  Many forefront observatories are located in remote areas and are difficult to
visit, and the global pandemic made visits even harder. Several virtual tours
have been executed on YouTube or Facebook Live, however, it is difficult to
feel a sense of immersion and these are far from the actual experience of
visiting a site. To solve this problem, we pursued an astronomy outreach event
on the virtual reality social platform VRChat. To provide an experience similar
to visiting the site, we performed a virtual tour of the ALMA Observatory in
VRChat guided by an ALMA staff member. 47 guests participated in the tour. The
post-event survey showed that the overall lecture and guided tour were very
positively accepted by the participants. Respondents answered that the
communication in the VRChat was more intensive than in other online outreach
events or on-site public talks. The ratio of respondents who answered that they
were able to communicate well with the guide was higher for those who used head
mounted displays than for those who participated in other ways. 40 answered
that the tour increased their interest in astronomy, and this did not show a
clear difference depending on how they participated. In the free descriptions
in the responses, there were noticeable mentions of the physical sensations
received from the realistic 3D space, which left a positive and strong
impression on the participants. The responses show that VRChat has the
potential to be a strong tool for astronomy communication in the pandemic and
post-pandemic eras.
