Eurybates has one kilometer-sized satellite, named Queta, that was discovered in images taken by the Hubble Space Telescope in September 2018.

Eurybates was discovered on 19 September 1973, by Dutch astronomers Ingrid and Cornelis van Houten at Leiden, on photographic plates taken by Tom Gehrels at the Palomar Observatory in California, United States.

[13] Eurybates has been characterized as a carbonaceous C-type asteroid by both the Lucy mission team and Brian Warner's Lightcurve Data Base.

[13]: 23 In May 1992, a rotational lightcurve of Eurybates was obtained from photometric observations by Stefano Mottola and Maria Gonano–Beurer using the now decommissioned ESO 1-metre telescope at La Silla Observatory in northern Chile.

[18][19][20] The Collaborative Asteroid Lightcurve Link agrees with IRAS, and derives an albedo of 0.0491 and a diameter of 72.08 kilometers with an absolute magnitude of 9.6.

[22] The flyby is scheduled for 12 August 2027, and will approach the asteroid to a distance of 1,000 km (620 mi) at a relative velocity of 5.8 km/s (13,000 mph) and a solar phase angle of 81°.

[26] Provisionally designated S/2018 (3548) 1, the satellite was discovered by Keith S. Noll and colleagues in images taken with the Hubble Space Telescope in September 2018.

In the naming citation, Enriqueta Basilio was recognized as the first woman torchbearer at the 1968 Summer Olympics, analogous to the role of heralds like Eurybates.

[28][10] The presence of the satellite does not pose any adverse effects on the Lucy mission, though it provides an additional object for the spacecraft to study during its flyby in 2027.