Touching will be useful to detect stimuli like coldness and hotness.
Smelling on the other hand will help to make observations on smell and change in smell. These two are among the five senses that we use to make observations as we record what we see, hear, touch and feel, smell and taste.
The bright head of the comet Hale-Bopp, called the comma, is shown near the Sun. The combo is made up of dust and gas, concealing a solid comet nucleus made of rock, dust, and ice.
The solid nucleus or core of the hale bopp comet consists mainly of ice and dust coated with black matter, and ice formed mainly of frozen water but possibly other cold substances, such as ammonia, carbon dioxide, carbon monoxide and methane.
