In this intriguing exploration, we delve into the quest for artificial light sources within our very own solar system. The inspiration for this search stems from a casual conversation during a tour of the dazzling city lights of Dubai, which, according to the guide, could be seen from the moon. This sparked a curiosity about the visibility of city lights across the vast distances of our solar system.
The Loeb-Turner Test: A Key to Unlocking Secrets
One of the central challenges in this search is distinguishing between natural reflections of sunlight and artificial light sources. This is where the Loeb-Turner test comes into play. Developed by Ed Turner and myself, this test relies on measuring the change in brightness of a light source as it moves away from the Sun. By doing so, we can determine whether the light is from a self-luminous source or a reflection.
A Journey into the Trans-Neptunian Realm
The focus then shifts to the trans-Neptunian objects, those mysterious bodies beyond Neptune. A decade ago, I posed a simple yet profound question to Mike Brown, a pioneer in their discovery: "Did you check whether their brightness declines as expected for sunlight reflection?" His response, a dismissive "Why should I check?", highlights a common prejudice in science - assuming we understand a phenomenon without rigorous testing.
Unveiling Anomalies and the Promise of Rubin Observatory
Our recent study, in collaboration with my brilliant postdoc Omer Eldadi, analyzed the brightness variation of these trans-Neptunian objects. The results? Current data is insufficient, with many objects exhibiting anomalous slopes, likely due to calibration issues. However, the upcoming NSF-DOE Rubin Observatory promises to deliver the necessary precision, potentially revealing artificial light sources within our solar system.
The Broader Implications and Scientific Inefficiencies
This journey also prompts a deeper reflection on the inefficiencies of science. The idea of detecting Jupiter-mass planets near Sun-like stars, proposed by Otto Struve in 1952, was ignored for decades, only to be rediscovered and rewarded with a Nobel Prize in 1995. It makes one wonder how many "unborn babies" - potential scientific discoveries - are lost due to such prejudices.
Conclusion: A Universe of Possibilities
As we await the insights from the Rubin Observatory, the prospect of discovering spacecraft with city-scale lights within our solar system is both thrilling and thought-provoking. It serves as a reminder that the universe is full of surprises, and our understanding is always evolving. Science, at its best, is a journey of continuous discovery and reevaluation. Personally, I find this process of questioning and exploration to be the most fascinating aspect of scientific endeavor.
