David O. Rankin (born 1984) is an American astronomer, fossil hunter, and discoverer of asteroids. He works as an R&D Operations Engineer at the Catalina Sky Survey. Among the minor planets he has discovered is , a small meteoroid that impacted the Earth on 19 November 2022 near Toronto, Ontario.
Rankin was born in 1984. He grew up in Big Water, Utah, United States.
He holds a B.S. in Natural resource management from the University of Utah with minors in Earth science and Middle Eastern studies.
From a young age, he has been interested in fossil hunting. Rankin has discovered several important specimens from the Tropic Shale: In 1998, at the age of 14, he found a well preserved specimen of Brachauchenius lucasi. In 2001, he discovered the fossil of a new species of plesiosaur, which was named Eopolycotylus rankini after him. Two years later, he co-discovered Nothronychus graffami, a new species of therizinosaur. In 2017, he found a new site of 220,000-year-old pleistocene deposits at lower Wahweap Creek, which bears some of the oldest mammoth fossils in the Colorado Plateau.
Rankin has been a park ranger and a videography intern at Glen Canyon National Recreation Area. He is a self-described "flash flood chaser" and has worked on improving forecasting for flash floods in southern Utah. Rankin is an ambassador for the telescope manufacturer Explore Scientific.
Rankin began to observe asteroids as an amateur astronomer in 2015. Since February 2016, he reported observations to the Minor Planet Center from his home observatory in Big Water (observatory code V03). Later that year, he discovered his first Near Earth asteroid, provisionally designated , which he named after his wife. In 2019, he moved to Tucson where he was hired by the Catalina Sky Survey, becoming a professional astronomer.
In 2025, Rankin became one of the initial members of the Minor Planet Center's (MPC's) newly formed Singleton and archival observations committee, to help the MPC develop policy recommendations for the evaluation and publication of archival data.
Rankin was raised a Mormon, but he is no longer associated with the church. He is married and has two sons.
, Rankin is personally credited with discovering four minor planets (all from Big Water) and 15 comets (including one from Saguaro Observatory at his home in Tucson):
In addition, he has discovered numerous Near Earth objects at Catalina, including the small impactor , the 6th asteroid in history to be discovered before it collided with the Earth.
Eopolycotylus rankini, a species of plesiosaur, is named after him. In 2019, the main belt asteroid was named in his honor.