3 ways to defeat killer asteroids

If astronomers found a large asteroid headed towards Earth, could we defeat it before it smacked into our atmosphere, raining down fire and destruction?

Image: Artist’s rendering of an asteroid’s view from the Kuiper Belt. Text: Killer Asteroids--3 ways to defeat asteroids and prevent Armageddon
Cover of November/December issue of Popular Mechanics magazine
Cover of November/December issue of Popular Mechanics

Astronomers, physicists and engineers have been watching for “planet-killing” asteroids and other space bodies and making plans for decades. I just finished reading the Space column in my November/December issue of Popular Mechanics by Jennifer Leman, titled “Could a Cosmic Lasso Divert Extinction-Level Asteroids?”

It’s a good read and I recommend you check it out. In the meantime, I was thinking of the 3 basic ways to defeat an asteroid, which can be found in discussions with scientists and also in Sci Fi film and literature: pound it, push it, or pull it.

1) Pound it

That’s right, pound the asteroid with missiles, nukes, bombs, whatever! Throw everything we have at it. Blow it up! So simple and easy, a 5-year-old could figure it out.

That is possible, but a “blown up” giant asteroid can be as dangerous, sometimes more dangerous, than an intact one. Consider a Mack truck rushing towards you at 100 miles per hour. If it hits you, you’re a pancake. But if I disassemble that Mack truck into its thousands of metal and plastic pieces, put them on a cart, and shove them at you at 100 miles per hour, the pieces are just as dangerous as the fully assembled Mack truck.

The point is that “blowing up” an asteroid does not change the overall mass of ice and rock. Unless the explosion threw most of that mass off its course with Earth, it would still be a devastating blow for life on Earth whether the asteroid was one solid piece, hundreds of one-ton pieces, or even a massive cloud of dust. In fact, sometimes pieces are worse.

Here’s what Jennifer Leman says on this topic in her Popular Mechanics piece:

“It’s risky to Hulk-smash an Earth-bound, extinction-level asteroid, though. ‘In general, when we move an asteroid, we want to keep it in one piece,’ says planetary astronomer . . . Andrew Rivkin, Ph.D., of Johns Hopkins Applied Physics Laboratory. The rock could break apart and create a wave of several smaller ‘city-killing’ asteroids instead.’ (This risk also applies to an Armageddon-style nuclear solution, we’re told–there are no plans to test a space nuke at this time.)”

Dust is also a problem.

According to killerasteroids.org, “to lead to a global catastrophe, an asteroid or comet only has to be big enough to launch large amounts of dust into the atmosphere. That leads to the abrupt change in climate that wipes out species.”

If an intact asteroid enters the atmosphere as one giant mass, hits the ground, and releases a giant cloud of dust, it’s bad. But if the remains of a blown-up asteroid hit the atmosphere as a giant cloud of dust, it’s still very bad.

2) Push it

In Arthur C. Clarke’s 1993 novel The Hammer of God, scientists on Earth in the year 2109 decide to use the “push it” method to divert an asteroid on a collision course with Earth. They send the spaceship Goliath to the asteroid with the “ATLAS propulsion module,” which is basically a super-powered rocket that uses nuclear fusion-powered thrusters.

Cover of The Hammer of God by Arthur C. Clarke
Cover of The Hammer of God by Arthur C. Clarke

Clarke explores several problems with this method, including the fact that asteroids are not designed by engineers to be pushed. Asteroids are random collections of metals, rocks, water ice and other ices. They can have soft spots.

After weeks of pushing the asteroid, the Goliath sinks a few meters into the asteroid and the ship is damaged. The Goliath ends up losing its fuel and is stranded on the asteroid. And the asteroid is still headed towards Earth!

On Earth, the scientists come up with a back-up plan to blow up the asteroid with nuclear weapons. That’s the “pound it” approach. That strategy does not turn out as expected, either. But I won’t spoil this Sci Fi classic for you. Check it out!

3) Pull it

I’m not a scientist, so to my simple mind this seems like a variation of “push it.” You need a rocket or some other method of propulsion. The only real difference seems to be how you attach the rocket to the asteroid. But is there an even better way?

According to Leman’s Popular Mechanics article, Flaviane Venditti at the Arecibo Observatory in Puerto Rico and other scientists are studying a “lasso” method that could pull a “killer asteroid” off course.

By tying another smaller asteroid to the “killer asteroid” with a long tether, you change the center of mass. Given time, that will change the asteroid’s trajectory. Even an asteroid only one-thousandth the size of the “killer asteroid” can divert the larger asteroid by millions of miles if the tether is long enough and the angle of the tether is right. This could require a strong tether that stretches for nearly 2,000 miles. (That may be a challenge for engineers to build, but so is a fusion rocket.)

Here’s another post where you can learn more about asteroids:

5 fascinating facts about Navy SEALs

Science fiction brims with space marines and special forces that fight hand-to-hand in space, on land, in the air, and in the sea. Some of these fictional warriors may be inspired by the U.S. Navy SEALs.

Image: Silhouette of U.S. Navy Seal arising from water revealing only the outline of his head, shoulders, and rifle.
Source: National Navy SEAL Museum

Here are 5 fascinating facts about U.S. Navy SEALs:

1. What does SEALs mean?

Their full name is United States Navy Sea, Air and Land Teams. The term “SEAL” comes from combining SEa, Air, and Land. As the name indicates, SEALs are trained to operate on and under the sea, in the air and on land.

They train to jump from planes and helicopters. They operate watercraft above and below the water. And they perform operations on land as well.

2. What do Navy SEALs do?

SEALs operate in small teams on special missions to capture or kill important enemies. (Here’s how the U.S. Navy describes it: “Carrying out small-unit, direct-action missions against military targets.”) SEAL Team Six killed Osama bin Laden in his compound in Pakistan in 2011. SEAL Teams also conduct very dangerous surveillance missions to spy on an enemy from behind enemy lines. Getting in and out of a foreign country or war zone without being detected is one of their key skills.

Want more fascinating facts about Navy SEALs? Of course, you do! Make sure to keep reading to Fascinating Fact No. 5 to learn about SEALS in space!

3. What is the SEAL motto?

SEAL team members are incredibly tough dudes, and their grueling training only makes them tougher, both physically and mentally. They have two mottoes:

The only easy day was yesterday.

It pays to be a winner.

4. What are some nicknames for U.S. Navy SEALs?

  • Frogmen
  • The Teams
  • The Men with Green Faces

The Navy SEALs earned the last nickname during their time in Vietnam in the 1960s. SEAL team members performed many special functions during the Vietnam War, including training South Vietnamese soldiers, interrupting enemy movements, and performing special operations to capture or kill key North Vietnamese Army personnel. During combat missions, the Navy SEALs wore camouflage paint and the Viet Cong began describing the mysterious, deadly enemy as “the men with green faces.”

5. Have any Navy SEALs been to space?

Yes! Three U.S. Navy SEAL team members have served as U.S. astronauts, showing that SEALs can conquer sea, air, land and space.

Bill Shepherd–The first SEAL in space, Capt. Shepherd is a legend among astronauts and SEALs. He commanded the first crew of the International Space Station. He was awarded the Congressional Space Medal of Honor.

Capt. Bill Shepherd
Bill Shepherd
Source: NASA and National Navy SEAL Museum

There is also a rumor that he will not confirm or deny, saying “it’s too good a story.” It’s said that NASA gave him a standard interview question, asking what he did best, and he answered, “Kill people with knives.” Of course, this is a vital skill for Navy SEAL team members and he should be very good at it, so the story certainly seems plausible.

Christopher Cassidy–Capt. Cassidy is in space right now! He is the commander of Expedition 63 aboard the International Space Station. He returns to Earth this Wednesday, October 21, 2020, after 6 months aboard the space station. Read here about the details planned for his departure from the space station and his return to Earth.

Capt. Christopher Cassidy
Christopher Cassidy
Source: NASA and National Navy SEAL Museum

Cassidy also flew on the space shuttle Endeavor and served on Expedition 35 on the space station. He has completed 6 spacewalks. In total, Cassidy has spent more than 31 hours in spacewalks. By the time he returns to Earth on Wednesday, he will have spent 378 days in space, giving him the fifth highest total among U.S. astronauts.

Watch this great video from Smarter Every Day on YouTube about SEALs who became astronauts, including a great interview with Cassidy.

Jonny Kim–Dr. Jonny Kim is the third SEAL selected by NASA for astronaut training. He completed more than 100 combat missions for the Navy and rose to the rank of lieutenant. After serving his country, he completed a degree in mathematics and then earned a Doctorate of Medicine at Harvard Medical School.

Dr. Jonny Kim
Jonny Kim
Source: NASA and National Navy SEAL Museum

But that was not enough achievement for Dr. Kim. He became an astronaut candidate in 2017 and has completed his two years of training. He serves in NASA’s Astronaut Office performing technical duties while awaiting flight assignment. While at NASA, he remains on active duty as a Navy lieutenant.

More fascinating facts about Navy SEALs

Navy SEALs have a long history with the U.S. space program dating back to the Gemini and Apollo space missions. To learn more fascinating facts about Navy SEALs, visit the National Navy SEAL Museum in Fort Pierce, Florida. Until you can make it in person, check out the museum website, starting with this section dedicated to the space program.

This is the first winner of the Matthew Cross Writing Contest!

Photo by Andreas Dress (unsplash.com/@andreasdress)

The winner of the Matthew Cross Flash Fiction Collaboration Contest is Frasier Armitage!


Frasier wins a $25 Amazon gift certificate and the narwhal amigurumi collectible shown below.

I received so many great entries, and I’ll share some more of them later this week. You can read some of my thoughts on why Frasier’s entry shone above all the rest. (It’s stellar!)

Photo of crocheted narwhal amigurumi, which is a prize for the contest, along with $25

October Contest: I’ll be announcing the October contest soon! (Probably next Monday.)

I started the story below, and see how seamlessly Frasier picked it up after the red line and gave it his own twist!

But this is Frasier’s moment, so enjoy the story!

Hello, Universe!

Jess leaned back in the blue, plastic Adirondack chair on the back deck.  It was a kids chair and he had almost outgrown it.  But it was the only chair that allowed him to tilt his head back to look at the stars.

Tunes from the 1960s purred from the outdoor speaker.  His Mom kept the family speakers on a steady rotation of “decades” music going back seventy years.

They lived in the suburbs.  With light pollution, Jess knew he wasn’t even seeing half the stars up there.  But this summer, with all the bad news online, he found himself escaping to the quiet of the back deck and looking at the starry sky.

In school, he had read about the Civil War and the Holocaust and the Civil Rights Movement and a bunch of other depressing stuff.  And then his grandfather had died.  Jess and his grandfather were not close, but everyone went to the funeral and everyone cried.  Even Jess cried.

Sometime that summer, Jess realized everyone else in his family would die.  Not anytime soon.  Probably not, anyway.  But, eventually, his parents would grow old and die.  And, eventually, Jess would also grow old and die.  And if he ever had kids, they would grow old and die.  Someday, everyone Jess knew would be dead.

It sucked.

Staring up at the night sky made him feel small and a little scared.  It never used to before.  But when he was little, he didn’t know how much empty space was really up there.  And how tiny the Earth really was.

Last week and the week before he had stared up at the stars.

Maybe, he had thought, it would be OK to die as long as I’m remembered.  Maybe I could get famous like Elvis or Beyonce.  So famous that no one would ever forget me.

Jess had thought about that for a couple of weeks.  He would have to be really famous to be remembered in two million years.  Like Hitler famous.  And he didn’t want to be evil.  He remembered seeing photos of the gas chambers and shuddered.

In two million years, the wind might even wear down the Great Pyramids and the even the pharaohs of Egypt would be forgotten.

Words floated from the speaker on the dark, night air.

Words are flowing out like

Endless rain into a paper cup

They slither wildly as they slip away across the universe

It was “Across the Universe” by the Beatles.  His Dad loved the Beatles.  All of the Beatles were dead.

Pools of sorrow, waves of joy

Are drifting through my opened mind

And that’s when the idea struck Jess.  He rummaged through the junk drawer and found a penlight.  He sat back in the kid-size Adirondack and shone the light into the sky.

Dad was an engineer and he knew lots of science.  He said light beams were made of photons.  In space, photons just keep traveling forever–travel at the speed of light, Dad said–unless they hit something. Like a planet or a star.

Jess sent the weak beam of light into space.  He clicked the light on and off.  If he knew Morse Code, he could send a message on a stream of photons into space.  And if that beam never ran into a star or a planet, it would travel forever.  Unlike the pyramids, it would never be worn down by wind or time.

The next day Jess bought a brand new flashlight–the most powerful one he could afford at the big box hardware store.  That night on the deck, he sent coded messages into space.  He looked up Morse code on his phone and shot off the messages in different directions into the sky.


I am here

My name is Jess

Im alive

I dont want to die

Never forget me

 . . .

Halfway through high school, Jess had learned enough about lasers to build his own high-powered laser from a kit.  He even got his Dad to help mount it on the roof.  Mom thought he was crazy, but Dad was into science stuff and thought it was a cool project.

Jess studied star charts and learned how to aim his laser using the computer in his room.  He sent coded messages into the night sky almost every night.  He aimed the laser into the empty stretches between stars, nebulae, and galaxies to give his messages the best chance of flying forever through space.

No human would ever see them.  Racing at the speed of light away from the Earth, no human could ever catch up with them to capture the light and decode it.

And what alien would ever know how to decode Morse code?  Or care to try?

But Jess knew that his coded messages racing through space would last longer than even the Earth itself.  Eventually, the sun would supernova and the Earth and the Moon and every human landmark in the Solar System would be absorbed, melted, obliterated.  But Jess’s small, silent, staggered rays of light would live on.


. . .

In college, he studied engineering and physics, trying to decide which way to go.  Both were incredibly tough.  Jess had programmed the computer in his bedroom at home to aim the roof-mounted laser at the emptiest reaches of space.  He had saved hundreds of different coded messages and each night, his computer sent the messages into space.

He was so busy at school, he forgot about the laser most of the time.  And, miracle of miracles, he finally had a girlfriend!

But when he came home on breaks, he checked the laser on the roof.  He cleared the dead leaves away, wiped the lens, applied another coat of water proofing.  He checked his sky maps and scheduled some new programs to run when he was away.  At night, sitting on the deck, he thought up new messages to send.


I am Jess

This message will outlast everyone

The pharaohs

The presidents

Taylor Swift


Remember me

Jess was not trying to reach anyone out there.  He never thought to try to look for replies to his messages.  Besides, detecting a laser reply from space would be quite a trick.  That would take more physics, engineering and money than he had.

So it was merely by luck that he was sitting on the back deck after graduation, drinking a beer and peering up into the sky, that he saw it.

A single star blinked a rhythm of dots and dashes, over and over, like ocean waves. Jess’s beer crashed on the deck, spilling between the planks. He scrambled for his phone and recorded a video, pointing to the heavens, and muttering the words that flickered in clumsy Morse.

Hi Jess

Its grandpa

Dont worry

Everything will be alright

Jess staggered backwards and flipped his camera. He garbled something about his grandfather’s funeral and uploaded it to the Web.

Twenty likes.

Fifty likes.

Three hundred.

Eight thousand.

Within ten minutes, more than a million views ticked across the screen.

Was this really happening?

All he could think about were the lyrics to that Beatles song, stuck on repeat.

Images of broken light
Which dance before me like a million eyes
They call me on and on across the universe

His phone shuddered. Unknown number.

Jai Guru Deva, Om
Nothing’s gonna change my world
Nothing’s gonna change my . . .


“Hello, is this Jess Dawson?” A voice sharp as gravel crunched down the earpiece.

“Who are you?”

“Name’s Grant Knox, FBI. We’re sending a chopper for you.”

In the distance, a low rumble carried across the sky. Jess shook his head. “A chopper? Why?”

“For your protection, Jess. We saw your video. Half the world’s seen it by now. You’ve no idea how long we’ve been trying to make contact.”

“Contact? With who?”

“You’d best pack some things. We need to get you secure.”

“What are you talking about?”

“You’re about to go down in history, Jess. People will be talking about this forever.”

“About what?” Jess looked at the sky. The flashing dots.

Dont worry

Everything will be alright

I hope you enjoyed this piece of flash fiction that Matthew and Frasier wrote together. It was a fun collaboration!

For more fun endings to this story, look for some honorable mention finalists in a separate blog post later this week. And next week, we’ll reveal the October Contest story beginning and the new prize!

Finally, if you enjoyed Frasier’s prize-winning ending, please make sure to share some kind comments below.

Be stellar!

Matthew Cross and Frasier Armitage