Post by Chicago Astronomer - Astro Joe on Jul 5, 2006 16:24:00 GMT -6
JULY 2006
7/1 The Moon is at apogee, subtending 29'33" from a distance of
404,448 km, at 20:00; asteroid 2 Pallas (magnitude 9.5) is at
opposition at 20:00; minimum lunar libration of 1.2 degrees occurs at
23:00
7/2 Venus is 4.1 degrees north of the first magnitude star Aldebaran
at 5:00; Mercury (magnitude 1.7) is 9.6 degrees west of Saturn
(magnitude 0.4) at 9:00
7/3 The Galilean satellites Io, Europa, Ganymede, and Callisto form a
zig-zag pattern to the west of Jupiter at 3:00; First Quarter Moon
occurs at 16:37; Earth is at aphelion (152,095,745 km from the Sun)
at 23:00
7/4 Mercury is stationary at 2:00; the Moon is 0.1 degree south of
the first magnitude star Spica (an occultation occurs in southern and
western Africa) at 17:00; Mercury is at aphelion at 23:00
7/5 Jupiter is 4.4 degrees north-northeast of the Moon at 22:00
7/6 Jupiter is stationary in right ascension, with direct (eastward)
to resume, at 19:00
7/8 The Moon passes 0.2 degree south of the first magnitude star
Antares (an occultation occurs in New Zealand, New Guinea, and
northern and eastern Australia) at 8:00; maximum lunar libration of
8.8 degrees occurs at 16:00
7/9 Mars (heliocentric longitude 162.1 degrees) and Uranus
(heliocentric longitude 342.1 degrees) are at heliocentric opposition
at 13:00
7/11 The Full Moon, known as the Hay or Thunder Moon, occurs at 3:02;
Ganymede disappears into eclipse by Jupiter's shadow at 3:17
7/13 Neptune is 2.9 degrees north-northwest of the Moon at 5:00; the
Moon is at perigee, subtending 32'48" from a distance of 364,289 km,
at 18:00
7/14 Uranus is 0.38 degree north of the first magnitude star Antares
(an occultation occurs in southeast Asia and the southern tip of
South Africa) at 23:00
7/15 The Moon is at the ascending node (longitude 357.5 degrees) at
20:27
7/17 Last Quarter Moon occurs at 19:12
7/18 Mercury is in inferior conjunction with the Sun at 7:00
7/20 The Moon is 0.53 degree northwest of the center of the bright
open star cluster M45 (the Pleiades) at 8:00; Venus is 1.5 degrees
south of the open cluster M35 in Gemini at 21:00; the Sun enters the
constellation of Cancer (ecliptic longitude 118.08 degrees) at 23:00
7/22 Maximum lunar libration of 8.7 degrees occurs at 2:00; Mars
(magnitude 1.8) is 0.64 degree north-northeast of the first magnitude
star Regulus (magnitude 1.4) at 16:00
7/23 Venus is 5.6 degrees south of the Moon at 0:00; Venus is at its
greatest northern declination (22.8 degrees) at 6:00
7/24 The Moon is 2.1 degrees south-southwest of the first magnitude
star Pollux at 11:00
7/25 Mercury is at its greatest heliocentric latitude south (-7.0
degrees) at 5:00; New Moon (lunation 1034) occurs at 4:31; the Moon
is 2.3 degrees north-northeast of the bright open star cluster M44 at
15:00
7/27 Mars is 1.1 degrees south of the Moon (an occultation occurs in
Europe, Great Britain, and part of Greenland) at 17:00
7/28 The Southern Delta Aquarid meteor shower (approximately 20/hour)
peaks at 7:00; Mercury is stationary in right ascension, with direct
(eastward) motion to resume, at 17:00
7/29 Minimum lunar libration of 0.9 degree occurs at 7:00; the Moon
is at apogee, subtending 29'28" from a distance of 405,406 km, at
13:00; the Moon is at the descending node (longitude 176.3 degrees)
at 16:58
The waning Moon occults some of the bright stars of the Pleiades for
observers in eastern North America on the morning of July 20. For
further information on this noteworthy event, browse www.lunar-
occultations.com/iota/2006plnam/pleiadna.htm
Times and dates for the lunar light rays predicted to occur this
month are available at www.lunar-
occultations.com/rlo/rays/rays.htm
The planets on July 1: Mercury (1.4 magnitude, 10.0", 21%
illuminated, Cancer), Venus (-3.9 magnitude, 12.1", 85% illuminated,
Taurus), Mars (1.8 magnitude, 4.0", 96% illuminated, Cancer), Jupiter
(-2.3 magnitude, 40.8", 99% illuminated, Libra), Saturn (0.4
magnitude, 16.6", 100% illuminated, Cancer), Uranus (5.8 magnitude,
3.6", 100% illuminated, Aquarius), Neptune (7.8 magnitude, 2.3", 100%
illuminated, Capricornus), and Pluto (13.9 magnitude, 0.1", 100%
illuminated, Serpens Cauda).
Morning planets: Mercury, Venus, Uranus, and Neptune
Evening planets: Mars, Jupiter, Saturn, and Pluto
Mercury leaves the evening sky and is lost in the glare of the Sun as
it approaches inferior conjunction on July 18. It reappears in the
morning sky about 7 degrees below Venus at the very end of the month.
For observers at a latitude of 40 degrees north, Venus is just a bit
more than 20 degrees in altitude in the east-northeast at dawn. Venus
journeys through Taurus and enters Gemini during the course of the
month.
Mars, shining at its minimum brightness of 1.8 magnitude, is very low
in the west at sunset. It moves from Cancer to Leo in early July. The
Red Planet lies within 1.3 degrees of Regulus for four nights
centered around July 21 and July 22. On July 22, Mars is just 41'
above Regulus at dusk.
During July, Jupiter halts its retrograde motion and heads eastward
toward Alpha Librae (Zubenelgenubi). By month's end, the separation
between them is approximately 5 degrees. According to predictions,
the Great Red Spot (GRS) and Red Spot Junior, which is officially
designated as Oval BA and is located in the South Temperate Belt,
will be closest to each on July 4. Click on
skyandtelescope.com/observing/objects/planets/article_107_1.asp
to determine transits of the central meridian by the GRS.
Saturn is a difficult target for northern observers but can be seen
with difficulty low in the west at sunset until the third week of the
month.
Uranus is approximately 1 degree away from the third magnitude star
Lambda Aquarii on July 1. Sir William Herschel's planet passes
between 82 Aquarii (magnitude 6.2) and 83 Aquarii (magnitude 5.4) on
July 24.
In the early part of July, Neptune is located about halfway between
fourth magnitude Iota Capricornii and fifth magnitude 29 Capricornii.
By the end of the month, the planet's retrograde movement places it
0.9 degree to the south of 29 Capricornii. Neptune forms a
false "double star" on July 10 when it is just 2' south of an eighth
magnitude star.
Pluto is well placed in the southern sky on July evenings. It is
located just to the southeast of Xi Serpentis (magnitude 3.5) as the
month begins. Pluto passes 11' south of a sixth magnitude star that
is 10' south of Xi on July 17. By the end of July, Pluto is about 0.5
degree southwest of Xi Serpentis.
The periodic comet 71P/Clark travels southward through southern
Sagittarius this month. 71P/Clark has a period of 5.5 years and is
predicted to glow dimly at 11th or 12th magnitude as it passes
several degrees to the east of the fourth magnitude star Alpha
Sagittarii.