SciX: Science Explorer online databaseThe Science Explorer (SciX) is a digital library portal for researchers in astronomy, earth science, heliophysics, physics, and planetary science. The four bibliographic collections maintained by SciX cover astronomy (including astrophysics, heliophysics, and planetary science), physics, earth science, and general science. Over all the system contains over 20 million records covering refereed publications plus all arXiv, ESS Open Archive, and EarthArXiv preprints.