November 2005 Sky from the Keeble Observatory
The early evening is highlighted by our two nearest planetary neighbors.
At the onset of twilight, you’ll notice a very bright “star”
to the southwest. That’s Venus, catching up to us as it orbits
closer to the Sun than we do, and hence moves faster. The brilliance
is for two reasons: first, it’s getting closer. Second, it
is shrouded in clouds, which reflect most of the visible light striking
the planet. That Venus is almost the same size as Earth and covered
in clouds once led astronomers to believe that conditions there
would be somewhat like on Earth, but perhaps a bit warmer. Steamy
jungles and dinosaurs were common fare in pulp science fiction,
not to mention fair maiden princesses ready to be rescued by an
intrepid hero from your home planet.
We now know otherwise. The clouds are not water, rather they are
sulfuric acid. “A bit warmer” turns out to be 750 K!
The dense atmosphere is mostly carbon dioxide, and about 90 times
as dense as our own air. CO2, known to be a factor in global warming
on Earth, is responsible for a “runaway greenhouse effect”
To the east, you’ll see Mars rising a few minutes earlier
each evening. Directly opposite the Sun on the 6th, you’ll
see this bright red light climb higher and higher as the month progresses.
We’ve nearly caught up to Mars as I write this, and we’ll
pass it on the inside lane, much as Venus is catching up to us,
and will eventually pass us and move from the evening to the morning
Mars is only a third the size of Earth, so it cannot hold on to
a dense atmosphere. Even though its thin CO2 atmosphere keeps it
warmer than it would be without, that still leaves Mars a very cold
planet. The permanently frozen polar caps are believed to contain
most of the water on the planet, with deposits of frozen carbon
dioxide (dry ice) providing the seasonal variations. The pressure
at the surface is so low, less than 1% that on Earth, that liquid
surface water is not possible. Even at the cold temperatures found
there, liquid water would boil away quickly.
Only on Earth among the three do we find conditions for liquid
water! It’s sort of like Goldilocks: Venus is too hot, Mars
is too cold. Earth is just right!
Lunar phases for November: New Moon at 8:25 pm, on the 1st; First
Quarter on the 8th, at 8:57 pm; Full Moon on the 15th, at 7:57 pm;
and Last Quarter on the 23rd at 5:11 pm.
Early morning sky watchers will still get to follow Mars –
look for a bright red “star” to the southwest, about
where Venus was the previous evening. Jupiter rises about an hour
before sunrise by mid-month, stretching that to 2 hours by the end
of November. Mercury will return to the morning sky at the end of
the month. Look for it about half-way to the sunrise point from
Evening skywatchers will also have a chance to see Mercury, but
low on the southwestern horizon at the beginning of the month. On
the 3rd it reaches its greatest eastern angular separation from
the Sun, but the plane of its orbit makes a very shallow angle to
the horizon at sunset. Mars reaches opposition on the 6th, rising
about 4 minutes earlier each day. By month’s end, Mars rises
an hour before sunset, so it will be visible until about an hour
About two hours after sunset at mid-month, an overhead look finds
the Milky Way dividing the sky from northeast to southwest. Deneb,
in Cygnus, is about 20 degrees northwest from zenith. Another 20
degrees in that direction brings your line of sight to Vega, in
Lyra. Another 20 degrees and you’re looking at the constellation
Hercules. Binoculars early in the month, near New Moon, should allow
you to find several deep sky objects in Hercules, including a fairly
large globular cluster. If we go back to Deneb, and shift our line
of sight toward the northeast, we’ll find the familiar “M”
shape of Cassiopeia, tipped on its side about 55 degrees off the
horizon. Follow the bottom “leg” of the M toward the
right about 15 degrees, and you’ll find the Andromeda Galaxy.
It’s not bright, it’s somewhat diffuse, so your best
bet is on a moonless night.
(Finder chart produced with Starry Night Pro 3.0, from Sienna Software.)
For your own monthly star chart, you can direct your web browser
You will find extensive descriptions of what's worth looking for,
and you can download and print a single copy for your personal use.