Ken MacLeod, associate professor of geological sciences at MU, will give a talk April 2 as part of the “Cosmic Conversations” lecture series. His lecture is titled “It Came from Outer Space: Recent Controversies Regarding the K/T Boundary.”
The K/T boundary is the boundary between Cretaceous and Tertiary geological periods. The word “Cretaceous” stems from the Latin word for chalk, or “creta.” MacLeod said the letter “K” may be used to abbreviate the boundary because there are other geological periods that also begin with “C.”
“This is a topic I have been researching on and off for almost 20 years,” MacLeod said. “At one point, where I was working happened to be where the best records for that time interval had been found.”
The Cretaceous period is when the dinosaurs walked the Earth. At the end of this period, an asteroid struck the Earth. Many scientists and geologists believe this led to the mass extinction of dinosaurs, but not all agree.
“The leading hypothesis for causation (of the K/T boundary) is an asteroid impact,” said MacLeod.
“There is evidence for one and only one asteroid.”
This is the sixth month for the lecture series, which was initiated in October by Angela Speck, assistant professor of physics and astronomy at MU. As the only observational astronomer in the department, she was approached by amateur astronomers to start a series.
The series is on Wednesdays, the same day Laws Observatory is open to the public from 8 to 10 p.m.
The lecture series is scheduled through December with a wide range of topics, such as a discussion on nuclear processes in the cosmos in August to coincide with the anniversary of the dropping of a nuclear bomb on Hiroshima.
Not all topics are strictly science. For example, one lecture will cover astronomy and religion, and another is on night photography.
Speck said that if the series were strictly science-based, it would limit the amount of people she could approach for lecture topics.
“Astronomy being something that is more inspirational, I wanted it to cover more than just ‘here’s the science of stars,’” she said. “I wanted it to be something more far-reaching.”
Speck said she is excited about each of the lectures.
“The next one is about meteorites and extinction, and I have a personal interest in meteorites because it relates to some of the stuff I do, but I do have a 4-year-old that’s completely obsessed with dinosaurs right now,” Speck said.
Cosmic Conversations will be held at 7 p.m. April 2 in room 126 of MU’s physics building. Subsequent lectures will be the first Wednesday of every month at the same time and place. After the talks, the telescope on the fifth floor will be opened for night-sky viewing if the weather permits.