013 4:00 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Equinox Earth (2013 Sep 28)
Replies: 51
Views: 12975

Re: APOD: Equinox Earth (2013 Sep 28)

The Sun illuminated both poles on the date the APOD was taken, but the view doesn’t extend clear to both poles because the satellite isn’t high enough. Since the Earth’s radius is 6,378 and the satellite (and all others in geostationary orbits) is 42,164 km from the Earth’s center the maximum latit...
by barakn
Sat Feb 11, 2006 6:13 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: NGC 1309 And Friends 2/09/06
Replies: 15
Views: 6453

the two reds at 5:00 seem kind of fussy. May these be stars out of focus or distant galaxies? Orin They are not out of focus. Everything in this image is so far away that for the purposes of focal control they can all be considered to be at the same distance: infinity. There are examples of in-focu...
by barakn
Sat Feb 11, 2006 6:11 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: NGC 1309 And Friends 2/09/06
Replies: 15
Views: 6453

the two reds at 5:00 seem kind of fussy. May these be stars out of focus or distant galaxies? Orin They are not out of focus. Everything in this image is so far away that for the purposes of focal control they can all be considered to be at the same distance: infinity. There are examples of in-focu...
by barakn
Tue Feb 07, 2006 6:54 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: UB 313: Larger than Pluto
Replies: 15
Views: 6288

That isn't all

The entire night side of the "planet" is brightly and evenly backlit, which is hard to explain given the size and position of the moon. As noted the sun is too large, but even stranger is the fact that the sun and moon have the same apparent diameter, as if they were airbrushed using the s...