The Bridgeport times and evening farmer., 1918-01-01
Favorable Time to Study PeerIes VeIlus-ResembIa to
 the Earth

(By Dr. c. s. Brainin, of the Colum- bia University bservatory Staff.)
 The heavens this month present for our pleasure a notable array of plan cts and fixed stars. In our map we are able to show the location of two of the brightest planets, Jupiter and Saturn; but the brightest of them all is Venus. and, though setting just a little too early to be shown on our nine o'clock map, she can easily be re- cognized in the southwestern sky for several hours after sunset.
 Now is particularly favorable time to observe and study this latter planet, for on the fourth of the month it will be at it's maximum of brightness. This will probably be a new idea to some of our readers-that planets change their brightness-but it is true, and the entire phenomenon is extremely interesting in the case of Venus. Only two of our regular celestial bodies are brighter than Venus, and these are the two monarchs of the sky, the sun and the moon Sometimes a comet which is brighter comes as a transient visi- tor, but it does not stay long to com pete with Venus. At certain times she can be seen in the daytime, even when the sun is well up above the horizon, and many persons have thus seen her It is said that the light of Venus is strong enough to make ob- jects cast perceptible shadows. In the absence of the moon and other ex- traneous sources of light. it seems quite possible.
 Is Venus Inhabited?
 In spite of all the talk that there has been about the inhabftabilfty of Mars, it really seems that of all the planets in the solar system it is Venus on which the conditions are most like those which exist on the earth. For one thing, the size of Venus is very nearly that of the earth, the mean diameter being about 7,700 miles to the earth's 1900. The mass of the planet is not very accurately known, but is probably about four-fifths that of the earth. Nearly the same ratio seems to hold her for the density of the material making up the planet and for the strength of the gravitation on its surface, r. s--.. -.. s.-.
 The reason why these things are not known with the accuracy which
 
 astronomie folk is because computa- tions of mass can be made with great est accuracy when the planet has a satellite rotating about it. Since neith- CT Mercury nor Venus has such moons of their own, their masses have had to be calculated from the disturbances or perturbations which their gravita- tional attractions produce in the orbits of the neighborihg planets. Surface conditions on Venus probably ap- proaeh those on the earth more nearly than on any other planet, because il seems to be established that water and water vapoF exist there. Water is the great necessity for the main tenanee of form of life like that or the earth, and in the case of Mars the best scientific evidence seems to be entirely against v,the presence of tha1 indispensable form of matter, at leas to any appreciable extent, on that planet. However, the evidence is al in favor of there being plenty of it or Venus and probably more even thar on the earth. While the spectrOscopit results are not conclusive, the appear ence of an illuminated ring about tn, planet at the time of transit acros. the face of the sun are quite conVinc ing.
 Several observers report having seer markings on the surface of Venus, bu all such observations are open to gray, doubt Observation of the planet i! Very difficult both because of it nearness to the sun and because of it heavy atmosphere. The rotation per ied or length of Venus day, is there fore, not very well known, and it i Impossible to tell definitely what thu esmperature conditions on the surface are. The probability is, however, tha no extremes of temperature exis there and that conditions are quite ii for the existence of human life. Ina is about all that can be said.
 The Phases of Venus
 The person who has. not the goo, fortune ts possess a telescope vii hardly suspect that Venus passe through a series of phases very mucl like those of the moon. Venus is no seif-luminous, and her appearanc from the earth win depend upon tn FelatiVe positions Of the sun and earth The orbit of Venus about the sun lie FfthiR that of the earthI so that VI