Late in the evening on July 7, 2000, during my first field season at Santa Catalina Island, I lay on my stomach on the dock in Big Fisherman Cove, beside my husband Brian and our 5-year old son Tom. We lowered a dive light into the water and peered down to see what creatures might approach it, watching as a few small fish and then some larger kelp bass appeared out of the darkness. A few other people stood on the dock, enjoying the summer evening. When we rose to walk back to the house, we saw a bright white streak arc silently upward from the northeast. “Look at that contrail,” I said, and we watched the streak broaden and grow more brilliant. The leading edge became a gigantic expanding pillowy orb. Not a contrail, I thought. That’s either an incoming asteroid and this is the end of the dinosaurs all over again or it’s a North Korean missile. Either way we’re finished! Then a blue light throbbed, and a ring of white expanded out from the center of the orb. “That was an explosion,” Brian said, “Let’s get off the dock before the shock wave hits.” Tom whimpered and reached to be picked up. There was no other sound but the slow slap, slap, slap of the waves against the piers, the sigh of water washing over the gravelly beach, the murmur of startled conversation, and the sleepy calls of seagulls. The white orb and its tail faded away, slowly and silently.
On the radio the next morning, we found out that we had watched the failed test of an intercontinental missile defense system. A Minuteman II intercontinental missile with a mock nuclear warhead had taken off from Vandenberg Air Force Base and an interceptor kill vehicle was launched from Kwajalein, a faraway central Pacific atoll, to shoot it down over the ocean. But the kill vehicle failed to separate from its launch rocket, the test was aborted, and the missile was shot down over 100 miles above Santa Catalina Island. There was never any sound or smell or sensation, never a hint that anything unusual was happening in the sky. A colleague napping inside our house missed the whole event.
What is it like to witness a mass extinction? Just before the asteroid entered the atmosphere 66 million years ago, was any small mammal or dinosaur looking up into the sky? Were they given any sign?
The event at the end of the Cretaceous era that extinguished the dinosaurs and half of all existing genera was far from silent. The mother of all sonic booms reverberated as the 10-km asteroid smashed the atmosphere and plowed into the Earth. The instant after it hit the Yucatan, the asteroid was vaporized, as were millions of tons of Yucatan limestone and bedrock. All this molten rock was ejected far above the atmosphere, much of it falling back to earth as a global rain of refrozen glass droplets called tektites (from the Greek word for “molten”). As the tektites fell, superheated forests around the North American inland sea burst into flame. Sap boiled out of the trees and some of the tektites falling out of the sky were captured in it and frozen in amber. The asteroid impact triggered earthquakes which in turn set off a series of 10-m waves or seiches in the interior sea, water sloshing back and forth, washing mud and debris into the sea. Imagine the shaking rumble of earthquakes, the sudden intense heat, the suffocating roar of the inferno, the crashing of seiches, the screams of the dying. It’s fair to say that no one slept through it.
In the minutes before the impact, a group of shark-sized paddlefish swam in the inland sea, upstream toward the Tanis River. The electrosensors on their heads and snouts quivered in response to electrical currents caused by tiny aquatic swimmers. They opened their mouths, ready to take in water and prey, using the comb-like filaments in their gill rakers to sieve out the food. Then unexpectedly the river current was overwhelmed as a giant wave rushed up the seaway. The water was now filled with mud, flowers, ferns, nests, leaves, twigs, seeds, logs. The paddlefish struggled and gasped, gill rakers meant to collect dinner now clogged with tektites. Mud encased them with their dorsal fins upright. The tektite rain continued to fall. Globules of glass plunged into the soft mud by the seashore. Another wave came, and another.
At a music party in 2018, I chatted with my friend, a geologist at UC Berkeley. He recounted that one dark night in 2017 he and his wife were witnesses across time to the most extreme and sudden disaster the living Earth has ever known. They had collected samples from the Hell Creek Formation in North Dakota all day and were huddled over a microscope to look at fossils. They saw the funnel of sediment layers bent down by the impact of a small glassy bomb striking the mud at terminal velocity. They saw the tektite-filled gill rakers of a paddlefish, struggling for air. The tektites never even made it into their stomachs before the fish suffocated. The whole disaster took less than two hours.
We now live in the Anthropocene, a time during which our own species has become a geologic force. We pump carbon and sulfur dioxide into the atmosphere, warming the globe, depleting oxygen in the ocean, acidifying the rain and the sea. The worst of this has happened over the last ~250 years, too fast for many plants and animals to adapt to the new conditions. Unlike the deafening end of the dinosaurs, the modern poisoning of the Earth and its creatures is marked by the loss of beating wings, whirrs, calls, and chatter from insects and birds, nocturnal clicks from bats and barn owls, the constant underwater popping of snapping shrimp. A loss so gradual that a creature alive now might not notice how the sounds of the natural world have been replaced by the dull monotone of the freeway, the thwock-thwock-thwock of helicopters, the scream of police and fire sirens, and the artificial tones of the electronic world.