2608 Seneca, provisional designation 1978 DA, is a stony asteroid and sub-kilometer near-Earth object of the Amor group, approximately 0.9 kilometers in diameter.
It was discovered on 17 February 1978, by German astronomer Hans-Emil Schuster at ESO's La Silla Observatory in northern Chile, and named after Roman philosopher Seneca.
[6] In addition, radiometric observations by L. and M. Lebofsky with the 71-cm reflector gave a mean-diameter of 1.0±0.3 kilometers and albedo of 0.15±0.03.
[6] The Minor Planet Center classifies Seneca as an object larger than 1 kilometer ("1+ KM Near-Earth Object"),[4] while Collaborative Asteroid Lightcurve Link derives an albedo of 0.20 and a diameter of 0.9 kilometers based on an absolute magnitude of 17.59.
[5] In 1994, astronomer Tom Gehrels published a diameter of 0.9 kilometers with an albedo of 0.21 in his Hazards Due to Comets and Asteroids.