Imagine a cosmic pebble, blasted from a distant star system by a cataclysmic event, hurtling through the inky void for eons before briefly gracing our solar system. These interstellar objects (ISOs), the flotsam and jetsam of other worlds, offer tantalizing glimpses into the conditions around faraway suns. But their fleeting visits pose a significant challenge: how do we study them up close before they disappear back into the interstellar wilderness?

The late 2017 arrival of ‘Oumuamua, a Hawaiian word for « scout, » was a watershed moment. This elongated object, confirmed as the first known ISO to visit our solar system, ignited a flurry of astronomical activity. Two years later, Comet Borisov offered a second fleeting encounter. These encounters are a window into exoplanetary systems. But the astronomical community yearns to move beyond fleeting glimpses.

While it’s estimated that over 10 septillion (that’s 1 followed by 24 zeros) ISOs wander the Milky Way, our detection rate remains astonishingly low. The problem isn’t a lack of ISOs, but rather our inability to predict their arrival and react quickly enough. Large, easily detectable ISOs appear infrequently, and they travel at breakneck speeds. Ground-based and space-based telescopes struggle to respond in time, often catching them only as they recede into the distance.

However, a paradigm shift is underway. Innovative space missions, guided by breakthroughs in artificial intelligence (AI), promise to transform these fleeting encounters into profound scientific opportunities. AI, in this context, isn’t about sentient robots, but rather algorithms capable of rapidly processing vast amounts of data to identify incoming ISOs and guide spacecraft for optimal interception. Approaching these objects offers an unprecedented chance to understand their composition, geology, and even potential activity, offering insights into the genesis of planetary systems light-years away.

Getting close requires overcoming immense technological hurdles. ISOs zip past Earth at incredible speeds, giving us less than a year to launch an intercept mission. While gravitational slingshot maneuvers – using the gravity of planets to accelerate a spacecraft – are theoretically possible, they are complex, costly, and time-consuming.

Despite these challenges, the first wave of ISO-hunting missions is already in motion. NASA’s proposed ‘Bridge’ mission aims to intercept incoming ISOs after detection. The European Space Agency (ESA) is set to launch the ‘Comet Interceptor’ in 2029, a spacecraft with two robotic probes designed to lie in wait a million miles from Earth, ready to ambush a long-period comet or, potentially, an ISO. These « storage orbits » allow for rapid deployment when a suitable target is identified.

Project Lyra, from the Institute for Interstellar Studies, explored the feasibility of chasing down ‘Oumuamua retroactively, finding it theoretically possible but technically daunting. The limitations of these initial missions, primarily speed, highlight the need for more radical approaches.

Future missions will likely leverage AI and deep learning (AI emulating human decision making) to identify and respond to incoming objects in real-time. Researchers are also exploring coordinated « swarms » of small spacecraft that can image targets from multiple angles and adapt mid-flight. The Vera C. Rubin Observatory, with its upcoming 10-year survey of the night sky, is expected to detect dozens of ISOs annually, heralding a potential detection boom.

Reaching high speeds while maintaining a stable energy source is critical. Solar sails, using sunlight for propulsion, offer a lightweight alternative to fuel tanks. The next generation could use lasers to boost solar sail speeds. A spacecraft approaching an ISO must also withstand extreme temperatures and dust erosion. Advanced carbon fibers, 3D-printed materials, and innovative uses of traditional materials like cork and ceramics are being explored to create lightweight and durable shields.

A holistic approach, combining ground-based telescopes, space-based missions, and advanced AI, is essential for anticipating, chasing down, and observing ISOs. However, proposed cuts to space science funding, threaten progress. To transform these cosmic flybys into scientific windfalls, we must embrace emerging technologies. Otherwise, we risk remaining mere spectators as these emissaries from other worlds slip through our fingers.

Cet article a été fait a partir de ces articles:

https://www.sciencealert.com/agencies-are-making-plans-to-catch-rocks-from-other-solar-systems, https://www.sciencealert.com/ancient-killer-is-rapidly-becoming-resistant-to-antibiotics-study-warns, https://www.sciencealert.com/differences-in-our-mouth-spray-could-contribute-to-infection-super-spreaders, https://www.sciencealert.com/our-relationships-with-indoor-plants-come-in-4-types-study-finds, https://www.sciencealert.com/amazing-physics-experiment-reveals-quantum-rain-for-the-first-time