Large quasars can eat a hole in a galaxy
They send out bursts of deadly radiation
A quasar's beauty comes from energy released when a black hole crushes matter around it
Our solar system would quickly be destroyed by one
Breathtaking blossoms nearly the size of our solar system are strewn across the universe – hundreds of thousands of them. Quasars are, at the same time, among the most fiery monsters.
Astronomer Maarten Schmidt was the first to discover one and revealed it to the world 50 years ago Saturday in an article in the journal Nature.
His discovery was a sensation in the 1960s and made its way into pop culture. It was the age of the first manned space flights.
“It reverberated,” Schmidt recalls. “It drew a lot of attention.”
In the popular TV series Star Trek, the original crew of the Starship Enterprise was tasked with inspecting the newly discovered phenomenon close up.
Electronics company Motorola branded a line of televisions Quasar. A decade later Marvel Comics created a superhero with the same name.
Luckily, no quasar is anywhere close to Earth, said Schmidt, who made the discovery at the California Institute of Technology in Pasadena.
If so, “we would all be dead.” It would cook the Earth’s surface with massive bursts of radiation called gamma rays, he said.
Then, if it were close enough, the quasar would devour our planet, our sun, the whole solar system, in a matter of months, Schmidt said.
The largest ones can eat a hole out of the center of a galaxy. Then their vast gravitational pull makes the rest of the galaxy orbit around it.
‘Supermassive’ black hole
Quasars have at their core a “supermassive” black hole, which contains as much matter as a billion suns. A typical black hole contains as much as about 10 suns.
The “supermassive” black hole sucks in and crushes any material that comes near it – whole stars and planets, Schmidt said.
In the process, the material glows infinitely hot and forms a very bright, colorful disc.
That disc, called an accretion disc, often covers an area almost the size of our solar system.
It’s what gives a quasar its luminous beauty. “That disc then is brighter than … a whole galaxy,” Schmidt said.
Quasars also shoot off beams called “jets” reminiscent of phaser fire coming from the Starship Enterprise. Jets are made up of subatomic particles racing away from the quasar nearly at the speed of light.
We don’t want our planet to get shot by one.
“I think that would be indeed destructive,” Schmidt said.
For decades, astronomers mistook quasars for stars in our own galaxy, but Schmidt took measurements that showed that they are infinitely distant – billions of light years away.
To still be visible to a telescope on Earth, he figured out that they had to be infinitely bright as well. “It looked like a star, yet it was more luminous than a whole galaxy.”
A lifetime of star gazing
Schmidt has been hooked on star gazing since childhood.
“I was a school boy in Holland, and during World War II,” he said. There were constant blackouts, leaving cities pitch black at night. The stars shown more brightly than ever before.
His uncle had a telescope and showed Schmidt heavenly bodies close up.
“Soon I built myself a small telescope and it sort of took off from there,” Schmidt said.
And at 84, he still gazes out many billions of light years into the universe to find new quasars.
Their vast distance from us is what makes them particularly interesting.
Because they are so far away, by the time their images traverse the universe at the speed of light and arrive here for Schmidt to see them, more time has passed than the Earth and the sun are old.
Often, he is looking at something that happened 10 billion years ago – in a universe that scientists believe to be 13 billion years old. The quasars provide him a view on the history of the universe.
So much time has passed, that the quasars no longer even exist anymore. In fact, they’ve been dying out handily, he said.
“10 billion years ago there were 100 times as many quasars in the universe as there are now,” Schmidt said. It shows how massively the universe has evolved.
After all this time, Schmidt still has a child’s fascination for the heavens.
“I certainly enjoy going to the desert and just seeing the sky from a dark location,” he said. “It is a joy to me.”
He leaves the telescope at home and stares into the endless night sky with the naked eye.
And still, he often sees something he’s never noticed before.