What did hooke find in his research

Robert Hooke, (born July 18 [July 28, New Style], 1635, Freshwater, Isle of Wight, England—died March 3, 1703, London), English physicist who discovered the law of elasticity, known as Hooke’s law, and who did research in a remarkable variety of fields.

Explanation:

In 1655 Hooke was employed by Robert Boyle to construct the Boylean air pump. Five years later, Hooke discovered his law of elasticity, which states that the stretching of a solid body (e.g., metal, wood) is proportional to the force applied to it. The law laid the basis for studies of stress and strain and for understanding of elastic materials. He applied these studies in his designs for the balance springs of watches. In 1662 he was appointed curator of experiments to the Royal Society of London and was elected a fellow the following year.

One of the first men to build a Gregorianreflecting telescope, Hooke discovered the fifth star in the Trapezium, an asterism in the constellation Orion, in 1664 and first suggested that Jupiter rotates on its axis. His detailed sketches of Mars were used in the 19th century to determine that planet’s rate of rotation.

i believe that it is a exoplanet