Key facts
- Category
- Comets
- Object class
- Comet nucleus
- Mass
- ~20 billion metric tons
- Scale fact
- 8 kmmaximum extent
- Estimated age
- ~4.5 billion years
- Composition
- Water ice, dust, frozen volatiles
8 kmmaximum extent
Details
19P/Borrelly is the bowling-pin-shaped comet nucleus that NASA's Deep Space 1 probe imaged in 2001, the second comet ever seen up close. It has a dark, ridged surface and bright jets erupting from a smooth central region.
Deep Space 1 passed 2,171 kilometers from Borrelly in September 2001 after engineers recovered the spacecraft from a failed star tracker. Its images resolved an elongated, dark nucleus and showed that the main dust jet originated from a restricted region rather than uniformly across the surface. The encounter was an extended-mission result for a spacecraft designed primarily to test new technologies.
Key facts
Links
Size neighbors
On the logarithmic size axis, 19P/Borrelly falls between 9P/Tempel 1 and 52246 Donaldjohanson. Compared below with other objects classed as Comet nucleus.
Sources
Measurements and descriptive context are compiled by the Scale of Space team from the references below. If you find an error, write to hello@scaleofspace.org.
Continue with nearby objects or open the full scale.
About
Scale of Space is a scroll-based journey through the universe, placing objects on a single logarithmic scale so you can compare size across an unbroken range.
Guides explain selected parts of that range, while focused views filter the objects by subject.