The year 2025 delivered a series of compelling space discoveries and observations, prompting renewed contemplation of our place in the universe. From a rare interstellar comet to a potentially unstable dark energy field, here’s a breakdown of the most significant events that captivated scientists and the public alike.
A Visitor From Beyond: Comet 3I/ATLAS
For the third confirmed time, our solar system hosted an interstellar visitor in 2025: Comet 3I/ATLAS. Discovered in July by the ATLAS survey telescope, this comet moved at over 200,000 kilometers per hour, swinging around the sun before receding into interstellar space. Despite debunked claims of alien origin, the comet has shown signs of icy volcanism and has been observed by spacecraft including rovers on Mars. It remains visible through spring 2026, providing further opportunities for study.
The arrival of interstellar comets is rare, offering a glimpse into the composition of other star systems.
First Sounds of Lightning on Mars
The Perseverance rover captured the first audio evidence of lightning-like discharges on Mars. Scientists initially dismissed clicking sounds as dust interference, but later analysis revealed the presence of triboelectricity – electrical charges generated by dust particle collisions. This confirms long-suspected atmospheric phenomena, though the “mini-lightning” is distinct from Earth’s larger storms.
Betelgeuse’s Doomed Companion
Astronomers may have finally observed Betelgeuse’s companion star, a sun-mass object orbiting the red supergiant in Orion. While confirmation is ongoing, the star’s orbit places it within Betelgeuse’s atmosphere, meaning it will be consumed within the next 10,000 years. Proposed name “Siwarha” (meaning “her bracelet”) reflects its orbital relationship.
Artificial Eclipses Created in Orbit
The Proba-3 mission achieved the first controlled artificial solar eclipse in space. The synchronized spacecraft allowed scientists to block sunlight on demand, providing extended observation of the sun’s corona. The mission has already created 51 eclipses and plans over 100 more in 2026.
This technique enables more precise solar studies, bypassing the limitations of natural eclipses.
The Vera Rubin Observatory Begins its Cosmic Survey
The Vera Rubin Observatory in Chile initiated its decade-long sky survey, capturing high-resolution images of the Southern Hemisphere every few days. This will create the largest cosmic movie ever made, tracking changes in supernovae, asteroids, and the evolution of billions of galaxies. The data will also aid research into dark matter and dark energy.
Dark Energy: A Shifting Force?
Data from the Dark Energy Spectroscopic Instrument (DESI) continues to suggest that dark energy, previously thought constant, may actually change over time. Three years of observations covering 14 million galaxies strengthen the case for “dynamical” dark energy, challenging established cosmological models.
Private Lunar Landing Success
Firefly Aerospace’s Blue Ghost lander achieved the first successful soft landing on the moon by a private company. Operating for over two weeks, it tested scientific instruments, including a lunar GPS system, drill, and X-ray telescope. Two other private missions (Athena and Resilience) failed, highlighting the challenges of independent lunar exploration.
A Distant Threat: Solar System Instability
Calculations revealed that a passing star could destabilize our solar system, potentially ejecting Earth or causing catastrophic collisions. The probability of this occurring in the next 5 billion years is low (0.2%), but the scenario underscores the dynamic nature of cosmic environments.
In conclusion, 2025 brought a mix of routine observations and groundbreaking discoveries, reinforcing the sense of wonder and uncertainty that comes with exploring the universe. From interstellar visitors to the mysteries of dark energy, these events remind us of the vastness and complexity of the cosmos.
