Earth's Shadow Hunts for Alien Probes ⚡ экспресс
Astronomers have pondered the possibility of inhabited worlds for centuries, but the deliberate search for artifacts and probes from extraterrestrial civilizations within the Solar System was long neglected due to technical and social challenges. The rise of automated surveys and new observational techniques in the last decade now allows for a systematic hunt for anomalous objects. This work briefly outlines four detection methods: analyzing pre-satellite-era images for glints, using space telescopes, examining reflection spectra to spot reddening of metallic surfaces caused by space weathering, and the Earth-shadow method. The last is explored in greatest detail: Earth's shadow serves as a filter to highlight optically bright objects in near-Earth space. A proof of concept was achieved using data from the Zwicky Transient Facility: two searches for short-lived events on consecutive 30-second exposures turned up previously uncatalogued events at small angular distances from the shadow's center. This opens up a new search domain for local SETI.
Back in the 18th century, William Herschel was searching for life on Mars. Today, astronomers are targeting not planets but artifacts — for example, alien probes lurking in the Solar System. The problem is that spotting a tiny object next to the blinding Sun is nearly impossible. A new idea: turn Earth's shadow into a natural filter.
The shadow works like a deep well. During the day, you can see stars from the bottom of a well because the walls block out direct light. Similarly, the cone of Earth's shadow, stretching 1.5 million kilometers into space, blocks the Sun and makes faint flashes visible. A team of scientists analyzed images from the automated telescope Zwicky Transient Facility (ZTF), which photographs the sky every night. They searched for objects flickering near the shadow's edge for just a couple of seconds.
In the data, they found dozens of unknown rapidly changing flashes, previously uncatalogued. Most likely, these are space junk or asteroids, but the technique itself proved its power. A systematic sweep of the "well" could turn the search for extraterrestrial intelligence from a dream into observational science.
🎯 Earth's shadow reaches about 1.4 million kilometers — almost four times the distance to the Moon.