· · · ·


19 Fortuna

A relatively large asteroid named for the Roman goddess of luck (who also gave her name to the Fortuna Tessera formation on the surface of Venus). Fortuna takes a little under four years to complete each circuit of the Sun, following a somewhat eccentric orbit through the Solar System's main Asteroid Belt. At times Fortuna comes close to the inner edge of the Belt, while at other times it travels through the denser parts of the Belt to approach its outer edge.

Fortuna is a carbonaceous asteroid, with significant quantities of carbon detectable in its make-up. In itself this is not unusual (and in fact most asteroids are of the carbonaceous variety) but Fortuna also shows signs of water in its composition. This places it among the much rarer 'G-type' asteroid classification, suggesting that it is has some similarities to the dwarf planet Ceres, which also falls into this category. Indeed, after Ceres, Fortuna is the largest body of this type to be found in the Asteroid Belt (though it is less than a quarter of Ceres' diameter).

In shape Fortuna is approximately spherical, though not perfectly so. Its diameter varies by as much as 30km depending on the axis being measured, with its longest diameter running to some 225km. It is notably dark in colour, with an extremely low albedo measurement (that is, very little of the sunlight it receives is reflected back into space).