M-Type: Metallic

• Fairly Rare
• Big chunk o' metal
• Probably formed from differentiated core of large former body
• Examples: Psyche

Basaltic

• Very Rare
• Much like mare on the Moon...
• Probably Formed from differentiated crust/mantle of large former body
• Examples: Vesta

Question: How do you suspect we determine the composition of an asteroid?