The Doctor asks the Silurian scientist if he has any celery. This refers to the habit of the Fifth Doctor, who always wore a sprig of celery. The celery was a cure for several poisons that affect Time Lords.
Although the theory that the moon was captured by Earth's gravity, a more accepted theory is that the moon was created not long after the Earth itself. It's thought a very large object impacted the recently formed Earth and the debris from the collision coalesced and formed the moon.
A deleted segment from the scene in which the Silurians are marching the Doctor and Nasreen to the court hall had The Doctor saying that the "last time I was executed it really put a blight on the day."