ML Data 

 

Questions most often asked by individuals planning to visit Marfa are (1) What are the odds of getting to see mystery lights (MLs) on any given night, and (2) What are the best times to look for them?  My answers in 2002/2003 were (1) ~ 10% (based on an ML detection rate of around 30 times a year), and (2) the first two hours after sunset with diminishing opportunities until about three hours after sunset.  Those were the best answers available at that time but today I would say that the odds of seeing MLs are significantly lower (these really are rare events) and would rate the chance of seeing them anytime of night higher.  

What has happened to cause these changes?  Part of the answer may well be long term phenomena cycles not yet understood but at least part of the answer has to do with better filtering of artificial light sources.  Astronomy video cameras now in use at all three monitoring stations are on the order of a hundred times better at seeing in the dark and personal cameras and lenses I use on site have been vastly improved as well.   Add to that a growing experience base of knowing exactly were every ranch light, gate and roadway is located.  

One thing people seem to love is light.  In today's modern world people employ lights everywhere they go (or stop) at night creating a target (light) rich environment even in remote West Texas.  The process of investigating light phenomena in today's well lit world requires extraordinary care to filter out artificial lights (ALs).   ALs include ranch lights (RLs) and some of those are turned on only once or twice a year, aircraft lights (ACs) of every description including both fixed wing and rotary wing,  vehicle lights (VLs) of many types and even occasional hoax light.   The first line of defense against data contamination is to keep monitoring station cameras looking away from major regional roadways (i.e. US 67, US 90 and state roads 2810 and 169).  But that still leaves a net work of ranch roads that exist throughout Mitchell Flat.  Filter rules to deal with these light sources are simple enough.  Any light that originates at or stops at a known ranch house, originates at a known point of entry (i.e. road entry point), kicks up dust, or that pauses at known locations of ranch gates is automatically assumed to be a head light.  In addition, detection of a light beam automatically labels the light source artificial. 

With experience and good photography elimination of artificial lights becomes routine but there are still times when available information is inadequate to clearly classify the light source.  Questionable light sources are identified as Unknown Lights (ULs) and are kept in a separate database.  This alternative UL database can be a useful mine for statistical analysis and is a potential source of mystery light (ML) events when subjected to additional analysis.  

As an ML investigator I would rather omit valid MLs than to risk including artificial lights in saved data.  For this reason I require a subjective 70% confidence level for all events assigned an ML label [confidence scores as low as 70% are unusual.  Most are in the 90% to 95% range].  This requirement and the fact that monitoring stations are able to cover only a portion of Mitchell Flat means that my ML scores are understated.  The bottom line is that your chances of seeing an ML are likely to be a little better than my statistics might indicate. 

 

 Summary charts for high probability events

 

Most events are of short duration, typically well less than an hour as this chart shows:

Early data tended to show ML start times favored the first two hours after sunset but current data reflects a fairly even distribution of event start times for at least the first four hours after sunset as shown below:

Following are data samples involving various characteristics:

Wind direction at ML start is shown in the following chart:

 

Recent ML Data Summary

 

Listed below is a brief summary of ML events logged since July 2006.   This is summary level information only; the complete log includes additional information such as directional vectors, coordinates (when computation is possible) and many details regarding brightness, ON/OFF states, ground tracks (when possible), etc.

UT = Universal Time.  (Subtract 5 hrs for CDT or 6 hrs for CST.  In most cases UT dates are one day later than CDT/CST dates).   

Date (UT)	Day (local time)	hh:mm after sunset	hh:mm:ss Duration	Photographed By	Comment
15 Jul 2006	Friday	01:37 Owlbert A3	00:31:43 Owlbert A3	Roofus, Snoopy, Owlbert
16 Jul 2006	Saturday	01:37 Owlbert A3	00:32:19 Owlbert A3	Roofus, Owlbert
17 Jul 2006	Sunday	01:49 Snoopy	00:01:33 Snoopy	Snoopy
11 Aug 2006	Wednesday	04:17 Owlbert A3	00:18:12 Owlbert A3	Roofus, Owlbert, me	See Owlbert Page
20 Oct 2006	Thursday	01:15 Snoopy	00:21:49 Snoopy	Snoopy, me	See Owlbert Page
7 Nov 2006	Tuesday	01:38 Owlbert A1	00:05:05 Owlbert A1	Owlbert
22 Nov 2006	Tuesday	02:32 Owlbert A1	unknown, camera failed after 21'9"	Owlbert A1
23 Nov 2006	Wednesday	03:27 Owlbert A1	01:12:58 Owlbert A1	Owlbert A1
02 Dec 2006	Friday	00:58 Owlbert A1	01:34:19 Owlbert A1	Owlbert A1
01 Jan 2007	Monday	12:23 Roofus	00:00:04 Roofus	Roofus	See Roofs Page
14 Mar 2007	Wednesday	04:47 Owlbert A1	01:10:05 Owlbert A1	Owlbert A1
20 Jun 2007	Tuesday	02:09 Owlbert A2	00:02:44 Owlbert A2	Owlbert A2	Est. Speed = 14.5 mph
20 Jun 2007	Tuesday	02:58 Owlbert B1	00:00:47 Snoopy & Roofus	Snoopy, Roofus, Owlbert B1
8 Aug 2007	Tuesday	01:45 Snoopy	00:01:43 Snoopy	Snoopy
8 Aug 2007	Tuesday	02:05 Snoopy	00:01:56 Snoopy	Snoopy
27 Sept 2007	Wednesday	02:27 Owlbert A2	00:22:01 Owlbert A2	Owlbert A2	Moonlight whited out more sensitive cameras
27 Sept 2007	Wednesday	04:50 Owlbert A2	00:00:17 Owlbert A2	Owlbert A2	new start point and reversed direction of travel
23 Oct 2007	Monday	10:07 Owlbert A2	00:00:17 Owlbert A2	Owlbert A2	Above horizon (Type IV)-- see Owlbert Page
13 Jan 2008	Sunday	3:17 Owlbert A4	00:04:54 Owlbert A4	Owlbert A4	Bearing 226.3 degrees true
13 Jan 2008	Sunday	5:02 Owlbert A4	00:02:56 Owlbert A4	Owlbert A4	Bearing 226.3 degrees true
27 Mar 2008	Wednesday	1:10 Snoopy	00:13:24 Snoopy	Snoopy, Owlbert A4
27 Mar 2008	Wednesday	1:23 Snoopy	00:00:39 Snoopy	Snoopy
27 Mar 2008	Wednesday	1:24 Snoopy	00:01:27 Snoopy	Snoopy
27 Mar 2008	Wednesday	1:28 Snoopy	00:00:20 Snoopy	Snoopy, Owlbert A4
27 Mar 2008	Wednesday	2:14 Owlbert	00:07:22 Owlbert A4	Owlbert A4
27 Mar 2008	Wednesday	3:15 Owlbert	00:03:57 Owlbert A4	Owlbert A4
1 May 2008	Wednesday	6:32 Roofus	00:00:33 Roofus	Roofus
1 May 2008	Wednesday	6:51 Roofus	00:00:28 Roofus	Roofus

Sample Temperature, Due Point and Humidity profiles:

I regret poor quality of the following plots.  They are as clear as I could make them given limitations of the data source. 

These are typical temperature and humidity profiles associated with ML appearances.