Class 17: Small bodies of the solar system: comets, asteroids, and dwarf planets

Comets

Icy bodies that release gas or dust and develop tails when near the Sun.

Asteroids

Rocky objects found primarily in the asteroid belt between Mars and Jupiter, varying in size and composition.

Dwarf Planets

Celestial bodies that orbit the Sun, similar to planets but do not clear their orbital path; examples include Pluto and Eris.

Ceres

The largest object in the asteroid belt, classified as a dwarf planet, known for achieving hydrostatic equilibrium.

Vesta

The largest asteroid, about half the size of Ceres, and does not have a spherical shape.

Eros

An asteroid that is homogenous with an old cratering surface.

OSIRIS-Rex

A mission that observed asteroid Bennu and provided insights into its low-density, possibly hollow interior.

Kuiper's Belt

A region 20-200x more massive than the Asteroid Belt, containing several known dwarf planets including Pluto.

Pluto

A distant dwarf planet with a unique surface, an orbital period of 248 Earth years, and an inclined orbit.

Comet Tails

Formed by the sublimation of ices and the release of gas and dust as a comet approaches the Sun, consisting of a gas tail and a dust tail.

Albedo

The reflectivity of a surface, indicating how much sunlight is reflected back into space versus absorbed.

The Oort Cloud

A huge spherical cloud of comets outside the Kuiper belt, formed near Jupiter and ejected by gravitational interactions.

What is the main distinction between an asteroid and a comet?

Its composition.

What is unique about the crater on Pluto's moon Charon?

Charon has more craters than Pluto and its surface is mainly water ice.

Why is the activity on Ceres significant?

It suggests a complex interior structure, potentially containing a subsurface ocean.

What caused the Cretaceous-Paleogene Extinction Event?

An asteroid or comet approximately 30km across struck the Earth, leading to the extinction of most dinosaurs.