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Is There No End to Its Incessant Demands?

This image from NASA's Chandra X-ray Observatory shows the center of our Galaxy, with a supermassive black hole known as Sagittarius A* (Sgr A* for short) in the center. Using intermittent observations over several years, Chandra has detected X-ray flares about once a day from Sgr A*. The flares have also been seen in infrared data from ESO's Very Large Telescope in Chile. Click to embiggen.

How did I miss this story? Early in February, the folks working with the Chandra X-ray Observatory announced that they’ve been watching the black hole at the heart of the Milky Way Galaxy munching down on asteroids. According to them, this happens pretty frequently. They’ve seen the evidence: once-a-day x-ray flares from Sagittarius A* (that’s the name given to our central black hole), or Sgr A* for short. The flares last a few hours, and have also been seen in infrared light by detectors at the Very Large Telescope in Chile.

The idea is that there is a cloud around Sgr A* containing hundreds of trillions of asteroids and comets. Where did they come from? Astronomers suggest that this debris collection is made of material stripped from the parent stars by the force of gravity.

An asteroid that gets too close to another object, such as a star or planet, can get thrown into an orbit that places it on a heading for Sgr A*. If it gets too close — say within 100 million miles of the black hole (about the distance between Earth and the Sun) it would be torn into pieces as it encountered the tidal forces from the black hole. These fragments would be vaporized as they pass through the hot, thin gas that continually flows toward Sgr A*. This is very similar to what happens to a meteor when it encounters Earth’s atmosphere for example. It heats up and glows, and eventually it vaporizes, and we see a flare marking the end of the meteor’s trip. When an object does this near Sgr A*, we can see it in x-rays and infrared. Whatever’s left of the asteroid gets sucked into the black hole.

This is kind of a cool thing to see at an object so far away, and Chandra’s still on the case. Over the next year or so, the satellite will study more of these things that go “fuff” in the night near Sgr A*.

What You Should Know

I see that “big” media has picked up on the idea of solar storms, in the wake of two most recent and very strong X-class events on the Sun. The headlines are breathless and I’ve already spotted some science bloopers on some sites that should know better (sites that used to have good science reporters, but who let them go in order to concentrate on important things, like Snooki’s baby).

Anyway, for all news about solar activity, I first turn to Spaceweather.com. The folks there have noted the impact of the coronal mass ejection was light at first, but warn it could pick up in the coming hours. Thus, people who live at high latitudes — northern regions around 50 degrees north or more — should get to see even MORE auroral displays than usual. If the storms get strong enough, those of us at lower latitudes might get to glimpse some aurorae, too.

All this solar activity is actually pretty much on schedule for the Sun. It goes through cycles of high and low activity, and we’re headed into a time of very high activity called “solar maximum”. So, increased numbers of flares and coronal mass ejections and sunspots are part of this process. It’s perfectly normal and nothing to get worried about. But, there will be the big media reports, and there will be some fascinating whack jobs tying this to something mysterious and paranormal.

Check out MIT Haystack Observatory's Space Weather FX vodcasts at the link below!

That, too, is perfectly normal and nothing to get excited about.

Space weather, which is a term that covers all the solar-caused and geomagnetic disturbances that occur in near-Earth space, does have its down sides. While we gaze at lovely aurorae, giant disturbances in Earth’s uppermost atmospheric layers and nearby space can disrupt power grids, satellite communications, GPS signals, and many other bits of our modern technology. So, that IS of concern, and during such events you will read reports that warns of GPS outages or communications outages due to space weather (solar storms). This happens because these bits of technology rely on radio signals which bounce off the layers of our atmosphere in order to propagate (travel) long distances on our planet. In the case of GPS, those signals go THROUGH the atmosphere. So, if the upper atmosphere is disturbed by space weather, those signals can get broken up, delayed, or even lost. It’s an interesting and potentially dangerous side-effect of living near a star.

A while back we worked with MIT’s Haystack Observatory on a series of short videos about space weather. The series is called Space Weather FX. You can watch the whole series here and learn more about the effects that the Sun has on us and our technology. Also keep an eye on Spaceweather.com for the latest and most accurate info on solar activity.

The Spacewriter's Ramblings

Black Hole Munches Asteroids

Is There No End to Its Incessant Demands?

Solar Storm!

What You Should Know

Exploring Science and the Cosmos