Tartu becomes the centre of a space mission at the end of April

In 2029, the European Space Agency's Ariel mission will take place, with contributions from scientists at the University of Tartu in its preparation and execution. Ariel is the first space telescope designed to study the atmospheres of thousands of exoplanets to understand their formation and analyse potential conditions suitable for life. From April 23 to 26, scientists and engineers from the Ariel consortium will gather for a conference in Tartu.

The study of exoplanets, which are planets beyond our solar system, is crucial for placing our life on Earth in a broader context. Understanding how other planetary systems form and evolve allows us to better comprehend the history and evolution of our own solar system. Researching exoplanets enables scientists to search for signs of life beyond our solar system and conditions suitable for life, thereby enhancing our understanding of the spread and diversity of life in the universe.

Leading researchers and engineers in the space field will discuss mission preparation, technical tasks, and scientific questions at the conference in Tartu. Additionally, the Tartu Observatory and companies in the field will provide an overview of Estonia's activities and capabilities in space technology.

Estonians help select targets for observation. 

To ensure the success of the mission, suitable stars and planets must be chosen for investigation. Astrophysicists at the Tartu Observatory conduct preliminary studies to determine the main parameters of planet-hosting stars and their chemical composition. According to astrophysics researcher Heleri Ramler, determining the physical properties of the host star allows for the reconstruction of the planet's formation history and characteristics: "Know the star, know the planet. Additionally, measuring the physical parameters of all host stars with the same method ensures the accuracy and consistency of exoplanet atmosphere studies," said Ramler.

Tartu Observatory is helping to prepare the schedule for planet observations.

The Ariel space telescope will operate about 1.5 million kilometres from Earth, where it will measure the spectra of exoplanet atmospheres for analysis. This is only possible when starlight passes through the atmosphere. Therefore, observations must occur when the planet transits in front of the star as seen from Earth. Estonian astrophysicist Tõnis Eenmäe explains the Estonian task before and during the mission: "To avoid unnecessary waiting for the planet to transit in space, astronomers in Tõravere measure the transit midpoints of exoplanets using the local telescope. These data are used to compile the most accurate observation schedule for the Ariel space telescope."

Since the transit midpoint of an exoplanet can change due to influences from other planets in the system, numerous star systems must be monitored throughout the entire Ariel mission. Telescopes worldwide, including those in Tõravere, are utilised, and amateur astronomers are involved.

The European Space Agency officially confirmed the Ariel mission in 2020. During the mission, efforts are made to find answers to questions such as how planets form, their internal structure, and the chemical composition of their atmospheres. Currently, work is underway on building prototypes of the telescope's components.

The conference in Tartu is intended for members of the Ariel consortium, but everyone is welcome to attend the public science evening on April 23 at 7 p.m. at Jakobi Jalats (Tähe 29, Tartu). NASA scientists David R. Ciardi (NASA Exoplanet Science Institute) and Douglas M. Hudgins (NASA Ames Research Centre) will discuss breakthrough discoveries in exoplanet research and the search for potential habitats in space.

Read more on ERR Novaator (in Estonian). 

The conference is supported by the city of Tartu and the Estonian Research Council as part of the "ESA Estonian Science Consortium" project.