Sentences with phrase «total planetary mass»

Here's the problem: Many of these planets begin with super-thick atmospheres comprised of noxious hydrogen and helium, comprising around one percent of the total planetary mass.

Not exact matches

Those measurements reveal that the B ring, which makes up 80 percent of the total ring mass, is about 15 billion billion kilograms, or 0.4 times that of Saturn's moon Mimas, planetary scientist Luciano Iess of Sapienza University of Rome said at the meeting on December 12.

Occasionally these objects look something like planetary nebulae, as in the case of the Crab Nebula, but they differ from the latter in three ways: (1) the total mass of their gas (they involve a larger mass, essentially all the mass of the exploding star), (2) their kinematics (they are expanding with higher velocities), and (3) their lifetimes (they last for a shorter time as visible nebulae).