Milky Way’s Black Hole Munches On Supercooked Gas

It’s a simple menu, but smoking hot. The black hole at the center of the Milky Way galaxy is sucking in ultra-hot molecular gas, as seen through the eyes of the Herschel space telescope.

“The biggest surprise was quite how hot the molecular gas in the innermost central region of the galaxy gets. At least some of it is around 1000ºC [1832º F], much hotter than typical interstellar clouds, which are usually only a few tens of degrees above the –273ºC [-460ºF] of absolute zero,” stated the European Space Agency.

Herschel, which is out of coolant and winding down its scientific operations, will continue producing results in the next few years as scientists crunch the results. The telescope has found a bunch of basic molecules in the Milky Way that include water vapour and carbon monoxide, and has been engaged in looking to learn more about the gas that surrounds the massive black hole at our galaxy’s center.

In a region called Sagittarius* (Sgr A*), this huge black hole — four million times the mass of the sun — is thankfully a safe distance from Earth. It’s 26,000 light years away from the solar system.

At left, ionized gas in the galaxy as seen in radio wavelengths; at right, the spectrum at the center seen by Herschel. Credit: Radio-wavelength image: National Radio Astronomy Observatory/Very Large Array (courtesy of C. Lang); spectrum: ESA/Herschel/PACS & SPIRE/J.R. Goicoechea et al. (2013).
At left, ionized gas in the galaxy as seen in radio wavelengths; at right, the spectrum at the center seen by Herschel. Credit: Radio-wavelength image: National Radio Astronomy Observatory/Very Large Array (courtesy of C. Lang); spectrum: ESA/Herschel/PACS & SPIRE/J.R. Goicoechea et al. (2013).

Trouble is, there’s a heckuva lot of dust blocking our view to the center of the galaxy. Herschel got around that problem by taking pictures in the far-infrared, seeking heat signatures that can bely intense activity in and around the black hole.

“Herschel has resolved the far-infrared emission within just 1 light-year of the black hole, making it possible for the first time at these wavelengths to separate emission due to the central cavity from that of the surrounding dense molecular disc,” stated Javier Goicoechea of the Centro de Astrobiología, Spain, lead author of a paper reporting the results.

The science team supposes that there are strong shocks within the gas (which is magnetized) that help turn up the heat. The shocks could occur when gas clouds butt up against each other, or material shoots out Fast and Furious-style between stars and protostars (young stars.)

“The observations are also consistent with streamers of hot gas speeding towards Sgr A*, falling towards the very center of the galaxy,” stated Goicoechea. “Our galaxy’s black hole may be cooking its dinner right in front of Herschel’s eyes.”

Source: ESA

Experts Urge Removal of Space Debris From Orbit

Action is needed soon to remove the largest pieces of space debris from orbit before the amount of junk destroys massive amounts of critical space infrastructure, according to a panel at the Sixth European Conference on Space Debris.

“Whatever we are going to do, whatever we have to do, is an expensive solution,” said Heiner Klinkrad, head of the European Space Agency space debris office, in a panel this week that was broadcast on ESA’s website.

“We have to compare the costs to solving the problem in an early stage as opposed to losing the infrastructure in orbit in the not-too-distant future.”

The panel estimated that there is $1.3 billion (1 billion Euros) worth of space satellite infrastructure that must be protected. The 200 most crucial satellites identified by the space community have an insured value of $169.5 million (130 million Euros), Klinkrad added.

Critical infrastructure, though not specified exactly by the panel, can include communication satellites and military eyes in the sky. Also at risk is that largest of human outposts in space — the International Space Station.

A view of the International Space Station as seen by the last departing space shuttle crew, STS-135. Credit: NASA
A view of the International Space Station as seen by the last departing space shuttle crew, STS-135. Credit: NASA

The conference concluded that without further action — even without launching any new rockets — it’s quite possible there could be a runaway effect of collisions producing debris within a few decades. Even a tiny object could act like a hand grenade in orbit if it smashes into a satellite, Klinkrad said.

A recent example of the problem: a piece of Chinese space debris smashed into a Russian satellite in March. It didn’t destroy the satellite, but altered its orbit.

To mitigate the situation, representatives suggested removing 5 to 10 large pieces of debris every year. They added they are uncertain about how soon a large problem would occur, but noted that the number of small objects is definitively increasing annually according to measurements done by the Walter Baade 6.5-meter Magellan Telescope.

“[It’s] something we haven’t know until now. We have been suspecting it is the case … this is a new result which is very important.”

While highlighting the risk, the European representatives of the panel added they are not standing idly by. Already, there are regulatory changes that could slow the problem for future launches — although there still will be cleanup to do from five past decades of space exploration.

Artist's conception of DEOS (German orbital servicing mission). Credit: Astrium
Artist’s conception of DEOS (German orbital servicing mission). Credit: Astrium

A few of the points brought up:

– German officials are working on an in-orbit satellite servicing solution called DEOS. “The DEOS project will for the first time demonstrate technologies for the controlled in-orbit disposal of a defective satellite,” Astrium, the prime contractor for the definition phase, wrote in a press release in 2012. “In addition, DEOS will practice how to complete maintenance tasks – refuelling in particular – that extend the service life of satellites.”

– France’s Parliament passed the Space Operations Act in December 2010. “Its chief objective is to ensure that the technical risks associated with space activities are properly mitigated, without compromising private contractors’ competitiveness,” French space agency CNES wrote on its website. “The government provides a financial guarantee to compensate damages to people, property or the environment.”

– A United Nations subcommittee of the Committee on the Peaceful Uses of Outer Space is working on space sustainability guidelines that will include space debris and space operations practices. More details should be released in June, although Claudio Portelli (a representative from Italy’s space agency) warned he did not expect any debris removal proposals to emerge from this work.

For more technical details on the space debris problem, check out the webcast of the ESA space debris conference.