Search found 11 matches

by walfy
Wed Feb 20, 2013 5:54 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Saturns Hexagon and Rings (2013 Feb 20)
Replies: 35
Views: 6705

Re: APOD: Saturns Hexagon and Rings (2013 Feb 20)

I'm surprised the APOD writers didn't even know that very excellent science was done in trying to figure out this strange structure. Here's your answer: http://www.planetary.org/blogs/emily-la ... /2471.html
by walfy
Sat Jul 21, 2012 5:19 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: A Hole in Mars (2012 Jul 18)
Replies: 48
Views: 8465

Re: APOD: A Hole in Mars (2012 Jul 18)

Perhaps there was a thick layer of ice under there at first, then the meteor punched through the soil and exposed it. The ice subsequently sublimated (evaporated), leaving the cavern below.
by walfy
Mon Jun 07, 2010 12:22 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Lunokhod: Reflections on a Moon Robot (2010 Jun 06)
Replies: 24
Views: 4900

Re: APOD: Lunokhod: Reflections on a Moon Robot (2010 Jun 06

Hmmm... you all can be sarcastic with Russian space technology, but look who will be providing the only means of getting to the Space Station when the shuttles are phased out very soon (just 2 or 3 more flights left for them), when we are still years away from a replacement vehicle. The Soyuz is sup...
by walfy
Sun Jun 06, 2010 5:41 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: Lunokhod: Reflections on a Moon Robot (2010 Jun 06)
Replies: 24
Views: 4900

Re: APOD: Lunokhod: Reflections on a Moon Robot (2010 Jun 06

Ten years ago a high-school exchange student from Russia lived with my family for 8 months. I was surprised that he did not believe that the U.S. sent people to land on the moon. It was not taught in his schools. Instead, he told me how they rigged it in a Hollywood-like studio. He was totally serio...
by walfy
Wed Aug 26, 2009 1:47 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: Morning Glory Clouds Over Australia (2009 Aug 24)
Replies: 27
Views: 3803

Re: Morning Glory Clouds Over Australia (2009 Aug 24)

How do these clouds form? Maybe it has to do with the temperature differences between the air above the ocean and the air above the land, considering these clouds form near the coast, if I understood correctly. Considering the hot Australian sun baking the land surface, then the way the heat is let ...
by walfy
Mon Aug 24, 2009 4:49 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: Morning Glory Clouds Over Australia (2009 Aug 24)
Replies: 27
Views: 3803

Re: Morning Glory Clouds Over Australia (2009 Aug 24)

When probes are on their way down to the surface of Saturn's moon Titan or our neighbor Mars, they take images looking down through the atmosphere and would surely qualify without quibble for inclusion on APOD. It makes no sense to exclude our own planet, from any perspective, at least occasionally.
by walfy
Wed Aug 05, 2009 10:50 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: APOD: A Triple Sunrise Over Gdansk Bay (2009 Aug 04)
Replies: 338
Views: 49720

Here's a crude experiment on this 3-sun problem...

I just did a very quick crude experiment with my Nikon D700, 70-200 VR lens, using a flashlight as the sun, and taking two pictures of it from outside my house. I have single-paned windows, side by side. One slides open, which doubles up the two panes. So I turned off all the lights, set the flashli...
by walfy
Sat Dec 06, 2008 8:40 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: Lunar Diamond (APOD 2008 Dec 06)
Replies: 13
Views: 1773

Re: Lunar Diamond (APOD 2008 Dec 06)

APOD always surprises, and I found this painting to be one of the best. That someone spent a long while and in chilly conditions to paint such a fine depiction of an astronomical event speaks to me of real interest, love and enjoyment of the night sky. That's what it's all about, isn't it? And this ...
by walfy
Tue Oct 14, 2008 5:14 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: Cassini Enceladus Tiger Stripe, crater chains (14 Oct 2008)
Replies: 12
Views: 2496

Also, is that really a shadow?

Is that really a shadow in the main rift? (Down with tiger stripes!) It looks like liquid may have oozed out and froze in place, but it looks too dark for ice. Or is it indeed just pure black shadow with digital noise?
by walfy
Wed Oct 01, 2008 4:32 am
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: True? A True Image from False Kiva (APOD 29 Sep 2008)
Replies: 32
Views: 13819

Thanks, Wally...

I was one of the skeptics that felt superimposing of the sky was going on. I stand corrected! The lack of haze in the sky was the main culprit, and the moon light explanation clears it up. Very amazing effect. I don't think anyone was trying to tear down Wally's work, just natural skepticism, and si...
by walfy
Mon Sep 29, 2008 7:38 pm
Forum: The Bridge: Discuss an Astronomy Picture of the Day
Topic: True? A True Image from False Kiva (APOD 29 Sep 2008)
Replies: 32
Views: 13819

No atmospheric fade-out as well...

Here's another thing that really makes me think this is NOT just one exposure, besides the ones mentioned above: There is no fading out of the stars caused by the increasing amount of earth's atmosphere the closer to the horizon you look. The starry sky looks the same throughout. The landscape itsel...