 As an additional check, it is possible to recover the isotope Titanium-44 (44Ti) from meteorites; this provides a measurement of activity that is not affected by changes in transport process or the geomagnetic field.Although it is limited to about the last two centuries, it is consistent with all but one of the 14C and 10Be reconstructions and confirms their validity.The energetic flare events discussed above are rare; on long time scales (significantly more than a year), the radiogenic particle flux is dominated by cosmic rays.