Asteroid Connect

Observation of asteroids

Large sky surveys and enthusiastic amateurs alike observe minor planets (small objects like asteroids that orbit the Sun).
In particular, the Large-Scale Survey takes pictures of part of sky as if scanning the entire sky, automatically detects a huge number of moving objects (i.e., asteroids) from a huge amount of images, and reports the results to the Minor Planet Center (MPC, an international organization affiliated with the International Astronomical Union that coordinates the observations of asteroids around the world).

Currently, more than 1.4 million asteroids have been found, the majority of which have accurately determined orbits based on long-term observations. The trajectories of these objects can be predicted with extreme accuracy, and the answer to where they will be in the sky tonight is an easy one to figure out. If such an object with a precise orbit is detected in a series of images taken by an observer of the sky, the observer can immediately recognize the object using software databases. The observation is then reported along with the name of the object.

On the other hand, if the location of a detected object does not match the predicted location of an already discovered object, it is reported to MPC as an undiscovered asteroid with an internal code assigned by each observer for convenience. These observations that are not linked to already known asteroids are stocked by MPC as ITF (Isolated Tracklet File), which are available on the MPC website.

However, some of known asteroids do not have well-defined orbits. Since these objects' current positions cannot be accurately predicted, even if they appear in images observed tonight, they will be recognized as “unidentified asteroids” without being noticed as one particular known asteroid. Such observations can also end up in the ITF, waiting to be linked.

In addition, a new asteroid must be observed on multiple nights before it can be registered (assigned a provisional code) as a new object. However, with the exception of some near-Earth asteroids and amateur observations, large-scale surveys do not perform the tedious and inefficient process of follow-up obserbation new objects detected on one night, one by one, for multiple nights, and reporting them as tracked observations to the MPC.
In other words, the ITF remains stocked with identical combinations of new objects.

Linkage!

As the astrometry reports of those objects are published on ITF, the work starts to make connections (or 'linkages') between them to determine which batches of observations belong to the same object. Sometimes this is done by the MPC, sometimes by amateur astronomers using their own algorithms for linking. In other cases, researchers develop more effective algorithms and publish their code along with their papers.

Three nights of observations are usually required to have an ITF observation recognized as a new provisional sign object by linking (ITF-ITF). 3 nights of links can be established and the link submitted to the MPC to indicate that a new provisional code object has been discovered.

It is also important to link observations in the ITF with objects already registered as provisional sign objects (ITF-DES). This allows the movement of a particular asteroid to be tracked over a longer distance and period of time, allowing orbits to be determined more accurately using the orbit determination method.

In less likely cases, sometimes the isolated tracklets of the same object are connected among themselves, but are falsely recognized as different objects and two different designations are created. If those designations are later found to be the same object, this is a (DES-DES) identification.

Why are you needed?

Although computers can do linkages in automated manners, some objects in particular, such as distant objects like Trans-Neptunian Objects and Centaurs, or odd objects on highly eccentric orbits, may especially be a bit more difficult to classify by computerized efforts. It is also possible that a computer can miss seemingly simple identifications since the efforts of larger organizations may be more often geared towards handling NEOs, Near-Earth Objects. So, a new approach, in which the human eye is used to review images that make the pattern of observations visible, may facilitate the process for objects that have been missed.

We have developed a program, Connectonomicon, to enable this approach.
https://github.com/arda-guler/Connectonomicon

The program projects onto a chart all the tracklets that may fit the two tracklets that are already known to belong to an identical object. By checking this with the human eye, the program prevents the computer from missing something that it is prone to miss.

The disadvantage is that each chart image must be checked by human eyes one by one. Therefore, with the help of many volunteers interested in asteroids and minor planet astronomy, a large number of images can be visually checked to extract linkages that have been missed!

Read more about identifications on Minor Planet Center's documentation:
https://www.minorplanetcenter.net/mpcops/documentation/identifications/

If you have further questions, don't hesitate to create a discussion in the talk page!