If an alien ship left its trash near Earth, here’s what it might look like | Science

2 bulan ago kesimpulan 0
Bringing you the latest Science news from the world.

What is happening in our world? Who is discovering what? What is going on now? These are questions that will be answered. Enjoy.

If an alien ship left its trash near Earth, here’s what it might look like | Science


Iridium flares are a familiar sight for sky watchers: The brilliant flashes take place when sunlight bounces off the solar panels of the 66 low-orbiting satellites in the iridium communications system. Now, a researcher involved in the search for extraterrestrial intelligence wonders what similar flashes farther out might mean—perhaps a shiny alien artifact or spacecraft?

To find out, he calculated what a shiny “technosignature” might look like. He started with the observation that even though a reflective surface can be seen from a long way off, our ability to see it from Earth depends on the surface area, which way it is oriented, whether it is spinning, and the sensitivity of Earth-bound telescopes. The Panoramic Survey Telescope and Rapid Response System (Pan-STARRS1), a 1.8-meter telescope on Haleakala in Hawaii that scans the sky for potentially threatening near-Earth objects, for example, could spot a mirror the size of a coaster out to 1 astronomical unit, the distance between the sun and Earth, if it was rotating slowly. For Pan-STARRS1 to see a fast-rotating mirror at the same distance, it would need to be the size of a tennis court.

Given these variables, the researcher estimates there would need to be millions of mirrors across the inner solar system to see one in a single Pan-STARRS1 exposure, he reports today on the arXiv preprint server. Those chances might go up by focusing on Lagrange points, gravitational sinkholes where alien detritus might accumulate. If only a few hundred mirrors were present, a much smaller telescope could spot one. But the fact that we haven’t seen such flashes yet suggests any alien visitors—if they are out there—are doing a good job of cleaning up after themselves.

Source link