Scientists have no way of knowing exactly when the " Caloris" impact happened.

科学家无法确切的弄清楚卡洛里斯盆地何时形成的。

The largest is called Caloris Basin, a whopping huge impact feature 1600 kilometers across.

其中最大的被称为卡洛里盆地，是在一个巨大的冲击力下形成的直径1600千米的陨石坑。

But imagine if the mighty object that formed Mercury's Caloris Basin crashed down on the site of Meteor Crater.

想象一下造成水星上卡洛里斯盆的巨大小行星撞击在这个亚利桑那陨石坑的地方。

The most prominent feature, is a feature called the " Caloris Basin" , which is a very large impact crater that is about maybe 900 miles in diameter.

这个特征最显著的陨石坑被称作卡洛里斯盆地这个坑如此大直径可能有900英里。