We present the detection of helium in the extended atmosphere of the sub-Saturn WASP-107b using high resolution ( R \approx 25000 ) near-infrared spectra from Keck II/NIRSPEC .
We find peak excess absorption of 7.26 \pm 0.24 \% ( 30 \sigma ) centered on the He I triplet at 10833 Å .
The amplitude and shape of the helium absorption profile is in excellent agreement with previous observations of escaping helium from this planet made by CARMENES and HST .
This suggests there is no significant temporal variation in the signature of escaping helium from the planet over a two year baseline .
This result demonstrates Keck II/NIRSPEC ’ s ability to detect atmospheric escape in exoplanets , making it a useful instrument to further our understanding of the evaporation of exoplanetary atmospheres via ground-based observations of He I .