NEAT detects moving objects - asteroids and comets - by observing the same part of the
sky 3 times during an interval of about 1 hour. The automatic data analysis system
searches for moving objects by comparing the 3 images.
A representation of the 3 images developed by Dr. Daniel MacDonald is show below. It is
based upon the old image represenation shown below.
There are three notable additions to the older representation:
1.A theoretical picture of the streak that the asteroid should produce in the image is shown
in the small box under the 3x3 pictures.
2. The velocity space now contains the object of interest (red cross) and other known
objects: mainbelters (blue dots), known and artificial Hungarias (green dots-interesting
asteroids but not NEAs), Trojans (grey dots-interesting asteroids but not NEAs), and
other NEAs (purple dots).
3. A "match" and "note" field that contains a previously known asteroid name that is close
to the object of interest and may be the object of interest.
The older representation of the 3 images developed by Dr. David Rabinowitz is shown
The candidate object appears to move from the upper left to the lower right. Each small
panel is a 25 x 25 pixel sub-image extracted from the 4096 x 4096 pixel raw images. The
moving object is found at 3 different positions during the 3 observation times. The top 3
panels are centered at position 1 during times 1-3. The moving object is centered in panel 1
only. The middle 3 panels are centered at position 2 during times 1-3. The moving object is
centered in panel 2 only. The bottom 3 panels are centered at position 3 during times 1-3.
The moving object is centered in panel 3 only. Notice that fixed stars, if any, remain in the
same relative position in all 3 horizontal panels.
To summarize, the moving objects can only appear in the center of the panels in the upper
left to lower right diagonal. All the other panels are "anti-coincidence" tests. The object
can not be centered in any of them.
The diagram to the right of the images depicts object motion, the "+", in degrees per day,
along the ecliptic longitude (horizontal axis) and latitude (vertical axis) directions. The
above object, 1996 TO5, is moving at -0.42 degrees per day, mostly in ecliptic latitude. The
polygon shows the boundaries for the expected motions of main-belt asteroids. 1996 TO5 is
a Near-Earth asteroid, an Earth-approaching Amor, consistent with the fact that its
motion falls outside the polygon. In some cases the polygon delineating the main-belt
motions will not be closed because the boundaries are not known precisely. Eger was
moving about 4 degrees/day in the upper images and the main-belt motion was off the
Some images shown in Previous Breaking Images are in the original linear format
developed by Jean Lorre and Dr. Steven Pravdo. An example of this is shown below, with
Eger again. In this format, panels 1-3 correspond to the top 3, panels 4-6 to the middle 3,
and panels 7-9 to the bottom three, as described above.
The asteroid or comet will be found centered only in panels 1, 5, and 9. Fixed stars (if any)
will be seen in the same positions in panels 1-3, 4-6, or 7-9.