salutations celestial sight seers I'm David fuller welcome to eyes on the sky
what's up this week well on November 11th there is a very rare but regularly
enough occurring event that we can actually see it several times in our
lifetimes depending on the timing and for much of North and South America and
including even over in Europe in the Middle East and Africa
there is an event that is possible to be seen provided that you have some clear
skies and that is the transit of mercury the last one occurred in 2016
although the next one will not occur until 2032 and that one really is
centered on Africa so if you're in North America this is your chance to check
this out now well that's gonna happen is let me
actually show you the map of who can see what and when this is the map of what's
visible and what you either will see full transit or partial transit so the
eastern part of North America basically not quite from the Mississippi over to
the east a little east of the Mississippi because I here in Chicago
will just barely not be able to see the whole thing to the east will be able to
see the entire transit and then the very eastern excuse me western edge of Africa
and all of South America will be able to see all of it however if you are west of
that line then you will have to see it sometime after the Sun rises where you
are and if you are to the east of there you will be able to see the transit in
progress as the Sun sets, so you won't get to see it as it finishes but you will at
least be able to see it when it starts so that includes really as you can see
the Middle East and Europe and Africa so that's what we have available for a lot
of the world which is fortunate because that's a lot of my viewers I know I've
got some folks over in India who will unfortunately miss it but you can watch
online they're gonna be a number of live streaming feeds for that so do
searches probably on Friday or Saturday the 9th and 10th to see who's gonna be
live-streaming that I probably will not be just because I don't think I'm gonna
have a good enough internet connection to be able to do that but if I have the
opportunity to do a little bit that I will try to when we watch this trans it
occurring now I'm just gonna show you from my location the Sun will rise and
the trains in itself lasts for about five and a half hours or so and so that
means for me looking here at just after 6:30 in the morning here's the Sun as it
would be rising and if you look if we let it bring that up just a little bit
like this and then kind of zoom in you can see how at least on the Stellarium
view it shows a number of sunspots the Sun does not have a lot of sunspots
right now it has pretty much no sunspots it's been quiet the last couple of years
but right over here this little teeny dot will bring this up just a little bit
more and you can see that better and you can see how that dot is actually moving
pretty substantially across the face of the Sun and we can kind of speed that
across in a couple hours like that and I will have until about 11:56 in the
morning to be able to catch the transit all the way across so there we go at
11:56 that's what's for me will be the 3rd contact right there where the the
planet is just about ready to touch the limb of the Sun I can go actually just a
couple seconds forward into that and what we want to if you want to do some
real science here if you have a pretty decent zoom on it this is probably much
more than you'll get at a telescope but the best you can do you want to try to
time that contact as closely as possible and then you can actually submit that
information on Eclipsewise.com is a website that would take that information I
believe if I read their information correctly and would be able to use that
information to help us to accurately locate the distance of our Sun it's a
useful exercise but when this happens when that tangent of the planet meets
the tangent of the Sun like that we call that the contact one of the contacts
so second and third contact are where the edge meets there now on the
other side of that you can see what's that's gonna happen really fast the
first and fourth contact are actually really difficult to see in white light
because you don't really have anything to tell you what's actually having wick
where's the planet you don't necessarily know where exactly it's exiting because
there's nothing behind it but if you happen to have a Lunt or Coronado
h-alpha telescope which shows the solar flares you may have enough of a flare
behind where the planet is at the time that it transits that you can actually
record either the first or the fourth contact as that's actually occurring
because there may be enough light behind the planet to provide that and if you
have that information then by all means to definitely do that so that
doesn't take very long if you notice that's only about what a minute and
forty seconds or so that that takes to actually exit the Sun because mercury is
not very big if I back out a little bit of this so I can actually get the planet
itself you notice that the apparent diameter is about ten arc seconds across
that's small so you will need a lot of magnification using a telescope probably
anywhere between at least fifty to a hundred times ideally if you have one
a mount that will motorize your telescope to follow the Sun as the Earth
rotates so you don't have to keep moving it is gonna make things a lot easier for
you if you happen to have that available and also of course use a proper solar
filter please do not try to stack a bunch of mylar seeds or a bunch of other
crazy things that sometimes people do use a proper solar filter if you are not
going to use a solar filter you may use a refractor telescope with an eyepiece no
star diagonal just a straight through you may use that to project an image of
the transit occurring I did this with the transit of Venus back in 2012
you can see how got the there's the dowels that I used to kind of make an
extension and it was about 12 to 14 inches behind where the actual
eyepiece was and I just used some simple duct tape and I had some screen material
that was supposed to be good for like TVs and things but you could use use a
white piece of paper because the image is spread out enough that it won't cause
any issues with heat or anything but Venus was much larger it has a much
larger disc but mercury will be much smaller I'm going to show you the 2016
one I did not take this photo but you can
see how small mercury is in comparison to what Venus was and even if i zoom
that in to give you kind of a similar view of what I had with the Venus Sun I
mean that's Mercury's gonna be small but it'll probably be the only black spot on
the Sun because I don't suspect there to be really much in the way of any
sunspots so that should make it simpler to be able to locate where the planet is
actually going to be crossing now one thing I do want to show you is the
timing of when this will be happening here's the different times in Universal
Time for the various contacts and then the point at which it's in the middle of
the Sun really now these you will have to use a time converter depending on
what your actual location is but this is when it's gonna happen so as you can see
we've got about five-and-a-half hours of time to be able to witness this event so
it will take a while you've got some time to be able to adjust things you
know once the planet is actually transiting the disk of the Sun itself
but do try to see if you can see the planet entering during contact one
because you don't have a whole lot of time as that enters and also as it exits
so look for that contact two and three and one things you might notice at that
contact two and three is something called the teardrop effect where you
want to see that tangent where it actually kind of touches in on the
surface there but there's an optical effect that occurs where it sort of
looks like it has like a little bridge from the planet over to the disk of the
Sun I'm not sure why that occurs but it does occur so that's an interesting
effect and if you can capture that use astrophotography of any kind if you have
some ability to be able to do that then that is an interesting capture for sure
I did not quite get that with my transit of Venus photos this one does show kind
of that tangent where it's just about there
and I thought that was actually a pretty good capture considering I had a much
lesser cellphone back then and that was just a cell phone held up to the
eyepiece type of photograph and cellphones have certainly gotten much
better in the last seven years with their camera abilities so you can even
try that so definitely look for this if you have the ability to do so if you
happen to be in that area where the transit will be visible and see if you
can witness the transit of mercury for the 2019 transit that's all for this
week keep your eyes on the sky and for this week hopefully it's just clear
skies because we don't necessarily need lights off or anything but we do need
clarity of the atmosphere in order to be able to see the transit of mercury
you