The Asteroid Belt Flashcards
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
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)
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
The E-belt
disruption of this - by movements of Jupiter and Saturn, may have caused the Late Heavy Bombardment
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
Kirkwood gaps
Caused by orbital resonances with Jupiter.
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
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
How many main belt zones are there in the asteroid belt
Three
What is the most significant group of the inner zone of the Main Asteroid Belt
what type of asteroids are these
Eunomia (250km mean radius)
“stony” S-type asteroid
6th largest family in the asteroid belt
What happened shortly after Piazzi discovered Ceres
who came to the rescue
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.
What is the AU range of the Main Belt
2.06 - 3.28 AU
What is the first major group outside of the Main Belt
Cybeles at around 3.5 AU
What is the second major group outside of the main belt Roughly how far out
Hildas About 4 AU
Where are the majority of the metal asteroids
The mid section of the main belt But remember overall they are still less common than the S and C types
Where is the peak of the S and C type asteroids respectively
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
What type of asteroids do you get in the Jupiterian Trojans
D type
What are the largest families in the main belt
Eos, Koronis, Themis
What type of meteorites are associated with Vesta
HEDs Howardite, eucrite, diogenite Only useful to remember the former
How is the mass of asteroids distributed by type
75% are C type 15% are S type 5 % are M type The rest is other
Can you put the four main asteroids into their main belt zones
Vesta - inner
Pallas and Ceres - middle
Hygeia - outer
What is the semi major axis distance of the following asteroids
Vesta
Ceres
Pallas
Hygeia
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
Which asteroid has almost the same mean diameter as Enceladus
And what is that
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!
how to astronomers identfy and asteroids type?
their spectra (light curve)
What do you call a space rock that gets burned up in the atmosphere and does ‘t reach the surface
Bolide
Why are their most carbon rich asteroids as you go away from the sun
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
Why are their most carbon rich asteroids as you go away from the sun
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
What type of asteroid is Vesta and what makes it special
V type
It’s unique in its basaltic content showing it was once volcanically active
What type of asteroid is ceres
Explain
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
What type of asteroid is Pallas
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
