Analyzing the remaining dust with mass spectrometry, they found traces of the isotope iron-60, which is primarily produced in two ways: by exploding supernovas or by cosmic rays zapping interplanetary dust.

通过质谱法分析剩余的尘埃， 他们发现了同位素铁 60 的痕迹，铁 60 主要通过两种方式产生：超新星爆炸或宇宙射线撞击行星际尘埃。