- School News
“Right now, an enormous cloud of gas is hurtling towards the supermassive black hole at the center of our Milky Way galaxy. It's too close as it veers towards the black hole. That doomed cloud will be shredded and stretched into a piece of cosmic string over 100 billion miles long.” With this dramatic image, Dr. Dan Evans began his presentation to the Middle School at a special assembly in December
Dr. Evans co-leads NASA’s $8 billion science program at NASA headquarters in Washington, DC. During his tenure, he has launched some of NASA’s most ambitious science missions, including the James Webb Space Telescope, the Perseverance Mars Rover, and the Ingenuity Mars Helicopter. And, as he told students, he’s been studying black holes every day for twenty years.
“Elsewhere in the universe, two black holes are dancing. They're spinning around one another in an ever-tightening grasp, but as they pull towards one another, the black holes will merge together so ferociously that the very fabric of space and time gets ripped in another galaxy. Nicknamed the Death Star, this is one that I discovered myself.”
It was Dr. Evans’s mission this day, “to reveal the hidden beauty behind these spectacular events.” And, to separate science fact from science fiction.
Students watched and listened, excited, as Dr. Evans helped them understand black holes—“some of the simplest” and “also most powerful” objects in the universe. They learned about the event horizon and the black hole at the center of our own galaxy. They learned that black holes can be described by mass, spin, and charge and that the singularity at the heart of every black hole pulls everything toward itself.
With the help of a video simulation, students watched what it could look like for a black hole to swallow an object. Students saw the object approach the black hole, drawn in by extraordinary gravity, moving faster and faster. Then, they saw how space and time can twist and the way the universe “doubles back on itself” as the object falls in.
Students had many questions. One student wanted to know where you would end up if you fell into a black hole. “I don’t know,” Dr. Evans said. “Could you end up in another universe? Maybe you might. You ever heard of worm holes? It’s a possibility.”
Then, the presentation took a strange turn as Dr. Evans recounted a trip to the office of Senator Bill Nelson, the administrator of NASA and his boss. “You don’t go to the administrator’s office very often, so I was kind of scared. It’s like going to the principal. He said, ‘Dan, I’d like you to look into UFOs.’ I said, ‘Okay.’’’ And that was what launched Dr. Evans’ investigation of top-secret encounters, pilots, and objects flying in restricted air space—otherwise known as UFOs.
This is where fact must be separated from fiction. Dr. Evans and his team have investigated about 500 UFOs both in air and in water, most having been observed by military aircraft or radar. Students guessed what could explain the UFOs — space junk, foreign adversaries, and previously unidentified species were some of their ideas.
It's risky business, this investigation of UFOs. The Department of Defense — and many others — are eager to see the results of the study produced by Dr. Evans and his team. The reputation of NASA is on the line. When working on a high-profile project like this — or launching a giant telescope or the Mars Rover — what does Dr. Evans fall back on to guide him? The scientific method. Collaboration with his team. And sometimes, the importance of taking risks and failing:
“There's a phrase at NASA that many of you will have seen, ‘Failure is not an option.’ While that mantra is most certainly true when we're sending astronauts — precious human life — up to the Moon, that mode of operation isn't always the right thing to do when you're running a space agency or even in life itself. Because if we're unwilling to take risks and fail from them, then we won't learn.”
Prior to his position at NASA, Dr. Evans worked at the White House where he oversaw the International Space Station. He holds a Ph.D. in astrophysics from the University of Bristol, England, and he previously held postdoctoral fellowships at Harvard and MIT.