JULY 2010 – OBSERVING HIGHLIGHTS
See http://www.skymaps.com/downloads.html
for a great map and list of monthly events.
http://www.skyandtelescope.com/observing/ataglance
July 123
http://cs.astronomy.com/asycs/forums/p/47041/447929.aspx binocs, poetry,
http://www.jodrellbank.manchester.ac.uk/astronomy/nightsky/#highlights
July 2010 Highlights
* Venus, Mars and Saturn close in on each other in the evening sky
* Venus passes within 2° of bright star Regulus on the 8th
* Mars and Saturn within 1.8° of each other on the 30th
* Mercury has a mediocre evening apparition in July/August
* Mercury passes within 0.3° of Regulus on the 27th
* Comet 10P/Tempel 2 reaches small telescope brightness in the morning sky
Notes from Stan, an Aggie Amateur Astronomer:
Right now, even newbie astronomers can be experts at
planet locations. At sundown, you may
notice an unusual string of almost perfectly aligned stars in the west. But, they are NOT (all) stars! Four planets, 1 bright star and 1 dwarf
planet (asteroid) can be seen. From W to
SW they are VENUS (Mag. -3.96), REGULUS (Mag. 1.35), MARS (1.51) and SATURN
(1.27). The dwarf planet, Vesta (Mag. 7.17 and fading to 7.32 later in the month) can
be seen in this vicinity with the help of binoculars and a star chart or an
astronomy computer program such as Stellarium. Where’s the 4th planet? It can be seen by looking down at your toes. Keep watching each evening as they all
steadily converge, to be briefly joined by MERCURY just above the setting sun
from the 21st to the end of the month. Get set for an amazing August arrangement of
Venus, Mars and Saturn.
JUPITER:
Jupiter (Mag. -2.09) rises in the East just after 1:00AM, and is easy to
see before dawn. Be sure to check out
the 4 Jovian moons during the month as they stay in line but change positions
next to Jupiter. Callisto
(Mag. 6.31), Europa (Mag. 5.97), Io (Mag. 5.69) and
Ganymede (Mag. 5.29) do a nightly dance around the King of Planets which rises
earlier as the summer continues. By the
end of the month, Jupiter will rise around 11PM. As a bonus, you may be able to see blue
Uranus (Mag. 6.01) shining about as brightly as Europa
all this month. Look for it about two
degrees SE of Jupiter in the 2 o’clock position from Jupiter.
NEPTUNE: With a noticeable blue gray hue, Neptune will lie about 24 degrees SE of Jupiter between
Aquarius and Capricorn. I find that my
best way of spotting Neptune (Mag. 7.84) is by
following it nightly using medium to large binoculars and an astronomy program
such as Stellarium 0.10.2 (free from the internet or
the ACA). I can definitely identify it
after a few nights of comparison with nearby similar magnitude stars (within my
binocular field).
Asteroids
Binocular and Small Telescope Asteroids (V < 9.0)
(1)
Ceres -Spot a Dwarf Planet:
Ceres, now
classified as a dwarf planet. It lies in southern
Ophiuchus
in a region of the Milky Way.
However,this
month it is passing in front of a dark cloud of dust and gas known as Barnard
78. This hides most of the
milky way stars allowing
7th magnitude Ceres to be easily seen. As shown on the chart, it lies below the
star Theta
Ophiuchi. On the 6th of July it will lie
next to a 6th magnitude star 2.5 degrees southeast of Theta
Ophiuchus.
With a telescope you may well be able to see Ceres move relative to the star over a few hours.
Ceres is the biggest asteroid in the Main Belt with a diameter of 585 miles
or 975 km. Classified as a carbonaceous
(carbon-rich) Cg-type asteroid, there are suggestions that it may be rich in
volatile material such as water. Some even propose that an ocean exists below
its surface. Ceres is the other target of NASA’s Dawn spacecraft which is scheduled to visit it in 2015.
This month Ceres will be at opposition and brightest. The asteroid will
start the month at magnitude 7.4 and fade to magnitude 8.1 by the end of the
month. All month long it will be retrograding on the border of Sagittarius and Ophiuchus.
A finder chart can be found at the Royal Astronomical Society
of New Zealand (needs to be flipped upside down for Northern Hemisphere
observers). , and also at Heavens-Above.com.
(2) Vesta - See the mention of Vesta in Stan’s comments above.
I. EARTH SATELLITES: Moon –
Last quarter – July 4th
New moon - July 11th
1st Quarter
– July 18th
Full moon – July 26th
July 8th: The crescent Moon close to the Pleiades Cluster.
Early morning on the 8th will provide a nice skyscape
with the waning crescent Moon - perhaps showing Earthshine - just to the right
of the Pleiades Cluster. Its brightness will hide the fainter stars in the
cluster, but binoculars should show the brighter ones.
July 20th: Two great Lunar Craters: Tycho and Copernicus
This is a great night to observe two of the greatest
craters on the Moon, Tycho and Copernicus, as the
terminator is nearby. Tycho is towards the bottom of
Moon in a densely cratered area called the Southern Lunar Highlands. It is a
relatively young crater which is about 108 million years old. It is interesting
in that it is thought to have been formed by the impact of one of the remnents of an asteroid that gave rise to the asteroid Baptistina. Another asteroid originating from the same
breakup may well have caused the Chicxulub crater 65
million years ago. It has a diameter of 85 km and is nearly 5 km deep. At full
Moon - seen in the image below - the rays of material that were ejected when it
was formed can be see arcing across the surface. Copernicus is about 800
million years old and lies in the eastern Oceanus Procellarum
beyond the end of the Apennine
Mountains. It is 93 km
wide and nearly 4 km deep and is a clasic
"terraced" crater. Both can be seen with binoculars.
Near Earth - July is still a very good time to spot Noctilucent Clouds! Also known as
polar mesospheric clouds, they are most commonly seen in the deep twilight towards
the north from our latitude. They are the highest clouds in the atmosphere at
heights of around 80 km or 50 miles. Normally too faint to be seen, they are
visible when illuminated by sunlight from below the northern horizon whilst the
lower parts of the atmosphere are in shadow. They are not fully understood and
are increasing in frequency, brightness and extent; some think that this might
be due to climate change! So on a clear dark night as light is draining from
the north western sky long after sunset just take a look towards the north and
you might just spot them!
II.
ARTIFICIAL SATELLITES:
Check out “Spaceweather.com” and click on “Satellite
Fly Bys.” It shows only the brightest satellites, such as the ISS, Hubble space
Telescope, the Iridium wreckage, etc. It also gives their data, such as rise time,
direction, elevation, and magnitudes.
See also “Heavens-Above.com” for satellites crossing your
specific location.
III.
PLANETS:
MERCURY: July 13, Mercury in Beehive cluster with
crescent Moon nearby.
July 28,
Mercury and Regulus close.
Mar 2011
Messenger spacecraft to enter elliptical orbit. See http://en.wikipedia.org/wiki/Mercury_%28planet%29
VENUS: July 10,
Venus and Regulus close..
July 15: An evening line up of the planets
Given a good low western horizon around July 15, you should be able to
spot the planets Saturn - up to the left, Mars and Venus - to the lower right.
July 31: Mars, Saturn and Venus close. Watch for closer
situation as August comes on.
IV. DEEP
SKY: Constellations – Enjoy the summer Triangle, Scorpus,
Sagittarius, Hercules, Ursa
Major, Ophiuchus, and many
more this time of year.
V.
NEBULA: The dumbbell Nebula M27 is easily seen in
binoculars. It lies in Valpecula.
This magnificent planetary nebula is very bright and large. The Ring Nebula M57
lies in Lyra. With a
filter you can also see the veil nebula in Cygnus the Swan.
VI. CLUSTERS:
M13 in Hercules is the largest globular cluster in the Northern
Hemisphere. Look for it in Hercules’ keystone. M5 another fine
globular cluster lies in Serpens.
M11, the Wild Duck cluster is one of the richest and most compact open
clusters. Lying in Scutum,
it’s one of the grandest views in the sky.
VII. GALAXIES:
M81 and M82 can be seen in the same field of view in binoculars and wide field
telescopes. Look in Ursa
Major for the gems. Check out the whirlpool galaxy M51 in Canes Venatici.
VIII. COMETS:. On July 2, newly discovered Comet
McNaught makes its closest approach to the Sun. A finder chart for Comet McNaught
can be found at Comet
Chasing.
IX. METEORS: July 28, 29 - Southern Delta Aquarids
Meteor Shower. The Delta Aquarids
can produce about 20 meteors per hour at their peak. The shower usually peaks
on July 28 & 29, but some meteors can also be seen from July 18 - August
18. The radiant point for this shower will be in the constellation Aquarius.
Best viewing is usually to the east after midnight.
*Don’t
forget to see one of the most beautiful double stars in the heavens – Alberio
in Cygnus the Swan.
