Salt Lake Telegram | 1923-02-25 | Page 8 | Measuring Star Heat

I Measuring Star Heat I T LOWELL observatory In Arizona Ari Ari- Arizona rl AT zona W W. W W. Coblentz and C. C 0 O. O Lampland have made a number of measurements of the ratio of ot r reflected re reflected re- re energy to the energy reradiated after being absorbed absorbed This latter energy Is of much longer wave wavelength wavelength wavelength length than the former and is en entirely entirely entirely en- en absorbed ed by placing a thin cell of water In the path of the light from the planet The measurements were made by means of a delicate thermocouple capable of detecting the heat from a 8 tallow candle at a distance of many miles roBes The Th ratio of the measurements made with and without the water cell Is called the water cell transmission and denotes the ratio of the reflected energy to th the whole The discussion of the these e observations observations may give some indications of the actual surface temperatures o othe of f tho the planets but the number of or corrections corrections cor cor- corrections to be applied to the original I energy between the time It loaves leave s the planet and energizes the thermocouple thermocouple ther ther- I is stupendous says Dr Donald H. H Menzel of the University I lof of Princeton observatory We Ve know that the Martian equator r nears hears no snow at noon so flO if it th the e temperature is actually raised to zero centigrade the tho temperature of melling meltIng melting melt melt- I e Ing snow we wo would expect It t to b be 60 or more degrees s below zero during the night It appears that the atmosphere at atmosphere atmosphere at- at I does shielding and 1 Is much less leas than that of the earth or orI o r I Venus It lr It looks as though the maxImum maximum max max- mum temperature of Mars Mara is no not t much above freezing I For Venue the observations indi midi IndIcate indicate cate that the temperature Is greater greate r han than that of ot the earth perhaps b by y I 20 degrees The moons moon's temperature e appears to range from boiling water wate r to perhaps as 5 low as as as' or or- de do degrees dc- dc grees green below zeu ze according as It 1 Is o Illuminated by the sun or exposed to t cold empty space pace For the two larger planets Jupiter r rat and Saturn It ft la is very definite that th at they radiate some Borne heat of ot their ow own If they were warmed only by the th e heat of the sun Bun they would be 16 e degrees to degrees below zero centigrade The temperatures obtained obtained ob ob- for these planets are probably Y fairly accurate and we have hae f for or Jupiter obtained something less than the 90 30 below centigrade while Saturn is Is I hotter b by some 20 degrees a resu result It i not unreasonable for Saturn is muc much h less dense Il