Comet Hartley 2, officially known as 103P/Hartley, visits the inner solar system about every 6.5 years. The comet was discovered in 1986 and received a visit from a NASA mission, Epoxi, in 2010.
Though the comets visits the Sun frequently, it's a very active small body. NASA has called Hartley 2 a "weird little comet", and one NASA astronomer characterized Hartley 2 as "a hyperactive little comet, spewing out more water than most other comets its size."
|Comparison of sizes of well known comets|
- Hartley 2 spews out a lot of water vapour rather than carbon dioxide
- Hartley 2 rotates on two different axes, principally spinning in one direction while also tumbling in another.
- Core of Hartley 2 made up of several types of ices
- Hartley 2 could last up to 700 more years before it breaks up
- This comet is a good point for scientists to study how the Sun alters comets as they make each trip
- Hartley 2 has provided a new model for the composition of comets