Lentorama 2022: It Happened on Easter

Day 9: Vesta is discovered

Heinrich Olbers went to university to become a doctor, but wound up being best known as an astronomer. He also studied mathematics while at university, and while tending to a sick student came up with a new way to calculate the orbit of comets. He would set up a medical practice in Bremen, Germany after graduation, but found lasting fame from what he did in the observatory he set up on the top floor of his house.

Olbers discovered the asteroid Pallas the year after the asteroid Ceres was discovered, and theorized that they were remnants of a planet that had been destroyed. He wrote of this theory to astronomer William Herschel, with the suggestion that studying the area where the orbits of Ceres and Pallas intersected might lead to further discoveries. That idea bore fruit on Easter Sunday (March 29) 1807, when Olbers discovered another asteroid in that part of space. He let Carl Frederich Gauss name it in honor of his work calculating the orbit of Ceres, and Gauss gave it the name Vesta after the Roman goddess of hearth and home.

It turned out, though, that Olbers was looking in the right place for the wrong reason. These asteroids weren't pieces of a destroyed planet, but pieces of what could have accreted into a planet if it weren't for the gravitational force of Jupiter. That force kept the pieces moving too quickly to fuse together, so collisions would typically destroy them. Over time this created the asteroid belt that currently exists between Mars and Jupiter, with Vesta being one of the larger objects to survive. 

Olbers would go on to become the namesake of a comet, minor planet, lunar crater, and a paradox that asks why the night sky is dark if there are an infinite number of stars that should be visible in the night sky. How that paradox was named for him is a bit of a mystery, as it was posited by other astronomers, but his discussion of it in an 1823 almanac seems to have linked him to it for good. He died in 1840 at the age of 81.