The other 20% to 25%..
It's a small mass, but mass, nonetheless..
If the comet is a loose ball of powder rather than a hard lump, what holds it together as it arcs around the sun?
Just a guess here, but I would say electrostatic charge..
Through ionization, the particles have "clumped" together, and are held together by "static electricity"..
Just like a dust bunny..
Comets... The intergalactic dust bunny.
And coming soon, the intergalactic version of the dreaded BROOM!!!
:-)
It's a small mass, but mass, nonetheless
Yes, but the mass is fixed, and was known beforehand wasn't it? I would think the mass can be determined from observations of the orbital path. The size of the comet is known, so there was an expectation of the object's density. The article indicates that the Deep Impact results show the density is 20 to 25% of the expected value. That doesn't seem to add up.