Special Issue : 10/01/2004
A scientific publication by SGF and NEODyS

The history of Hermes

An interview to Timothy Spahr (Minor Planet Center)

Timothy Spahr alerted the scientific community that the newly discovered object on Skiff's images was probably Hermes


Question: Can you tell us Hermes' story from your point of view? How were you involved in the rediscovery phase? What are your feelings as a researcher ?

T. Spahr: My job at the Minor Planet Center (MPC) is to process and attempt to identify the unidentified Near-Earth Object (NEO) candidates reported to the MPC by the various observers around the world. Largely these submissions are from professionally-funded American projects, but I of course process the batches from amateurs around the world with the same spirit and zeal. I often work odd hours, and sometimes long hours.
On the morning of October 15 local time, I was up at around 5-6 AM processing NEO candidates from the various search programs. One of the NEO candidates was a very bright NEO reported by Brian Skiff of Lowell Observatory (read Brian Skiff's interview). After this object passed the routine cecks, I installed it on the NEO Confirmation Page on the web (http://cfa-www.harvard.edu/iau/NEO/ToConfirm.html). Within an hour or so, Jim Young at code 673 provided follow-up astrometric observations.

At this point I had an idea that the object was in fact Hermes, but the orbit was very uncertain. A quick check of recently reported, yet still unidentified, objects produced a critical third night for this object. A full general solution could then be computed, and once these orbital elements were run through a simple check program (checkneals), it suggested that this object was Hermes based on similarity of orbital elements.

At this point I was absolutely convinced of the identification, and bolted out of my chair to tell Brian and Gareth of the identification. It was awfully exciting, especially since we were looking for this object for so long.

Once we were certain of the identification, we attempted to differentially correct the orbit and produced a linked orbit from 1937 to 2003. In the middle of this process, we received an e-mail from Andrea Boattini congratulating us on the Hermes recovery, cleary indicating that he was paying close attention to the NEO Confirmation Page! (read Andrea Boattini's interview) At the time it was unclear how Andrea arrived at this idenification, but it is certain that Andrea himself deserves some of the credit for independently noting the identification.

Question: Why was Hermes so difficult to find? Why was there a doubt that 2002SY50 and Hermes could be the same object?

T. Spahr: Hermes was so difficult to discover because it approached the earth on several approaches from below the ecliptic, and was only bright when in southern skies. Given the paucity of observatories or active surveys for minor planets in the southern hemisphere, Hermes went undetected.

2002 SY50, [a different NEO], had similar orbital elements to Hermes, but it was largely clear from the start that they were not the same object. MPEC 2002-T14 was largely to alert people to the striking similarity of the orbits and encourage other observations.

Question: Can you tell us about the central role of MPC?

T. Spahr: The present role of the MPC is to process and check all astrometric observations of small bodies in the solar system. Once observations are processed and checked, orbits are published, and eventually, the observations. It is not uncommon to receive several hundred thousand observations in a week's time. In terms of discoveries, recoveries, and identifications of minor planets by the MPC, the number is in the hundred thousands.

Question: From the MPC point of view, how does the discovery and the recovery technically happen?

T. Spahr: . Discovery right now is defined as having confirmation of an object, this generally means multiple observations over a significant time span on two nights. The discovery credit is usually given to the first observer to report and object during the observing period, but this is not always the case. Recovery or identification of objects is largely automatic, and becomes much easier when each object has a long arc at each opposition.


Question: Are there other "famous lost asteroids" that the scientific community is trying to recover?

T. Spahr: Most definitely! These include:

PLS5025
PLS6344
1972 RB
1979 XB
1984 QY1

along with many others...