QUESTIONS: Comet 209P/LINEAR

many different sources | Feb 27, 2014 | Yosemitest

[Yosemitest]

John Bochanski wrote an article tilted
The Next New Meteor Shower,
Astronomers confirm that debris from Comet 209P/LINEAR should create a sky show on May 24, 2014
on November 12, 2013 that is one of the most detailed I've read so far.
Here are some excerpts from it.

"Most meteor showers ... occur when Earth plows into the debris trail left behind by a comet.
The comet throws this debris off as it’s heated by the Sun, but while all comets heat up as they enter the inner solar system, many do not have orbits that intersect with Earth’s.

... The tried-and-true list of showers might change soon, though.
As we noted in 2012, the comet 209P/LINEAR, which passed by the Sun in 2009, may produce a big meteor shower on May 24, 2014.

... Detailed calculations of its orbit indicated that in May 2014 the comet’s debris trails would pass extremely close to Earth
(about 0.0002 Earth-Sun distances, or within spitting distance of our planet’s outermost atmosphere).
These thousands of particles could burn up in Earth’s atmosphere as meteors when our planet plows through the debris field.

... Ye and Wiegert report in an upcoming Monthly Notices of the Royal Astronomical Society, the team’s calculations suggest that the comet has been producing relatively large particles (on the order of 1 mm), meaning that the upcoming meteor shower may be chock-full of bright meteors.

... With the low dust production, as well as the team’s lower estimate of how many debris streams from the comet's previous passes are hanging around in this region of space,
it’s highly unlikely that we’re in for a “meteor storm” (1,000 per hour) —
although the team couldn’t quite rule it out.

... It’ll be worth going out to look in May.
The meteor shower is set to peak around 7h Universal Time on May 24, 2014, with the radiant point (where the meteors appear to come from) in the constellation Camelopardalis.
That’ll be a fist-width or two above the horizon for those around latitude 40° N;
the shower should be easily visible from much of the Northern Hemisphere.

As Comet 209P/LINEAR enters the inner solar system again, it will brighten but still be relatively faint with an apparent magnitude of 11 around the time of the shower.
Nonetheless, skywatchers will have their telescopes trained on this comet, as new data on its position and brightness will be crucial for updating models of its behavior. ... "


Kelly Beatty wrote an article titled Meteor Storm Brewing for 2014 ? on October 9, 2012 and he stated:

" ... It follows a looping but relatively tight path that carries it just inside Earth's orbit every 5.04 years.
According to dynamicist Syuichi Nakano, Comet 209P/LINEAR's next perihelion occurs on May 6, 2014, at a point 0.969 astronomical unit from the Sun and with Earth not far away.

Just 18 days later, we should cross through dozens of particle streams shed during past orbits.
The predictions are still rough, but three different models suggest the sky show could be spectacular.
"All the trails ejected between 1803 and 1924 cross Earth's path in May 2014," notes Jérémie Vaubaillon (IMCEE, France).
"As a consequence, this shower might as well be a storm,"

... The best part of all this prognostication, at least from a U.S. perspective, is that the meteor display should peak between 7:00 and 8:00 Universal Time on May 24th — it'll be dark across virtually all of North America.
... And the Moon will be a narrow waning sliver just a few days from new. "

Mikhail Maslov wrote

" ...The Earth is expected to encounter a great number of the comet 209P trails in 2014.
The main source of activity should become 1898-1919 trails,
however some meteors could be produced by the earlier trails of the comet, down to 1763 trail, which is the oldest computed trail, and even earlier.
The computed time of maximum activity is May 24, 2014, at 7:21 UT,
theoretical radiant is RA=122.8�, Dec=+79.0�.
It is difficult to estimate expected intensity of the outburst due to the lack of past observed cases of activity from the given comet meteor shower,
as well as due to very small size of the comet itself and unknown level of its past activity.
However, considering high computed density and high number of encountered trails, we can very approximately estimate ZHRex as 100 meteors.
Its a very cautious estimation, and it is very possible that real activity will turn to be much higher.
Storm levels are also far from being excluded.


Also take a look at the 3D view of the 1903 meteoroid trail in the Solar system of comet 209P/LINEAR (2004 CB) :



And the Equivalent 2D view (XY).








So my first question is:

What does this Noeds-Earth2014.jpg , or the 3D model above, actually tell us?




I assume this is a 3-dimensional chart, and we can't tell the 2 dimensional danger it represents to us.

Are there any Radar Images of Comet 209P/Linear or Hubble photos of it showing its core?

[Errant]

I need to get a copy of Stellarium for myself.

The issue, as I see it with Linear, is the fact that it has broken up. That means there could be some large objects hiding in the dust trail, trailing the main body of debris. Since the earth is crossing through that same trail close behind this main body passage (relatively), it should mean the chances of encountering larger objects in this particular comet's dust trail are greater than normal, or of say a single body comet's trail in which the main nucleus passed months before the earth encounters its dust trail.

No model is going to be able to predict this. It's something we'll just have to wait to see if we do or don't encounter larger objects, unless of course NASA wishes to share radar returns or observations with us. Not likely of that happening if there is something coming our way and they thought it might cause a panic.

There was a comet that we watched breakup some years back (I forget the name now) which now consists of about 60 objects NASA is tracking. The pieces are presently scattered over a trail with millions of miles between the separated chunks.

Which brings up another question in my mind: Why isn't NASA putting out more detailed data on Linear? Just seems kind of strange, if you ask me.

Btw, good work on the numbers!

[Yosemitest]

I like Stellarium, the free version, and there's a $49.99 SkySafari Pro that I plan on purchasing.
Thanks, for noticing the math.

"Since the earth is crossing through that same trail close behind this main body passage (relatively),
it should mean the chances of encountering larger objects in this particular comet's dust trail are greater than normal, ...

No model is going to be able to predict this.
It's something we'll just have to wait to see if we do or don't encounter larger objects,
unless of course NASA wishes to share radar returns or observations with us.
Not likely of that happening
if there is something coming our way and they thought it might cause a panic. ...

... Why isn't NASA putting out more detailed data on Linear?
Just seems kind of strange, if you ask me. "

I agree.
My mother talks of an event in the 40s or 50s of watching many shooting stars, 100s at a time, when she was a little girl, one night.
But she can't remember what Comet it was associated with.

The Figure 2 Chart on page 5 of that .pdf probably shows more information about the cumulative threat from all those different Comet 209P/Linear Orbital Passes through time, that we'll go through.
I can only assume that it shows only the level of the Earth's Orbital Plane as it intersects with all those combined Comet trails, and where their model predicted the debris to be.
I also assume that its cross-section is a top-down view from 209P/Linear's trailing tail being blown out from the Sun, even though Linear is traveling at a slight angle as it crosses below Earth;s Orbital Plane.

[Yosemitest]

Ping.

[messierhunter]

You suck at math. Badly. You really haven’t learned ANYTHING from your ISON experience. Log10(radius(m)) = -1.0 means the largest possible fragment size in their model is 1*10^-1.0 m, or 100 cm. The peak particle size on that chart is about 1 cm or less.

[messierhunter]

You guys should know better than to trust BPearthwatch. I guess you don’t though.
http://www.youtube.com/watch?v=-Kcuxcn9BYE

[Yosemitest]

I was under the impression that you multiplied the radius of the object by the log.

[messierhunter]

Can you not read? It plainly says log(radius(m)). Log of the radius in meters.

[Yosemitest]

"The peak particle size on that chart is about 1 cm or less."

If your statement is true, what would particles sizes be from figure 4 oftheir paper that state:

"Mean = 3.20971"

"Mode = 2.93205"

I don't believe they use the letter "m" to mean meter, but I could be wrong, as I am not schooled in this field.

Explain their statement to me that states:

"An equal amount of dust is assumed to be released between the sizes of 10−9 to 10−1 m in radius,
though only particles larger than 10−5 m are simulated:
given our assumed size distribution,
this gives a fraction > 0.99999 of the mass and 4×10−7 of the number of particles simulated. "

[messierhunter]

It’s a simple log function. Log(Radius(m)) = -3 would be 1 cm. 1*10^-3 m = 0.1 cm. At Log(Radius(m)) = -2 where most of the density ends, the radius would be 1 cm.

Their statement is pretty self-explanatory. If you don’t get it then you need to go back and take some remedial science and math courses. Your constant confusion with log functions suggests you probably should do so anyway. Please, drop this nonsense, it’s making free republic look ridiculous. There are plenty of forums on the internet for pseudoscientific discussions. I’m begging you, this is embarrassing.

[messierhunter]

Should be .1 cm, not 1 cm.

[messierhunter]

Aka 1 mm. Sorry, didn’t get enough sleep.

[Yosemitest]

"1*10^-1.0 m, or 100 cm. The peak particle size on that chart is about 1 cm or less.",

Wouldn't that be 1 decimeter ?

deci- (d-) 10-1
1 tenth

centi- (c-) 10-2
1 hundredth

milli- (m-) 10-3
1 thousandth

micro- (µ-) 10-6
1 millionth

nano- (n-) 10-9
1 billionth

pico- (p-) 10-12
1 trillionth

Notes:
I am often asked about prefixes for other multiples, such as 104, 105, 10-4, and 10-5.
The prefix myria- (my-) was formerly used for 104, but it is now considered obsolete and it is not accepted in the SI.
To the best of my knowledge, no prefixes were ever accepted generally for 105, 10-4, or 10-5.

[Yosemitest]

Go get some sleep and answer me tomorrow.
I really want to understand this particle math. This doesn't explain large pieces that break off that are larger (+1 meter) than their model.

I hate the metric system.
For religious reasons, I hate it, I hate it, I hate it, I hate it, I hate it, I hate it, ...

[Errant]

I’m begging you, this is embarrassing.

Should be .1 cm, not 1 cm.

Aka 1 mm. Sorry, didn’t get enough sleep.

It's not lack of sleep that's causing you to embarrass yourself, it's the natural outcome of mixing a heaping of idiocy with too much arrogance and impatience.

Yosemitest was upfront and was asking for help in understanding the math and expressions.

While you may have learned a few mathematical symbols and operations, it surely hasn't helped with your lack of maturity or common sense.

[Errant]

You guys should know better than to trust BPearthwatch.

He's pretty far out in left field on some things. On others, he is dang close. He is also sincere, humble, hard working, and entertaining. Not everyone can be the perfect, all understanding, tolerant human like yourself...

[Yosemitest]

Thanks, but let him get some sleep.
I've been too tired to think myself, before.

[Errant]

I don't believe they use the letter "m" to mean meter...

Now you're getting somewhere... Don't feel bad about confusing metric symbols. Even NASA gets symbols wrong sometimes. They once crashed into Mars because of confusion not between metric units, but between the two systems .

The great thing about metrics is once you know what you're dealing with, it's easy to convert between the units.

:-)

Still, the model you're using only predicts dust particles. It isn't going to help much in predicting how many large rocks are trailing a fragmented comet nucleus. Best to use observation/radio returns for that.

[Yosemitest]

You'd think they be able to model those larger pieces also.
It's not like things don't collide in space.

[Errant]

You'd think they be able to model those larger pieces also.

Too many variables, beginning with the composition of the comet itself. At best, they're able to get somewhat of a useable calculation based on size, speed, distance from the sun, and repeated observations of the dust particles being emitted. And this all based on an intact nucleus. A breakup creates more surface area that is exposed and no really good way to even calculate the increased area with that model. And again, we're taking dust particles, not the big chunks dependent upon the comet's makeup.

Take another look at ISON's breakup. How do you calculate that? Look at the comet that impacted Jupiter and the one I was telling you about that has broken into about 60 pieces, the last piece coming near to earth. I think this might be it: http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=73P-C

[Errant]

It's not like things don't collide in space.

Like what they are saying caused this: