Astronomers have once again looked at thousands of known exoplanets — and concluded that there are not that many truly interesting candidates for the role of a “second Earth.”
Researchers have compiled a list of 45 rocky planets that could potentially support life.
The key word here is “rocky.” The scientists were interested specifically in solid worlds located in the so-called habitable zone — the region around a star where temperatures could theoretically allow liquid water to exist. Out of more than 6,000 known exoplanets, they left only 45 candidates. And if a more conservative model is used, there are only 24.
The list again includes the famous Proxima Centauri b — the nearest potentially habitable exoplanet to Earth. It is about 4.2 light-years away. In cosmic terms, that is practically next door.
The list also includes planets in the TRAPPIST-1 system — d, e, f, and g. This system has long been a star of astronomical news. It is about 40 light-years from Earth and is interesting because several of its planets orbit at the right distance from a red dwarf.
Scientists are now talking about sensible prioritization. Modern astronomy has accumulated an enormous amount of data, and the problem is no longer a lack of planets, but a lack of telescope time. The James Webb Space Telescope cannot look in all directions across the Universe at once, impressive as it is.
This new catalog is intended to help choose the best targets for observations. The study’s authors emphasize that even “imperfect” planets can reveal a great deal about how potentially habitable worlds work in general.
Ten years ago, the main sensation was simply the discovery of an exoplanet. Today, scientists are already drawing up shortlists, ranking worlds by promise, and effectively preparing a roadmap in the search for extraterrestrial life.
