Messenger-Mission / Merkur

[karmaka]

'Silky Slopes' - Die sanften Hänge des Merkur, ganz scharf

FOTO

INFO

[karmaka]

Die ältesten sichtbaren Gebiete der Merkuroberfläche sollen ein Alter von 4 bis 4,1 Milliarden Jahre haben.

Now, a team of scientists has concluded that the oldest visible terrains on Mercury have an age of 4 billion to 4.1 billion years, and that the first 400 to 500 million years of the planet's evolution are not recorded on its surface
Quelle

Global resurfacing of Mercury 4.0–4.1 billion years ago by heavy bombardment and volcanism

Simone Marchi,  Clark R. Chapman, Caleb I. Fassett, James W. Head, W. F. Bottke, Robert G. Strom

LINK

    Nature
    499,
    59–61
    (04 July 2013)
    doi:10.1038/nature12280

The most heavily cratered terrains on Mercury have been estimated to be about 4 billion years (Gyr) old1, 2, 3, 4, but this was based on images of only about 45 per cent of the surface; even older regions could have existed in the unobserved portion. These terrains have a lower density of craters less than 100 km in diameter than does the Moon1, 3, 5, an observation attributed to preferential resurfacing on Mercury. Here we report global crater statistics of Mercury’s most heavily cratered terrains on the entire surface. Applying a recent model for early lunar crater chronology6 and an updated dynamical extrapolation to Mercury7, we find that the oldest surfaces were emplaced just after the start of the Late Heavy Bombardment (LHB) about 4.0–4.1 Gyr ago. Mercury’s global record of large impact basins8, which has hitherto not been dated, yields a similar surface age. This agreement implies that resurfacing was global and was due to volcanism, as previously suggested1, 5. This activity ended during the tail of the LHB, within about 300–400 million years after the emplacement of the oldest terrains on Mercury. These findings suggest that persistent volcanism could have been aided by the surge of basin-scale impacts during this bombardment.

Supplementary information

[karmaka]

Mit Messenger über dem Merkur - Animationen aus Messengerfotos vom 4.10.13

VIDEO-LINK

This movie was assembled from 284 individual NAC images. Most of the images were acquired four seconds apart, the fastest that MDIS is capable of taking full resolution images, but the movie is shown with 15 images per second. In the second half of the movie, Mirni Rupes can be seen in the top right.

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VIDEO-LINK

This movie was assembled from 289 individual NAC images. Most of the images were acquired four seconds apart, the fastest that MDIS is capable of taking full resolution images, but this movie is shown with 15 images per second. The movie begins centered on the 191-km diameter Schubert basin.

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[Murchison´s friend]

hi Martin,

hat mich das jetzt getäuscht oder sind da wirklich Gesteinstrümmer vom NWA 7325 zu erkennen ?

LG,
Michael

[karmaka]

MESSENGER hat im Februar 2013 die Arbeit an der ersten kompletten Karte des Merkurs beendet:

Hübsch!

Nachdem nun der Merkur erstmals vollständig kartiert wurde, ist auch erst jetzt ein präziser Globus (Durchmesser ca. 30 cm) möglich.

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