TO KNOW THE STARRY HEAVENS 
/ 
half full, but having located it then, he 
can probably follow it for some weeks 
longer and observe its change into a 
narrow crescent. 
Venus is now so very near the sun 
that it cannot be seen at all during the 
present month. On July 3 it will pass 
to the east of the sun and become an 
evening star, but it will not emerge 
sufficiently from the sun’s rays to be 
easily seen until next autumn. 
Those who have been watching the 
retrograde motion of Mars in Virgo 
have seen how this planet has been 
drawing nearer and nearer to the bluish 
star Spica (at S), until by June 1 it 
has almost reached this star, but is two 
degrees north of it. But on this even- 
ing at eight o’clock the westward mo- 
tion of Mars will cease, and from then 
on until the end of the year it will run 
eastward again ; it will cross Ophiuchus 
and reach the borders of this month’s 
map by December. The planet is still 
in excellent position for observation, 
although during the month its distance 
from us will increase from 61,000,000 
to 78,000,000 miles, and it will diminish 
one-half a magnitude in brightness. The 
last was not the most favorable possi- 
ble opposition, for even when nearest 
us the planet was 54,000,000 miles 
away, while its distance at an opposi- 
tion occurring in August may be but 
36,000,000 miles. Yet doubtless during 
the past months this little world has 
been kept under constant observation 
at many observatories, and the results 
will be published in due time. 
On June 24, at to hours and 43 min- 
utes P. M., the moon will pass to the 
east of Mars. As seen from the United 
States, the two objects will then be a 
little more than the diameter of the 
moon apart. Mars being north of the 
moon. Observers in southern lati- 
tudes, however, will see the planet hid- 
den by the moon. On the same evening, 
and only four hours earlier, they will 
see the moon hide Spica, but to us our 
satellite will be seen to pass some dis- 
tance south of the star. 
Jupiter continues its slow southward 
and eastward motion toward the east- 
ern borders of Cancer, but is still in 
good position for observation. Inter- 
esting phenomena of its satellites may 
be observed on the evenings and nights 
of June 3, 16, 19, 23 and 28. 
Saturn is moving southward and 
eastward, a very little to the east of 
the star at V. The rings are now seen 
so obliquely that they appear very nar- 
row, but they will not entirely disap- 
pear until next November. The great 
moon, Titan, is farthest east of the 
planet on June 5 and 21, and farthest 
west on June 13 and 29. This moon, 
notwithstanding the great distance 
away of Saturn, can readily be seen in 
Figure 3. Apparent path of Beta Scorpii during 
its occultation on the early morning of Jun-e 28. 
a small telescope. It is no less than 
3,500 miles through, much larger than 
Mercury and nearly as large as Mars. 
The next largest moon, Iapetus, is 
2,000 miles in diameter; this can aUo 
easily be seen. As both the satellites 
move in circles which we now view 
nearly edgewise, they seem to oscillate 
from one side of the planet to the other. 
Titan occupies a little less than sixteen 
days in one revolution and Iapetus sev- 
enty-nine days. The latter will pass 
from the east to the west of the planet 
on June 20. 
S$C i-C 
The Longest Day. 
On June 21 at o hours and 40 min- 
utes P. M. (Eastern Standard time), 
the sun will reach its highest point in 
the heavens and this will accordingly 
be the longest day of the year. In a 
latitude of 40 degrees, the sun will rise 
at 4 hrs. 31 min. A. M., and set at 7 
hrs. 32 min. P. M., the day being thus 
6 hrs. 2 min. longer than the night. In 
higher latitudes the difference is, of 
course, still greater. For example, in 
latitude 60 degrees the sun will rise at 
2 hrs. 36 min. and set at 9 hrs. 28 min., 
so that the night is but 5 hrs. 8 min. 
long. In these latitudes twilight will 
last throughout the night, and north of 
the Arctic Circle the sun will ,of course, 
