Mike's Astro Photos

The north east was graced with yet another fireball early yesterday morning. Witnesses from Ontario, Michigan, Ohio, Vermont, New York, Pennsylvania and Maryland all reported seeing a bright green fireball in the sky at approximately 5:15 AM EST.

The AMS received over 40 witness reports. The initial run through my plotting software was a bit confusing. This is what all of the plotted witness reports look like: (red icon means movement left to right; green icon means movement right to left; green line is starting point, yellow line is ending point)

Green Fireball - February 23rd, 2011

At first glance, this looks to be a tricky fireball. Usually the green and red icons will delineate the flight path pretty well, but in this instance, the green and red icons, don’t help make much sense of the flight path.

One of the biggest challenges with making sense of the witness reports is eliminating the noise (or bad reports). For big events (and small ones) there are always reports that conflict with each other, so its a bit of an art to determine which reports are good and which are bad. To help combat this, I recently added a field to the AMS fireball report form called observer experience. The purpose of the field is for the witness to rate his or her observing experience — 1 = no experience and 5 = very experienced.

I made some changes to the plotting software today so I could filter the witnesses by their level of experience. Here is what the witnesses with observing experience of 2 or higher looks like:

Green Fireball - February 23rd, 2011

Things are starting to shape up a bit, but lets see what the plot looks like with only level 3 observers and higher:

February 23, 2011 - Green Fireball

Now it looks like we have a clear ending point. To determine this we try to find a common intersection among all of the yellow lines.

The flight path, is still a bit unclear to me, but there are two reports on the western side of the track that indicate “Up To Down” movement. This generally means the witnesses’ field of view is usually parallel to the meteors flight path and the meteor is moving away from the witness. For this reason they do not see side-to-side movement. Because of this, my initial estimate is West to East movement, starting in Michigan flying over Lake Ontario and ending on the Pennsylvania-New York border near Addison, Lawrenceville and Horseheads New York.

February 23rd, 2011 - Green Fireball - Possible Drop Zone