It’s time to say goodbye to Rosetta, the European Space Agency’s comet chaser and one of the most successful planetary missions of all time.
Rosetta has spent more than two years orbiting comet 67P Churyumov-Gerasimenko and has sent back the first ever ‘in-situ’, or ring-side, observations of a comet as it approaches the Sun and becomes active. In November 2014, Rosetta released the Philae lander, which sent back the first images and measurements from the surface of a comet. In addition to Rosetta’s groundbreaking science results, Philae’s dramatic journey – bouncing across the surface of 67P to rest up against a cliff face in the comet’s Abydos region – captured the imagination of the world.
Europlanet has supported the mission through an initiative to coordinate ground-based observations of 67P, in the context of Rosetta. From 2012-2016, this initiative provided a single, world-wide, coordinated observing campaign, reporting to ESA and the Rosetta project. Europlanet funded a kick-off workshop in London in 2012, in which professional and amateur astronomers came together to design the observing campaign, and a final workshop in June 2016 held at Schloss Seggau, near Graz, Austria, in which team members exchanged results and discussed the link between ground-based observations and results from Rosetta’s instruments.
The campaign used two approaches to studying comet 67P: professional observers reserved time on large observational facilities worldwide, such as the Isaac Newton Group of Telescopes in the Canary Islands and the Very Large Telescope in Chile, for imaging the comet at various wavelengths and for spectroscopic observations. The campaign also enlisted a global network of skilled amateurs, who could use smaller telescopes to make regular observations and provide almost constant coverage of the comet.
The observational campaign has assisted understanding of 67P, including:
The activity of the comet, such as total production rates, seasonal effects and outbursts
The composition of the coma, including the chemistry of the coma and what we can learn from comparison of large-scale and in situ measurements
The morphology of the comet, including evolution with seasons, linking small and large scale changes and interactions with solar wind
Inferred nucleus properties from ground observations and comparison with ‘ground
truth’ from Rosetta
The campaign has also set a template of ground based support for future missions, providing valuable experience, lessons learned, observing guidelines and new data repositories.
The first results from the amateur observation campaign will be presented at the Joint DPS-EPSC meeting next month.