Holidays and family events usually keep us busy this time of year, but
we are expecting a special surprise guest to join us on the sidewalk in
Monrovia on December 2. We'll have a big lovely Moon just two days from
full to show. The giant planets will return to the early evening sky
very soon, but not for another month or so.
Our special guest has been with us before on the sidewalk, and he is
there with us in spirit each month as we aim our Dobsonian reflectors
skywards, beckoning all within earshot to "come see the Moon." Yes John
Dobson will be with us this weekend. If you haven't met John, stop by
to say hello! For those who haven't heard of John, he invented the
Dobsonian telescope mount and founded the Sidewalk Astronomers. Mojo and
I used to bring John out on the San Francisco sidewalks before we moved
south, so it is a special treat when his visits collide with one of our
sidewalk astronomy nights.
Elsewhere in the solar system in December:
Three planets grace the dawn during the first part of December. Jupiter,
Mercury and Mars can be spotted in the southeast low in the sky before
sunrise. Mars is much dimmer than the other two planets. Look for them
from December 7-14. The three planets fit in a binocular view, getting
closer between December 9 to 11. On December 10, these three planets
bunch closer than any three planets will during the next quarter century!
Saturn rises by 10:00 p.m. at the beginning of December and by 8 p.m. by
the end of the month. On December 9th the Moon rises close to Saturn.
The bright Moon will obscure the annual Geminid meteor shower on
December 12-14.
Hope to see you on Saturday night between 5 and 9 p.m. We'll skip
Friday night in Pasadena this month, and resume our normal schedule in
January. We'll just have the one target, the nearly full moon to view
this month.
Jane
--
Jane Houston Jones
Monrovia, CA
34.2048N 118.1732W, 637.0 feet
http://www.whiteoaks.com
Old Town Astronomers: http://www.otastro.org
The lyrics of "King of Pain", by Sting & Police starts like this:
There's a little black spot on the sun today
It's the same old thing as yesterday
But today there is a different little black spot on the sun! It's
the planet Mercury passing between the Sun and the Earth!!
Today, November 8, the planet Mercury passes inferior conjunction
with the Sun, where it is in between the Sun and Earth. Because of
the tilt of the planetary orbit, Mercury is usually not QUITE
aligned, but passes either above or below the solar disk. This time,
however, the planet passes right across the Sun for a "transit."
Transit seasons are early November and May. November events are
separated by intervals of 7 or 14 years. May transits (which take
place with the planet farther from the Sun) are rarer, and can, but
don't have to, recur in 14 years. (Transits of Venus are far rarer.
There were none in the twentieth century; the last one was in 2004,
the next in 2012.)
Unfortunately, Transits of Mercury are NOT visible to the naked eye,
even with appropriate
filters, but are readily visible with the telescope. However, they
should be viewed by projection only; do not even try without
professional-level knowledge or help. The event begins at 1:12 PM
CST (2:12 EST, 12:12 MST, 11:12 AM PST, 9:12 AM Hawaii), and lasts
for about 5 hours as the planet slowly moves in orbit. Only the
western US and Canada will witness the whole thing before sunset. The
timings of such transits were once used in attempts to local times
and thus longitudes. This description courtesy of Jim Kaler:
http://www.astro.uiuc.edu/~kaler/skylights.html
Since this is a telescopic event, and then only through solar safe
telescopes, I thought I'd provide our OTAstronuts with a virtual
viewing of the transit. I'll be here at JPL, with three solar-safe
telescopes, Mojo is at work with one additional safe telescope, and
our frequent sidewalk astronomy telescope operators Gary and his
daughter Elizabeth are setting up a solar safe telescope at
Elizabeth's school today.
So sit back, and use these links. The transit begins at 11:10 a.m.
here on the west coast and ends at 4:10 p.m. If you miss this one,
don't worry, it'll happen again in 2016!
APOD (Astro Photo Of the Day) - simulated transit of Mercury
http://antwrp.gsfc.nasa.gov/apod/
A nice animation and description
http://science.nasa.gov/headlines/y2006/20oct_transitofmercury.htm
A webcast - one of many, you can probably find others if this is
busy using your favorite search engine:
http://www.exploratorium.edu/transit/
A nice visual description, shows size of Mercury - looks fine on the
screen, white text doesn't show up on printed copies:
http://www.exploratorium.edu/transit/what.html
I am using this handout:
http://sunearth.gsfc.nasa.gov/eclipse/OH/tran/TM2006sun.GIF
Todays sunspots here - the sunspot image also shows size of Earth and
Jupiter for a great size explanation. :-)
http://sohowww.nascom.nasa.gov/
Finally, this transit is not visible everywhere on Earth. The transit
will be widely visible from the Americas, the Pacific Ocean, eastern
Asia, and Australia
US map here http://sunearth.gsfc.nasa.gov/eclipse/OH/tran/TM2006map.GIF
Global view here
http://sunearth.gsfc.nasa.gov/eclipse/OH/image1/TM2006Nov08-Fig2.GIF
Jane
--
Jane Houston Jones
Senior Outreach Specialist, Cassini Program
JPL - 4800 Oak Grove Drive, MS 230-205
Pasadena, CA 91109 818-393-6435
jane.h.jones(a)jpl.nasa.gov
Cassini Saturn Observation Campaign
http://soc.jpl.nasa.gov/index.cfm
