ScienceCasts: Smallest Terrestrial Planet?

NASA's Dawn probe, now orbiting Vesta in the asteroid belt, has found some surprising things on the giant asteroid--things that have prompted one researcher to declare Vesta "the smallest terrestrial planet."

Category:

Science & Technology

Tags:

• ScienceCasts:
• Smallest
• Terrestrial
• Planet?

[CrazyAngelDude]

I have a feeling I'll be stuck watching NASAtelevision for the upcoming four hours or so..

[DiverseLA]

@hardstyle905 Atmosphere isn't mentioned, true, but it doesn't have a spherical/round shape. It also hasn't "cleared the neighborhood" since it's in the middle of an asteroid belt.

[hardstyle905]

@DiverseLA

"The definition of planet set in 2006 by the International Astronomical Union (IAU) states that, in the Solar System, a planet is a celestial body which:

is in orbit around the Sun,

has sufficient mass to assume hydrostatic equilibrium (a nearly round shape), and

has "cleared the neighbourhood" around its orbit."

No mention of atmosphere.... all criteria are met.

[httprover]

Is the crustal material of a terrestrial planet like the slag produced while smelting iron? By the same definition the Moon might be considered a terrestrial planet. The Earth and the Moon would be a "double planet" in an analoby with "double stars."

[raphael77ful]

How can u call that a Smallest Terrestrial Planet, since u don't have enough information about it?

[sbergman27]

@BannedUfos "They still haven't figured out what the definition of a planet is."

The real issue is classification. A good system of classification is important in science. One need only look to the the periodic table of elements or the linnaean system of species classification to see just how powerful a tool it can be. Meanwhile, some folks want the issue to revolve around some bizarre emotional attachment they have with a non-visible, magnitude 15 body that they've never actually seen.

[feuchster]

@BannedUfos Calm down, stop getting so mad over the internet, kid.

[DiverseLA]

@RangerParus Mercury has a trace atmosphere. Very thin, but it has one.

[MsMcBell]

Very interesting, thank you! =))

[RangerParus]

@DiverseLA So you disbelieve Mercury as a planet?