Talk:Colonization of the Moon/Archive 2

Advantages of Moon Colonization
There seems to be a major point missing under the advantages section of the article. There is a failure to discuss the possibility of "spin-off tech" resulting in a mission of such caliber, and its consequences to earth bound technology. Effort should be made to include this point as a matter of priority. —Preceding unsigned comment added by Rohannesburg (talk • contribs) 02:58, 24 July 2009 (UTC)
 * There is a problem in dealing with technology spin off in a Wikipedia article because it is so unpredictable. There is a section of the outline for technology spin off giving the reasonable idea that lunar colony technology should be applicable to other space venues.  What else can be said about future technology spin off that is verifiable?--Fartherred (talk) 03:11, 25 July 2009 (UTC)
 * I added a citation needed tag to the claim that rockets from the Moon get to Mars faster than those launched from Earth. There will not be any reliable source for this claim since it is well understood that that is not generally the case.  Can we just delete the claim?  I do not know what I should state as the reason for deleting it?--Fartherred (talk) 04:50, 25 July 2009 (UTC)


 * You could look into the possibility of comparing how previous Moon missions were advantageous to earth-bound technologies, and possibily predicting what may result from future colonization; such as the exploitation of Heilum3 and its contribution to future energy production. Or you may also attempt to discuss the various medical advances which will almost certainly result from an established colony on the Moon.--Rohannesburg (talk) 04:29, 26 July 2009 (UTC)
 * Addressing your second point, there was a recent article in the New Scientist publication about the development of an ion engine called the VASIMR, that would be able to power a mission to Mars in just 39 days, but would only be effective in distances equivalent to that between the Earth and Mars. As for rocket question, only under certain conditions will a rocket launched from the Moon be able to reach Mars faster than a rocket launched from the Earth. It would be mainly dependent on if a gravity assist maneuver is executed or not, and also on the Moon's relative position from the Earth. --Rohannesburg (talk) 04:29, 26 July 2009 (UTC)
 * I am so set in my way of thinking of minimum rocket use on the Moon that it is difficult to switch gears and consider the possibility of rockets going from the Moon to Mars. Whether or not rockets launched from the Moon can reach Mars more quickly than rockets launched from Earth depends upon the assumptions that are used.  If the payload takes a Hohmann transfer to Mars the time is fixed and a much smaller rocket can get the payload to Mars from the Moon than from Earth, because it does not need to escape from Earth's much larger gravity well.  If the same size rocket is used in both cases and it boosts a payload to a Hohmann transfer trajectory from Earth, it could leave the Moon at thousands of meters per second higher departure velocity enabling quicker transfer trajectories with higher arrival velocities to kill in Mars' atmosphere.  The problem is that this faster trip to Mars is not necessarily an advantage to a Moon colony.  Rocket fuels typically contain hydrogen which is in famously short supply on the Moon.  Nearly every time I read about the evidence for hydrogen at the Moon's poles reported for the general public the report contains the suggestion that the hydrogen could be used for rocket fuel.  I marvel at the idea of using something worth its weight in gold as rocket fuel.  Of course the Apollo program did that, but Apollo level technology will not support a colony on the Moon.  I have read about someone testing a liquid aluminum liquid oxygen rocket engine on Earth but I do not have the internet address, so the information is useless to me unless I find it again.  It would be possible to launch a rocket from the Moon completely horizontally within a long pressure vessel open at the end for the rocket to escape.  Then close the vessel and recycle the hydrogen.  There is the same problem as the last idea, no reference.  I just think that claiming faster rockets to Mars as an advantage is very open to being challenged by someone who assumes all hydrogen must be shipped from Earth.  If there is no reference, it would be better left out. FARTHERRED--24.118.183.189 (talk) 15:06, 26 July 2009 (UTC)
 * If we can predict medical advances likely to be achieved through a lunar colony, we should publish these predictions in a respectable journal. Then someone else or even we ourselves can refer to these reliable publications in a Wikipedia article.  Exploiting Helium-3 is already referred to under the Economic development, Exporting material to Earth section.  That section could use a citation or two.  An article on Wikipedia should be more reliable than some undisciplined blog.--Fartherred (talk) 12:30, 27 July 2009 (UTC)
 * I do not want to seem as though I am setting myself up to tell others how to behave. I am perhaps not the best source for such information, but there are definite Wikipedia policies to keep in mind: There are Verifiability and No original research.  Put WP:WELCOME in the search box to get to the welcome page and find some useful information.--Fartherred (talk) 03:04, 28 July 2009 (UTC)
 * I don't see a claim in the article that is is faster to get to Mars from the Moon than it is from Earth, only that it requires less delta V, which is true. Most discussion I've seen of using the Moon to supply other colonies (e.g. L5) do not assume hydrogen as a fuel. Unless large supplies of hydrogen are found, say at the Lunar poles, other propulsion methods are likely to be used, probably some combination of an electromagnetic accelerator on the surface for initial delta V and an ion engine. --agr (talk) 23:00, 28 July 2009 (UTC)
 * The claim that it is faster to get to Mars from the Moon was in a version by Schmeater on the 24th of July. This was subsequently modified by 87.242.150.177 at 19:30 on the 26th, 3 hours and 26 minutes after I referred to it.
 * All rockets that have put payload into Earth orbit so far have had hydrogen as a considerable portion of the fuel. When not pure hydrogen, the fuel has always contained considerable carbon.  I agree that people ought to and probably will get away from using such fuels for conventional rocket launch from the Moon, but it will take time.  A possible development is small payloads that have only enough rocket power to circularize before being collected and shipped to geosynchronous Earth orbit with VASIMR thrust.  Rockets large enough to continue on to Mars independently and launched from an electric launcher fast enough to make the journey with the addition of only VASIMR thrust would be a later development.  I hope to read enough about such things to be able to make an intelligent addition to the article, but can not promise any particular date.--Fartherred (talk) 00:49, 31 July 2009 (UTC)
 * Well, see Ammonium perchlorate composite propellant. Hydrogen and carbon are a small part of the weight, tho it does use other light elements. Light elements are ideal for rocket fuel because they offer a lot of chemical energy per kilogram. As they are plentiful on Earth, it's no surprise they dominate rocket fuel. But we have a long time before building rockets on the Moon becomes an issue and I suspect good solutions will be found. Remember that by mass there is 8 times as much oxygen as hydrogen in water. Rockets that burn H2 and O2 run hydrogen rich to cool down the burn, but still most of the lift off mass is oxygen, not hydrogen. Substituting aluminum, say, as the fuel and burning oxygen rich might be quite practical.  --agr (talk) 20:48, 31 July 2009 (UTC)
 * The question of whether or not the claim of a future site for launching rockets as an advantage of a Moon colony ought to be removed as insufficiently documented and upon which there is a lack of general agreement is sufficiently unclear to me that I will not remove it.--Fartherred (talk) 22:43, 1 August 2009 (UTC)

Copyright violation?
The "Water discovered on moon" section seems to contain material directly copied from http://www.sciencemag.org/cgi/content/abstract/sci;1178658v1?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=water+on+moon&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT --Fartherred (talk) 18:13, 28 September 2009 (UTC)
 * Yes, that's a copyvio, it was added three days ago. I've deleted the relevant material. Hut 8.5 20:10, 28 September 2009 (UTC)

There was more copyvio. I removed material from http://www.hindu.com/2009/09/23/stories/2009092357770100.htm --Fartherred (talk) 21:09, 1 October 2009 (UTC)

Synthesis tag

 * As indicated in the “Launch Costs” thread in Archive 28 of this talk page, there has been ample opportunity for those interested in maintaining a synthesis tag on the article to voice that opinion. I therefore intend to remove the synthesis tag.  Those who disagree with this can still comment.  FARTHERED--75.73.162.171 (talk) 16:04, 6 October 2009 (UTC)

Claims made at the Earth's north pole.
The article compares possible territorial claims on the moon to the territorial claims at the north pole, yet the link to north pole territories directly says "Under international law, no country currently owns the North Pole or the region of the Arctic Ocean surrounding it. The five surrounding Arctic states, Russia, the United States (via Alaska), Canada, Norway and Denmark (via Greenland), are limited to a 200 nautical miles (370 km; 230 mi) economic zone around their coasts."

I believe that a better reference would be the south pole, which already shows us many diagrams indicating the divided territories between nations. i.e. "Currently there are seven claimant nations who maintain a territorial claim on eight territories in Antarctica." I feel that this better represents the possible colonization of the moon while comparing it to that of territorial claims at the poles. —Preceding unsigned comment added by Adamckillip (talk • contribs) 21:26, 9 October 2009 (UTC)


 * I agree. Now all that we need are the reliable sources for this information.--Fartherred (talk) 02:00, 10 October 2009 (UTC)
 * I've edited the bit about claims to polar territory so it is at least true and supported by the linked articles sources. It would be better to refer to Antarctic claims if the referrences become available.--Fartherred (talk) 05:40, 10 October 2009 (UTC)

Organization
Doc Tropics' addition and removal of a fact tag on 10 october 2009 show a defect in this article. A statement was duplicated in the "Advantages" and the "Disadvantages" sections, and had a reference only in the latter. People should not have to look that far for a reference. I think my moving the statement and eliminating duplication helped the organization a little, but there is more reorganization needed than I know how to do.--Fartherred (talk) 16:28, 10 October 2009 (UTC)

Center of the Moon
digging a tunnel to the center of the moon may have nice side effects in the core such as 0G inside an atmosphere. On the way down may be interesting rock formations, there is no volcanism on the moon so this would be a fairly cool tunnel.


 * Right, I'll get started on it... —Preceding unsigned comment added by 86.152.242.213 (talk) 04:23, 13 November 2009 (UTC)

Terraforming Moon
I doubt that User:Nakakapagpabagabag is serious about improving Wikipedia with an image of a Terraformed Moon. Terraforming the Moon might not be impossible according to the laws of Physics, but I think this article should be about things that have some arguable practical possibility. The image of an artist's conception of a terraformed Moon is one that was previously added by User:Ittiz at 18:38 on the 7th of January 2007 and deleted at 00:55 on the 8th of that month. The image appears to have been unwanted then and I intend to remove it now.--Fartherred (talk) 13:48, 16 October 2009 (UTC)
 * I don't think I violated the assume good faith policy, but we can talk about it. Nakakapagpabagabag  Removed an image that comes much closer to describing a practical effort at colonizing the Moon than the one he replaced it with.  Discussion of terraforming the Moon can be found in archive 19 archive 1, #11 as the discussions have been rearranged.--Fartherred (talk) 19:19, 16 October 2009 (UTC) corrrection added--Fartherred (talk) 00:46, 12 November 2009 (UTC)
 * Belatedly, I think of the editor whose work I undid. It is certainly possible for someone with only slight familiarity with colonization of the Moon to think that Terraforming might be a necessary step in such colonization.  Let us suppose that Nakakapagpabagabag finding a picture of a terraformed Moon, thought he was moving it to its proper place.  The picture was wrongly added, but I should not be too hard on Nakakapagpabagabag.--Fartherred (talk) 23:10, 16 October 2009 (UTC)

Using plastics does not involve substantial difficulty
I removed the last clause in the sentence "The cost of volatiles could be reduced by constructing the upper stage of supply ships using materials high in volatiles, such as carbon fiber and other plastics, although converting these into forms useful for life would involve substantial difficulty." I'm not sure what the last clause is based on, but at the least, plastics could be burned in oxygen to produce CO2 and water plus smaller quantities of other compounds, such as NOx. The CO2 and water can be used directly by plants, of course. More likely ground up plastics would be mixed with lunar soil or rock and solar heated to extract oxygen (in the form of CO2 and water) and produce metals. Significant work would be required to make such processes practical (as it would for just about everything else this article mentions), but I don't see any justification for the "substantial difficulty" claim.--agr (talk) 22:15, 18 November 2009 (UTC)


 * I fail to understand the distinction that ArnoldReinhold makes between "Significant work" and "substantial difficulty." The two seem synonymous to me.  My experience with burning plastic brings to mind plastic melting into a gooey difficult to manage mess that emitted fumes that were toxic chlorine compounds. It produced significant black smoke, char, and a cleanup problem.  I can imagine plastic ground at low temperature into a powder that is blown with carbon dioxide into a combustion chamber where it mixes with sufficient oxygen to produce a high temperature stream water vapor, carbon dioxide, carbon monoxide and nothing else.  Poly vinyl chloride would either be excluded from the process or the process modified to handle chlorine compounds.  I cannot put my guess work into the article, but I can do the next best thing and tag the misleading statement that resulted from ArnoldReinhold's editing with a citation needed tag.--Fartherred (talk) 16:24, 19 November 2009 (UTC)


 * The distinction I make between "significant work" and "substantial difficulty" is that the later suggest feasibility is in serious doubt. As you point out there are a number of ways to envision such a process. And I would point out that the composition of plastics selected for use in supply vehicles could be tailored to facilitate recycling. My real concern, however is not with the exact choice of words, but signaling out this approach to supplying light elements for the substantial difficulty disclaimer. Pretty much every effort to use lunar material in chemical processes will require substantial engineering work. The level of discussion in our space colonizations articles is that if an element is present on a solar system body then it is available for future colonists to use. Iron, aluminum, titanium and oxygen are plentiful on the moon so colonists will have all they need. Obviously this is grossly oversimplified and a lot more work will have to be done before that is a real possibility. So I have no objection to a general disclaimer to the effect that significant engineering development will be required for any use of local material in building space colonies.--agr (talk) 16:33, 20 November 2009 (UTC)
 * I do not grant agr's interpretation of the meaning of "significant work" and "substantial difficulty." There is definite meaning to "cost of volatiles could be reduced by."  There is the rub.  As the space shuttle proved that it is possible to reuse an Earth to orbit vehicle and convinced many people that there is almost no likelyhood of saving money that way any time soon; it ought to be possible to salvage plastic parts of lunar lander vehicles, if one puts enough money into the effort, but I see no evidence that such a program would save money.--Fartherred (talk) 04:03, 21 November 2009 (UTC)The standards for a reliable source for this article are not currently very difficult.  An even somewhat reliable source to claim that salvaging plastic parts from lunar lander vehicles would save money would be sufficient.--Fartherred (talk) 13:58, 21 November 2009 (UTC)
 * You raise a fair point. I haven't seen any study of what the overall cost of lunar recycling would be, though it's hard to imagine that direct imports would be cheaper in the long run. Note that the International Space Station is already recycling urine into drinking water, an old science fiction theme. I've edited the article text to limit the statement to transportation costs. --agr (talk) 17:19, 22 November 2009 (UTC)
 * Good old agr is more slippery than an eel. There is no longer any need for a citation.--Fartherred (talk) 03:25, 23 November 2009 (UTC)

Habitat
One possibility not considered for the Habitat is moveable structures. The new British Antarctic Base is an example of such a structure. The concept by Faber Maunsell and Hugh Broughton Architects for the Halley VI station places the base on skis. Wheels would probably be a better idea on the moon.

The main advantages of Mobile Habitats are:

1. They could be protected from dangerous metiorites by being fed long range reports on any meteriorites on a collision course with the moon, that they would receive from a network of space telescopes, that in addition to being used for scientific work, would provide an early warning system. 2. They could move to different areas of the planet, not only to avoid danger, but to explore it,collect food from farms, and energy from Solar power plants, whenever they needed it. 3. As a 'foot in the door' they would be perfect, because they would be able to transport the population on mass to wherever they were needed, and being able to collect data on possible sites for more substantial development, would increase the chances of picking the right site.

Long term, all the ideas currently being suggested will be tried, but Mobile Habitats will remain a part of the mix, because of their flexibility, usefulness, and the hazards of living on the moon. —Preceding unsigned comment added by 89.107.3.171 (talk) 05:04, 26 March 2010 (UTC)

Temperature below surface
The average temperature on the moon is about −5 °C. The day period (two weeks) has an average temperature of about 107 °C (225 °F), although it can rise as high as 123 °C (253 °F). The night period (also two weeks) has an average temperature of about −153 °C (−243 °F).[55] Underground, both periods would be around 24 °C (75 °F), and humans could install ordinary air conditioners.[56]

I believe that this is wrong and should read -24 °C (-11.2°F)

The maths is

(153+107)/2=130 and 130−153= −23 or 107−130= −23 —Preceding unsigned comment added by 121.219.255.201 (talk) 23:21, 26 March 2010 (UTC)

You're right, also see. I'm editing it. Also, the part about the aircondioners doesn't make sense now, but I didn't dare to remove it, because of the reference behind it. --94.224.152.35 (talk) 18:59, 21 April 2010 (UTC)

Lunar night
Could anyone bring some consistency in this article on how long the lunar night is?

Growing crops on the moon faces many difficult challenges due to the long lunar night (nearly 15 earth days) The use of electric lighting to compensate for the 28-day night might be difficult The night period (also two weeks) has an average temperature of about −153 °C However, the long lunar night (14 Earth days) is a drawback for solar power on the Moon's surface. On the Moon, they would only be needed for 13.7 days — the length of the lunar night.

See my point?

94.224.153.224 (talk) 17:54, 15 April 2010 (UTC)


 * Yup. I've edited it to be more consistent.--agr (talk) 21:04, 15 April 2010 (UTC)

Removal of a doubious claim
I noticed that Birddog165 put a citation needed tag on the disadvantages point about the detrimental effects of gravity. While most of that point is rather well known stuff, a reference could be helpful. I suspect the bit about astronauts wearing weights on their shoulders might be original speculation. Does anyone object if I remove that part on the basis of its not being referenced? --Fartherred (talk) 20:21, 29 June 2010 (UTC) The bit about astronauts wearing weights is gone. --Fartherred (talk) 03:43, 8 July 2010 (UTC)

Biggest Supply Problem Of Lunar Colony: Nitrogen
I note that this article doesn't mention the nitrogen problem. Breathable air is mostly nitrogen, and there is no nitrogen on the Moon. Every ounce of nitrogen in the colony's air supply would have to be brought from Earth. Opening and closing airlocks, etc. would cause a steady leakage of air which could be replaced by oxygen, water vapor from the Moon. Carbon dioxide might be obtained as a byproduct from the life-support systems. But the nitrogen would have to be brought from Earth. —Preceding unsigned comment added by 67.182.156.184 (talk) 05:32, 28 August 2010 (UTC)

Location of the International Space University
I removed Strasbourg from the article because if anyone wants to know the location of the International Space University, they can click on the link to the article that provides that information. --Fartherred (talk) 18:05, 6 September 2010 (UTC)

Notable Moonbases
Given that the Moonbase [in Star Ocean 3] is a major research area which contains a couple of major events in game [including Fayt, Maria and Sophia's realisation of their powers and destiny], should it be classed as a Notable Moonbase in the video games section of this article? User:Hogtree


 * No. The article is meant to portray a moonbase in reality. No works of fiction need mentioning. —Preceding unsigned comment added by 76.169.12.219 (talk) 02:31, 29 September 2010 (UTC)

Yup. That's right.Marker 20:21, 13 November 2010 (UTC) —Preceding unsigned comment added by Curiosity567 (talk • contribs)

Apollo-era plans
This article should probably mention canceled Apollo era plans: Apollo Applications Program. (I would do it, but I know literally nothing about the subject other than what I discovered in the last ten minutes of idly looking through Wikipedia.) -- Walt Pohl (talk) 11:20, 7 September 2010 (UTC)

The solar energy section has some vague assertions.
In the sentences: "Solar energy is a strong candidate. It could prove to be a relatively cheap source of power for a Lunar base, especially since many of the raw materials needed for solar panel production can be extracted on site." strong candidate, relatively cheap, and especially are just blather. I will substitute: "Solar energy is a possible source of power for a Lunar base. Many of the raw materials needed for solar panel production can be extracted on site." I find the suggestion that solar power could be relatively cheap useless without some explanation of the potential circumstances in which that relative cheapness is to come about. --Fartherred (talk) 03:08, 5 November 2010 (UTC)

Yeah, I agree on what you wrote. Why don't you go and edit it?Marker 20:25, 13 November 2010 (UTC) —Preceding unsigned comment added by Curiosity567 (talk • contribs)
 * Thanks Curiosity,


 * Encouragement is helpful. I edited the article as I suggested.  --Fartherred (talk) 00:26, 16 November 2010 (UTC)

Colonization vs. colonisation; and a word about power cost
Keeping a consistent spelling in an article is good, and the Wikimedia Commons link works with the z spelling, but I should not have changed the speling of the French language title. Luckily, SilvonenBot repaired my carelessness after three hours, thirteen and a half minutes of bad French. User 209.150.104.110 removed the word "enough" from the discription of potential power cost on the moon. The lack of this word damaged an acurate discription of David R. Criswell's position. I will restore it. Fartherred (talk) 06:41, 16 May 2011 (UTC)

Solar Panels
Under "Locations>Far Side" it mentions ilmenite being present on the moon. I read on the Ilmenite page that it's mostly used to get Titanium Dioxide, which is a key ingredient for "memristor" which can be used for Solar Panels. http://en.wikipedia.org/wiki/Titanium_dioxide#Other_applications 184.166.26.1 (talk) 20:14, 30 May 2011 (UTC) == re: "A Lunar base could also hold a future site for launching rockets, to distant planets such as Mars. Launching rockets from the Moon would be an easier prospect than on Earth due to the Moon's lower gravity requiring a lower escape velocity. " ==

This is one of the most illogical things I have ever read, let alone read on Wikipedia... Sure, launching rockets from the moon is easier than earth, because its gravity is 1/6th that of earth, but there are no spare rockets just sitting around on the moon. It would take way more energy to send a rocket from here, slow it down and land it on the moon, and then shoot it off to the mars again. Until we have industrialized the moon so much that we are capable of building a rocket on the moon, it doesn't make any to talk about the advantage of shooting rockets from the moon, because it would obviously be easier to go straight to mars, instead of going to the moon, landing, and then building up the momentum needed to get to Mars. Right? Until someone addresses this argument, this "reason for a moon colony" should be removed. myclob (talk) 22:32, 12 February 2012 (UTC)


 * There could be another advantage. A rocket which lands on the Moon could then be refueled there (with fuel delivered to the Moon previously).  This would allow it to launch from the Moon with far more reserve fuel.  Of course, this refueling operation could also be done in space, but working in zero g is a bit trickier.  You could also develop a system where the rocket is launched from the Moon using electromagnets and a deep shaft, saving all the fuel for later use.  This wouldn't work well in orbit, since the "launch pad" would go flying in the opposite direction.  StuRat (talk) 03:06, 13 February 2012 (UTC)


 * I have added the specification of locally manufactured fuel to the article. Now it should be clear to anyone that this advantage refers to a future situation in which some manufacturing capability is available on the moon. As for rockets going to Mars, that is questionable.  It would be easier just to stay on the moon which offers the potential to electromagnetically launch exports to cis-lunar space.  That is something that cannot be got from Mars so it is better not to go there at all.  Going there should not be listed as an advantage.  Fartherred (talk) 04:28, 14 February 2012 (UTC)

== re: "A Lunar base could also hold a future site for launching rockets, to distant planets such as Mars. Launching rockets from the Moon would be an easier prospect than on Earth due to the Moon's lower gravity requiring a lower escape velocity. " ==

This is one of the most illogical things I have ever read, let alone read on Wikipedia... Sure, launching rockets from the moon is easier than earth, because its gravity is 1/6th that of earth, but there are no spare rockets just sitting around on the moon. It would take way more energy to send a rocket from here, slow it down and land it on the moon, and then shoot it off to the mars again. Until we have industrialized the moon so much that we are capable of building a rocket on the moon, it doesn't make any to talk about the advantage of shooting rockets from the moon, because it would obviously be easier to go straight to mars, instead of going to the moon, landing, and then building up the momentum needed to get to Mars. Right? Until someone addresses this argument, this "reason for a moon colony" should be removed. myclob (talk) 22:32, 12 February 2012 (UTC)


 * There could be another advantage. A rocket which lands on the Moon could then be refueled there (with fuel delivered to the Moon previously).  This would allow it to launch from the Moon with far more reserve fuel.  Of course, this refueling operation could also be done in space, but working in zero g is a bit trickier.  You could also develop a system where the rocket is launched from the Moon using electromagnets and a deep shaft, saving all the fuel for later use.  This wouldn't work well in orbit, since the "launch pad" would go flying in the opposite direction.  StuRat (talk) 03:06, 13 February 2012 (UTC)


 * I have added the specification of locally manufactured fuel to the article. Now it should be clear to anyone that this advantage refers to a future situation in which some manufacturing capability is available on the moon. As for rockets going to Mars, that is questionable.  It would be easier just to stay on the moon which offers the potential to electromagnetically launch exports to cis-lunar space.  That is something that cannot be got from Mars so it is better not to go there at all.  Going there should not be listed as an advantage.  Fartherred (talk) 04:28, 14 February 2012 (UTC)