After a half hour with Greg Redfern, you are likely to spend the rest of your day looking over your shoulder. And up at the sky.
Redfern – an astronomer, professor, writer, media personality and “solar-system ambassador” for NASA and the Jet Propulsion Laboratory – positively oozes enthusiasm about things that go bump in the night. In his case, that means the Earth and things that careen into it. Asteroids, comets and the like.
“We don’t always see these things coming,” Redfern said during an Oct. 26 presentation for the Kiwanis Club of Arlington, where he pressed the case for more investment in scientific advancements to keep a closer eye on incoming objects.
“The dinosaurs are dead because they didn’t have telescopes or a space program,” Redfern noted. “We have to be watchful. There are impacts all the time.”
And not too far away, either – in September, a 10-foot-long piece of wayward interstellar detritus exploded over Luray, Va. No damage was done, but it was another wakeup call that the cosmos is hurling fastballs, change-ups and the occasional curveball at us all the time.
Redfern’s Oct. 26 remarks focused on the relatively little-known impact that occurred when either a comet or an asteroid (probably the latter) smashed into what today is the Chesapeake Bay area but 35 million years ago was under 1,000 additional feet of seawater.
“Hell came to Earth in the form of this impact,” he said, pointing to a vaporization of everything close by and a 4,000-foot tsunami that took out life forms as far west as the modern-day Shenandoah Valley. The debris field was scattered over 4 million square miles, and billions of tons of seawater, rock and debris were ejected into the atmosphere, eventually falling back in a rain of terror for whatever creatures remained alive to witness it.
The event “reshaped, temporarily, the Atlantic Ocean, the Atlantic seaboard,” Redfern said, delivering the equivalent force of 10 million tons of TNT. “You can’t believe the energy,” he said.
The possibility that something unusual may have happened in the Hampton Roads area was known as early as the 1860s. During the Civil War, military attempts to drill for fresh water in the vicinity turned up nothing but brackish seawater, which confused the soldiers.
[The reason for it: When the impact occurred those millions of years back, all the fresh water in the vicinity turned to vapor. The Atlantic Ocean, which was pushed back due to the blast, eventually returned and filled not only the impact crater, but every available geological nook and cranny. “Water always wins,” Redfern noted.]
The mystery remained just that, but by the 1960s, the U.S. Geological Survey entered the picture to investigate, and in 1983 quartz was found in core samples in the area that could only have been produced by a cataclysmic event.
In 1993, scientists found the smoking gun – using geological maps from Exxon and Texaco, they discovered evidence of a 56-mile-wide crater centered on what today is Cape Charles, Va.
Scientists descended on a soybean farm to begin taking core samples; the farmer, who offered them unfettered access for 90 days, provided “a great service to science and humanity” with his support, Redfern said. The scientists drilled down to 5,700 feet and still were unable to reach the bottom of the crater.
Unless another competitor is uncovered, the Chesapeake Bay impact will go into the record book as the largest such event in what today is the United States. It came about 30 million years after the larger strike on Mexico’s Yucatan Peninsula that was the likely demise of dinosaurs.
Could the expiration date of the human race be determined by the next major collision? Redfern said the chances of a species-destroying impact are “very minimal.”
But never say never.
“The odds are low, but not zero,” Redfern said. When it comes to humanity’s survival, “the universe doesn’t care” one way or the other, he said.
Kiwanis Club president Mary Anthony, a Redfern devotee who invited the Charlottesville resident to speak, called him “my favorite astronomer.”
“He has a style that really resonates with passion,” Anthony said.