Northern Territory Rural Students to Observe Pluto’s Shadow

Students from Charles Darwin University (CDU) are joining a team of NASA-funded scientists to observe Pluto in Katherine, Northern Territory. On June 1, the university students will join teams of observers from the United States who brought twelve portable telescopes set up between Darwin and south of Katherine to watch Pluto pass in front of a distant star.   

An event where a body, such as a planet or an asteroid, passes in front of a bright star is known as a stellar occultation. In this type of event, the place of observation, the body, and the star all align perfectly in a way that can be used as a rare and unique tool for astronomy. Occultations can be used to observe details of the intervening body like ring-systems and atmospheres with high spatial resolution. These events typically last for hours, giving astronomers time to observe how the intensity of the star’s light changes as the object passes in front of it. This technique was used in the 20th century to discover that both Neptune and Uranus have rings. 

What makes the occultation on June 1 so interesting is that Pluto’s orbit is elliptical and tilted compared to the rest of the planets in the Solar System, making Pluto a dynamic world. This unusual orbit means that Pluto’s atmosphere and surface change over the course of its 248-year long trip around the Sun. The stellar occultation will allow scientists to observe any changes to the structure and state of Pluto’s atmosphere in the seven years since NASA’s New Horizons spacecraft visited Pluto in July 2015. The centre of Pluto’s shadow during this occultation will be located north of Katherine. 

Occultations like this are relatively rare, considering that they are such precisely timed events. Observing them takes practice, so plenty of practice time has been planned to acquaint the students with the telescopes and equipment so they can be full participants in this astronomical observation. Dr Carla Eisemberg, a CDU STEM Pathways lecturer commented on the importance of this once-in-a-lifetime astronomical event to the students and local community.

“It is fantastic that NASA is engaging with our CDU students and the community. Their research is fascinating and will help to inspire Territorians interested in careers in technology and science,” she said.  

This is the first time that NASA telescopes have been set up in Australia, marking this occultation as a uniquely important event and a great opportunity for students and the local community to get involved in astronomy. A community workshop was held on May 29 at CDU’s Katherine rural campus, where the community was welcome to meet the astronomers as they practised with the telescopes. This was a unique opportunity for locals to look at the stars and planets through the NASA telescopes.

The NASA-funded science team is planning some outreach programs in which they will present an overview of the observation campaign and an update on NASA's New Horizons mission since its Pluto flyby.