National Aeronautics and Space Administration Logo
Follow this link to skip to the main content NASA Banner
Solar System Exploration
News & Events
Meet Asteroid Espenak
Meet Asteroid Espenak
17 Apr 2003
(Source: Goddard Space Flight Center)

Bill Steigerwald
NASA Goddard Space Flight Center
Greenbelt, Md 20771
Phone: (301-286/5017)

Release 03-38


Years spent charting a shadow dance between the Moon and the Sun paid off last month for NASA astronomer Fred Espenak, an alumnus of Wagner College, Staten Island, N.Y., with an asteroid that bears his name.

The organization that assigns official names to celestial objects, the International Astronomical Union (IAU), designated "minor planet 14120" as "Espenak" in the Smithsonian Astrophysics Center Minor Planet Circular #48157, issued March 18.

"It's quite an honor to have a piece of real estate in the solar system named after you," said Espenak, who is a world-renowned authority on solar eclipse predictions at NASA's Goddard Space Flight Center, Greenbelt, Md. "I have to be humble, though, because it's a small piece, probably just 5 to 10 miles in diameter," he adds with a laugh.

The IAU cited Espenak as "widely recognized for his calculations of solar eclipses, his agnificent maps of these phenomena, and his book 'Totality: Eclipses of the Sun'."

Asteroid Espenak is mysterious because it is a faint object, making observations to determine its shape and composition difficult. "One of the things I'll probably do when I retire is try to take its picture from my observatory," said Espenak. It was discovered on August 27, 1998 by the Lowell Observatory Near-Earth Object Search using a 60-centimeter (24-inch) Schmidt telescope from Anderson Mesa, Arizona.

The object is a main belt asteroid with an orbital period of 1,344 days (3.68years). The tiny body travels in an elliptical orbit whose distance from the Sun varies from 325 million to 388 million kilometers (202 million to 241 million miles). The most recent close approach of asteroid Espenak was on 2002 November 22 when it was 178 million kilometers (111 million miles) from Earth. Presently, the asteroid is an 18th magnitude object in the constellation Taurus, which is visible throughout the spring during the early evening hours.

Notification was informal, according to Espenak, "Colleagues that subscribe to the IAU circular saw it and told me." He looked up his asteroid in the circular and found it among a list of others recently christened with new names, including "Sciam" for the magazine Scientific American and "Robinwilliams" after the comedian.

Espenak learned that two friends from Belgium had nominated him: Dr. Jean Meeus, an expert in orbital mechanics, and Patrick Poitevin, an amateur astronomer who organizes international conferences of professional and amateur astronomers to discuss the state of eclipse science and solar physics research. "I guess they both appreciated the eclipse work I do," said Espenak.

Normally, the discoverer of an asteroid has the first right to name it after someone else, but recent automated telescopic surveys gave the IAU a surplus of asteroids with nothing but prosaic catalog designations. Anyone can petition the IAU to name an asteroid in someone's honor, but the process often takes years. Also, IAU's Committee for Small Body Nomenclature has specific rules for names, including a limit of 16 characters (including punctuation), a requirement that the name be pronounceable (in some language), and no names from pet animals allowed. Espenak considers himself fortunate to have a job so closely related to his passion: observing and photographing solar eclipses. He will travel to Iceland in May for an annular eclipse (a partial eclipse where a ring-shaped portion of the Sun remains), and to Antarctica in November aboard a Russian icebreaker for a total eclipse.

Espenak publishes the definitive guide to solar eclipses, the NASA eclipse bulletin, for every total and annular eclipse with colleague Jay Anderson, a meteorologist with Environment Canada, a weather and environmental news website. The bulletins include detailed maps of the eclipse path, with voluminous information about the location, viewing conditions, and climate along the path for eclipse chasers. Also included are tips on how to view eclipses safely and photograph them successfully.

Espenak posts this information on the web at

For more about how the IAU names celestial objects, refer to:

News Archive Search  Go!
Show  results per page
Awards and Recognition   Solar System Exploration Roadmap   Contact Us   Site Map   Print This Page
NASA Official: Kristen Erickson
Advisory: Dr. James Green, Director of Planetary Science
Outreach Manager: Alice Wessen
Curator/Editor: Phil Davis
Science Writers: Courtney O'Connor and Bill Dunford
Producer: Greg Baerg
Webmaster: David Martin
> NASA Science Mission Directorate
> Budgets, Strategic Plans and Accountability Reports
> Equal Employment Opportunity Data
   Posted Pursuant to the No Fear Act
> Information-Dissemination Policies and Inventories
> Freedom of Information Act
> Privacy Policy & Important Notices
> Inspector General Hotline
> Office of the Inspector General
> NASA Communications Policy
> NASA Advisory Council
> Open Government at NASA
Last Updated: 28 Apr 2003