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J. W. Daniels, MSc

One of Dr. Neish's new "friends."

Try Everything!

The CPSX Field School experience has just ended, and so now the Grad-school summer vacation has officially begun!  Which means I can start making GIS projects for my Mercurian craters of interest….

                                               *~*Field School!!*~*

Meteor Crater — up close & awesome!!
Upheaval Dome:  impact crater, salt diapir, or a bit of both?

To say this CPSX course was/is one-of-a-kind is practically an understatement.  Every day feels like it goes by so quickly, yet when one wakes up the next day it feels as if the day before happened so long ago!  So much generally happens each day that even when you want to return home to civilization you still hope the field school could go on for longer.  Never experienced anything like it!  That’s not even getting into the myriad of stops….

Being that I’m currently studying impact craters on other worlds, it was only natural that I pay special attention to the confirmed+unconfirmed craters looked at during the trip:  Meteor Crater is a confirmed simple crater ~1.2 km in diameter, created mere thousands of years ago, complete with ejecta blanket and overturned strata on the south end of the rim.  As for Upheaval Dome, a ~5 km wide structure of uncertain origin, because a kilometer of strata has been removed via erosion what is seen now is only the very bottom-most “roots” of whatever it was that formed this structure — there are synclinal structures, faulting (including a graben or two), steeply dipping strata, and the presence of the “Paradox Formation” present at/near the central “uplift.”

Comparing Upheaval Dome to the Onion Creek salt diapir, once again the Paradox Formation resides at the center of it all; Onion Creek strata are also steeply dipping leading up to the Paradox, but there is intense folding present in the Paradox itself and faulting appears quite rare here.  Gypsum (& sometimes halides) was also found in situ in some of the Paradox units.

Other highlights include the hematite concretions at the Petrified Dunes, the eolian cross-stratification at the Grand Canyon, and the many interesting-looking cinder cones & other volcanoes (like the maar at Rattlesnake Peak) at the San Francisco Peaks area.

Because I wasn’t the only one who partook in this adventure, feel free to check out some of the other trip-goers for their own stories (assuming they post on it sometime between now & tomorrow…):

>>Elise.

>>Gavin.

>>Josh.

For everything else, there’s Twitter!

#PS9605

And now I shall return to my Mercurian craters….

 

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An upcoming hiatus, + another small update.

As the Winter 2017 school year wraps up for me, I am soon coming up on many months of “free time” where I can really spend time on my Masters thesis — instead of any chance I can get for myself.

But, that’s still a month or so away for me….  As soon as Winter 2017 ends, CPSX field school 2017 begins; then, when I return at the middle of May, I have an annual committee meeting to tackle.  Fun-fun-fun!

Blog-wise, this means that I won’t be able to post for around two weeks.

That said, here’s a small update before I disappear to Arizona:

>All named craters have MDIS (Mercury Dual Imaging System) + MLA (Mercury Laser Altimetry) files associated to them — 13 craters in all.  There are still 13 or so nameless craters that need to be done.

Screen Shot Hokusai_MDIS
Hokusai (global MDIS mosaic — 166 m/pixel resolution)
Screen Shot Hokusai_MLA
Hokusai (MLA dataset — much lower resolution!)

>I’ve started gathering all the MDIS-NAC (the MDIS Narrow-Angle Camera) image files of the named craters — for use later on….

>I’m hoping to convert the files for Abedin, Hokusai, and Stieglitz to “polar-stereographic” sometime this week.  I also would like to try viewing at least some of the MDIS + MLA images in ArcMap before the Field School.

>If I can, I’d like to download the MDIS + MLA for the nameless craters before I go as well….

I have also been working on my Annual Committee Meeting report, and am very nearly finished.  The next thing to do now is to draft-up a presentation (more fun).

 

Post-Space Day: a slight update.

Current crater count = 14 named craters, 13 unnamed craters (27 total; removed a couple craters that weren’t viable for the study, but (re-)added a few more new + previously identified craters).

Smallest crater = Ailey @ 23 km in diameter.

Largest crater = Abedin crater @ 116 km in diameter.

Three cases:

1 = one melt deposit (15 craters); usually the smaller craters.

2 = two or more melt deposits (8 craters); usually the larger craters.

3 = melt inside adjacent crater (4 craters); no size preference.

In other news, I’m still not completely out of the school-work woods just yet — and I’ll be busy with school until the middle of May (June through August looks pretty free, though!); would still like to figure out how to find unnamed craters in the MDIS database, & get some craters mapped by May; also, GUI doesn’t like, so far, the MLA datasets I downloaded (I think it’s to do with the .lbl files but the GUI won’t even select them)….

That’s about it, at the present moment.  Have a great Easter, all!

 

What I know so far…: Mercurian craters.

With “Space Day” coming up next week @UWO, I figured it’d be a good idea to jot down what I’ve noted about fresh crater impact melts on Mercury in preparation for that fateful day.

As if I didn’t already have enough to do…!

Here’s what I’ve got so far:

>>15 named craters + 9 unnamed craters = 24 craters in total.  Up to 6 other, less-promising candidates….

>>Smallest crater w/ exterior melt = Ailey crater with a diameter of 23 km; Ailey appears to be on the transition from simple to complex crater form.

Ailey crater

>>6 craters, most of them >100 km in diameter, have more than 1 unique pooling of impact melt.  Most have 2, but a couple, like Hokusai, have 3 or more.

Tyagaraja crater

>>6 craters are found adjacent to older craters, and as such their collection of melt is almost exclusively found within that older crater.  For this group, for some reason the older crater tends to be located just to the north of the fresher crater.

Balanchine crater

>>For the remaining craters, the majority of the smaller complex craters, have only 1 collection of melt present.

Plath crater

To recap, here’s what Neish et al. (2016) & Neish et al. (2014) have found for Venus & the Moon, respectively:

>Venus — 19% coincide, 31% up to 45*, 17% up to 90*, and 33% >90*.

>Moon — 53% coincide, 27% up to 45*, 7% up to 90*, and 13% >90*.

 

That’s all I got at the moment!  The next step now is to locate the rim-crest low for each crater, and for that I’ll need to figure out the topography dataset….  I’ll also stress that my work so far is preliminary and I still have a fair number of things to do yet that hopefully will confirm these initial findings of mine.

The results look promising already, though.  More to come in due time!

[the images are screencaps from:  https://messenger-act.actgate.com/msgr_public_released/react_quickmap.html]

Pi(e) Day!

Did you know today is Pi Day?

Well, now you do!

Every year, on March (3) 14, at 3:14 pm.  How many digits of pi have you memorized?

Me:  3.14159 — thanks to Stargate, of all shows….

😀

Fresh impact melts – the best of the best (so far).

The following are the absolute finest Mercurial craters in possession of impact melt located just beyond their respective crater rims, listed from most to least optimal candidates:

1 = Hokusai (57.75, 16.71; 114 km).  Lots of quality images available, and lots of instances of impact melt residing just outside the crater rim; much of the melt is found along the west-to-south trace of Hokusai, but another large collection exists off the eastern rim as well as a small pooling off the northern rim.

2 = Abedin (61.73, -10.54; 116.25 km).  Virtually all the visible melt can be found off the western (from NW to SW) rim of the crater; once again, a fair number of high-resolution images are available for this crater.

3 = Apollodorus (30.57, 163.28; 41.5 km).  Besides having a fairly unique radial pattern associated with it, this crater also possesses a nice collection of melt located in a sizeable area south of the crater itself.

4 = Seuss (7.65, 33.16; 64 km).  The melts present at this crater aren’t exactly the best-looking, but are found in two very large collections located to the east and south of the crater itself.

5 = Degas (37.10, -127.37; 54 km).  The high-resolution images available for this crater were instrumental, more than most of the other craters I’ve looked at thus far, in determining where the melts were located; there are, in fact, two small collections located south and west of the crater itself.

6 = Kulthum (50.72, 93.56; 31 km).  There are three small collections of melt present, located NE, NW, and SW of the crater itself.  Once again, the high-resolution images were instrumental in determining more exact locations for these melts.

The following craters also contain excellent collections of external impact melts, but are located within a much older crater situated right beside the crater in question (usually just to the north of the fresh crater):

1 = Erte (27.41, -117.31; 242.5 km).  Largest crater in the list overall, at roughly twice the size of Hokusai; there are two large collections of melts, the larger of which are located to the north inside an even larger, older, crater while the smaller is located to the E/NE of Erte.

2 = Balanchine (38.46, 175.50; 38 km).  Melts are pooled within an old crater located between Balanchine and a middle-aged crater located to the NW.

3 = Ailey (45.58, 177.92; 23 km).  Smallest crater in the list, overall; one large pool of melt is located within the old crater located just north of Ailey.

4 = Kyosai (25.16, 4.90; 39 km).  Virtually all melt is located within an older crater located north of Kyosai.

That’s it!  For now, that is!  This list shall be expanded once I search the high-resolution images for all the unnamed craters I’ve identified as promising candidates (still figuring out how to make the site search an area by coordinates…) and I search Braden et al. (2013) for any Kuiperian craters I’ve missed.  I hope to have those results by next week, or so….

[crater data – lat, long; diameter – obtained via https://messenger-act.actgate.com/%5D

 

 

The awesome-est exoplanetary system to-date.

Finding seven “Earth-sized” worlds orbiting within the Habitable Zone (HZ) of a nearby dwarf star is definitely something worth celebrating — even if one has to “fudge” the HZ parameters for four of them to make that happen.

Behold, TRAPPIST-1:

Image result for trappist-1

(https://www.thestar.com/content/dam/thestar/news/world/2017/02/22/what-to-know-about-the-newly-discovered-trappist-1-solar-system/exoplanets2.jpg)

The star in question is a red dwarf located roughly 40 light years away, and the worlds were detected using the Belgian-based TRAPPIST telescope system.  Because we’re dealing with a red dwarf star, and therefore the HZ is much closer to the star itself, chances are very good that most, if not all, of the exoplanets will be tidally-locked to TRAPPIST-1.

The fact that all seven exoplanets are more-or-less Earth-sized, and that at least three of them reside within TRAPPIST-1’s actual HZ, implies the very real possibility that up to three of those worlds, maybe more, could actually hold liquid water and even some form of life.

Like everything else in the Universe, the TRAPPIST-1 system has its own website:  http://www.trappist.one/

Of course, the TRAPPIST telescope itself has a website…:  http://www.trappist.ulg.ac.be/cms/c_3300885/en/trappist-portail

We could literally be within a year or two of confirming a truly Earth-like world, with the launch of the James Webb telescope next year.  If this new-fangled space telescope happens to catch sign of oxygen and methane co-mingling in the atmosphere of at least one of those exoplanets, then it is generally agreed that the possibility for life as we know it is considered to be quite strong since normally atmospheric oxygen and methane readily react to create new compounds (ie, if these gases are detected in noticeable amounts it means these gases are being replenished – the most efficient candidate we Humans currently know of is Life itself).

No matter how one looks at it, the TRAPPIST-1 system is exciting for Science and Humanity in general; unlike Gliese 581 and Gliese 667 C before, TRAPPIST-1’s worlds are confirmed with great confidence; the next step is to spectroscopically analyze the atmospheres of those seven worlds in the hope of detecting the ever-promising O2 + CH4 combination as a promising indication of an alien biosphere.

It just keeps getting better and better!!

 

Do ya wanna… search for impact melts around fresh Mercurian craters?

This week will be the second that I’ll have spent on the new, alternative thesis idea involving attempting to correlate occurrence of impact melts about fresh impact craters on Mercury to the location of the rim-crest highs of those same craters for the sake of comparing the results to Venus and the Moon for any similarities/differences that appear.

I spent all of Reading Week, last week, with my family down in Mickey Mouse Land (Florida, I mean), so naturally not much school work was undertaken….

In preparation for the next stage in the timeline of this new topic – should I decide to commit to it, and abandon the MARSSIM project – I browsed through the craters I’ve chosen thus far, most of them being complex in nature, and highlighted promising occurrences of impact melt just outside the rims of these craters as well as a number of candidates that might possess impact melts upon closer inspection under higher resolution (to be undertaken in the next step in the timeline).

The result of my preliminary analysis, given the limitations imposed by the quality of the MESSENGER images, can be found in the document below:

the-rayed-craters-of-mercury-complex-crater-candidates-for-exterior-impact-melts

[Images in document are modified screenshots of MESSENGER data from: https://astrogeology.usgs.gov/search/map/Mercury/Messenger/Global/Mercury_MESSENGER_MDIS_Basemap_BDR_Mosaic_Global_166m%5D

Should everything go well for me with this project this week, I’ll probably decide to make the switch and start going down this new crater road for the duration of my time here on the Masters train at Western.

 

So, what’s the point anyway?

To switch, or not to switch?

It’s an interesting situation, being told that swapping thesis topics as a Grad student is unwise yet being faced with just such a situation a mere five months in.  In a way, it’s like being caught between that proverbial Scylla and Charybdis….

My current topic, eroding fresh craters with MARSSIM and comparing the results to craters on Earth, is still pretty interesting, but after five months I’m still trying to grasp exactly why anyone besides my supervisor and myself should really care.  Every time I think I have a handle on it, I am shown otherwise.  Perhaps, being offered a topic of study that is far more straight-forward in its primary purpose is worth making the switch in the end?

This potential, new topic still involves looking at impact craters, but in this case I’ll be looking at ray craters (craters with ejected material strewn out radially around it, like a splatter pattern – these are usually the freshest craters) on Mercury; I would be looking at images from the recent MESSENGER mission to Mercury, examining the most promising ray craters for impact melt (rock that was melted by the heat of impact and then re-solidified).  The main objective here appears clear enough to me:  See where the melts tend to bundle-up on and outside the rims of these Mercurian ray craters, then compare the results to what has already been determined of fresh craters on the Moon and Venus in the hope of finding a correlation between the three worlds.

My supervisor has already determined that impact melts flowing out from Venusian craters tend to do so away from the suspected direction of impact of the original projectile, whereas on the Moon the majority of flows appear to lead in the direction of the lowest part of the crater rim.  Examining Mercurian craters, it is hoped that we can figure out if Mercurian impact melts behave more like the Moon’s, like Venus’, or somewhere in between.

neish_2016_lpsc_moon_venus_craters_impact_melt_correlation_figure
Correlation between exterior melt flows and the lowest part of the crater rim for (a) the Moon, and (b) Venus.  “Coincide” means melt flows out from crater rim’s lowest part (“rim crest low”), and “~90*” thus means flow emerges roughly from rim’s apex.  From:  Neish, LPSC 2016 (see below).

neish_melts_lpsc16

To get a feel for this new project, I began by finding promising complex craters from the MESSENGER global mosaic image of Mercury.  Theoretically, the northern hemisphere has the better data, so the craters I looked at are located there.

Here are the best examples I’ve found so far, which cover the majority of complex ray craters listed by Beary Xiao (sharp-faint_rayed-20150722):

Once I finish finding all the promising ray craters, that also show evidence of external impact melt, then the next step is apparently to download higher-resolution images of the select craters from this site:  http://ode.rsl.wustl.edu/mercury/.

But, that’s if I decide to switch thesis projects….

 

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