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Virtual ALMA Tour in VRChat: A Whole New Experience

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.


Introduction
Astronomy observatories in various locations of the world and in orbit are producing a number of amazing pictures of the universe and unravelling a variety of cosmic mysteries. The results are disseminated daily through websites, press releases, and social media. People can access the latest results through these media, however, they face difficulties learning about the research process.
Visiting the observatories and getting explanations from the researchers and engineers actually working In the pandemic era, several observatories have provided online virtual tours. For example, the E 3 ALMA is a radio astronomy observatory located in the Atacama desert, northern Chile. It consists of 66 parabolic antennas combined to function as one giant telescope.

Results of Questionnaire to the Participants
At the conclusion of the tour, we asked the participants to answer the questionnaire on their experiences via Google Forms 14 . We received 44 responses. In this section, we summarise the responses and discuss the advantages of using VRChat in astronomy communication.

User Environments and their Background
Among 44 respondents, 21 were in their 20s or younger, accounting for nearly half of all 14 The survey was done in the Japanese language.
Quotations in these sections are literal translations. We asked about the level of interest in astronomy before the event. Figure 5 shows graphs of the responses from VSP members and others separately.
In total, 25 answered that they were "very interested" in astronomy, 16 answered "some level of interest", and 3 had "little interest".  We asked if their interest in astronomy had increased after this event.27 said it had, 13 said it had increased somewhat, and 4 said it had remained the same. Of the 41 participants who said they were "very interested" or "somewhat interested" in astronomy before participation, 38 said the interest was "increased" or "somewhat increased" after the tour. Among the three who answered that they had "little interest" in astronomy before the event, two answered that the interest somewhat increased after the event, and one answered that the interest level keeps same. This result indicates that the program had the effect of arousing further interest in astronomy in participants who were already interested, and also had a positive impact on the participants less interested in astronomy.
We asked the participants if they had attended any in-person or online science public lectures prior to this tour. Out of 44, 27 answered that they had attended in-person science lectures before, and 16 answered that they had attended online lectures.
Half of those who have attended an in-person lecture said they have never attended an online lecture.
Considering that the demand for expert's talks as described above, this indicates that there is still a great potential for VR lectures, but that the science side has not yet captured it. To see the difference in user experience through different media, we separately summarised the responses in Figure 7. More than 70% of the HMD users answered that they had interacted with the

Difference between Face-to-Face Events and VRChat
To find out how participants felt about the event in the VRChat world, we asked those who had attended face-to-face lectures in the past about the biggest difference between the face-to-face event and this virtual tour. 27 out of 44 respondents answered that they have attended in-person lectures, and 24 described the differences. Two characteristics in VR emerged from the responses. One was the realistic experience, and the other was the closeness to the lecturer.
The HMDs provide an immersive experience, allowing one to look around the realistic virtual antenna like they could do if they were actually at the observatory. Selected responses to this question are as follows.
 "It was as if I had actually been there in Chile."  "The explanation with the virtual model in front of me is easier to experience it as something that is happening to me proactively than the video or slides, and it seems to attract more interest."  "Since the lecture was given in the VR world, which is a reproduction of the observatory site, it left a stronger impression than explanations and questions using only slides." In addition, the lecturer felt as if he was actually guiding the participants in the real observatory because he could feel the participants' "eyes" on him even though they were in avatars, and he also could hear the participants voice their impressions. Overall, for both the guide and the participants, the VRChat tour were felt similar to the actual on-site observatory tour. The ALMA Observatory is far away from most of the cities and it is difficult to visit. The pandemic is making it even more difficult, but the VRChat tour is a valuable way to experience the atmosphere in which cutting-edge astronomy is being performed.
As for the second point, six respondents pointed out the closeness to the lecturer. A representative answer was "it was very easy to ask questions because I was physically and psychologically close to the lecturer." Here we have two non-exclusive possible reasons why the psychological distance between the participant and the guide becomes closer in a guided tour in VR space. One is that the participants and the guide are spatially close to each other. In the tour participants could "stand" next to the lecturer through avatars. This is in contrast to typical face-to-face lectures where there is a distinct difference in locations between the lecturer and the audience. The other is that the use of friendly-looking avatars by both lecturers and participants increased anonymity and reduced the authority of the lecturer, creating an atmosphere where it was easy to talk to the lecturer. One respondent clearly stated that "participating with an avatar is fun and friendly." It is interesting to discuss whether this closeness is characteristic of VR. Even in face-to-face activities, it is possible to minimize the physical distance between the lecturer and the audience by mixing the lecturer into the audience rather than having the lecturer stand behind the podium, and this may also contribute to reducing the psychological distance. In an in-person event, however, it is difficult to reduce the authoritative nature of the appearance of the lecturer, since the appearance of the lecturer cannot be changed. Nevertheless, wearing familiar costumes in the real world could also create a sense of discomfort because it is unnatural that only the lecturer has a different appearance than usual. On the other hand, in the VR space, since everyone participates using avatars, it is possible to reduce authority without creating a sense of discomfort.

Difference between Conventional Virtual Events and VRChat
We also asked the participants about the difference between conventional online talk events and the tour in VRChat. Many participants expressed similar sentiments to those described in "Difference between Face-to-Face Events and VRChat".
Notable points are: 1. A higher-quality audio-visual experience, 2. Participants can sense the responses of other participants.
As for the first point, VRChat provides an immersive experience in which one can get a 3D sense of place both visually and aurally. It is as if they were actually there. Some selected responses are as follows.
 "I enjoyed the realistic feeling of being able to see the antennas from a 360-degree direction, which is not possible with photographs."  "It was easier to see and hear than a lecture through a two-dimensional screen."  "The image quality of VR tours is much better than normal online lectures. The user experience is much better than Zoom lectures, and there are no distractions, so I was able to concentrate more on the lecture." The immersive feeling cannot be obtained in normal  Once the guide is sure that the participants are receptive to technical explanations, the guide can take full advantage of the detailed reproduction of the antennas in front of the participants to explain the technical details, which will be easier to understand than in other virtual events and also leave a strong impression.
 The technical difficulties for virtual tours using the VRChat world is the limitation of the number of participants in one event. In fact, there were several people who could not enter the world by the time due to the heavy access a few minutes before the start. One of the workarounds is to extend the waiting time for entering the world. The findings from our activity align well with those by Kersting et al. (2021). Despite the difference of the VR contents and the format of the experience, the importance of high-quality visualisation, interaction between professionals and participants, and collaboration is common to the two for realizing engaging and effective experience in science outreach.
Even after the pandemic, virtual tours in VR worlds will be very useful for the public to gain a deeper understanding of inaccessible astronomical facilities.