The passage weighs an explanatory theory against a rival emphasis. The theory says that the asteroid formed near the sun because its minerals resemble heat-altered rocks; the evidence supporting it is that spectral data match laboratory samples heated to high temperatures. The rival emphasis becomes attractive because the same spectra can result when unheated material is exposed to solar wind for long periods, yet the author concludes more moderately that the heat-formation theory is plausible but underdetermined by the spectra.