射纹系统包括从撞击坑喷发过程中抛出的纤细纵向条纹，这许多的条纹看起来有点像来自轮子枢纽的辐条。这些辐射状物经常有较大喷发物造成的二次与后续撞击伴随着，向外延伸原始的撞击坑直径的数倍。在月球、水星、金星和太阳系内其它的行星的一些天然卫星上，都确认了一些射纹系统。原先我们认为射纹系统只存在没有大气层的行星或卫星上，但最近在来自火星轨道上的奥德赛号的热影像成像的火星红外线影像上也发现了射纹系统。

当喷发物的材料沉积在表面时会有着不同的反射 (这是指反照率) 或热性质，射纹可以在可见光以及某些红外线波长的情况下被看见。通常，可见的射纹有着比周围其它物质更高的反照率。比较罕见的是撞极挖掘出的物质反照率比较低，例如沉积在月海的玄武岩的熔岩。热射纹，如同在火星上看见的，在斜坡和阴影不影响到火星表面的红外线辐射能量时特别容易看见。

A ray system comprises radial streaks of fine ejecta thrown out during the formation of an impact crater, looking somewhat like many thin spokes coming from the hub of a wheel. The rays can extend for lengths up to several times the diameter of their originating crater, and are often accompanied by small secondary craters formed by larger chunks of ejecta. Ray systems have been identified on the Moon, Mercury, and some moons of the outer planets. Originally it was thought that they existed only on planets or moons lacking an atmosphere, but more recently they've been found on Mars in infrared images taken from orbit by Mars Odyssey's thermal imager.