“The Earth is just a small spot in a huge, hostile universe. It is our only home.”

As “senior researcher” in the astronomical institute of Leiden university (“Sterrewacht”), I mostly work on the design of the new astronomical instrument METIS. With it we will likely take the first image of an Earth-like planet around a “nearby” star. Nearby, however, is still very far away for human dimensions... Next to this, I also frequently engage with the general public in talks (these days: online), in star shows or on Twitter. Besides communicating about galaxies and planets, I see it as my duty to also convey the “astronomical picture” to the wider public: The fact that we are just a “pale blue dot” in a (as far as we know) lifeless universe, has a transformative effect on many people: we are together on this spaceship Earth with nowhere else to go. Let’s take good care of Earth, our only home! Let me show this message to you more impressively in a little movie, because it is all about the pictures!:

This movie was produced as part of an advertisement campaign: It was a really special experience to act for such a production – and it allows me to convey this message to a wide audience.

The transformative event for me was last year’s annual conference of the European Astronomical Society. As a heat wave hit much of central and Southern Europe end of June 2019, we were all sweating in the lecture rooms of the university of Lyon. And we started to ask how much carbon emissions our own profession, with frequent trips to faraway conferences and astronomical observation sites, actually produces. And how we could raise

awareness to this among astronomers to reduce emissions. Likewise we realised that we needed to do more to convey the astronomical perspective to a broad public (see above).

My European colleagues and I then teamed up with a U.S. group called “Astronomers for Planet Earth” and we decided to make this a world-wide group of climate action for and by all people associated with astronomers: researchers, teachers, enthusiasts, ... One of the first big events we organised in Europe was a “special session” called “Astronomy for Future” at this year’s annual meeting of the European Astronomical Society (which I co-organised as a fully digital event).

The event was seen as very successful and one of the best visited sessions of the entire conference. Among the visitors was a senior editor of the journal “Nature Astronomy” who invited some of the speakers and organisers to publish a series of articles about astronomy and the climate crisis in this prestigious journal. The article series has been published two weeks ago [10 Sep 2020] and can be found online;(some of the articles are paywalled; links to legally available free copies of the articles can be found on my own homepage. Our only ambition can be to bring emissions from astronomical research down along a path compatible with the Paris agreement. There is still a lot to do and many people need to be convinced, but a beginning has been made.