MESSENGER Mercury Updates.

[nimbus]

I can read the full article but won't get around to it for a few days. If anyone without access has very specific questions, I'm willing to dig for answers in the text.

 

[neilsox]

If the volcanoes stopped about 2 billion years ago, the center of the core may have cooled to about 500 degree c by now. The average surface temperature is likely about 400 degrees c cooler, except cooler at the north and south pole, so the lava tubes = vocano vents likely average over 100 c which maybe ok for a spacesuit with air conditioning. The Moon's surface temperature at lunar noon was about as hot as Mercury's surface shortly after sunrise. The lava tubes are shielded from most of the surface ionizing radiation. I'm guessing, what do you think? Neil

 

[MeteorWayne]

If the volcanoes stopped about 2 billion years ago, the center of the core may have cooled to about 500 degree c by now. The average surface temperature is likely about 400 degrees c cooler, except cooler at the north and south pole, so the lava tubes = vocano vents likely average over 100 c which maybe ok for a spacesuit with air conditioning. Neil

On what basis do you derive these temperatures. Any physics?

 

[3488]

Hi Wayne,

I am just about not mentally tired enough now to recommence on here properly at long last. :mrgreen:

I agree, I too am curious as to where those figures come from.

I think neilsox is more or less correct about the timing, based on cratering densities, but I think it to be at least 1,400 Celsius at the centre of Mercury. Iron melts at what, 1,536 C under 1 atmosphere. Mercury has an active magnetosphere, one that is currently being generated, not a fossil field.

So Mercury's average global density at 5.4 GCM, with a basaltic crust & mantle, suggests an iron with perhaps some nickel inner core & a molten Iron Sulphide outer core which melts at 1,194 C under 1 atmosphere.

If Mercury's inner core is solid iron, surrounded by a moten iron sulphide outer core, which is generating the magnetosphere, the internal temperatures will still be far higher then 500 C, even if the inner core is below the 1,536 C for it to melt, as the outer core will be above the 1,194 C for it's melting point plus extra enrgy to convect it, so I reckon approx 1,400 C minimum core temperatures.

Whilst I am not a chemist. I do know that 500 C for the core temperature of Mercury is far, far too low & I have thought this through.

Clickable thumbnail of 96 KM wide Firdousi Crater in lava plains.


Enlarged sharpened crop of 96 KM wide Firdousi Crater.

Clickable thumbnail of 159 KM wide Steichen Crater & 151 KM wide Kipling Crater.


Enlarged sharpened crop of 159 KM wide Steichen Crater. There is lava flooding on the floor.

Enlarged sharpened crop of 151 KM wide Kipling Crater. There appear to be volcanic pits on the floor as in the smaller crater to the bottom, south. Further evidence of volcanic activity on Mercury in the past.

Countdown to Orbital Insertion around Mercury.
221 Days.
09 Hours.
00 Minutes.
00 Seconds.

Andrew Brown.

 

[3488]

Earth & Moon in Libra from MESSENGER during Vulcanoid search.

Emily Lakdawalla article.

The Mercury bound MESSENGER spacecraft imaged a region of space very close to the sun (just to the west, sun not far to the left off the frame) seeking a postulated population of Vulcanoid asteroids orbiting the Sun at approx half of Mercury's average distance from the Sun or approx 0.17 AU on Thursday 6th May 2010, when MESSENGER reached Perihelion during that particular Mercury chasing orbit, when MESSENGER was only 46 million KM / 39 million miles from the Sun.

Sunlight, well solar incidence at this distance is approx nine times as strong as at Earth, so getting a suntan here would not be a problem .

MESSENGER a while back approached the sun ever more closely than this where solar incidence was nearly twelve times as strong as at Earth!!!!!!

Whilst the May 9th observation was seeking vulcanoids, MESSENGER caught the Earth / Moon pair in the background from 183 million KM / 114 million miles away. The moon can be seen to the right of the much brighter Earth.

Earth & Moon were in front of the constellation of Libra as seen from MESSENGER during this observation. It is a fabulous image, Earth & Moon together in front of the stars, one I can see that will be shown over & over far into the future.

The frame is ten degrees wide using the MDIS Wide Angle Camera.

Clickable thumbnail.


MESSENGER this week has again reached Perihelion, this time passing only 40 million KM from the Sun.

From Sunday 15th to Wednesday 18th August 2010, MESSENGER had resumed the search for Vulcanoids. So far none have been found & I expect that to remain so. However, if the search is not made, we'll never know.

Further Vulcanoid search. August 2010.

This time it looks like we may have Mars in the field of view in the background. So we'll have seen Venus, Earth & Mars as well as Jupiter from near Mercury space if so.

Countdown to Orbital Insertion around Mercury.
211 Days.
06 Hours.
33 Minutes.
45 Seconds.

Andrew Brown.

 

[3488]

Excellent finding by EarthlingX.

Pity poor Mercury. The tiny planet endures endless assaults by intense sunlight, powerful solar wind and high-speed miniature meteoroids called micrometeoroids. The planet's flimsy covering, the exosphere, nearly blends in with the vacuum of space, making it too thin to offer protection. Be...............

Extreme Effects: Seven Things You Didn't Know About Mercury.

This week's MESSENGER spacecraft update.

Young Volcanism on Mercury.

290 KM wide Rachmaninoff Crater in enhanced colour. MDIS NAC & WAC composite. Encounter #3. September 2009.

IAG Planetary Geomorphology Update.

Countdown to Orbital Insertion around Mercury.
197 Days.
02 Hours.
16 Minutes.
45 Seconds.

Andrew Brown.

 

[3488]

This week's update.

24 KM wide Matabei Crater with curious dark rays.

CLickable thumbnail of entire image in release.


Below an enlarged sharpened crop by me of 24 KM wide Matabei Crater, with the strange dark rays.

A little background info to the mission, for those who are new to the MESSENGER mission.
[youtube]http://www.youtube.com/watch?v=_F7qFUmKJHE[/youtube]

[youtube]http://www.youtube.com/watch?v=wVh-DF_1O1E[/youtube]

Countdown to Orbital Insertion around Mercury.
184 Days.
02 Hours.
06 Minutes.
45 Seconds.

Andrew Brown.

 

[3488]

MESSENGER encounter #3 encounter video.
[youtube]http://www.youtube.com/watch?v=nhenSSyBdjU[/youtube]

Countdown to Orbital Insertion around Mercury.
174 Days.
02 Hours.
28 Minutes.
15 Seconds.

Andrew Brown.

 

[3488]

Latest update.

Mercury's scarps tell of planet's unique history.

Well unique until LRO discovered similar, smaller scarps on the Moon.

Huge image. 6.2 MB. Image is reprojected & gives a great 3D effect (without the stupid glasses). From encounter #2.


Below, an original #2 encounter frame of the same scarp. This scarp was discovered by MESSENGER.


Countdown to Orbital Insertion around Mercury.
169 Days.
05 Hours.
00 Minutes.
00 Seconds.

Andrew Brown.

 

[3488]

A sample of some stuff I have been working on. Frames from the Planetary Image Atlas. I have downloaded raw images from that, rotated & contast enhanced them & the results of a few are here.

All images in this big spam of a post are clickable thumnails to full sized images.

Encounter # 1 inbound. Monday 14th January 2008.




Encounter # 1 outbound. Monday 14th January 2008.




Encounter # 2 inbound. Monday 6th October 2008.







Encounter # 2 outbound. Monday 6th October 2008.












Encounter # 3 inbound. Tuesday 29th September 2009.

MESSENGER went into Safing around Periherm in the cryonically cold shadow of the night side of Mercury, during encounter # 3, so only a tiny handful of very distant images were obtained outbound after recovery, but the inbound did show a large area never seen before.











A few odd ones.

Sirius / Alpha Canis Majoris on: Tuesday 26th September 2006, from MESSENGER as a navigation observation & MDIS test.


Pleiades / M45 on: Tuesday 26th September 2006, from MESSENGER as a navigation observation & MDIS test.


Jupiter & Sagittarius on: Wednesday 4th June 2008, from MESSENGER during a Vulcanoid search.


Earth & Moon in front of Libra from MESSENGER from: 183 Million KM, Thursday 6th May 2010, during a Vulcanoid search.


Andrew Brown.

 

[AdmiralRitt]

Mr Brown: This Photo below your posted..That's what a Manned Descent Vehicle would see.
It sure looks like Lunar Module approach profile: Great Photos.

For the Other who have "Educated Theories" is there any reason to believe that Mercury might hold much more
water than our moon at the poles. Mercury has much more gravity, The Sun brings in alot of cometary debris.

Latest update.



Below, an original #2 encounter frame of the same scarp. This scarp was discovered by MESSENGER.


Andrew Brown.

 

[3488]

Mr Brown: This Photo below your posted..That's what a Manned Descent Vehicle would see.
It sure looks like Lunar Module approach profile: Great Photos.

For the Other who have "Educated Theories" is the........

Latest update.

Andrew Brown.

Hi Admiral Ritt,

It stands to reason. The orbit of Mercury is approx .3 of an AU from the gravity well of our solar system, namely the Sun. Perhaps Mercury does have ice in the craters, I am not sure, but we never know. Certainly the permanently shadowed floors of the polar craters on Mercury are cryonically cold, certainly below minus 240 Celsius, permanently.

Below 167 KM wide Chao Meng Fu Crater (on right about a third of the way down), almost on the South Pole of Mercury, as seen during the second encounter by Mariner 10 on: Saturday 21st September 1974. Mariner 10 only to date has imaged the south polar region of Mercury in detail. MESSENGER thus far has passed over the equatorial regions. Chao Meng Fu has 45% of it's floor in permanent shadow & during the Mariner 10 second pass, the entire floor was in shadow.

Countdown to Orbital Insertion around Mercury.
161 Days.
03 Hours.
54 Minutes.
15 Seconds.

Andrew Brown.

 

[3488]

Some more MESSENGER spam. I worked on these earlier, all from the out bound leg of encounter #2 on: Monday 6th October 2008. I had improved the contrast of many & reorientated some so north is top.













Below an enlarged crop of the 170 KM wide Petrarch Crater (from frame no 4 on top row above) as seen by MESSENGER during the second encounter. Mariner 10 also got a good view, under a lower sun. This crater has a floor that is one of the very smoothest on Mercury. Perhaps MESSENGER may get some decent views during the oribtal mission?? As Petrarch Crater is 30 degrees south, MESSENGER will be near Apoherm, so perhaps not. If not during the primary mission, perhaps periherm could be shifted south so Petrarch & also the Rembrandt Basin will be seen in high resolution!!!

Countdown to Orbital Insertion around Mercury.
160 Days.
08 Hours.
05 Minutes.
00 Seconds.


Andrew Brown.

 

[3488]

Latest update,

The curious 190 KM wide dark floored Derain Crater.

Clickable Thumbnail of reprojected image from encounter #2: Monday 6th October 2008.


An enlarged sharpened crop by me of the 190 KM wide Derain Crater.


Also close by is a curious 21 KM wide dark floored, right rayed Berkel Crater.


An enlarged sharpened crop by me of the 21 KM wide Berkel Crater.


What is interesting will be to compare spectral data & once hermcentric orbit has been achieved, to get higher resolution images of both. To me it seems as if that whole area has a darker basalt layer beneath a lighter layer & that impactors have exposed it locally. Certainly the hermian crust in this area is layered. We can see that in the Rambrandt Basin, but there it appears mostly one colour, but here a much darker subsurface is very evident.

Countdown to Orbital Insertion around Mercury.
155 Days.
05 Hours.
23 Minutes.
15 Seconds.

Andrew Brown.

 

[MeteorWayne]

What's the Lat/Long of the crater? Will the post insertion orbit provide a closer view?

"MESSENGER's orbit about Mercury is highly elliptical (egg-shaped), 200 kilometers (124 miles) above the surface at the lowest point and more than 15,193 kilometers (9,420 miles) at the highest. At the outset of the orbital phase of the mission, the plane of the spacecraft’s orbit is inclined 82.5° to Mercury's equator, and the low point in the orbit is reached at a latitude of 60° North. The low-altitude segments of the orbit over the northern hemisphere will allow MESSENGER to conduct a detailed investigation of the geology and composition of Mercury's giant Caloris impact basin - the planet's largest known surface feature.

 

[3488]

Hi Wayne,

Derain Crater 8.7°South 340.3°West / 19.7 East.

So perhaps not. Apoherm at 60 South.

The orbit has certainly been designed for Caloris Basin observations. the 75 KM wide shield volcano will be fairly well placed (the volcano & another pyroclastic vent remain unnamed). Raditladi Basin too is well placed.

Rembrandt Basin being in the southern hemisphere will not be seen at such high resolution, perhaps something for a potential extended mission to take periherm over the hermean southern hemisphere??????

Andrew.

 

[3488]

Obtained during the outbound phase of the first encounter on: Monday 14th January 2008.

390 KM wide Tolstoj Basin & 80 KM wide Basho Crater.


Below my own original enlarged sharpened crop of Tolstoj Basin from the same encounter, which is almost as good as NASA's own.

What is very apparent to me, is that in many locations, the near surface crust of Mercury appears to be layered, it is certainly not homogenous in places.

Countdown to Orbital Insertion around Mercury.
142 Days.
03 Hours.
16 Minutes.
30 Seconds.

Andrew Brown.

 

[3488]

The first MESSENGER update for a little while.

Caloris Basin reprojected from encounter #1. Monday 14th January 2008.

The entire 1,550 KM wide Caloris Basin has been reprojected to appear as if the basin was directly in beneath MESSENGER.

Clickable thumbnail below. Depsite being a JPEG, it is still 12.3 MB. The Bitmap original I have is 51.7 MB. :shock:


The entire Caloris Basin is seen here, with the curious Pantheon Fossae (41 KM across) with Apollodorus Crater (25 KM across) in the centre of the basin.

At the Eight O'Clock position on the outer rim is a 75 KM wide 3,800 metre tall shield volcano with a 25 KM wide heart shaped summit caldera.

During the primary orbital phase of the MESSENGER mission, the narrow angle camera on MDIS will reveal features within Caloris as small as 18 metres (as well as a large swathe at the same latitude as Caloris around the Hermean Northern Hemisphere). During a possible extended mission, perhaps even higher resolution imagery as Periherm may be lowered (perhaps Periherm also swing around over to the southern hemisphere).

Countdown to Orbital Insertion around Mercury.
128 Days.
03 Hours.
42 Minutes.
15 Seconds.

Andrew Brown.

 

[3488]

Latest Update.

Section of equatorial Mercury lava plains 1,450 KM / 900 miles across, obtained inbound on: Tuesday 29th September 2009.

MDIS (Mercury Dual Imaging System) NAC (Narrow Angle Camera) view. Smallest detail in this particular shot is 1.4 KM / 0.88 mile. Much higher resolution views were obtained closer in. This view shows the extensive lava plain as one unit.

133 KM wide Picasso Crater on the left hand side is a cruirious pit floored crater where it appears magma drained away from under the floor leaving behind giant lava tubes, or magma withdrawal through fissures.

96 KM wide Firdousi Crater is lava flooded but also appears relatively young, as there are small secondaries radiating from the main crater & they appear unmodified from from further impacts & / hermelogical processes (Hermelogical, Mercury equivalent of Geological).

159 KM wide Steichen Crater is also lava flooded & shows a curious ring peak like structure sticking up through the lava flooded floor.

Mercury, lava plains on the equator. Encounter #3 September 2009.

Clickable thumbnail to large 1.4 MB image. It has been compressed from the original 6.3 MB one on the MESSENGER site.


Countdown to Orbital Insertion around Mercury.
114 Days.
02 Hours.
34 Minutes.
15 Seconds.

Andrew Brown.