Finland has a long history of communicating astronomy to the public. Finland also (allegedly!) has the largest number of amateur astronomers per capita in the world. Ursa Astronomical Association, the oldest and largest of its kind in Finland, is currently the most active and versatile it’s ever been.

We must be doing something right! So what have we been doing? And how did I get here?

The speaker has been the press officer and outreach astronomer for Ursa Astronomical Association since 2011. This talk offers some personal musings and insights into communicating astronomy in a small, northern country.

Keynote lecture by Prof. Dr. Richard P. Binzel, MIT

Abstract
Asteroid (99942) Apophis will make an extremely close but completely safe passage by the Earth on 13 April 2029, passing closer than orbiting geosynchronous satellites. The world will be watching. More than two billion people in western Europe and Africa will have the opportunity to see with their own unaided eyes the 340-meter (Eiffel Tower-sized) Apophis asteroid passing overhead as a faint star. Such a close 0.1 lunar distance (6 Earth-radii) passage of such a large asteroid is an extremely rare celestial event, occurring once-per-thousand years, or less often. With many parallels to the transformative knowledge gained through dedicated investigation of the 1994 Comet Shoemaker-Levy-9 Jupiter impact, planetary scientists see the 2029 Apophis encounter as a rare "natural experiment" and unique science opportunity. By measuring how the Apophis asteroid responds to the strong gravitational and tidal forces exerted by Earth as it safely passes, we may obtain revealing evidence for the deep interior structure of a potentially hazardous asteroid. Such findings could be some of humanity's most valuable knowledge gained from space exploration if any large asteroid were ever confirmed as an actual threat to Earth. The unprecedented 2029 Apophis opportunity is therefore a defining moment for "planetary defense as applied planetary science," requiring and receiving broad international support for collaborative in situ and Earth-based investigations.

Keynote lecture given by Dr. Claire A. Mondro, Caltech

Abstract
Symmetric ripples, which we have interpreted as shallow water oscillation wave ripples,
were observed in the Amapari Marker Band (AMB) along the Curiosity Rover traverse (sols 3693 - 3744). At the Amapari location, the ripples have a symmetry index, wavelength, and aspect ratio consistent with orbital wave ripples. Modeling of the wind shear and associated water depths required to create wave ripples at this scale shows that ripples of wavelength 3 - 6 cm would have formed in shallow water, 2 m deep or less, under a range of Mars conditions. The presence of shallow water wave ripples in the AMB indicates that, during ripple formation, the lake surface was open to the atmosphere and being acted upon by wind. This provides key geologic evidence for paleoclimate conditions that support standing water on the surface at this point in Mars’ history. Current climate modeling of early Mars is inconclusive on the stability of ice-free standing water at the surface and the associated atmospheric conditions necessary to support such lakes, and these model results provide constraints on the possible atmospheric conditions to allow for an ice-free lake surface, which will help validate ongoing paleoclimate models.

Panel discussion with Julia de León, Leigh Fletcher, Laura Inno, and Karri Muinonen

Background:
Space observatories and survey missions such as the James Webb Space Telescope (JWST), Hubble, GAIA, and EUCLID have made substantial contributions to the field of planetary research. These missions have not only expanded our understanding of the universe but have also provided invaluable data that have led to significant discoveries in planetary science. However, the potential of these missions could be further enhanced by integrating planetary science objectives early in their development and preparation phases.

Objective:
The proposed debate aims to explore strategies to strengthen the importance of planetary science in the early stages of astronomy missions. By bringing together experts in the field, we can discuss how to better integrate planetary science goals into the planning and development of future space observatories and survey missions.

DPS Sagan Award Keynote lecture given by Prof. Lisa Kaltenegger, Cornell University

Abstract
Our first glimpses of rocky exoplanets show a large diversity. Our Solar System provides references for rocky worlds, but critical input for understanding a rocky planet’s evolution will come from observations of rocky extrasolar planets, filling in the patterns. The snapshots of evolutionary stages of rocky exoplanets in and beyond the Habitable Zone we have just started to observe will probe how position and age influence their diversity and observable spectra.

However, spectroscopy remains time-intensive, and therefore, initial characterization is critical to prioritize targets. Machine Learning algorithms hold a promise to initially identify water and biota on the surface of exoplanets using broad-band filter photometry to aid prioritization of targets for time-intense follow-up observations. Telescopes like JWST now, PLATO, Ariel, ELTs in the near future ,and designs like HWO and LIFE can probe the parameter space.

I will highlight key results and challenges to interpreting spectra of rocky exoplanets - and how considering dinosaurs can be helpful.

References:

Purple is the new green: biopigments and spectra of Earth-like purple worlds, LF Coelho, L Kaltenegger, S Zinder, W Philpot, TL Price, TL Hamilton, MNRAS 530 (2), 1363-1368, 2024

Oxygen bounty for Earth-like exoplanets: spectra of Earth through the Phanerozoic, RC Payne, L Kaltenegger, MNRAS Letters 527 (1), L151-L155, 2024

Hot Earth or young Venus? A nearby transiting rocky planet mystery, L Kaltenegger, RC Payne, Z Lin, J Kasting, L Delrez, MNRAS Letters 524 (1), L10-L14, 2023

Follow the water: finding water, snow, and clouds on terrestrial exoplanets with photometry and machine learning, Pham D. & Kaltenegger L., MNRAS, V513, L72,1, 2021.

Color classification of Earth-like planets with machine, Pham D. & Kaltenegger L., MNRAS, 504, 4, 2021.

Finding signs of life on Earth-like planets: high-resolution transmission spectra of Earth through time around FGKM stars, L Kaltenegger, Z Lin, S Rugheimer, ApJ 909 (1), 2021

Past, present and future stars that can see Earth as a transiting exoplanet, L Kaltenegger, JK Faherty, Nature 594 (7864), 505-507, 2021

A Catalog of Spectra, Albedos, and Colors of Solar System Bodies for Exoplanet Comparison, Madden J.H. & Kaltenegger L., Astrobiology, 18,12, 2018.

How to characterize a Habitable Planet, Kaltenegger L., Annual Review of Astronomy and Astrophysics 55, 433-485, 2017.

Transits of Earth-like planets, L Kaltenegger, WA Traub, ApJ 698 (1), 519, 2009

Spectral evolution of an Earth-like planet, L Kaltenegger, WA Traub, KW Jucks, ApJ 658 (1), 598

Keynote Lecture by Dr. Richard J. Cartwright, John Hopkins University

Abstract
Our knowledge of the ice giant Uranus and its system of rings and moons is largely limited to
the analysis of data returned by Voyager 2 during its brief flyby in 1986. Since that time,
ground-based facilities and space telescopes have slowly progressed our understanding,
revealing that Uranus’ large moons are candidate ocean worlds with surfaces enriched in
carbon dioxide, especially Ariel. The future holds much more promise for dramatic
improvement in our understanding of the Uranus system with a conceived orbiter and probe
mission arriving around 2050 and future observations by NASA’s Habitable Worlds Observatory,
which will reveal the ultraviolet properties of the outer Solar System and beyond. In the here
and now, our community is unraveling the outer Solar System’s secrets in the near-infrared
with NASA’s current great space observatory, the James Webb Space Telescope (JWST). I will
discuss the latest JWST/NIRSpec results for Uranus’ four largest moons, placing them in context
with existing ground-based data and Voyager 2 results, and set the stage for the next era of
Uranus system exploration in the decades to come.

Keynote Lecture by Gemma Domènech Rams, Montsec Observatory, Spain

Abstract
In the new era of exoplanet characterisation, keeping track of a planet’s transit time is like catching a train without a timetable: miss one, and you risk missing the science entirely. As transit timing uncertainties grow linearly with each unobserved epoch, many worlds are already drifting beyond the thresholds needed for space and large ground-based follow-up. For ESA’s upcoming Ariel mission, which is set to launch in 2029 to survey the atmospheres of a thousand exoplanets, scheduling is a critical challenge; and without accurate, up-to-date ephemerides, prime targets could be lost before the spacecraft ever turns its gaze toward them.

This talk will highlight how the ExoClock project, born as part of Ariel’s Ephemerides Working Group, has turned this logistical challenge into a global collaboration and public engagement opportunity. By merging data from the literature, space missions, professional observatories, and a dedicated network of ground-based observers – from amateur astronomers and student groups to professional facilities – ExoClock maintains a continuously updated catalogue of transit ephemerides through an open, collaborative platform in support of Ariel and ensuring for hundreds of planetary systems remain on schedule.

Drawing from my own involvement in the project, I will spotlight the contributions of the Sabadell Astronomical Society team: a small group consisting mostly of amateur astronomers and early-careers working within the Europlanet Telescope Network. Our efforts focus on making sure high-quality transit light curves are also obtained for challenging, low signal-to-noise targets, using meter-class facilities such as the IAC80 in Tenerife, the 1.23m telescope in Calar Alto, and the Joan Oró Telescope in Montsec through competitive observing calls.

Beyond the technical achievement, this is a story of how diverse participants, from students to trained amateurs, are making indispensable contributions to space missions. It is a case study in how planetary science thrives when it is open, collaborative, and inclusive: bridging continents, cultures, and career stages to prepare for one of the most ambitious exoplanet missions yet.