SpaceAlien messages responding to NASA signals could reach us by 2029 Radio signals sent to NASA spacecraft could have already reached four neighbouring star systems, and if any aliens tried to respond, we might hear from them within a few years from now ¿ìè¶ÌÊÓÆµ
ChemistryCrystal impervious to radiation could be used in spaceship computers Putting two forms of semiconductor material called gallium oxide together seems to make it completely resistant to radiation ¿ìè¶ÌÊÓÆµ