View Full Version : temperature of space
alistair
May4-04, 03:06 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>What is the magnitude of the temperature of space at 20 - 70 AU from the sun?\nAnd how much would a piece of metal contract by at this temperature?\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>What is the magnitude of the temperature of space at 20 - 70 AU from the sun?
And how much would a piece of metal contract by at this temperature?
John T Lowry
May7-04, 06:35 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>Seems to me that solar radiation absorption and re-radiation would be the\nmain thing to look at.\n\nJohn\n--\nJohn T Lowry, PhD\nFlight Physics\n5217 Old Spicewood Springs Rd, #312\nAustin, Texas 78731\n(512) 231-9391\njlowry100@earthlink.net\n"alistair" <alistair@goforit64.fsnet.co.uk> wrote in message\nnews:861c1b21.0405040700.410272a0@posting .google.com...\n> What is the magnitude of the temperature of space at 20 - 70 AU from the\nsun?\n> And how much would a piece of metal contract by at this temperature?\n>\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>Seems to me that solar radiation absorption and re-radiation would be the
main thing to look at.
John
--
John T Lowry, PhD
Flight Physics
5217 Old Spicewood Springs Rd, #312
Austin, Texas 78731
(512) 231-9391
jlowry100@earthlink.net
"alistair" <alistair@goforit64.fsnet.co.uk> wrote in message
news:861c1b21.0405040700.410272a0@posting.google.c om...
> What is the magnitude of the temperature of space at 20 - 70 AU from the
sun?
> And how much would a piece of metal contract by at this temperature?
>
Peter Tobias
May7-04, 06:36 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>alistair:\n> What is the magnitude of the temperature of space at 20 - 70 AU from the sun?\n\nI\'m not sure if the question, phrased in this way, makes sense. What,\nif a planet comes between your point and the sun? What, if the emission\ncoefficient of a body at the point is not the same on surfaces pointing\nin the orbital plane as on surfaces pointing perpendicular to it?\n\n> And how much would a piece of metal contract by at this temperature?\n\nThat is possible to compute under certain assumption. Assume, for\nexample, that the emission coefficent of the metal is the same in all\ndirections and all wavelengths. The steady-state temperature of the\nmetal is reached, when the absorbed energy is equal to the emitted energy.\n\nRegards,\n\nPeter\n\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>alistair:
> What is the magnitude of the temperature of space at 20 - 70 AU from the sun?
I'm not sure if the question, phrased in this way, makes sense. What,
if a planet comes between your point and the sun? What, if the emission
coefficient of a body at the point is not the same on surfaces pointing
in the orbital plane as on surfaces pointing perpendicular to it?
> And how much would a piece of metal contract by at this temperature?
That is possible to compute under certain assumption. Assume, for
example, that the emission coefficent of the metal is the same in all
directions and all wavelengths. The steady-state temperature of the
metal is reached, when the absorbed energy is equal to the emitted energy.
Regards,
Peter
Joseph.D.Warner
May7-04, 06:42 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>alistair wrote:\n> What is the magnitude of the temperature of space at 20 - 70 AU from the sun?\n> And how much would a piece of metal contract by at this temperature?\n\n\nYou probably can use the background radiation temperature of ~3K for the\ntemperature. But temperature itself is defined by the collective motion\nof particles and at 70 AU the density of particles is very low and I am\nnot sure you could define the temperature of particles in the region.\n\nThe second question can be answered by looking up material properties in\nCRC Handbook of Chemistry and Physics and see what the contraction would\nbe from the tables and formulas inside, or you can go to www.nist.gov\nand look through their site for the material of interest.\n\n\n\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>alistair wrote:
> What is the magnitude of the temperature of space at 20 - 70 AU from the sun?
> And how much would a piece of metal contract by at this temperature?
You probably can use the background radiation temperature of ~3K for the
temperature. But temperature itself is defined by the collective motion
of particles and at 70 AU the density of particles is very low and I am
not sure you could define the temperature of particles in the region.
The second question can be answered by looking up material properties in
CRC Handbook of Chemistry and Physics and see what the contraction would
be from the tables and formulas inside, or you can go to www.nist.gov
and look through their site for the material of interest.
Oliver Jennrich
May12-04, 02:37 PM
<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no, location=no,scrollbars=yes,resizable=yes,status=no ,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>* Joseph D Warner writes:\n\n> alistair wrote:\n>> What is the magnitude of the temperature of space at 20 - 70 AU from the sun?\n>> And how much would a piece of metal contract by at this temperature?\n\n> You probably can use the background radiation temperature of ~3K for the\n> temperature.\n\nCertainly not. A body at 3K emits about 4.5927 microW/m^2, but receives\nabout 0.27 W/m^2 from the Sun\n\nAssuming perfect emissivity, a sheet of metal facing the sun would get\ndown to about 40K.\n\n--\nSpace - the final frontier\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form"> View this Usenet post in original ASCII form </a></div><P></jabberwocky>* Joseph D Warner writes:
> alistair wrote:
>> What is the magnitude of the temperature of space at 20 - 70 AU from the sun?
>> And how much would a piece of metal contract by at this temperature?
> You probably can use the background radiation temperature of ~3K for the
> temperature.
Certainly not. A body at 3K emits about 4.5927 microW/m^2, but receives
about .27 W/m^2 from the Sun
Assuming perfect emissivity, a sheet of metal facing the sun would get
down to about 40K.
--
Space - the final frontier
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