The exploration of Mercury, the closest planet to the Sun : that is incredible challenge of the BepiColombo mission, the product of a collaboration between ESA and JAXA, the European and Japanese space agencies. Following on the Mariner 10 and MESSENGER missions, this will be the third one to visit the eenvironment and surface of this rocky planet, which is the least well known in this category.
The challenges of this space mission
Launched on Friday, October 19th at 22h45 local time from the Kourou Space Center in Guyana, BepiColombo will arrive at its target at the end of 2025. Thus, for the first time ever, two space probes will be placed in orbit at the same time around Mercury : ESA’s « Mercury Planetary Orbiter » (MPO), renamed « Bepi », for a study of the planet’s surface ind internal structure ; and the « Mercury Magnetospheric Orbiter » (MMO), renamed « Mio », under the responsibility of the JAXA, for the study of the planet’s magnetic environment and its interaction with the solar wind.
Mercury raises a multitude of questions. Since its rotation is very slow - 176 terrestrial days between two sunrises on Mercury - and there is no atmosphere to control the temperature, Mercury, of all the planets in the Solar System, has the widest temperature variations : going from -180 °C on the night side to + 430° C on the day side.
Consequently, the space probes, their solar panels and the sixteen scientific instruments on board have been designed to resist these extreme temperature variations.
The scientific contribution of the Paris Observatory
At the Laboratoire d’études spatiales et d’instrumentation en astrophysique – LESIA (Laboratory for Space Studies and Instrumentation of the Observatoire de Paris/CNRS/Sorbonne Université/Université Paris Diderot), scientists have made use of their expertise to design and create two subsets of instruments :
- On the MPO, for planetology : The scientists have contributed to the instrument set SIMBIO-SYS and have developed a part of the VIHI instrument, a spectro-imager in the visible and near infra-red domains, which will effectuate a complete mineralogical mapping of Mercury’s surface, with an exceptional accuracy. Since there is no atmospher, and thus no meteorological phenomena, the surface carries a perfect memory of the impact craters, geological structures and internal activity (cracks, relief…). Changes are essentially caused by the solar wind and extra-galactic particle streams. Mercury is a genuine laboratory for the study of the effects of space erosion on a planetary surface.
- On the MMO for planetary environment studies : : LESIA scientists and engineers have designed the SORBET instrument, which is part of the instrument package PWI (Plasma Wave Investigation), for the measurement of plasma waves around Mercury : both the magnetospheric plasma and that of the solar wind. In particular, SORBET will be able to map the density and electron temperature, using the method referred to as « thermal noise spectroscopy », which is of world wide repute and which is used on numerous interplanetary mission, and in particular on the recent Parker Solar Probe.
For the Science Fair : an ambitious organization for scientific culture
Paris Observatory scientists have set up an extensive system for communicating scientific culture, which will come into operation in various stages during the Science Fair, whose date coincides with the launch of BepiColombo. This operation is coordinated by Alain Doressoundiram, an astronomer at the Paris Observatory, in scientific charge of the VIHI instrument, at LESIA and by Léa Griton, a recent astrophysics Ph.D. at the Paris Observatory, member of the BepiColombo « Young Scientists » team. Both of them are deeply involved in the popularization of science.
• The « Planètes en Guyane (Planets in Guyana) » operation »
Over a hundred of the scientists involved in the BepiColombo mission are going to Kourou for the launch. With the support of the Guyane Academy, over forty of them will give talks to over fifty school classes in various schools, from October 15th to the 19th and also to science students at the Guyana University on October 18th.
In pairs, reflecting the diversity of specialists (engineer/researcher, male/female, francophone/anglophone), they have given themselves as objective to inform the youth, and in particular the girls, about the numerous possibilities of scientific careers and in particular those in the space sector.
A second aspect of the project, in collaboration with the CNRS, the CNES, the ESA, the JAXA, the society SpaceBus France and the Canopée des Sciences, aims to disseminate astronomical culture, in particular to the general public, via games, workshops and conferences, until October 24th.
• « BepiColombo : the game »
The Planets team in Guyana has created from scratch a game centered around the space mission. the players (from 10 years old) become members of a scientific team. They progress via dice, on a game map through a sequence of questions and answers centered on the scientific purpose and technologies of the mission.
Objective : win publications, scientific collaborations and measuring instruments before reaching the BepiColombo launch base. Then, during BepiColombo’s long cruise, the young scientists can use the flights over the Earth, Venus and Mercury to gather a maximum of data before orbit injection around Mercury in 2025.
Available to all, the game can be downloaded at no charge in a printable format, from the site « planete-mercure.fr » starting Friday October 19th 2018.
• A « resources » site : planete-mercure.fr
The Paris Observatory is launching a specific site for scientific culture. Very close to research activities, it gives the current state of knowledge about planets, the scientific and technological challenges related to the space mission ; it enables one to follow via a Twitter account and a blog, the movement of the Paris Observatory scientists who will be at the launch at the Space Center.
It also contains numerous pedagogical resources for teachers : the resources can be downloaded freely and used in school or at home : « BepiColombo, le jeu », 6 posters, pedagogical files, iconographic resources from the past and recent ones…
https://www.planete-mercure.fr/
• A stand at the Cité des Sciences et de l’Industrie
From the 5th to the 7th of October 2018, for the Fête de la science, the Paris Observatory has been invited to the Cité des Sciences et de l’Industrie. It will have a stand dedicated to the latest BepiColombo news. A team of young Ph.Ds will coordinate session of the game : « BepiColombo ».
Special day for teachers and schools, Friday October 5th.
Free entrance for the general public, Saturday 6th and Sunday 7th October 2018.
Practical information
http://www.cite-sciences.fr/fr/au-programme/evenements/fete-de-la-science-2018/
• Class sponsorship
For this coming start of the school year 2018, the Paris Observatory is putting its school sponsorship system under the colours of the planet Mercury and the BepiColombo space mission. In this way, school teachers at all levels can ask for an astronomy "sponsor" from the Paris Observatory to second the astronomy project of their class.
Information :
http://parrainages.obspm.fr/