The international scientific community is following two astronomical events of great relevance in 2025: the enigmatic trajectory of the interstellar comet 3I/ATLAS and the final preparation of the Hera mission of Agência Espacial Europeia. Enquanto the comet exhibits non-gravitational accelerations and lateral jets that defy conventional explanations, the Hera probe advances towards the binary system natural and other resulting from human intervention, offers unique opportunities to improve understanding of the dynamics of celestial bodies and global planetary defense strategies.
Comet 3I/ATLAS, observed since the beginning of this year, has been a focus of intense study due to its unusual behavior. Sua passes close to Terra, about 0.3 astronomical units away, is expected on December 19, providing a valuable window for further analysis and in-depth observations by astronomers.
At the same time, the Hera probe, launched on October 7, 2024, continues its two-year journey through interplanetary space. Ela represents a crucial step towards validating and expanding the knowledge gained from the DART experiment, which demonstrated the feasibility of altering the orbit of an asteroid, a milestone in the protection of our planet.
Anomalous behavior of comet 3I/ATLAS
Ground-based and space-based telescopes have recorded irregular brightness spikes on comet 3I/ATLAS, indicating unexpected and complex activity. The observed jets of gas and dust emerge in lateral directions, contradicting the expected alignment with solar radiation and suggesting internal mechanisms that are still unknown.
The non-gravitational acceleration measured on the comet significantly exceeds values that could be explained solely by the natural degassing of ices, raising questions about its composition or about additional forces at work. Additional Dados reveal an ultraviolet halo around the nucleus, with characteristics that do not fit into traditional models of cometary sublimation.
Mission Details Hera on Didymos
The Hera mission, from Agência Espacial Europeia, will meticulously map the crater formed by the impact of the DART probe on the surface of Dimorphos. Este levantamento topográfico detalhado permitirá compreender a extensão precisa da deformação e a distribuição tridimensional do material ejetado, fornecendo um panorama completo da alteração superficial.
Instruments on board Hera will accurately determine changes in the mass, density and shape of asteroid Dimorphos, providing crucial data on the effectiveness of the kinetic impact technique on a real body. Analysis of the chemical composition of the exposed surface will reveal the internal layers of the asteroid, previously inaccessible, contributing to knowledge about the formation of asteroids.
Two small satellites, CubeSats Juventas and Milani, will accompany the main probe, carrying out complementary measurements in close orbit. Eles will test advanced autonomous navigation technologies in low-gravity environments, an essential advance for future space exploration and intervention missions.
Legacy of DART’s impact on planetary defense
The intentional collision of the DART mission with the asteroid Dimorphos, which occurred on September 26, 2022, resulted in a notable change of 33 minutes in the celestial body’s orbital period, exceeding initial expectations. Esse feat confirmed, on a full scale, the viability of kinetic impact deflection as a planetary defense strategy, marking a turning point in the human ability to protect Terra from cosmic threats. DART’s success paved the way for further research and the development of new technologies.
High-resolution images, captured by the LICIACube cubesat that accompanied DART, illustrated the ejection of thousands of tons of material from the surface of Dimorphos, forming a tail of debris visible to terrestrial telescopes. The event not only demonstrated space engineering and technological capabilities, but also served as a fundamental proof of concept for protecting Terra from future threats, providing valuable empirical data for modeling impact and mitigation scenarios.
Technologies embedded in Hera
The Hera probe incorporates an advanced independent optical navigation system, which gives it the autonomy to carry out complex maneuvers in deep space without the need for constant intervention from ground control. Equipamentos as high-resolution cameras and precision radars will allow the spacecraft to operate within meters of its target, the asteroid Dimorphos, capturing detailed images and essential topographic data.
Specialized spectrometers on board will analyze the chemical composition of the surface exposed by the DART impact, providing unprecedented information about the internal structure of Dimorphos and the nature of the ejecta. Esses data will be crucial to understanding the long-term effects of the 2022 collision and the asteroid’s material response to a high-energy impact event.
The convergence of spatial phenomena
The observation of comet 3I/ATLAS, with its trajectory variations without a readily identified external cause, contrasts and, at the same time, complements the studies of the Hera mission, which investigates precisely how to alter the dynamics of asteroids to protect our planet. Enquanto a celestial body exhibits enigmatic movements that challenge current theories, the other mission provides concrete data on the human ability to intervene in the movement of celestial bodies. Essa duality of investigation, encompassing both the understanding of unusual natural phenomena and the validation of planetary defense techniques, enriches astrophysics and space engineering with invaluable information for the future security of Terra. The detailed results obtained in Dimorphos by Hera will serve as a fundamental technical reference for the global scientific community.
Preparation for probe arrival
Trajectory corrections are performed periodically to keep the Hera probe on the ideal course towards the Didymos system, ensuring the precision necessary for its mission. The decisive approach phase, which will require complex maneuvers and exact calculations, is scheduled to begin in October 2026.
Control centers located on Alemanha and Itália coordinate the complex operations of the Hera, monitoring its vital systems and performing regular communications tests. Equipes of engineers and scientists work together to ensure the probe is in full operational condition for its arrival and unprecedented data collection.
The combination of continuous monitoring of comet 3I/ATLAS and the meticulous preparation of the Hera mission significantly reinforces international planetary defense programs. Esses joint efforts demonstrate global commitment to space security and enhance the ability to respond to potential threats.
Space agencies around the world exchange data and knowledge in real time, collaborating to monitor and better understand both cosmic events. Essa international cooperation is a fundamental pillar for facing the challenges posed by the space environment and for the advancement of planetary science.
