Karin family
The most recent known asteroid collision in the main belt.
The Karin family, also known as the Karin cluster, is an asteroid family and a sub-group of the Koronis family, consisting of at least 90 main-belt asteroids. It is notable for being the most recent known asteroid collision, with the breakup of the parent body estimated to have occurred 5.8 ± 0.2 million years ago. Scientists have used the orbits of 13 members to calculate backwards and found they all share the same orbit, that of the original parent body.
- Number of members
- at least 90
- Largest member
- 832 Karin
- Diameter of largest member
- about 19 km (12 mi)
- Estimated diameter of parent body
- 33 km (21 mi)
- Age of family
- 5.8 ± 0.2 million years
- Mass of largest member relative to paren
- 15–20%
- Diameter range of other members
- 1–7 km (0.6–4.3 miles)
Lore & Background
The Karin family is named for its largest member, 832 Karin, an S-type asteroid with a diameter of about 19 km (12 mi). This member represents about 15–20% of the mass of the original body, which had an estimated diameter of 33 km (21 mi). The other members have diameters in the 1–7 km range (0.6–4.3 miles). The family is believed to have been created 5.8 ± 0.2 million years ago, making it the most recent known asteroid collision. Because the surfaces of the family members are relatively pristine, spectroscopic analysis can reveal much about their composition, potentially shedding light on the relationship between asteroids and meteorites. The known age of their surfaces also aids in determining the rate of crater formation on asteroids. It is estimated that in about 100 million years the family will have dispersed to a degree where it cannot be separated from the background population of asteroids. The asteroid (4507) 1990FV was originally thought to be a member but was identified in 2004 as an interloper.
Reader's Guide
The Karin family holds significant scientific importance as the most recent known asteroid collision, providing a unique window into the processes of asteroid breakup and evolution. Its young age—5.8 ± 0.2 million years—means the surfaces of its members are relatively pristine, allowing spectroscopic analysis to study their composition in detail. This could help clarify the connection between asteroids and meteorites, as the family may be the source of meteorites with compositions consistent with S-type asteroids and cosmic ray exposure ages of approximately 5.8 million years. Additionally, the family may be the source of one of the interplanetary dust bands discovered by the IRAS satellite. A study of the Karin family has for the first time detected the Yarkovsky effect in main belt asteroids, a subtle non-gravitational force that alters asteroid orbits over time. This detection has implications for understanding the long-term dynamics of small bodies in the solar system. The family's eventual dispersal in about 100 million years underscores its transient nature, making current observations particularly valuable.
Did You Know?
- The Karin family is the most recent known asteroid collision, occurring 5.8 ± 0.2 million years ago.
- A study of the Karin family detected the Yarkovsky effect in main belt asteroids for the first time.
More in Notable Asteroids, Part 4 1-24
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