MINOR
PLANET
FAQ's
Minor Planet Center Code 740
SFA Observatory
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Answers to Frequently Asked Questions
The following are some questions and answers from the Minor Planet Mailing List {MPML}.
What proportion of asteroids found each year are found by an amateur astronomer versus a full-time professional astronomer?
Some statistics from the past few years:
Year #Disc #Prof #Amat % Amat
1996 8745 6680 1322 15.1
1997 9974 9050 1973 19.8
1998 28427 26769 1811 6.4
1999 19698 19674 1572 8.0
Overall, amateurs have 13177 out of 159167 discoveries (8.3 percent).
The value for 1999, currently 8.0%, is comparable to the long-term average.
As promised last month, here are counts on the total number of professional
and amateur discoveries, with a break down by year (since 1980) and
by country (indicated by two-letter codes). The statistics for 1999
are complete through the 1999 May 4 MPCs. Apologies for the width of
the output, but I wanted to show the totals for a wide range of countries.
Year # Pro #Amat US IT JP UK AU FR DE CA PT SI SK MX ES AT CH
1980 2095 11 0 7 4 0 0 0 0 0 0 0 0 0 0 0 0
1981 3474 288 0 286 2 0 0 0 0 0 0 0 0 0 0 0 0
1982 2316 344 0 339 5 0 0 0 0 0 0 0 0 0 0 0 0
1983 1401 166 0 164 2 0 0 0 0 0 0 0 0 0 0 0 0
1984 1469 35 1 33 1 0 0 0 0 0 0 0 0 0 0 0 0
1985 1772 23 0 22 1 0 0 0 0 0 0 0 0 0 0 0 0
1986 2593 131 0 123 8 0 0 0 0 0 0 0 0 0 0 0 0
1987 2585 132 0 126 6 0 0 0 0 0 0 0 0 0 0 0 0
1988 2029 441 0 426 15 0 0 0 0 0 0 0 0 0 0 0 0
1989 2723 600 1 576 7 16 0 0 0 0 0 0 0 0 0 0 0
1990 4185 645 0 640 2 3 0 0 0 0 0 0 0 0 0 0 0
1991 4550 723 0 714 4 5 0 0 0 0 0 0 0 0 0 0 0
1992 3837 885 0 883 2 0 0 0 0 0 0 0 0 0 0 0 0
1993 6195 670 0 622 48 0 0 0 0 0 0 0 0 0 0 0 0
1994 5299 948 6 800 140 2 0 0 0 0 0 0 0 0 0 0 0
1995 7356 1187 28 960 156 25 0 0 2 2 0 0 0 0 0 0 0
1996 8699 1329 271 801 165 26 11 0 2 4 1 0 18 0 4 0 0
1997 9940 1994 365 1157 225 20 40 53 35 0 0 11 36 0 45 0 0
1998 28338 1850 285 586 215 4 203 49 52 0 0 1 48 6 21 1 1
1999 7461 972 140 311 62 0 71 2 14 5 0 11 9 8 6 0 12
Total 1231 10490 1074 102 325 104 105 11 1 23 121 14 76 1 13
Total number of professional discoveries = 144901
Total number of amateur discoveries = 14427
Some remarks:
Overall, the percentage of amateur discoveries is 9.1 percent. The rate
obviously varies from year to year (from a low of 0.5 percent in 1980 to a
high of 18.7 percent in 1992), but since 1988 the percentage has rather
consistently been above 10 percent. Since 1988 the total number of
amateur discoveries has increased five times, to 1997/1998 totals nearing
2000/year. This is comparable to the professional discovery rates
through the late 1980s.
For much of the 1980s the principal amateur effort was in Japan. The
number of Japanese discoveries peaked in 1997. Amateurs in other countries
got involved generally following the introduction of affordable CCD
technology, although the U.K. did manage 24 photographic discoveries in
1989-1991. Italian amateurs, although discovering at a low rate in the 1980s,
really got going in 1993. The U.S. followed suit in 1994, with Canada,
Germany and Slovakia starting in 1995 and Australia (principally) in 1996.
Overall, Japanese amateurs account for almost 77 percent of the amateur
discoveries since 1980. This percentage is falling as the Japanese
activity slackens and the activity in other countries rises.
If 1999 continues at the rate of the first 4.something months, the
number of amateur discoveries this year may approach 3000.
Gareth V. Williams, Associate Director, IAU Minor Planet Center
I keep hearing and reading this: "More people work in a single McDonald's restaurant that are employed worldwide to monitor asteroids."
Is this really accurate?
I don't know how many people work in a typical McDonald's. I avoid
getting to such place if I don't have to. For the number who work on
asteroid searches, as usual it depends on how you count. It can be made
relatively quickly, and hopefully accurately.
If we take into account the people who are paid to discover asteroids,
i.e. not follow up, just run the machine at night, hoping I do not
forget too many people:
Spacewatch : At the last count, there were 12 people on payroll for the
whole program (including stellar program), but maybe 4 observers
LINEAR : There are 5 people counted as observers, 3 more as measurers
LONEOS : 5 people maybe (Koehn, Skiff, Ferris, Levi, ???)
NEAT does not seem to observe currently
ODAS does not observe currently
Catalina : 4 if I am right (Larson, Hergenrother, Spahr, and ... ?)
SCAT (Beijing) 4 persons if I am right, but asteroid program is only a
small part of the telescope use. So one person full time is maybe right.
So we are talking about 20 persons.
Good nights,
Alain
LONEOS has two full time equivalent positions.
Spacewatch,
LINEAR,
CATALINA, and
NEAT
are the other "professional" US NEO searches. They
have slightly more full time positions. But even
if we average 5 FTE positions, that is only
25 people in the US.
It is harder for me to quantify the international
effort but I bet it is less.
A single Mickey D's has how many?
Of course, lots of others do this job for no pay.
Very few people work at Mickey D's for no pay.
Regards,
Bruce
I have a feeling that I am the only person in full time employment in the
southern hemisphere directly for NEO work. So it is certainly true for
the southern hemisphere!
Regarding multiple observations in Vaisala, this query was probably the
result of my comment in comparing extrapolation vs Vaisala. If a "best
fit" to several observations is made by linear interpolation in order to
extrapolate the path, then the Vaisala orbit will only be comparable if
(two) observations are used that are in exact agreement with the
interpolation. One must thus create the two input observations for the
Vaisala orbit from the interpolation, preferably at the times of the
extreme observations.
Cheers, Rob
Robert H. McNaught
rmn@aaocbn.aao.gov.au
Because of repeatedly hearing this, last time I was in the McDonald's in
Sierra Vista, I asked the manager how many employees the store had. (Sierra
Vista is a town of 40k people.) The answer was 155, much larger than I
expected. Now, as Alain said, I suppose it depends how you count asteroid
folks.
--
Jeff Medkeff ,
Hereford, AZ ,
Where can I find information on the method of Vaisala for orbit calculations?
"The Determination of Orbits" by A. D. Dubyago,
The Macmillan Company, New York, 1961.
MPC's New Object Ephemeris Generator uses Vaisala's method.
Check out this Vaisala Method of Orbit Determination Excel Worksheet.
Brian Marsden descirbed a variation of the Vaisala method mentioned in
Dubyago in an article in Asteroids I (edited by Tom Gehrels). In effect, you try, as David Tholen
suggested, various combinations of eccentricities and mean anomalies. The
combination needs to give results within certain parameters (I've forgotten
them). For each solution, you check the residuals against the observations
at hand and take the one that gives the best agreement. I've done some code
along these lines but don't claim it to be the most accurate in the world.
However, it has served to find targets a few days later and fairly close to
where predicted.
Clear Skies,
Brian Warner
716 Palmer Divide Observatory
Colorado Springs, CO
Online References
Dan Bruton
astro@sfasu.edu
Minor Planet Research