9994 Grotius

Grotius was discovered on 24 September 1960, by the Dutch astronomers Ingrid and Cornelis van Houten, on photographic plates taken by Dutch–American astronomer Tom Gehrels at Palomar Observatory in California, United States.

[10] Grotius orbits the Sun in the central main-belt at a distance of 2.1–3.0 AU once every 4 years and 2 months (1,518 days).

[9] In August 2010, a rotational lightcurve of Grotius was obtained from photometric observations in the R-band at the Palomar Transient Factory in California.

Lightcurve analysis gave a rotation period of 9.2189 hours with a brightness variation of 0.27 magnitude (U=2).

The approved naming citation was published by the Minor Planet Center on 11 November 2000 (M.P.C.