Astronomers, as with other scientists, require certain rewards to sustain them in the field of astronomy. First, they need to obtain research grants to continue their work, since most employers (chiefly universities in the case of professional astronomers) will not support them to do anything other than teaching and will not keep them on faculty unless they have a record of published research and of winning research grants. Second, astronomers, as with anyone else, need the respect of their peers. Finally, since they are investigators, astronomers need to satisfy their intellectual curiosity.
The problem with the task of NEO orbit follow-up is that it fails all three criteria for professional astronomers, and therefore receives very little or no attention from professional scientists or funding from federal science agencies.
Although several scientists have studied NEO's extensively, both out of curiosity and as a means to aid others in devising mitigation strategies should an impactor be discovered, there is virtually no scientific content in making NEO follow-up observations. There are a few papers published on NEO orbits, but they tend to be on the aggregate properties of NEO orbits based on initial data, which is accurate enough for the purposes of most studies of group properties of NEO's and how to detect NEO's based on the orbital properties. Thus, there is no scientific return in using precious telescope time to observe a particular newly discovered NEO to help refine its orbit.
It helps to understand what professional astronomers must endure to obtain observing time on a telescope. Most moderate (1- to 4-meter) and all large (6- to 10-meter) telescopes have Telescope Allocation Committees (TAC's) that allocate time on a competitive basis, because these telescopes tend to be oversubscribed. The community of users served by each telescope submits proposals to use the telescope a few weeks or months in advance of each scheduled time period, usually a semester (half a year). The TAC reviews several dozen to several hundred proposals and ranks them in order of scientific merit, then time is awarded based on this ranking.
Most professional observatories award time to groups of observers performing large surveys in blocks of time of a few dozen nights per year, while observing time to individual observers is usually awarded for a single proposal in a smaller segment of 2 to 5 nights per semester. In this "classical" mode of telescope time allocation, the observer then travels to the telescope site and uses the telescope the entire night each night the telescope is scheduled for their project. Due to the large number of proposals usually received, and the large variety of scientific programs that the TAC wishes to serve, that is all the time a particular program can hope to obtain. If the weather is bad for part or all of the scheduled time, that's too bad. If the astronomer's program is not completed that semester, they must reapply for more time the next semester their object is visible in the sky, which might not be for another year.
To perform NEO follow-up, an observer must have access to a telescope on a continuing basis, not 3 or 4 nights a semester. For an NEO follow-up program to be vigorous, a telescope needs to be dedicated to NEO follow-up, and cannot be shared with competing programs that need the telescope for full nights for several nights in a row. This requires a few hours of telescope time each night on a consistent basis. However, it does not require using the telescope the entire night each night, leaving time available for project partners with scientifically compatible programs willing to use the telescope in this non-classical mode.
Another feature of NEO follow-up is the use of special software tools that enable data reduction and reporting of results in a timely manner. To be useful, images taken one night must be reduced either that night or the next morning and the results reported to the Minor Planet Center the next day.
Since there is no professional scientific value in making NEO follow-up observations, in the sense of publishing papers, receiving peer recognition, winning research grants, and obtaining intellectual satisfaction, professional astronomers are not inclined to make these observations. Such observations also require quantities of telescope time that are difficult to acquire, and could be used for other observations of far greater scientific return and of greater benefit to their careers. The funding agencies, managed by scientists, do not fund this research because it has little or no scientific value and their institutional mandate is to use their budgets to maximize scientific return, not to save the nation from NEO attack.
The result of this situation is that we simply do not know what dangers to our planet may lurk in our own Solar System. For all we know, an asteroid or comet may be heading straight for Earth right now. A small, faint object could hit a large US city tomorrow and completely destroy it, and though we might find it, we could easily lose track of it with present telescopes now in operation.
Last modified: January 3, 2008.