William McKinnon

William McKinnon


Professor of Earth and Planetary Sciences

Contact Information
Media Contact

McKinnon’s research focuses on the icy satellites of the outer solar system and the physics of impact cratering. The last twenty odd years of planetary exploration can be characterized by both the unveiling of the outer solar system – initially by the Voyager missions, but now by the Galileo mission to Jupiter as well as ground- and space-based telescopes – and the growing realization of the importance of impacts in solar system evolution. Professor McKinnon and his students and colleagues are dedicated to exploring this frontier, concentrating on the origin, structure, evolution, and bombardment history of outer planet satellites and Pluto. This includes understanding the relative importance of large impacts, orbital dynamics, and internal processes for tectonics and other surface modifications, the origin and evolution of impactor populations, and the cratering mechanics in ice and other targets.

In the media

Stories

Arrokoth close-up reveals how planetary building blocks were constructed

Arrokoth close-up reveals how planetary building blocks were constructed

William B. McKinnon, professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis, led one of three new studies that together provide a far more complete picture of the composition and origin of Arrokoth. The new research published in Science points to the resolution of a longstanding scientific controversy about how such primitive planetary building blocks called planetesimals were formed.
Wonders of Pluto

Wonders of Pluto

William B. McKinnon, professor of earth and planetary sciences in Arts & Sciences, will deliver the McDonnell Distinguished Lecture on Wednesday, March 29, on the Danforth Campus of Washington University in St. Louis.
The realms of Mordor

The realms of Mordor

What gives Mordor Macula, the red dusted polar region of Pluto’s moon Charon, its color? New Horizons scientists, including Washington University’s Bill McKinnon, answer the question in the current issue of Nature.
Pluto: A cosmic lava lamp

Pluto: A cosmic lava lamp

Using computer models, New Horizons team members have been able to determine the depth of the layer of solid nitrogen ice within Pluto’s distinctive “heart” feature — a large plain informally known as Sputnik Planum — and how fast that ice is flowing. “For the first time, we can really determine what these strange welts of the icy surface of Pluto really are,” said William B. McKinnon, who led the study.
A bumper sticker inspires

A bumper sticker inspires

While at Washington University, Kelsi Singer noticed Bill McKinnon’s bumper sticker, “My other vehicle is on its way to Pluto.” Today, she works on the New Horizons mission and has her own sticker: “My other vehicle explored Pluto.”
It’s alive, it’s alive!

It’s alive, it’s alive!

It was bedlam at mission control when the first images of Pluto came down over the Deep Space Network. Not only were there few craters, but some areas of the planet were smooth as a billiard ball and others rumpled and rippled; some stained the color of dried blood and others gleaming bright white. The variety meant that there was geology on Pluto, alien though the geological processes might be to earthlings.​
Rough guide to Pluto-watching with Bill McKinnon

Rough guide to Pluto-watching with Bill McKinnon

New Horizons will fly through the Pluto system on July 14 at an angle of 46 degrees to the plane of the dwarf planet’s orbit, then turn to use sunlight reflected from Charon, Pluto’s biggest moon, to image areas of Pluto now in continuous darkness. Your host for the WashU Pluto watching party will be Bill McKinnon, a planetary scientist at Washington University in St. Louis, who will be commenting from mission headquarters at the Johns Hopkins University’s Applied Physics Laboratory in Maryland.
Europa, here we come

Europa, here we come

Scientists have been itching to go to Europa for a long time because this moon is thought to have a global ocean beneath an outer shell of ice — an ocean that may be hospitable to life. In May, NASA took the first step, selecting nine instruments to fly on a mission to Europa. Washington University’s William McKinnon, on the science team for two of the instruments, talks about the mission.
Coming soon: First encounter with a new class of worlds​

Coming soon: First encounter with a new class of worlds​

After an epic journey across the breadth of the solar system, the New Horizons spacecraft is finally nearing its destination: the Pluto system, a staggering three billion miles from Earth. William McKinnon, a planetary scientist at Washington University in St. Louis, explains that our understanding of Pluto has been transformed in the nearly 10 years the probe has been en route to its target. ​
Landslides on other worlds

Landslides on other worlds

Saturn’s ice moon Iapetus has more giant landslides than any solar system body other than Mars. Measurements of the avalanches suggest that some mechanism lowered their coefficients of friction so that they flowed rather than tumbled, traveling extraordinary distances before coming to rest. Scientists at Washington University in St. Louis, who have been studying the ice avalanches suggest a experimental test that might provide some answers.

How Iapetus, Saturn’s outermost moon, got its ridge

A team of scientists a team, including William B. McKinnon, PhD, professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis, propose an explanation for the bizarre ridge belting Saturn’s outermost moon Iapetus. At one time Iapetus itself may have had a satellite, created by a giant impact with another body. The satellite’s orbit would have decayed because of tidal interactions with Iapetus, and at some point it would have been ripped apart, forming a ring of debris around Iapetus that would eventually slam into the moon near its equator,

Saturnian moon shows evidence of ammonia

Data collected during two close flybys of Saturn’s moon Enceladus by NASA’s Cassini spacecraft add more fuel to the fire about the Saturnian ice world containing sub-surface liquid water, according to a report in the July 23 issue of the journal Nature that is co-authored by a planetary researcher from Washington University in St. Louis.

Return to Europa: A closer look is possible

NASA/JPLThick or thin ice shell on Jupiter’s moon Europa? Scientists are all but certain that Europa has an ocean underneath its surface ice, but do not know how thick this ice might be.Jupiter’s moon Europa is just as far away as ever, but new research is bringing scientists closer to being able to explore its tantalizing ice-covered ocean and determine its potential for harboring life. William B. McKinnon, professor of earth and planetary sciences at Washington University in St. Louis, is discussing some of these recent findings and new opportunities for exploring Europa in a news briefing on Thursday, Dec. 13, 2007, at the meeting of the American Geophysical Union in San Francisco.

Hot spot on Enceladus causes plumes

NASA/JPL/Space Science InstituteHot spots on Saturn’s tiny satellite, Enceladus, could be telltale signs of life on the frigid moon.Enceladus, the tiny satellite of Saturn, is colder than ice, but data gathered by the Cassini-Huygens Mission to Saturn and Titan has detected a hot spot that could mean there is life in the old moon after all. In fact, for researchers of the outer planets, Enceladus is so intellectually hot, it’s smokin’.

Planetary scientist says: Focus on Europa

NASALet’s visit Europa!William B. McKinnon, Ph.D., professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis, says the space science community suffers from an embarrassment of riches when pondering which of Jupiter’s moons should be studied next, because they all differ in the way that they can reveal more about planets and how they behave. But he thinks it is Europa that clearly commands the most attention.