As Summer approaches, the smell of fresh-cut grass and rain become more common. The Roar staff researched these smells to enlighten our readers.

Fresh-cut grass:  Everyone knows the tell-tale scent of summer that so many people enjoy. Candle companies have even created scents meant to imitate this one. According to research done by Texas A&M students, however, this refreshing scent isn’t as pleasant as it seems. The smell that grass gives off when being cut is actually a distress signal meant to warn the surrounding insects of the grass’ demise. The aroma given off attracts beneficial insects to the plant. In a world without lawn mowers, the grass would give off its signal when it was being eaten by a pest insect. Beneficial insects, such as parasitic wasps according to Texas A&M, are attracted to the scent and come to the anguished grass to lay their eggs. When the eggs hatch, the baby insects eat the pests and save the grass.  

Rain: The smell of rain is caused by two chemical reactions. The first smell starts during dry spells, when ground dwelling bacteria let off chemicals and oil. When rain hits the chemicals, they are released into the air, allowing people to smell it. In 1964 this smell was named Petrichor by two Australian scientists. 

The second rainy-day-smell comes from Ozone. This starts by lightning splitting oxygen and nitrogen molecules, which recombine as Nitric Oxide. The Nitric Oxide then combines with other chemicals in the atmosphere to form Ozone which has a Chlorine-like smell. This smell can oftentimes come before the storm, as the wind blows Ozone in front of the storm.