Skip to content
Do you have adblock enabled?
 
If you can read this, either the style sheet didn't load or you have an older browser that doesn't support style sheets. Try clearing your browser cache and refreshing the page.

(Big Think)   Mars had its own Chicxulub-like impact some 3.4 billion years ago, and the Viking 1 lander just happened to land where the ensuing megatsunami left boulders, boulders everywhere   (bigthink.com) divider line
    More: Weird, Mars, kilometer-wide crater, impact debris, liquid oceans, aftermath of this topography-creating event, Solar System, larger moon, remarkable story  
•       •       •

862 clicks; posted to STEM » on 01 Dec 2022 at 7:30 PM (9 weeks ago)   |   Favorite    |   share:  Share on Twitter share via Email Share on Facebook



14 Comments     (+0 »)
View Voting Results: Smartest and Funniest
 
2022-12-01 7:53:45 PM  
Its weird that mars got hit by a comet?
 
2022-12-01 8:11:28 PM  

Concrete Donkey: Its weird that mars got hit by a comet?


We sure it was a comet?
 
2022-12-01 8:27:11 PM  

PartTimeBuddha: Concrete Donkey: Its weird that mars got hit by a comet?

We sure it was a comet?


From TFA, looks like it was a moon
 
2022-12-01 8:59:32 PM  
And not a rock to drink.
 
2022-12-01 9:19:29 PM  
In this Map view, the crater in question is the big shallow one, top center. Viking 1 is on the left and Pathfinder on the right:

Fark user imageView Full Size
 
2022-12-02 12:00:36 AM  
It's not like they send these mars probes to randomly land.  The LZs are carefully chosen.
 
2022-12-02 12:29:11 AM  

leeksfromchichis: It's not like they send these mars probes to randomly land.  The LZs are carefully chosen.


I recall hearing at the time that Viking 1's landing zone was selected because it was thought to be relatively level and obstacle-free and "safe and boring." Boy, were they surprised.
 
2022-12-02 12:43:58 AM  
Thank goodness these strikes don't happen here.
 
2022-12-02 1:34:52 AM  
Are they sure it wasn't Paul?

Fark user imageView Full Size
 
2022-12-02 3:55:21 AM  

leviosaurus: PartTimeBuddha: Concrete Donkey: Its weird that mars got hit by a comet?

We sure it was a comet?

From TFA, looks like it was a moon


a very naughty moon that just quit? ("Fark it. I'm going in!")
 
2022-12-02 5:59:30 AM  

leviosaurus: PartTimeBuddha: Concrete Donkey: Its weird that mars got hit by a comet?

We sure it was a comet?

From TFA, looks like it was a moon


Moons dont fall into a planet. Stop believing hollywood. A moon will have its orbit decay until it reaches the point where the planets gravity rips it apart and it becomes a ring of rubble
 
2022-12-02 6:51:00 AM  

KRSESQ: leeksfromchichis: It's not like they send these mars probes to randomly land.  The LZs are carefully chosen.

I recall hearing at the time that Viking 1's landing zone was selected because it was thought to be relatively level and obstacle-free and "safe and boring." Boy, were they surprised.


I found a NASA tech report: "This area was chosen because there were a minimal number of impact craters and, therefore, a minimal number of blocks that might be hazardous to the lander; radar data showed intermediate reflectivity values of about 8 percent, a value close to the Mars average."

It then goes on to note that, in retrospect, the distribution of hazardous blocks cannot be discerned from orbital imaging or Earth-based radar:

Nor was it possible, with the Viking orbiter image resolution at 1500-kilometer periapsis elevation, to delineate the hazardous block populations shown in the lander photographs. Higher resolution images are needed to determine such local hazards and to interpret the processes that formed the rocks seen at the landing site.
In retrospect, several pertinent observations about the use of the available instruments can be made. The orbiter imaging photographs were used to determine nearness to large impact craters and the inferred associated blocks; nearness to craters less than 100 meters in diameter could not be determined with this camera from this orbital altitude. Determination of surface roughness by orbital observation depends on both the actual distribution of roughness and the response of the instrument. It is quite possible to have surfaces that appear rough in the orbiter images but smooth in the lander images or smooth in the orbiter images but rough in the lander images. In the Lunar Orbiter and Apollo Programs, small blocks and slopes were observed on the Moon by f l y i n g appropriate focal-length cameras with ultra high resolution film at sufficiently low altitudes. Although Earth-based radar data could be used to avoid areas where reflectivity values were low and root-mean-square slope values were high, these data could not absolutely certify the absence of hazardous blocks. The Earth-based radar could be used to obtain depolarized echoes on Mars to help interpret block abundancies at a site. Later attempts to obtain depolarized echoes of the site (needed to resolve block frequency) were unsuccessful. It was also difficult to verify block size and frequency on the Moon from Earth-based radar (refs. 19, 20, and 21) although depolarized echoes were more easily obtained there and were used for interpretations of block frequencies (refs. 22 and 23). Infrared observations of the proposed landing sites under predawn and noontime conditions might have helped to resolve the nature of the radar anomaly at the A1NW site (23.4° north and 43.4° west); however, this would have required orbiatchanges. Time constraints and uncertainty about the applicability of the results ruled out any orbiatchanges. The most direct method for determining block populations would be a much higher resolution (about 1 meter as was used for lunar site certification) imaging system supported by IR and radar observations. A radar altimeter for confirming the actual elevation would also be useful.
 
2022-12-02 9:33:46 AM  

KRSESQ: In this Map view, the crater in question is the big shallow one, top center. Viking 1 is on the left and Pathfinder on the right:

[Fark user image 850x384]



Fark user imageView Full Size
 
2022-12-02 5:28:34 PM  

Concrete Donkey: leviosaurus: PartTimeBuddha: Concrete Donkey: Its weird that mars got hit by a comet?

We sure it was a comet?

From TFA, looks like it was a moon

Moons dont fall into a planet. Stop believing hollywood. A moon will have its orbit decay until it reaches the point where the planets gravity rips it apart and it becomes a ring of rubble


...which according to TFA, fell onto Mars and resulted in the boulders we see today.

...an impact on early Mars actually created a system of three moons: outermost Deimos, intermediate Phobos, and an innermost, larger moon that did not survive. That closest moon eventually fell back onto Mars, explaining why the modern Martian system only has two small moons; the third larger one, an analogue of Pluto's giant moon Charon, fell back onto Mars long ago, likely after being gravitationally broken up into a ring of debris.

It's amazing what you learn when you read TFA
 
Displayed 14 of 14 comments

View Voting Results: Smartest and Funniest

This thread is closed to new comments.

Continue Farking




On Twitter


  1. Links are submitted by members of the Fark community.

  2. When community members submit a link, they also write a custom headline for the story.

  3. Other Farkers comment on the links. This is the number of comments. Click here to read them.

  4. Click here to submit a link.