The Asteroid Belt

Question 1

What is the innermost dense concentration of asteroids in the solar system

what is notably about their orbit?

what marks the outer boundary of the group

what interactions determine the innder boundary

What is the semi-major axis range in AU

Answer 1

Hungaria group (1.78 - 2.00 AU)

They have high inclinations 16-34 degrees (there are no dense numbers at lower inclinations at this orbit radius)

the outerboundary is marked by the Inner Kirkwood gap (4:1)

the inner boundary is determined by interactions with Mars. (lower inclinations would be thrown out by Mars)

Question 2

What hypothetical ancient group of asteroids is the the innermost concentration of asteroids a potential remenant

What might the disruption of the hypothetical group have caused

Answer 2

The E-belt

disruption of this - by movements of Jupiter and Saturn, may have caused the Late Heavy Bombardment

Question 3

What are the names of the gaps/dips in distribution of the semi-major axes of the orbits of main-belt asteroids.

What causes these gaps

Answer 3

Kirkwood gaps

Caused by orbital resonances with Jupiter.

Question 4

What is the second inner most dense concentration of asteroids

what are its two names

what type are they

Why might this group by famous

Answer 4

Flora group

aka Ariadne group

Stony family of asteriods

Its likely that Flora and Ariadne were aggregates of the debris of a disrupted body

Famous as a likely source of the K-Pg impactor

Question 5

How many main belt zones are there in the asteroid belt

Answer 5

Three

Question 6

What is the most significant group of the inner zone of the Main Asteroid Belt

what type of asteroids are these

Answer 6

Eunomia (250km mean radius)

“stony” S-type asteroid

6th largest family in the asteroid belt

Question 7

What happened shortly after Piazzi discovered Ceres

who came to the rescue

Answer 7

He got ill and lost it.

Astronomers hunted but couldn’t find it. Mostly because there maths wasn’t up to calculating where it should be based on its last position.

However, Gauss got in on the game and he of course could do, and with that Zach and his planetary police were able to find it.

Question 8

What is the AU range of the Main Belt

Answer 8

2.06 - 3.28 AU

Question 9

What is the first major group outside of the Main Belt

Answer 9

Cybeles at around 3.5 AU

Question 10

What is the second major group outside of the main belt Roughly how far out

Answer 10

Hildas About 4 AU

Question 11

Where are the majority of the metal asteroids

Answer 11

The mid section of the main belt But remember overall they are still less common than the S and C types

Question 12

Where is the peak of the S and C type asteroids respectively

Answer 12

S types peak in the first zone of the Main Belt, and are pretty uncommon beyond the main belt C types peak out zone of the main belt. They are also more common than a types in the second (mid) zone, and they are also found beyond the Main Belt

Question 13

What type of asteroids do you get in the Jupiterian Trojans

Answer 13

D type

Question 14

What are the largest families in the main belt

Answer 14

Eos, Koronis, Themis

Question 15

What type of meteorites are associated with Vesta

Answer 15

HEDs Howardite, eucrite, diogenite Only useful to remember the former

Question 16

How is the mass of asteroids distributed by type

Answer 16

75% are C type 15% are S type 5 % are M type The rest is other

Question 17

Can you put the four main asteroids into their main belt zones

Answer 17

Vesta - inner
Pallas and Ceres - middle
Hygeia - outer

Question 18

What is the semi major axis distance of the following asteroids
Vesta
Ceres
Pallas
Hygeia

Answer 18

Vesta - 2.36
Ceres - 2.77
Pallas - 2.77 (yes same as Ceres)
But also remember the high eccentricity and inclinations of orbits
Hygeia - 3.14

Question 19

Which asteroid has almost the same mean diameter as Enceladus
And what is that

Answer 19

Pallas
Around 510 km

And Vesta
Which has a mean diameter of 525km

Both asteroids are quite a lot denser to are a fair bit more massive!

Question 20

how to astronomers identfy and asteroids type?

Answer 20

their spectra (light curve)

Question 21

What do you call a space rock that gets burned up in the atmosphere and does ‘t reach the surface

Answer 21

Bolide

Question 22

Why are their most carbon rich asteroids as you go away from the sun

Answer 22

It’s the temperature gradient at the formation of the solar system

Silicates do better at hotter temperatures and volatiles so not

As you move further away you can get more material formed from carbon and volaitiles so these tend to dominate. It does not mean an absence of silica altogether as you get further out

Question 23

Why are their most carbon rich asteroids as you go away from the sun

Answer 23

It’s the temperature gradient at the formation of the solar system

Silicates do better at hotter temperatures and volatiles so not

As you move further away you can get more material formed from carbon and volaitiles so these tend to dominate. It does not mean an absence of silica altogether as you get further out

Question 24

What type of asteroid is Vesta and what makes it special

Answer 24

V type
It’s unique in its basaltic content showing it was once volcanically active

Question 25

What type of asteroid is ceres
Explain

Answer 25

Ceres is a G type. (Or a c type - it is dual branded)

So in broad composition is is basically a c type (and could be called the biggest c type) but because of the presence of certain minerals particularly clays on its surface it has a unique spectral signature , and this signature is called a g type

Question 26

What type of asteroid is Pallas

Answer 26

B type

Basically its unique signiture likely reflects its made mostly of silica with little iron, but its dark surface is more like that of c types