... Science . ... Science Users Information > Observing with ESO Telescopes > Visiting Astronomers > General Instructions . ... Science in Santiago . ... During their official mission in Chile, Visiting Astronomers are subject to the authority of the ESO Directorate. ... At least two months before the start of the observing mission, every Visiting Astronomer traveling to the ESO observatories in Chile will have to submit a Travel Form which will be handled by the VAtravel Office ( vatravel@eso.org ). ...