TIME astronomy

Black Holes? I’ll Take a Medium, Please

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A mosaic image of the starburst galaxy Messier 82. NASA-ESA/AP

Scientists may have identified an intermediate-sized black hole for the very first time

In one sense, black holes are just ridiculously exotic. Their surface gravity is so powerful that even something as fast as light can’t escape (that’s why they’re black). And what’s actually inside a black hole isn’t just strange: it’s literally indescribable by any known law of physics.

But while they’re among the strangest things in the universe, they aren’t especially uncommon. Astronomers now know that black holes with the mass of millions or even billions of stars lurk at the cores of most galaxies, including the Milky Way, while much smaller black holes, containing just a few tens of stars’ worth of matter, are scattered all over the known universe.

In theory, there’s no reason intermediate-size black holes shouldn’t exist as well, with masses of a few hundred or a few thousand stars. But so far, despite some tantalizing hints, nobody has definitively found one. That may just have changed, however: a new report in Nature has flagged just such an object in the nearby galaxy Messier 82, which lies about 12 million light-years from Earth in the direction of the Big Dipper.

The black hole in question weighs about 400 times as much as the Sun, and is “just amazing” in the words of co-discoverer Richard Mushotzky, of the University of Maryland. That’s true for several reasons; the first is that this object, known as M82 X-1, has been known about for years because it shines brightly in the X-ray part of the electromagnetic spectrum. That marked it from the start as a candidate black hole, since these voracious cosmic vacuum cleaners suck in gas at such a prodigious rate that the infalling matter heats to the kinds of temperatures that generate X-rays.

Astronomers also knew from the brightness of those rays that M82 X-1 was most plausibly a black hole of intermediate mass–somewhere above 100 but less than a thousand solar masses. The problem: while astronomers know how a small black hole forms (it’s created when a massive star dies in a supernova explosion), it’s not clear how a black hole of more than 50 or so solar masses comes to be.

That put a premium on making sure they truly had the mass right, and lead author Dheeraj Pasham, a Maryland grad student, used a novel technique to figure out what that mass must be. Astronomers have noted that the X-rays from small black holes in the Milky Way pulsate with a characteristic rhythm that is a consequence of general relativity. “It’s kind of complicated,” Mushotzky says. “You don’t really want to know.”

The rate of the pulsations depends on the mass of the black hole, and by carefully analyzing observations from NASA’s Rossi X-Ray Timing Explorer satellite, Pasham was able to do that calculation with unprecedented precision. “It took a lot of work,” says Mushotzky. “It was not easy to do.”

But they did it, and Mushotzky says the resulting mass—428 times the mass of the sun, if you’re counting—is a reasonably precise figure. “I wouldn’t bet my house on it,” he says. “But I might bet my car.”

If that answer holds up, it could help solve a longstanding mystery of astrophysics. There’s no way a multi-million- or billion-solar-mass black hole could form directly. The giants that lie at the cores of galaxies must have built up over time, from small seeds. But if the seeds were only a few tens of Suns in mass, it’s hard to see how they could have grown quickly enough to reach full size by just a billion years after the Big Bang–which they nevertheless did.

A black hole like M82 X-1 would have given those giants a head start, however. So it’s tantalizing to wonder if this and other objects like it may be leftovers from the earliest days of the cosmos—the potential seeds of giant black holes that somehow failed to sprout, and which are still hanging around in their original form.

If so, they’re like living fossils from the earliest period of cosmic history. It’s an idea Mushotzky calls “highly speculative at this point.” But it’s also highly intriguing.

TIME astronomy

Now We Know How This Giant, Earth-Bound Asteroid Is Held Together, We Can Learn How to Destroy It

Asteroid entering Earth's atmosphere
Erik Simonsen—Getty Images

New discovery might help Earth avert a collision with a menacing asteroid with a 1 in 300 chance of hitting the planet in 2880

An asteroid pointed toward Earth set to arrive in the year 2880 AD may not destroy all life as we know it after all, now that scientists know what’s likely not to work if we need to avert a collision.

Scientists at the University of Tennessee have discovered new cohesive forces that hold giant asteroids together, called van der Waals, that have brought scientists closer to understanding destructive asteroids that threaten to hit Earth.

The discovery could rule out previous methods scientists have proposed for dealing with rogue asteroids.

Previous research has shown that asteroids, which are loose piles of rubble, are held together by gravity. But scientists have now found that some asteroids—like the massive 1950 DA, which could smash into Earth in 2880—are spinning too quickly and defy the force of gravity, and would simply fall apart were they not held together by other means.

“We found that 1950 DA is rotating faster than the breakup limit for its density,” said Ben Rozitis, a postdoctoral researcher at the University of Tennessee. “So if just gravity were holding this rubble pile together, as is generally assumed, it would fly apart. Therefore, interparticle cohesive forces must be holding it together.”

The presence of cohesive forces in massive, life-threatening asteroids means that colliding a large object against the incoming asteroid could actually worsen the impact’s effect, potentially destabilizing the cohesive forces keeping the asteroid together and breaking it into several large asteroids headed for Earth.

That means destroying incoming asteroids with rockets a la the 1979 video game Asteroids may be a no-go. No word yet on the Armageddon (1998) solution, which involved burying a massive nuclear warhead below the surface of the Asteroid.

The asteroid 1950 DA is believed to have a 1-in-300 chance of striking Earth in the year 2880. If it does, scientists believe it would wipe out life on Earth and cause tsunamis and mass extinction.

TIME astronomy

What the ‘Supermoon’ Looked Like Around the World

A 'supermoon,' resulting from a full moon that moves around the planet at the nearest approach of its orbit appearing more than one-tenth larger and one-third brighter, was visible on Sunday night. From Spain to China and New York to Athens, here's how it looked around the world

TIME astronomy

This Supermoon Hogs the Spotlight Sunday (Sorry, Perseid Meteors)

This weekend marks the year's most super-duper supermoon

+ READ ARTICLE

This is the summer of the supermoon, with three full moons in a row that appear bigger and brighter than normal. But this weekend marks the year’s most super-duper supermoon: When the moon rises on Sunday evening, it’ll be as close as a full moon ever gets to Earth during 2014.

Purists will protest: At its closest, the full moon is about 14 percent wider and 30 percent brighter than it is at its farthest. That difference is virtually impossible to perceive with the naked eye. It becomes noticeable only when you compare two photos of the full moon taken under the same conditions at different times of year…

Read the rest of the story from our partners at NBC News

TIME space

See the Supermoon from the International Space Station

The Supermoon captured from the International Space Station.
The Supermoon captured from the International Space Station. Alexander Gerst—NASA


Astronaut Alexander Gerst tweeted this amazing picture of the above-earth view of a supermoon early Monday, when the moon was still behind the horizon.

Gerst is a German astronaut aboard the International Space Station and among many astronauts using the social media site to share incredible pictures of the view from space. Gerst often uses the hashtag #bluedot, a nod to the iconic image of Earth taken from Saturn. And earlier in July, NASA astronaut Reid Wiseman tweeted above-earth images of Super Typhoon Neoguri. Three astronauts recently spoke to TIME about life above the earth, read their comments in this week’s issue.

TIME space travel

Photos: Life Aboard the International Space Station

Ahead of TIME's July 9 talk with the astronauts on board the International Space Station, take a look back at ISS Expedition 41.

TIME Science

A Star With a Not-So-Nice Nickname for Putin Won’t Have to Change

Russian President Vladimir Putin Addresses To Ambassadors Of Russia
Russian President Vladimir Putin Sasha Mordovets—Getty Images

Ukrainian astronomers basically called it "Putin is a d—khead"

It’s one small step for man, one giant leap for galactic name-calling.

Earlier this month, it was reported that a band of Ukrainian astronomers gave star KIC 9696936 the name “Putin-Huilo!” — a phrase which reportedly roughly translates into “Putin is a d—khead” — through the star-adoption service the Pale Blue Dot project, which lets anyone name one of those giant glowing balls of space plasma for a minimum $10 donation toward space research and education.

In an interview with the Moscow Times, the project’s founder says the stellar name, which has become something of a popular saying in Ukraine after Russia annexed Crimea, is staying put.

“Free speech is now written in the stars,” said Travis Metcalfe, who notes that the astronomers adopted the star well before the meaning of the name came to light. “We have no plans to censor any of these star adoptions.”

Putin himself hasn’t commented, but if he did, his response would probably go something like this.

[Moscow Times]

TIME astronomy

Millions of Stars May Be Made of Nothing But Metal

Handout of the evolving universe is shown in this composite of separate exposures taken in 2003 to 2012 with Hubble's Advanced Camera for Surveys and Wide Field Camera 3
A composite of separate exposures taken in 2003 to 2012 with Hubble's Advanced Camera for Surveys and Wide Field Camera 3 of the evolving universe is shown in this handout photo provided by NASA, June 3, 2014. NASA—Reuters

Astronomers have yet to find one, but until now they haven't been looking

An astronomer at the California Institute of Technology has discovered that some stars — maybe as many as 1 in 10,000 — are made entirely of metal.

It’s the latest finding in a series of eureka moments fueled by recent studies of turbulence, a term that scientifically refers to “certain complex and unpredictable motions.” To keep an immensely complicated subtopic of fluid mechanics simple: in turbulent environments, we can witness something called “preferential concentration,” or the tendency of denser particles to gather together in concentrated regions.

Scientists recently discovered that preferential concentration can explain how raindrops are formed — by denser water vapor particles coalescing. It’s similar with stars, except in their case it’s elements coalescing in turbulent gas clouds rather than water.

If the densest particles in gas clouds are metallic elements, and preferential concentration impels dense particles to gather together, then it logically follows, researchers say, that some stars — which, at the end of the day, are nothing more than matter held together by their own gravity — must be made entirely of metal.

Of course, astronomers have yet to find one of these stars, but before the Caltech team released its research late last month, they presumably didn’t have much of a reason to look for one.

TIME astronomy

Photos: It’s Always the Fourth of July in Space

Some of the universe's most stunning galaxies, nebulas and stars are colored like the American flag—and have been for billions of years

See the best red, white and blue photos from space to celebrate the Fourth of July.

TIME astronomy

The Ocean on Saturn’s Moon Is as Salty as the Dead Sea

Titan's ice shell is believed to cover a very salty ocean. NASA/JPL/SSI/Univ. of Arizona/G. Mitri/University of Nantes

The level of salt in Titan's ocean may mean we have to rethink the chance of present-day life on Saturn's largest moon.

Scientists say the ocean within Saturn’s largest moon may be as salty as the Dead Sea.

A new analysis of data from NASA’s Cassini spacecraft, which has been studying Saturn’s moon Titan for the last ten years, allowed researchers to create a model structure for Titan, including its icy shell and the ocean of water and other minerals that lies beneath.

Based on Titan’s gravity, they determined that the moon’s ocean must be relatively dense. That suggests it contains a large a portion of salts–likely composed of sulfur, sodium and potassium–on par with Earth’s saltiest bodies of waters. Sadly, no taste test was involved. The latest findings about Titan were published in this week’s edition of the journal Icarus.

“This is an extremely salty ocean by Earth standards,” the paper’s lead author, Giuseppe Mitri of the University of Nantes in France, said in a statement. “Knowing this may change the way we view this ocean as a possible abode for present-day life, but conditions might have been very different there in the past.”

 

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