Talk:MESSENGER

A news item involving MESSENGER was featured on Wikipedia's Main Page in the In the news section on 5 July 2008.

Wikipedia

Why is there a 12 second window for 12 days starting August 2, 2004 for the launch of MESSENGER? What determines this 12 second window? - Vohiyaar

What was the reason for the delay from May to August? Rmhermen 03:01, Aug 5, 2004 (UTC)

2005 - 1975 = 30, not "more than 35" Lee M 19:34, 17 Jan 2005 (UTC)

But the orbital insertion won't be until March 18, 2011, which will be over 35 years. Richard W.M. Jones 19:26, 27 Feb 2005 (UTC)

Yes but it was a flyby so you should compare to the first flyby by MESSENGER in 2008...82.120.124.201 6 July 2005 04:04 (UTC)

I changed it from 35 to 30, which is correct. The upcoming flyby on 14th of January will be closer than any encounter done by Mariner 10 [1] (200 km for MESSENGER vs 327 km at closest for Mariner 10) --Harald Khan Ճ 15:17, 2 January 2008 (UTC)[reply]

Discovery Rupes

Rather beautiful and informative photograph on Discovery Rupes here: [2] Richard W.M. Jones 06:53, 14 July 2005 (UTC)[reply]

End of mission

Is there any plan to lanch the probe to crash in the surface after its mission is complete? Just like the Galileo in Jupiter. That is, the prove could even take pictures from the surface and mesure the temperature and the atmosfere from close while it crashes in the surface. -Pedro 14:12, 26 August 2005 (UTC)[reply]

Well, Mercury doesn't have much of an atmosphere, but other than that, I'd guess they haven't worked out what to do that far in advance.

—wwoods 06:42, 27 August 2005 (UTC)[reply]

Quote from [3]: "After eight years in space, the MESSENGER mission will end when the satellite crashes into the planet's surface." Althoug this might change, but it looks like that is the current plan. Awolf002 12:54, 27 August 2005 (UTC)[reply]

I think that's a nice idea if we can get some info and pictures while it crashes.

--Pedro 23:55, 28 August 2005 (UTC)[reply]

Rather difficult to do anything while it's crashing. Anything done at the end of the mission will depend on how the spacecraft is doing structurally, and if things like the camera are even working by then. It is, after all, Mercury. :) --Planetary 17:19, 19 July 2006 (UTC)[reply]

Mercury is like the moon, not like Venus... it shouldnt drop in a vertical crash but rather horizontal. There are no close-by pictures of Mercury, so it would make history. let's hope cameras will work, then. --Pedro 14:50, 20 July 2006 (UTC)[reply]

Blank space

Someone please edit to compensate for the enormous blank space in the introduction. It appears the table (mostly with question marks as of current), is causing this. --Marsbound2024 21:18, 16 April 2006 (UTC)[reply]

Done and done. --Planetary 17:17, 19 July 2006 (UTC)[reply]

reference

Robert E. Gold, Sean C. Solomon, Ralph L. McNutt, Jr. a, Andrew G. Santo, James B. Abshire, Mario H. Acuña, Robert S. Afzal, Brian J. Anderson, G. Bruce Andrews, Peter D. Bedini, John Cain, Andrew F. Cheng, Larry G. Evans, William C. Feldman, Ronald B. Follas, George Gloeckler, f, John O. Goldsten, S. Edward Hawkins III, Noam R. Izenberg, Stephen E. Jaskulek, Eleanor A. Ketchum, Mark R. Lankton, David A. Lohr, Barry H. Mauk, William E. McClintock, Scott L. Murchie, Charles E. Schlemm II, David E. Smith, Richard D. Starr, Thomas H. Zurbuchen (2001). "The MESSENGER mission to Mercury: scientific payload". Planetary and Space Science. 49 (14–15): 1467–1479. doi:10.1016/S0032-0633(01)00086-1.{{cite journal}}: CS1 maint: multiple names: authors list (link)

MESSENGER results

First images in: see: Encounter Observation Phases

File:MESSENGERanimation.gif

Not sure about the copyright status of this image; it's made of MASA images, but it was assembled by Emily Lakdawalla of the Planetary Society

Serendi^podous 22:22, 14 January 2008 (UTC)[reply]

Statement

gravity field to degree and order 16 - what does that mean? --Abdull (talk) 10:44, 15 January 2008 (UTC)[reply]

Gravity fields are modeled by spherical harmonic expansions. I've added a wikilink. mdf (talk) 18:27, 15 January 2008 (UTC)[reply]

About gravity wells

Just wanted to explain my edit: Yes, Mercury has a higher orbital velocity than does the Earth. However, a spacecraft falling from the Earth to Mercury's orbit would have a much higher velocity, still, because it falls toward the Sun. The flybys are to slow it down, not "speed it up" to Mercury's orbital speed.Fleem (talk) 12:14, 15 January 2008 (UTC)[reply]

Something odd about the orbits

The figure shows the spacecraft making a first pass by Earth with virtually no change in orbit, then making a pass by Venus with a huge change in orbit. But the pass by Venus is at higher altitude under weaker gravity... 70.15.116.59 (talk) 14:32, 15 January 2008 (UTC)[reply]

Look at the graphic more carefully. The first flyby of the Earth was a large change in orbit (see color change on the graphic): this put the probe onto the first Venus flyby. The first Venus flyby was minor, probably more for synchronization with Mercury (but I'm no specialist; there is in-article discussion about stuff related to this). The second Venus flyby was significant (again, see color change on graphic), and, with the help of DSM-2, put Mercury onto MESSENGER's crosshairs. It would be nice to find an animation. mdf (talk) 18:57, 15 January 2008 (UTC)[reply]

OK -- When I first looked at this I assumed the blue circle was the Earth's orbit, but I see now that's the faint dotted line. (With a certain literal-mindedness I was thinking the blue line couldn't be the probe because it runs straight into the ground...) The cyan line goes "right past" Earth but that's not a flyby and not listed on the chart which is why it doesn't change the orbit much. I see now that the lines even are color coded on the list of flybys, and since that's what I was about to suggest now I'm not sure what to say, except that maybe the dotted orbits could be a shade wider. Thanks for the clarification. 70.15.116.59 (talk) 03:10, 16 January 2008 (UTC)[reply]

Something the article doesn't mention

What is (planned to) happen at the "nominal end of the spacecraft's primary mission"? Neıl ☎ 09:50, 16 January 2008 (UTC)[reply]

NASA allocates resources and/or goes back to Congress and begs for more money to conduct an "extended mission"[4]. mdf (talk) 14:35, 16 January 2008 (UTC)[reply]

Why the change of the trajectory?

Why was the trajectory and launch window changed? --_{Piotr Konieczny aka Prokonsul Piotrus| talk} 18:31, 16 January 2008 (UTC)[reply]

Dunno. My guess is a slipped schedule changed the launch date, changing the optimal path.Fleem (talk) 07:15, 17 January 2008 (UTC)[reply]

Why do we have to have everything in space articles translated into feet, statute miles etc?

This is extremely irritating. As far as I know NASA, like all science bodies, uses SI units internally (except when it wants to crash space probes into distant heavenly bodies 'by accident'). Surely Wikipedia readers are also all familiar with SI measurements such that constant translation gives a spurious air of precision. —Preceding unsigned comment added by JohnBurton (talk • contribs) 22:04, 16 January 2008 (UTC)[reply]

Americans (including me) have become comfortable with liters, somewhat comfortable with meters, but have absolutely no intuitive grasp of how far a kilometer is: more than a mile, less than a mile, in what ratio to a mile? Also it seems that miles are still in favor when discussing navigation. Brian wessels (talk) 21:47, 18 January 2008 (UTC)[reply]

I still don't get it. Klick (for kilometer) came into usage in the US military in the 1950s - are you genuinely saying 'Americans ... have absolutely no intuitive grasp of how far a kilometer is'. I hate to think you're right. —Preceding unsigned comment added by JohnBurton (talk • contribs) 03:31, 19 January 2008 (UTC)[reply]

I wouldn't say they have no idea, but it's more comfortable to think in terms of miles than in kilometers as an American; and NASA is an American agency. -134.50.14.44 (talk) 16:08, 5 July 2008 (UTC)[reply]

Dating system

User Nickshanks (operating under IP 195.137.85.17) has changed the format for the dates in this article from standard American (Month day, year) to British (day Month, year). I don't think this is appropriate since the article seemed pretty consistent in the American version and was dealing with a primarily American based mission. I have reverted the edits, but wanted to open a dialogue here in case there's something I'm missing. Matt Deres (talk) 02:01, 17 January 2008 (UTC)[reply]

The dates all look fine to me, before and after your edits. But that's because I have set my preferences according to taste. After you have set yours, you can see WP:DATE for a tedious discussion on this subject. Maybe one day units of measurement will be included in the preferences too. mdf (talk) 02:51, 17 January 2008 (UTC)[reply]

Yeah we saw WP:DATE already:

Strong national ties to a topic: Articles on topics with strong ties to a particular English-speaking nation should generally use the more common date format for that nation; articles related to Canada may use either format consistently. Articles related to other countries that commonly use one of the two acceptable guidelines above should use that format.

And as noted, this is an American spaceprobe. S B H arris 03:50, 17 January 2008 (UTC)[reply]

Who can deny it? But perhaps I was misunderstood. If you select "my preferences" (near the upper right corner of the page), you'll find a "Date and Time" tab. There you can then select whichever date format you like to see. For example, I prefer the ISO stuff, and so all the dates, in all articles, look like "2008-01-17", even though this could be entered in articles as "[[January 17]], [[2008]]", "[[17 January]], [[2008]]" or even "[[2008-01-17]]".

Of course, if everyone already knows this and still wishes to fret about the YMD, MDY, DMY, etc, issue, that's ok too. All I ask is that the data be put in a form the wiki can convert. mdf (talk) 04:26, 17 January 2008 (UTC)[reply]

Okay, good point. What we should do is tell everybody who is changing stuff to any non-standard format to change it back, but so long as it's one acceptable format to another, we should just tell them to change their reader preferences. I'll do that now for mine. Oh, and BTW, perhaps the section on dates in WP:DATE should be changed to note that this is not like spelling, inasmuch as it' possible for everybody to see what they'd like (like the color of redlinks), so the only important thing is that a standard form be used. S B H arris 22:00, 17 January 2008 (UTC)[reply]

the "science case"

It would be helpful to have more information about the "science case" for the mission -- i.e., what particular scientific questions (other than "shrinking surface") the various mapping projects are meant to answer. What current theories about the planet, and planet formation and evolution in general, are the instruments designed to test? We have a huge amount on the engineering side, but not enough on this. 69.17.73.214 (talk) 05:09, 5 April 2008 (UTC)[reply]

There never is. However, as evidenced by the recent fly-by of Mercury we can tell the probe is designed to detect magnetic fields and analyze the atmosphere of the planet. --134.50.14.44 (talk) 16:11, 5 July 2008 (UTC)[reply]

Water on Mercury

They said "large amount", but didn't say it's liquid. So...do we expect life on it? Lightblade (talk) 06:21, 6 July 2008 (UTC)[reply]