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In this episode of Star Hopping with Kissimmee Park Observatory, we'll check out the early
morning sky, and show you how to find these beautiful solar system objects:
Comet LINEAR The Planet Mars
And the Planet Saturn
Alright, Let's Go Star Hopping!
Hey Hello Hi and welcome to Episode 28 of Star Hopping with Kissimmee Park Observatory!
I'm Dave Hearn, and I'm absolutely enchanted to be your host. In this series of programs
we'll show you the most beautiful sights in the night sky, and explain exactly how to
find them with your binoculars or telescope.
So this week we’re going to jump forward a bit in time as there is a lot going on in
the southeastern sky in the wee hours. Normally I would wait for the Earth to move along in
its orbit some more, but we have another visitor to our solar system, Comet LINEAR, designated
as Comet 252P, with the P standing for periodic, meaning it loops around the sun in a very
long elliptical orbit, and shows up in our skies every 5 years or so. The comet is floating
through the constellation of Ophiuchus. I captured it with the KPO Reflector this past
weekend at around 3:00 Am - don’t worry, I slept in the next morning! The moon has
been in the way until recently but now that it has returned to the evening skies as a
crescent, it has left the morning skies dark and with that, the visibility of the comet
has improved. The comet is now around 6th magnitude, which is barely visible to the
naked eye, but will be easy in binoculars.
Since I have you awake that late, or early as the case may be, I wanted to alert you
of a great sight in the morning, just a little south of the comet - the planets Mars and
Saturn have collected in the constellation of Scorpius, and it is quite a sight in the
southeast sky. Scorpius has a bright beacon of its own: the bright orange star Antares.
So the trio of bright objects, along with the shape of the scorpion’s claws, makes
for an interesting view!
So lets learn a bit more about Comet LINEAR, right after this.
Comet LINEAR was named for it’s discovering telescope, the Lincoln Near Earth Asteroid
Research 3.5 meter telescope at White Sands Missile Range in central New Mexico. This
program watches for any NEOs (Near Earth Objects), so it regularly picks up comets that are close.
And this was definitely the case for comet 252P - it passed only 3.3 million miles from
Earth on March 21st. That’s right out in our front yard on cosmological distance scales.
The comet appears decidedly green in all astrophotos taken of it. The big round part of it is called
the Coma, and it’s created by at the comet’s icy core converting directly into gas that
ends up trailing behind it in a tail. Mostly the coma is composed of methane and ammonia,
but there is another chemical called cyanogen, which, when ionized by the solar wind, glows
green just like a neon sign. A little worrisome part of this is that cyanogen gas is deadly
poisonous to human life, but we would have to pass directly through the comet’s tail
to be at all affected. In 1910 the Earth did pass through the tail of Halley’s comet,
but it’s cyanogen was so diffuse that there were no ill effects to the earthlings of that
era. But many people were convinced that everyone was going to be poisoned, so there were lots
of comet parties at that time, as people thought it would be the end of the Earth!
So let’s locate Comet LINEAR. Here’s a plot in SkySafari that shows the comet’s
retrograde loop. This strange path is caused by the comets motion overlaid with the orbit
of the Earth. The outer planets also exhibit these retrograde loops as Earth passes them
in our inner and faster orbital motion.
So at the time this video is coming out the comet will be just to the upper right of the
3rd magnitude star Cebalrai, otherwise known as Beta Ophiuchi in the constellation of Ophiuchus
the Serpent Bearer. But we’ll be starting from the brighter star Rasalhague, which shines
at magnitude 2.1. Now move about 8 degrees to the lower right
to Cebalrai. Now move about 3 degrees to the upper right
to a 5th magnitude star. You’re very close to the comet which will be only slightly fainter.
Now move about a degree and a half to the upper left and you’ll see the hazy glow
of Comet LINEAR.
This comet will be visible even in the smallest of telescopes and binoculars, so it should
be pretty easy to locate. Once you have found it, and know how it appears in your eyepiece
or binoculars, you can go out a week later and see how it has moved. I noticed that the
position moved even between my two minute exposures when I captured it the other night,
so this guy is really truckin’ along.
Well now that you have found the more challenging target, let’s move on to a much easier one,
the planet Mars.
Mars has always captivated people with stories of aliens coming from Mars in great movies
like H.G. Wells’ War of the Worlds. But we have learned a lot in the last several
decades with Man landing two rovers on the Red Planet, Spirit and Opportunity. I was
really impressed by this recent image from Opportunity that showed a dust devil skirting
across the martian surface. We are living in amazing times with these robot explorers.
So Mars is the most prominent point of light in the southeastern sky, beaming at magnitude
-1. It’s moving towards its May 22nd opposition, when it is at closest approach to Earth on
this side of the Sun. So this will be a great opportunity for you to use that high power
eyepiece of yours in your telescope. The smaller planets require a huge amount of magnification
to be able to see any surface features, because the planetary discs are just so darn small.
For example, the Moon is about a half a degree in size, which fills a wide field eyepiece.
That’s 30 arc-minutes, as there are 60 arc-minutes in a degree. Something like a large globular
cluster like Messier 13 that we talked about a couple weeks ago, is only about 4 arc minutes
across. Still pretty seeable with a medium magnification, say 100 power. But these planets,
geez. When Mars comes to opposition, it will be just 14 arc SECONDS across. There are 60
arc seconds in one arc minute. So converting the size of M13 to arc seconds, it would span
240 arc seconds across. Mars will only be 14 arc seconds wide. So M13 is 17 times larger
than Mars. Do you get the gist of this challenge? So the process will be, center Mars in your
low power eyepiece, then change it out for a medium magnification. If you can still see
it clearly, swap it out for your high power eyepiece. If the atmosphere is still, you
may be able to make out some of the markings on the surface of the planet. But if its not,
it will look like a round orange ball at the bottom of the swimming pool.
Here is a great map of the features of Mars, courtesy of Sky & Telescope.
So now let’s look at a little bit of a larger target in the solar system, right after this.
So Saturn is loved by everyone who sees it through the telescope. At public observing
session, I have been accused of having a little model of it hanging inside the telescope,
because what people see looks so amazing in the scope.
Saturn and its rings are definitely one of the most unique and spectacular sights you
can view through a telescope. We are lucky right now because the rings are almost fully
open from our perspective in space. In this configuration, it’s easy to see the shadow
of the rings on the planet and even the spaces between the rings themselves. Add to that
the motion of the Saturnian moons that orbit the planet, and even sometimes some cloud
bands on the planet itself. It’s an amazing sight!
Saturn is also easy to locate with the unaided eye, shining brightly at magnitude 0.3. It’s
a little bigger than Mars at 18 arc seconds across, and comparing to M13 as we did with
Mars, it’s 13 times smaller than M13. But the rings give you a much better target, and
as you increase magnification the sight is much more pleasing to the eye.
Saturn lies about 8 degrees to the left of bright Antares. You can see the color difference
between Saturn and it’s orange companions - Mars and Antares look very similar in color,
but Saturn is much more yellow.
So now that you have completed your solar system observing session, you can either go
back to bed, or just drink coffee until the sun comes up! Well while you sip, you can
review in your mind what we saw. First off we checked out Comet LINEAR, moving along
its retrograde loop in Ophiuchus. Then we moved about 10 degrees to the right into the
summertime constellation of Scorpius, and admired the two planetary beacons, Mars and
Saturn, as they danced with the bright red giant star in Scorpius, Antares.
If you have your camera, this would be a great wide field shot to capture. If any of you
get a chance to image this celestial scene, send us your shot and we’ll share it with
everyone on next week’s show, and give you a shout-out for your effort.
So that does it for this week’s episode. You can find the show notes on our website
at kpobservatory.org/SH028, where you can comment and leave any questions that you may
have. Thanks for joining us, and I’ll see you next week in our episode of Star Hopping.
I'm Cassie and I hope you've enjoyed star hopping around the Milky Way. We'll continue
to bring you these video astronomy tutorials every week on Thursday, and in their podcast
format on Fridays. They will be designed to help you find deep sky objects that are up
in the sky at the time we post them on the Internet.
The reason we create these video and podcasts is to help beginning amateur astronomers learn
the sky and get more enjoyment out of their telescopes and astronomy in general. If you
have any requests or suggestions of potential targets in the night sky that you would like
to see us present, just let us know down in the comment section below, or on our website
blog.
Don’t miss our free Field Notes for this episode, basically the script of the show,
with all the images and start charts we use for our star hopping activities. You can get
them for free at kpobservatory.org/FieldNotes.
If this is the first time you’re checking out Star Hopping, and if you found this video
useful, please consider Subscribing to our Channel by clicking the Big Yellow Button
down there, click the Thumbs Up on the video, and please share this tutorial out to your
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Also, please follow KPO on Facebook, where we post all of our astrophotos and keep everyone
informed about upcoming astronomical events. We'd love to hear from you to discuss all
this great stuff up in the sky.
All the links to these places including our website kpobservatory.org, can be found below
in the Episode Notes as well.
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support our efforts and let us make even more great astronomy tutorials like this one.
Well thanks again for watching, and we'll see you next time on Star Hopping with Kissimmee
Park Observatory.