| Show W my ekly biride de to sch t ace hy by permission of POPULAR SCIENCE MONTHLY IM WHY IS THE PLANET MARS CLOSER TO US SOME YEARS THAN OTHERS the orbits ot of the planets mars and and the earth included are not exactly circular they are oval also mars and ana the earth move at different speeds accordingly whether they are relatively near together on a given day or relatively tar far apart depends on what particular part of its orbit each one Is in astronomers calculate in advance just when the two plan planets e ts will be nearest together and arrange range e to make their observations at that time WHAT IS THE PLANET VENUS LIKE it Is about the same size as the earth and Is probably s good deal like it except that venus Is warmer being about dwerl million miles closer to the sun sul than we are what the surface ot of venus Is like we do not know for we see only a uniform glistening white probably a layer of clouds which always covers the planet an and I 1 never breaks away ARE ALL TIM PLANETS SOLID no some ol of them must be liquid they are too light in comp comparison arlson with their size to be solid jupiter neptune an and d uranus are only about one and a third times as heavy as water much lighter than any known rock saturn Is lighter than water ARE AHE THE OTHER PLANETS LARGER OR SMALLER THAN THE EARTH the largest planet Is jupiter eleven times the diameter ot of the eart earth h next la Is saturn nearly ten times the earths diameter neptune and uranus are ea each h about to lour u r times the eart earths we diameter venue to la only a trifle smaller than the earth mars Is IB about halt OUT our and mercury about 0 one n 0 third third I 1 I 1 wint ARE TIIE THE RINGS SATURN MADE KALDE OF they are really a ring shaped cloud c containing onta ining a great number of moons much like our moon but very much smaller HOW HOT WAS THE EARTH rot FORMED nIED scientists believe that billions of 0 years a ago go a passing star happened to come too near to our sun by its attraction of gravity this star etar pulled out of the sun a great cloud ot of broken fragments 0 of matter these fragments kept on revolving around the sun just as the rings ot of saturn revolve around it in the course of 0 ages the fragments gathered together into larger lumps thus they formed the earth and the other planets WHAT CAUSES AN eclipse OF oja THE SUN the moon as it moves around the earth happens to get exactly between us ua and the sun IS AN ECLIPSE OF THE NOON MOON CAUSED IN THE SAME WAY AS AN ECLIPSE OF THE SUN not exactly in this case the earth gets between the sun suit and the moon the shadow or of the earth falls on the moon and cuts off the sunlight from it HOW HOW CAN DATES IN ANCIENT HISTORY BE FOUND OUT FROM ECLIPSES f car ai 0 51 41 I 1 astronomers know very exactly the the paths of the earth and the moon in space they can calculate where either of these bodies wels was at any given time in the past so they can c calculate the dates of past eclipses as well as future ones it if any ancient record contains a mention of an eclipse astronomers can calculate in what year that eclipse occurred mir is TIM THC CARTH round INSTEAD OF SOME OTHER SHAPE because any mass of matter takes this from its of nf it if the earth were square and had bad cornera which stuck out the attraction of gravity of 0 the rest ol of the earth would pull these corners down to the general level of the surface of a sphere or close to it |
