Return to the Cloudy Nights Telescope Reviews home page


Observing >> Solar System Observing

Pages: 1 | 2 | (show all)
Rick Woods
Postmaster
*****

Reged: 01/27/05

Loc: Inner Solar System
Re: Mysteries of the Planets new [Re: CPellier]
      #6100161 - 09/25/13 11:23 AM

Wait - don't we see relief via shadow? Albedo differences are one thing, but why is catching the shadow of an object not seeing relief?

Post Extras: Print Post   Remind Me!   Notify Moderator  
blb
Post Laureate


Reged: 11/25/05

Loc: Piedmont NC
Re: Mysteries of the Planets new [Re: Rick Woods]
      #6100477 - 09/25/13 02:05 PM

If it were not for the albedo differences of the region and the shadows, then we would not be able to see any releif on our own moon.

Post Extras: Print Post   Remind Me!   Notify Moderator  
CPellier
scholastic sledgehammer


Reged: 08/07/10

Re: Mysteries of the Planets new [Re: Rick Woods]
      #6100479 - 09/25/13 02:06 PM

Well just a question of vocabulary - if you see the shadow of a mountain, are you seeing the mountain itself ? Not. But we are detecting a relief, yes...

Post Extras: Print Post   Remind Me!   Notify Moderator  
blb
Post Laureate


Reged: 11/25/05

Loc: Piedmont NC
Re: Mysteries of the Planets new [Re: CPellier]
      #6100486 - 09/25/13 02:08 PM

Are we seeing relief on our moon or just the evidence of relief? Is not this the same thing we can see on Mars?

Post Extras: Print Post   Remind Me!   Notify Moderator  
CPellier
scholastic sledgehammer


Reged: 08/07/10

Re: Mysteries of the Planets new [Re: blb]
      #6100697 - 09/25/13 03:41 PM

Well you're not wrong . Especially, on Mars the shadows that we see are not separated from their relief like it can be for a human body standing in the Sun for example. We are more seeing shadowy slopes that pure shadows separated from their mountains...
The case is rare though, and limited only to the Tharsis Mons and Valhalla.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Special Ed
Postmaster
*****

Reged: 05/18/03

Loc: Greenbrier Co., WV 38N, 80W
Re: Mysteries of the Planets new [Re: CPellier]
      #6101301 - 09/25/13 09:14 PM

I know there is some semantics involved here but bottom line is--we can see the indirect effects of relief on Mars (like shadows from volcanoes, dust moving down giant canyons, or frost in the bottom of huge impact basins) but almost no one thinks they can see craters or mountains on Mars (although Mars is peppered with them). Everyone has seen craters and mountains on Luna, but Luna is very close and Mars is very far away.

I was fortunate to see the shadow of Olymous Mons (and knew that it could be that because a spacecraft had discovered this giant volcano). Likewise, early observers might have seen that narrow dust storm that I saw and inferred that it was going down a huge canyon--only to have their inference confirmed a hundred or two hundred years later by spacecraft images. There were giants on the Earth in those days.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Rick Woods
Postmaster
*****

Reged: 01/27/05

Loc: Inner Solar System
Re: Mysteries of the Planets new [Re: Special Ed]
      #6102716 - 09/26/13 05:24 PM

Look at that link to the paper Christophe wrote (on the first page). It's to an entire newsletter, and his article is the first part; but farther down is the Letters section. Tom Dobbins wrote a letter about a sketch made by Ebisawa in (I think) the 50's, which appears to show the crater Schiaparelli (in the Edom area of Sinus Meridiani. The sketch he refers to is on the cover of V.A. Firsoff's "The World of Mars". He drew one; it's really there.

Post Extras: Print Post   Remind Me!   Notify Moderator  
azure1961p
Postmaster
*****

Reged: 01/17/09

Loc: USA
Re: Mysteries of the Planets *DELETED* new [Re: Rick Woods]
      #6105964 - 09/28/13 01:19 PM

Post deleted by azure1961p

Edited by azure1961p (09/28/13 01:21 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
azure1961p
Postmaster
*****

Reged: 01/17/09

Loc: USA
Re: Mysteries of the Planets new [Re: azure1961p]
      #6105970 - 09/28/13 01:22 PM Attachment (5 downloads)

If you could elaborate more Rick as I didn't read the article.

Thanks,

Pete


Post Extras: Print Post   Remind Me!   Notify Moderator  
Rick Woods
Postmaster
*****

Reged: 01/27/05

Loc: Inner Solar System
Re: Mysteries of the Planets new [Re: azure1961p]
      #6107804 - 09/29/13 04:23 PM

You mean the letter? Not much to elaborate on. Dobbins was asking if there had been any discussion of Mars craters among Japanese Mars observers prior to the Mariner IV flyby, since Ebisawa seems to have drawn one.

Post Extras: Print Post   Remind Me!   Notify Moderator  
stanislas-jean
Carpal Tunnel


Reged: 10/22/08

Re: Mysteries of the Planets [Re: Rick Woods]
      #6110546 - 10/01/13 03:22 AM

If I remember well, Antoniadi at the Meudon refractor reported sometimes the vision of craters of Mars.
I will not be surprised to hear something similar with Mr Capen observations at the Lowell obs. and from some others (Pickering,...) under excellent conditions.
Stanislas-Jean


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | (show all)


Extra information
0 registered and 3 anonymous users are browsing this forum.

Moderator:  Rich (RLTYS), star drop, dr.who 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 1258

Jump to

CN Forums Home




Cloudy Nights Sponsor: Astronomics