The ads build upon an article discovery feature Disqus introduced over the summer, a box below the comments that provides links to related articles either on the site or elsewhere on the Web.
In the session on article and feature writing, the lecture covered -- how to select a subject, how to write a theme sentence to determine the parameters of the subject, and how to collect and sort out the material.
The notion that it is these smaller, tens-to-hundreds of metres-sized objects that pose the greatest potential threat to Earth is explored in the BBC featurearticle Can we know about every asteroid?