What evidence is there that any public communication of space science is effective? In 2001, Sless and Shrensky pointed out that the evidence of the effectiveness of science communication in general is about as “… strong as the evidence linking rainmaking ceremonies to the occurrence of rain” . In 2017, very little has changed in effectively measuring the success of intended outcomes of Education and Public Outreach and outreach activities in space science-or in any other area of science. There still have been few attempts to formally measure the success of public engagement activities-such as public talks, science cafes, interactive events and festivals-against clear indicators of success. The focus of this research is to measure the effectiveness of science education and outreach activities in achieving their objectives; that is, changing or influencing participants' understanding, attitudes and perceptions of science. We report on a pilot study of four education and outreach activities held at a large museum in a major Australian capital city. Pre and post questionnaires containing validated Likert-scale items were used to measure participants' trust in science and scientists, their understanding of scientific practice, and their opinions on its relevance and value to society. A total of 46 pre and post surveys were matched-37 of the 46 data sets were from space science events. The results show that after the event, participants demonstrated more positive attitudes and an increase in trust, but a decrease in understanding of scientific practice. These results suggest that the way we are communicating space science is misleading the public's perception of science as absolute, instead of the tentative and evolving endeavour that it actually is. We argue that we need to change the way we communicate space science by focussing more on revealing how science is practiced. We need to be more open about the way conclusions are reached to increase the public's understanding of scientific practice. We also argue that increasing the public's understanding of scientific practice is key to understanding science itself and to increasing trust in science and scientists. The results of this pilot study also point to the need for the development of new instruments that are more sensitive in assessing the public's understanding of scientific practice and the impact of space science outreach and education efforts.