| Mercury, shot by MESSENGER on Oct. 5. |
The NASA probe MESSENGER will pass by Mercury for the second time at 08:40 UT Monday (which is the middle of the night for the US). I’ll get up first thing and write about what it saw, but it’ll probably be a few hours before we get the really cool stuff.
The last flyby was in January, and the pictures were incredible. As it happens, we’ll be seeing the other side of Mercury in this second flyby, so it’ll be all new territory (well, new to MESSENGER). Stay tuned! And check out Emily’s blog for the in-depth info.




October 5th, 2008 at 10:33 pm
I can’t think of anything to say because it is 5 o’clock in the bloody morning here in London, UK!
October 5th, 2008 at 10:53 pm
Just got up (05:51 here in UK) Thanks for the heads up.

October 6th, 2008 at 12:32 am
Best wishes to the MESSENGER team. I’m really looking forward to it.
THX Bad Astronomer - very good of you!
For those comparing global times its now 5 pm here in Adelaide, South Australia - and a couple of days since we put our clocks forward an hour for daylight saving!
For those who can answer this : How much of Mercury’s surface is now known versus how much do we still have to image? I understand one of the ‘Mariner’ spaceprobes (10 wasn’t it) only saw about half the planet in its series of initial fly-by’s? Then we got a bit more mapped and imaged last time MESSENGER went by this little planet; so will this complete our filling in the blanks on Mercury? Or is there something left for when MESSENGER finally enters orbit?
October 6th, 2008 at 12:43 am
@StevoR
From Emily’s blog linked above :
[quote]
“In 1975 and 1976, Mariner 10 acquired images of about 40 percent of Mercury, covering much of the hemisphere from 180 to 360 degrees east longitude. During MESSENGER’s January 2008 flyby, approximately another 20 percent of the planet was revealed in regions west of the Mariner 10 coverage. During the October 2008 flyby, MESSENGER will fill in much of the remaining terrain on the hemisphere opposite the Mariner 10 hemisphere, and will also fill in the gore crossing the northeastern portion of the Mariner 10 map.”
[Unquote]
Gore? On Mercury? Must be dried gore surely?
Much of the remaining terrain - but not all. How much? Much, much…
Also noted from there - MESSENGER is going solar sailing in a first for interplanetary exploration. Awesome.
Thanks BA & Emily - & THX & good luck to the MESSENGER team.
October 6th, 2008 at 1:13 am
AFAIK when MESSENGER enter orbit, only a few scraps here and there will need to be filled.
October 6th, 2008 at 1:25 am
One thing that I’m hoping they will find on Mercury is a volcano!
An item in the Britsih ‘Astronomy Now’ magazine back in their August 2005 issue ( “10 Big Mysteries of the Solar System - Are there Giant Volcanoes on Mercury” , page 71) suggested - based on Arecibo Radio telescope observations - that there might be a giant sheild volcano on Mercury’s as-yet unimaged areas covering about 500km in size.
A sheild volcano to rival Olympus Mons on a planet which we before thought of only as a larger, hotter version of our Moon - now that’d be absolutely marvellous! I hope its there and I hope we find it tonight!

October 6th, 2008 at 1:35 am
Oh the same article in the August 2005 ‘Astronomy Now’ mag noted that the Mariner 10 (&, yes, it was 10!) spaceprobe’s three fly-by’s of Mercury revealed 45 % of its surface at a resolution of about 1 km.
Don’t know how much of Mercury MESSENGER saw last time but it too is having three fly-by’s before entering orbit and the ESA’s Bepi-Columbo spoacecraft will join it in orbiting Mecrury in 2012 so it looks like we’ll have a complete mapping of this hot little planet within the next five years.
Oh & thanks MaDeR for your reply too.
PS. Is it good (n)etiquette to put posters names in bold here or not? Think it is but am unsure.
October 6th, 2008 at 5:47 am
So for one night only in its years long flight MESSENGER flies by Mercury - ie. Mercury propulsion!?
That is you’re saying (headlining) that for tonight its powered by droplets of mercury, Hg, quicksilver, that stuff mined from Cinnabar ore, the only metallic element that’s liquid at room temperature etc .. Right?
No? Nein? Non?
How would a mercury-fuelled engine work I wonder …?

October 6th, 2008 at 6:16 am
Already posted in another form as part of longer post on the old first fly-past ‘MESSENGER at Mercury : HAWESOME!” thread but thought worth posting here too …
Thinking netiquette is there a problem with acronymic names like MESSENGER which, being in all-caps, is like SHOUTING in net-ese?
Would it be more polite or less (certainly less accurate I ’spose) to have MESSENGER written in lower-case ie. ‘Messenger’ instead? Oh, & then if it is lower case there’s always the risk of confusing the spaceprobes name with the word ‘messenger’ itself ..
Hmmm, Tongue-twister potential here :
The MESSENGER team’s messenger came with the message that mercury had been discovered on Mercury and also that because saying MESSENGER not messenger sounds like shouting on-line the MESSENGER teams’ messenger wanted us to use ‘messenger’ instead of ‘MESSENGER’ - except for when also mentioning the MESSENGER’s teams messenger!
It would be kinda neat - & apt - if they did discover pools of the element mercury on Mercury wouldn’t it?
October 6th, 2008 at 8:48 am
…*waits patiently for the MESSENGER team to post pics or even a simple news update*…
October 6th, 2008 at 8:55 am
Six hours past closest approach - and still waiting for a written news update although there are some great images screening slide-show fashion on their site.
Have linked the MESSENGER site to my name - click on my name to go to Mercury! Or at least to the website of the spaceprobe that’s heading there.
Read there (FAQ’s) that the MESSSENGER spacecraft will impact Mercury at the end of its mission - wonder if there’s any chance they could soft-land it on the Mercurian surface the way the NEAR-Shoemaker spacecraft did on asteroid Eros?
October 6th, 2008 at 9:07 am
Right well the links working!
Six hours and twenty minutes since closest approach now - and still no written news updates but the photos are scrolling through (Not all loading on my machine - I’m just on dial-up.) and one of them says something like ‘Volcano on Mercury!’
(Yes I’m pleased to hear it! Wonder if its the one suggested by Arecibo data which I’ve mentioned here earlier?)
There’s also Caloris basin in colour & Mercurey’s Sodium tail … & more. Great!
Now if only we could have some explanatory accompanying text with these images …
October 6th, 2008 at 10:35 am
Is this a good idea to do right now? I mean, Mecury’s in retrograde!
October 6th, 2008 at 10:42 am
I am studying geology and would love to be a solar system geologist, but don’t want to study Mars like everyone else, looks like we will finally have a complete map of mercury in the near future.
October 6th, 2008 at 11:42 am
From the MESSENGER site’s news update:
“Tomorrow [10/7] at 1:14 a.m. EDT, the spacecraft will turn its high-gain antenna back toward Earth to start down-linking the data stored onboard. The first pictures from the flyby will be released around 10:00 a.m. on October 7, 2008.”
October 6th, 2008 at 4:58 pm
Okay thanks Bonez (sorry can’t do the Danish is it ‘o’) I’m waiting eagerly & as y’may have noticed checkinghere alot too - but what about all the photos appearing on their site???
Are they all just from the first fly-by or something?
October 7th, 2008 at 10:55 pm
I think a few of the close-ups were from the previous flyby, but at least two pics were definitely from the current flyby. They’ve added more, but then Phil has already blogged about that (as I am obviously behind in responding).