1. Size and density of the particles:
With dimensions of a arbitrary cube-shape of 0.12 mm at 1x10^14 times the density of lead 9 g/cm^3 works out to one metric ton.
(as the article says). But how can something that large (1/10th mm) go through the earth (about 4000 miles of which is molten and solid iron)... and keep going. I would expect more of a crater and explosion.
2. Relativistic mass factors additional energy.
It is going about 1/10 of 1% of c.
3. Within the past month or so the quark star has been tentatively identified... so this form of matter is otherwise believed to exist, but in a form more dense and trapped in gravity tighter than a neutron star. The "hot" stranglet must come from an early-cosmos event... or the collision of two quark stars?
4. Galactic (extra-solar system) objects (meteorites) are identified by their speeds... anything faster than about 130,000 mph cannot have originated in our solar system. Interesting.