September 22, 2014

Meteor Shower Observing.

   Stand outside on any clear, moonless night, and watch the sky. Odds are within a few minutes a meteor will slide silently by. While most things in universe and astronomy seem to happen on geological time scales, meteors are quick and fleeting, and a meteor storm can be one of the most awesome spectacles, such as the great Leonid outburst in 1833 and 1966.

The good news is, beyond just appearing cool, meteoritics (try saying that three times fast) is a field that the amateur scientist can still play a vital role. No fancy equipment is required, although radio observations of meteors are almost a sub-discipline of their own.  Meteors even “pop” on the FM band! All that is required is recording equipment, a working knowledge of the sky, and above all, patience. The recording equipment need not be any more sophisticated than a pencil and paper, although we prefer a digital voice recorder.

Recorder.

An indispensable tool of the trade… the Sony Digital Voice Recorder. (Photo by author).

With this, I can simply speak my observations of the sky and compile them later. Digital recorders are now tiny enough that they can fit in a shirt pocket and run for hours, no cords or wires needed! There is also the added advantage of being able to stay “eyes on” with the sky while dictating. You never know when that bright bolide will streak by!

Having more than one observer can be handy as well; most of us can cover maybe half the sky visually at a time. Three is probably optimal to deal with the overlap and get good sky coverage; more than that, and meteor counts can get confusing! But if you can find two good friends that are willing to stand out in the cold and the dark in the early AM hours, you are either loaded, or an amateur astronomer!

I generally only observe showers were the action is expected to have a Zenithal Hourly Rate (ZHR) of over 10 meteors per hour, although there are lesser storms. Occasionally, a minor storm, such as this weeks’ Taurid meteors, may be due to amp up, a bit. Don’t forget, early AM local is the best time to see meteors. The reason for this is that the Earth is rotated forward into its orbit after midnight. We are then colliding head on with the on coming meteor stream, usually left in the wake of a comet. Any meteors you see before midnight have to catch up! Hence, the rare evening meteor tends to be slow and stately, while the morning ones tend to be short and swift.

To make scientifically useful observations, simply note the time, location, sky conditions, and count the number of meteors you see. Don’t forget to differentiate, as more than one shower could be going on the same night! Meteors that do not trace back to a parent radiant are called sporadic and should be recorded as well. Some people also record the magnitude, color, position, and their philosophical ponderings on life (it can be fun to listen to my ruminations at 2AM!) but really, simple works.

Why don’t you see the same amount as advertised by the ZHR? Several factors conspire to work against this;

1. The number shown is the optimal amount an observer would see if the radiant were at the zenith, or directly over head. That’s one point on the surface of the Earth for any shower at any given moment, and the odds are, it ain’t you!

2. Light pollution drowns out all but the brightest meteors. A Moon past full is also not a good thing. Try to put something between yourself and the offending light source, such as the peak of a house.

3. You are but one man. See above. I always seem to be looking in the wrong place at the wrong time.

Also, keep a pair of binocs handy to check out lingering smoke trails. Also be alert for bizarre phenomena; a great debate was started on an unnamed chat board a while back as to weather meteors could illegally corkscrew!  Audible sounds may be very occasionally heard; as a child watching the Perseids from Maine, I heard a distinct “hiss” from a very bright fireball!

Don’t forget; the Leonids are coming up the week of the 17th this month; this is a shower well known for enormous outbursts, and is well worth keeping an eye on, even in off years. More to come in the Event of the Week section!

And now, finally, the all important resources;

-The Meteor Shower Calendar. Updated by the International Meteor Organization, this is a good place to get started. It’s a complete comprehensive listing of meteor showers, year by year.

-Meteoracle. A good freeware tool… this will give you a good idea of the real time rates you can expect locally versus the ZHR. I usually fire this up and look at the expected rates.

-The North American Meteor Network. This is a clearing house to report data…also Yahoo Groups has a pretty decent mailing list that will help you monitor the goings on around the world, as well as peek at what other people might be seeing.

Finally, want to view through a remote night sky camera? What to even set up your own? Check out this link.

Also, don’t forget to dress warmly and bring a lawn chair! Meteor observing is one of the most straight forward things one can do for astronomy and science. Plans are afoot to make this endeavor virtual; we’ve heard of a system were you will just enter your location, then tap your space bar on your computer while observing to register a meteor “hit” via the Internet! Meteors can also be “spotted” via your FM band or even Television, but that’s another post! Keep watching the skies, and stay warm!

Leonids.

Apocalypse…Wow! A famous depiction of the Great Leonid outburst of 1833.

Comments

  1. matt g says:

    Nice post. I’m often fascinated with many topics beyond the level of a museum-goer, say, but lack the expertise of an expert. So I typically find myself wondering what I can do for one interest or another that is both useful and attainable for a dabbler like me. This looks like a good candidate!

    I’m curious what the data is used for, however. Why is doing this important? Knowing that might make me feel like less of a fool when I’m freezing my butt off at 3am on a weeknight…

    I’d also be interested in reading that post on radiometeor stuff… I’m really just an interested spectator at this point (I don’t even own a telescope), but building my own radiotelescope is on my bucket list.

  2. webmaster says:

    Matt,
    With regards to what you mentioned about Meteor shower observing, the data provided by lone amateurs can enable researchers to model meteor streams as they intersect the orbit of the Earth. Not the most glamorous work in science, but the data has to come from somewhere. If enough observers record data from separate locations, an idea of how these streams behave can be modeled. Very occassionally, new ones are even found! of course, there is always the potential that nothing will be seen; I sat out this morning before sunrise, watching for a promised outburst from the Taurids, and didn’t see a thing!

  3. Al says:

    I enjoyed the posting. Your mention of “Audible” meteors reminds me of the
    1966 Leonid shower. Early that morning my parents got me up (a young teenager
    in NWest Texas). The sky was full of “falling stars”. I still recount the experience
    with mentioning their “sound”. I describe it as: toooffff … toooffff
    pronounced very softly, just blowing air over my lips, not using my vocal cords.

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  1. [...] enjoyed with the naked eye.Counting and recording what you see in a given interval can even yield useful scientific data, as the modeling of meteor streams is still not completely understood. Clouded out? You can even [...]