Photo of the Week.Blue skies always top the clouds.
Astronomy news for the week starting Friday, July 18, 2014.
The Moon passes through its third quarter
the night of Friday, July 18, shortly before Moonrise in North
America, and then spends the rest of the week thinning out in the
waning crescent phase, new Moon not
reached until Saturday the 26th. Early risers that have a clear
eastern horizon can see the thin
crescent just to the right of Venus the
morning of Thursday the 24th.
The two giant planets make the biggest splash. Jupiter, which
has been invisible in the solar glare for some time now, finally
passes conjunction with the Sun on Thursday the 24th, and thus
officially becomes a morning planet. Its rising, though, will not
clear dawn until the middle of August. Earlier in the week, on
Monday the 21st, Saturn ceases its
retrograde, westerly, motion against the background stars, and
resumes its normal easterly movement as it heads toward Scorpius. Number two in the Solar
System, Saturn has a third the mass of Jupiter, but because of
lower gravity puffs out almost as large, rendering it by far the
least-dense of the Sun's family. Farther away,
Uranus begins retrograde in Pisces on
Tuesday the 22nd.
Saturn and
Mars dominate the early nighttime sky, Mars to the southwest
as evening falls, somewhat dimmer Saturn not far to the east of
the red planet, Mars in Virgo
now a bit to the east of Spica,
Saturn in the next zodiacal
constellation over, Libra. Mars
sets about midnight Daylight Time, while Saturn goes down an hour
later. The morning sky hosts the two inner planets, Venus, which
rises as dawn starts to light the sky, then down and to the left
of the bright planet, Mercury, which is now past its prime and
hard to see.
