Current status Pioneer 11

simulated view of position of pioneer 11 of 8 february 2012 showing spacecraft trajectory since launch

on july 19, 2015, pioneer 11 90.716 au (1.35709×10 km; 8.4326×10 mi) earth , 91.672 au (1.37139×10 km; 8.5214×10 mi) sun; , traveling @ 11.376 km/s (25,450 mph) (relative sun) , traveling outward @ 2.4 au per year. spacecraft heading in direction of constellation scutum near current position (august 2017) ra 18h 50m dec -8° 39.5 (j2000.0) close messier 26.

pioneer 11 has been overtaken 2 voyager probes, launched in 1977, , voyager 1 distant object built humans.

pioneer anomaly

analysis of radio tracking data pioneer 10 , 11 spacecraft @ distances between 20–70 au sun has consistently indicated presence of small anomalous doppler frequency drift. drift can interpreted due constant acceleration of (8.74 ± 1.33) × 10 m/s directed towards sun. although suspected there systematic origin effect, none found. result, there sustained interest in nature of so-called pioneer anomaly . extended analysis of mission data slava turyshev , colleagues has determined source of anomaly asymmetric thermal radiation , resulting thermal recoil force acting on face of pioneers away sun, , in july 2012 group of researchers published results in physical review letters scientific journal.

pioneer plaque

pioneer 10 , 11 both carry gold-anodized aluminum plaque in event either spacecraft ever found intelligent lifeforms other planetary systems. plaques feature nude figures of human male , female along several symbols designed provide information origin of spacecraft.