Many paranormal researchers believe that certain phases of the moon may increase the chances that ghosts and spirits are more readily detected and observed. Supposedly, the most active periods of manifestation are two days prior to a full or new moon and two days immediately after these phases. The influx of solar X-ray radiation, heightened activity in the earth's geomagnetic field, and seismic activity also influence the frequency and magnitude of paranormal events. Investigators must additionally pay close attention to current weather conditions. Factors such as humidity, barometric pressure, and temperature must be closely observed and recorded during the investigative process in an effort to establish a correlation with suspected paranormal activity.