JIVE celebrated its scientists' role in the PRIDE experiment for ESA's JUICE mission

Published on 21 November 2023
© Silvio Zangarini

Leonid Gurvits, Mas Said and Giuseppe Cimò with their ESA's awards at the ceremony that JIVE held in their honour. ‪© Silvio Zangarini


"More than half a century after the first Very Long Baseline Interferometry (VLBI) observations of Jupiter, JIVE now has the privilege to contribute its extensive knowledge of VLBI to support the European Space Agency's flagship mission, JUICE, in exploring Jupiter and its icy moons as both planetary objects and possible habitats for life—JUICE stands for JUpiter ICy moons Explorer". With these words, Leonid Gurvits, astrophysicist at JIVE and Principal Investigator (PI) of one of the 12 JUICE experiments, PRIDE, opened his talk at the award-giving ceremony that JIVE held in honour of its three scientists participating in PRIDE: Giuseppe Cimò, Mas Said, and himself.

"In a sense, PRIDE (Planetary Radio Interferometry and Doppler Experiment) is entirely in line with what astronomy is about: using an instrument (VLBI in the case of JUICE) to observe celestial objects from the ground—without stepping on them or touching them, only quietly and respectfully observing them. Much like Galileo's use of his telescope, which, quite coincidentally, allowed him to see four moons of Jupiter for the first time", Gurvits provided historical context.

PRIDE employs spacecraft tracking through VLBI technologies. This technique offers ultra-precise estimates of the coordinates and velocity of the spacecraft. The measurements serve as crucial “anchors” for other observations conducted by the JUICE instruments. With the JUICE mission, the Galilean moons will be studied in situ and will become objects of direct planetary and geophysical investigation. The data from all JUICE experiments will shed light on how the icy worlds of the Jovian satellites originated and evolved.

The ceremony was introduced by JIVE director Agnieszka Słowikowska and the talks unfolded within a circle formed by the JIVE staff, its visitors, and members of the JIVE Council. The ESA awards were presented to the three JIVE scientists by the Chair of the JIVE Council, Pablo de Vicente, director of the Yebes Observatory in Spain. Special guests for this occasion were two members of the PRIDE team from TU Delft, Dominic Dirkx, Assistant Professor in Aerospace Engineering, and Marie Fayolle, PhD.

"Participating in a space mission has been a dream of mine since I was a high-school student, and with PRIDE, it is coming true", said in his talk Dirkx. "Using PRIDE, we can very accurately measure small changes in the motion of the JUICE spacecraft as it passes close to a moon of Jupiter. These changes allow us to infer properties of the interior and evolution of the moons, contributing significantly to JUICE's overarching goals of understanding the past and current conditions in the subsurface oceans of Jupiter’s icy moons". As the PRIDE Project Scientist, Dirkx's role involves coordinating the development of scientific products derived from the experiment's data. "JIVE provides the very high accuracy measurements of the spacecraft's position and velocity that are crucial for achieving our scientific goals".

"The scientific demands on JIVE for refining the near-field VLBI technique and, in this way, contributing to our knowledge of the position (ephemeris) of the Galilean moons will only grow over time. JUICE's spacecraft was launched only a few months ago and it will enter orbit around Jupiter in 2031. We are excited to work towards accomplishing our task", emphasised Cimò, Head of Space Science at JIVE and designated new PI of PRIDE. With Gurvits and now Cimò, JIVE proudly stands as the first institute in the Netherlands to have researchers assume the role of Principal Investigator in a planetary science mission. PRIDE also involves research organisations from Australia, France, Germany, and Hungary, along with observatories from the European VLBI Network (EVN), in which JIVE serves as the processor and support centre.

Mas Said, a post-doctoral researcher at JIVE and with a crucial role in PRIDE is "absolutely curious about the results of the JUICE mission in eight years". Her responsibilities involve assisting with observations and preparatory activities to ensure the high quality of the applied VLBI. Working closely with Marie Fayolle on the project, Said provides essential data for Fayolle and her PRIDE group at TU Delft to analyse. "I'm looking forward to examining the data when JUICE gets there", Fayolle anticipates the moment the JUICE spacecraft reaches the Jovian system. Said expresses her hopes, saying, "I really hope that with our observations, we can add more value to the scientific results".

The two PRIDE groups will meet again on Friday the 1st of December in Delft for an event organised by TU Delft. During the event, ESA awards will be given to TUD staff working on the JUICE mission, and short talks from members of both PRIDE groups in the Netherlands will be delivered. Additionally, ESA's documentary "The Making of Juice" will be screened for an audience of students and TUD staff, and questions from the audience will be answered.