For the others, one can only use relative age dating (such as counting craters) in order to estimate the age of the surface and the history of the surface.
The biggest assumption is that, to first order, the number of asteroids and comets hitting the Earth and the Moon was the same as for Mercury, Venus, and Mars. The bottom line is that the more craters one sees, the older the surface is.
As stated in the lyrics, the chemical is compared to a “vibe” or “beat.” While the chlorine has poisonous properties and could potentially cause harm, the narrator just can’t get enough.
A similar idea is found in an earlier song when Tyler says, In both cases, the concept of pain, or something which would generally be unwanted is flipped on its side and used as a metaphor for that which is beneficial.
When there is a scientific discussion about the age of, say a meteorite or the Earth, the media just talks about the large numbers and not about the dating technique (e.g. On the other hand, when the media talk about "more recent events," ages that are more comprehendible, such as when early Man built a fire or even how old a painting is (or some ancient parchment), then we bring up the dating technique in order to better validate the findings.
Chlorine, while being a deadly chemical, is used to eliminate unwanted substances.
For others, all we are doing is getting a relative age, using things like the formation of craters and other features on a surface.
By studying other planets, we are learning more about our own planet.
This is also a way to get at the abundance of the various isotopes of carbon.
We have an activity in one of the PSI workshops "Exploring the Terrestrial Planets," that deals with this topic.