One of these is visibility of the coma all around the orbit.
The standard model tries to explain comas by outgassing from a single nucleus as the comet approaches the Sun.
Taken in conjunction with the finding of bilateral symmetry in the Face and the anomalous nature of other nearby objects on Mars, the weight of existing evidence has, in this author's opinion, shifted in favor of an artificial origin of the Cydonia complex.
It was photographed several times by NASA's Viking Mars-orbiting spacecraft in the mid-to-late 1970s.
One of them, dubbed the "D&M pyramid" after its discoverers Vincent Di Pietro and Gregory Molenaar, is shown in Figure 3.
It has a more-than-passing resemblance to a four-sided, or possibly a five-sided, pyramid.
These may be viewed in (Carlotto, 1991), in (Di Pietro, Molenaar & Brandenburg, 1988), or on In (Van Flandern, 1993), the author provided extensive evidence of the explosion of a former major planet in the main asteroid belt.
We draw attention to the fact that the Both the line of inquiry that led to this discovery and a possible purpose for building such an artificial structure looking into space were suggested by the exploded planet hypothesis.
The explosion model expected debris clouds around asteroids and comets.
This led to a well-publicized 1991 prediction that satellites will be found around both types of bodies.
A few highlight points include the following: Asteroid orbits fill the available range of positions and velocities between Mars and Jupiter that are stable against planetary perturbations over millions of years.
Their original population was clearly far greater, with only a small percentage of the original mass still present.Many meteorites show evidence of separation of heavy elements from light elements by gravity (called "chemical differentiation"), as would normally require a planetary-sized parent body.