The European Space Agency’s Euclid mission has released its inaugural dataset, capturing images of 26 million galaxies and providing an unprecedented glimpse into the cosmos. This monumental achievement marks a significant step toward understanding the enigmatic components of the universe: dark matter and dark energy.
Launched in July 2023, Euclid embarked on its mission to map the large-scale structure of the universe. Positioned at the Sun-Earth second Lagrange point , approximately 1.5 million kilometers beyond Earth’s orbit, the space telescope commenced data collection in February 2024. Over its six-year mission, Euclid aims to observe more than 1.5 billion galaxies, creating a comprehensive 3D map that spans over a third of the sky and reaches back 10 billion years in cosmic history.
The initial data release encompasses observations from three “deep fields,” regions of the sky where Euclid focuses its farthest observations. These images include galaxies situated over 10.5 billion light-years away, offering insights into the universe’s formative epochs. The dataset covers an area more than 300 times the size of the full moon as seen from Earth, yet represents just 0.5% of Euclid’s total survey area.
Astronomers have cataloged approximately 380,000 galaxies from this release, revealing a diverse array of galactic structures, including numerous instances of galaxies in the process of merging. Additionally, Euclid has identified 500 strong gravitational lensing events, where massive galaxies, enveloped by dark matter, warp the surrounding space, magnifying and distorting the light from more distant galaxies. These observations are pivotal for studying the distribution and influence of dark matter throughout the cosmos.
The mission’s primary objective is to elucidate the nature of dark energy and dark matter, which together constitute approximately 95% of the universe’s total content yet remain largely mysterious. By analyzing the shapes, sizes, and distributions of galaxies across vast stretches of space and time, Euclid seeks to shed light on how these unseen forces have influenced the universe’s expansion and the formation of cosmic structures.
Prof. Adam Amara, a leading scientist on the Euclid mission, emphasized the transformative potential of this endeavor: “Euclid is not only a dark universe detective; it’s also a time machine. We will look back 10 billion years in cosmic history.” This sentiment underscores the mission’s capacity to provide a panoramic view of the universe’s evolution, offering clues about the fundamental forces shaping its destiny.
The data collected by Euclid is expected to catalyze an “avalanche of discoveries,” as noted by Prof. Stephen Serjeant, another prominent figure in the mission. The extensive dataset will enable researchers to test current cosmological models, explore the properties of dark energy, and potentially uncover new cosmic phenomena.
Processing the vast amounts of data generated by Euclid presents significant challenges. The mission is anticipated to send back approximately 100 gigabytes of data daily, necessitating advanced artificial intelligence algorithms and the collaboration of thousands of citizen science volunteers and experts to analyze and catalog the information effectively.