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Ebrenn y'n Nos mis-Du 2015

Nov 7, 2015

This is a transcript of the November 2015 episode of Ebrenn y'n Nos (The Sky at Night in Cornish)  which was broadcast in #248 of Radyo an Gernewegva.
Dydh da. Ottomma rann nowydh kevres "Ebrenn y'n nos" mis-Du.
An mis ma, yma an nosow hwath orth aga hirhe. Wosa an klokkys eth war-dhelergh an howlsedhes eth a-varra. 

War Kalann Gwav yma'n howlsedhes (diworth Kardhinan) 1655, ha'n diwedh an mis, dhe'n 30ves, 1618. Howldrevel yw 0709 dhe'n dhalleth an mis ha 0756 dhe'n diwedh.
Yma an pedrek Pegagus hag Andromeda hwath gweladow, dell leveris vy yn mis-Hedra.

My a vynn derivas nebes a'n bagas ster Pleiades, neb yw aswonnys avel 'An seyth hwoer', po M45. Yth yw an bagas na ogas ha peswar kans ha hanter blydhen-wolow diworthyn. Yn spit an hanow, yma moy es mil sterenn y'n bagas. Yma niwl-ster dastewynnyans a-dro dhe'n ster, nagyw es dh'y weles marnasyn skeusennow hir aga diskudhans.

An Pleiades, niver 45 yn Katalog Messier. Imaj diworth Wikimedia/Digitized Sky Survey.
Niwl-ster dastewynnyans y'n Pleiades. Imaj diworth Wikimedia/HST.

Yma an Pleiadespoesek yn henhwedhlow lies poblow, y'ga mysk an Geltyon. An kynsa delinyans an Pleiadesusiaswonnys yw Plasenn Ebrenn Nebra ogas ha 1600 KK. Hi yw plasenn alkan gans imaj an howl ha'n loer ha nebes sterennow. Diskudhys o hi yn tre Almayn, Nebra, ha dre hwilans isotop aswonnys yw bosowr ha sten ynno a dheuth a Gernow. Paperys skrifys a-dro dhe fenten an owr (Ehser et al. 2011, Eur. J. Mineral, Vol. 23 895-910) ha'n sten (Haustein et al. 2010, Archaeometry Vol. 52 5(2010) 816-832). Gwiasva Plasenn Ebrenn Nebra dhe'n Landesmuseum für Vorgeschichte Sachsen-Anhalt.

Plasenn Ebrenn Nedra. Erthygel Wikipedia - a vynn nebonan y dreylya dhe Gernewek? Gwydheo yn hy hever yn Almaynek.

Yn henhwedhlow Grek an Pleiadeso myrghes Atlas ha Pleione ha kowetha Artemis, a wrug bos treylys yn ster dhe dhiank rag Orion.
Rag lies henboblow, termyn an blydhen pan wrug an Pleiadesgwelys kynsa a-rag an howl yn bora o poesek y'ga kalendar.
An loer yw orth hy kwartron diwettha 3a mis-Du, loer nowydh an 11ves, kynsa kwartron 19ves ha loer leun dhe'n 25ves.
Nyns yw planetysgweladow y'n ebrenn gorthugher marnas Uran ha Neptun, yn gorthugher a-varr. Yth yns i re bell ha gwann aga splannder dhe vos gweladow dre dhewlagas noeth, mes gans map ster ha diwlagatell po pellweler y hyllons i bos gwelys. Nyns yw possybl dhe weles travythmarnas disk munys glas. Neptun yw poesek yn istori kernewek, drefenn wrug John Couch Adams o genys yn Lanest ogas ha Lanstefan yn Kernow y dhargana dre awrgrym. Yth esa an movyans Uran dihaval orth an pyth o gwaytys dre tybieth gravedh Newton. Nebonan yn Pow Frynk, Le Verrier a wrug gul an keth awrgrym yn kettermyn ha'n diskudhans y honan o gwrys yn Almayn.
Y'n ebrenn bora yma Meurth, Gwener ha Yow gweladow y'n soth-est kyns an howldrevel, ha Mergher isella y'n soth-est a-varr y'n mis ha dos ha bos anweladow ogas dhe'n howl diwettha y'n mis.
Kyn hwra New Horizonsspedya yn efander down, yma ev hwath danvonn y dhata. Ev a wrug danvonn skeusennow an loeryow Pluton: Charon, Hydra, Nix, Styx ha Kerberos. 
Imaj diworth gwiasva New Horizons.
An efanvos DAWN usi ow resegva an planet korr Keres a yn resegva isella, owth usya y jynn dhe diyskynn diworth ughelder 1470 km bys dhe 380km. Ev a wra gul skeusennow manylys anodho.
NASA a wrug kollenwel efanvos nowydh OSIRIS-REx a wra lonchya mis-Gwynngala nessa, ha mos dhe blanetik ogas dhe'n norvys, Bennu, usi 500m y vraster. An towlenn yw dhe dreyla 2 vlydhen y'n fordh dhe'n planetik, ha kavoes sampel doust ha temmigow karrek anodho, ha'y dhri dhe'n norvys arta yn 2023. 
OSIRIS-REx. Gwiasva NASA yn y gever.
ESA a wrug dewisa savle-tira rag ExoMars, an rosyell a vynnons i tira war eneb Meurth yn 2019. I a vynn hy thira yn Oxia Planum, mayth eus kanalys sygh a'n jeffa dowr yn termyn eus passyes. Mar nyns yw an efanvos parys rag lonch mis-Me nessa, y fydh delatys rag dew vlydhen dhe wortos an nessa alinyans Meurth ha'n Nor.
Rosyell ExoMars 2018. Imajys diworth Spaceflight Now/ESA.

Savle tira yw dewisys, gans ughelder lymnys dre liwyow.

Mars yw an lonch delatys, y hyll tira yn Oxia Planum hwath, po Aram Dorsum po Mawrth Vallis. Henn a styr 'Nans Meurth' yn Kernewek - an hanow 'Mawrth Vallis' yw kemmysk Kembrek ha Latinek. Yma lies Valles war Meurth gans hanow an planet Meurth yn lies yethow arnowydh ha hen. Yn sur yma lowr a nansow heb hanow war Veurth rag kavoes spas rag 'Meurth Vallis'.

Bys nessa prys.

The Southern Foothills of Tharsis

Nov 6, 2015

This will be the last of the southern hemisphere summary plots, covering the area south of the Tharsis bulge and surrounding areas.

It is a large area with relatively small numbers of scattered Souness GLFs, often found in crater walls.

HRSC DTM tiles in area south of Tharsis in western southern mid-latitudes.

Elevation colour ramp used for all HRSC DTM tiles above
MOLA elevation alone.

Elevation colour ramp for MOLA data
Hillshaded MOLA topography.

Below is an close up of a crater in the northern part of tile h2501.
The GLFs in this area, of which four are shown in the images below, are at an elevation of around 2000m above datum, with the crater floor generally around 1000m, and the surrounding plain at about 2500.

A crater found in the H2501 tile of HRSC at 100°W, 46°S.

There are four Souness catalogued objects and the classifier picks out areas with high similarity to the topography of the Souness GLFs (red - head areas, blue - extent areas). The crater walls also show areas of gullies, and an inner depression in the centre.
The north wall of the crater. A region close to the leftmost Souness GLF in this image is covered by HiRISE.

The western wall, containing a Souness GLF and areas of gullies. There is a HiRISE image covering an area near to the Souness GLF in the western wall.

The southern part of the crater

An oblique view of CTX imagery of the north wall of the crater. The red outline denotes HiRiSE coverage.
Looking SW towards the western wall of the crater.

A subpopulation of Souness GLFs at high elevation

This area has some of the highest elevation Souness GLFs there are. All 5 of the GLFs at higher than +6000m fall within HRSC tiles h0266 and h0453.

The Warrego Valles area showing HRSC tiles h0266 and h0453.
Part of h0266 showing 4 Souness GLFs.

The classifier may not be expected to work well, because the objects are outside the elevation range of the rest of the Souness GLFs. It does behave somewhat differently because the 'head' areas are much less prominent.

Part of h0453 showing Souness 844 which is the highest elevation GLF of all. The head area is at an elevation of 7485m.

Classifier output.

Summary of Argyre Planitia region

Nov 5, 2015

Here are some overview renderings of Argyre Planitia and surrounding areas in the southern hemisphere of Mars.

I have added a lat/long graticule using the Natural Earth graticule shapefiles, setting QGIS to tell them they are in Mars 2000 lat/long.

Argyre region, with MOC image mosaic overlaid by MOLA topography.

The elevation colour ramp used for all of  the Argyre HRSC tiles

Background MOLA elevation ramp

MOLA elevation alone.
MOLA elevation blended with hillshade.

I do not present anything like a comprehensive detailing of the glacier-like forms in this region, but here are a couple of interesting areas.

Baltisk Crater (55°W, 42°S)

HRSC nadir image in tile h0416. The HiRISE image at the left is PSP_007706_1375.

With the classifier results.

Nereidum Montes area (43°W, 37-38°S)

In HRSC tile h2625, two Souness GLFs on the rim of crater which also shows various channels.

Classifier results.
A little to the south of the previous image, several further Souness GLFs are found. This area contains a HiRISE anaglyph and DTM. The DTM coverage is outlined in yellow.

Classifier results.
HiRISE anaglyph ESP_013850_1415 just to the east of Souness 757.
Colourised elevation map of HiRISE DTM.

Summary of West Hellas region

Nov 4, 2015

Here is a summary map of another region of Mars from my MSc dissertation work, this time the region to the west of Hellas Planitia.

Elevation (MOLA) blended with underlying MOC image mosaic.

All tiles in this region except h2210 use this colour ramp for elevation

MOLA elevation only.

MOLA elevation blended with hillshade.

Preview of a single HRSC tile h2210

This is located to the SW of Hellas Planitia, around 47°E, 48°S. The elevations within this tile range from -4542 to 1064m relative to datum.

Elevation blended with nadir image layer, a single Souness object is visible, but...
The classifier predicts substantial areas, which are judged in a Bayesian sense to be similar topographically, taking account of elevation, slope, abs. aspect away from N, cross-sectional, and longitudinal curvature, to the head areas (red) and GLF extents (blue).

The Mars Express HRSC tile's nadir image.


Using Google Earth to view Mars Reconnaisance orbiter CTX images of Souness 1140:

The region to the SW of Souness 1140 has HiRISE coverage including a 3D anaglyph if you have a pair of red/blue 3D glasses handy:

Link to University of Arizona HiRISE page for this image.

Crater at 34°E, 47°S

There are many craters in the areas west of Hellas that have a system of dunes within. This example also shows several Souness GLFs on the north wall:

Seven Souness GLFs are found here, within HRSC tile h2441. There is a HiRISE anaglyph of the dune system.

HSRC nadir image.
Bayesian classifier results.

This is a colourised representatio of the topography that may be difficult to interpret, but I thought I would present it to show a little of what is being done with the derived topographic variables. In this case, I have made a RGB false colour rendering, with red mapped to slope, green mapped to cross-sectional curvature, and blue mapped to longitudinal curvature.

Preview of the SE highlands of Mars

Nov 4, 2015

As I wrote in the last post, I am in the process of dividing up my QGIS projects covering the Mars Express HRSC DTM tiles that cover areas where Colin Souness found 'glacier-like forms' in his PhD and research paper.

I now come to the southeastern highlands:

Again, I use the equicylindrical projection optimised for 40° latitude, units are metres.

The elevation colour ramp for the underlying backdrop of the MOLA/MGS topography. In the above rendering this is blended with the Mars Orbiter Camera image mosaic.

In this region, I am able to use a single colour ramp for all of the various HRSC DTM tiles.

The MOLA elevation alone.

The MOLA elevation, blended with hillshade.

There are relatively few Souness GLFs in this region,found in crater walls. There are a number of these that look quite interesting - where within the same crater part of it looks glacial, and other parts have terrain produced by erosion by liquid.

Crater at 125°E, 41°S 

Several Souness GLFs, including one covered by an anaglyph ESP_022494_1385.

The classifier results (blue for topographic similarity to 'extent' areas, and red for topohgraphic similarity to 'head' area) overplotted on the HRSC nadir image.

Crater at 126°E, 44°S

Several Souness GLFs and other areas showing flow features. Souness 928 appears to have its 'head' and 'terminus' locations interchanged in the catalog.

Classifier results.

Crater at 141°E, 40°S

Souness 915 appears in the northern wall of the crater, and fluvial-like channels in the south wall.

A closer look at the north wall.

The classifier results.
The channels visible in the southern wall.

Classifier results.

Crater at 169°E, 45°S

Four Souness GLFs are found in this crater.

With the classifier results.

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