Ira’s Ghost, Another Space Mystery …
Ever since my “Hanny’s Voorwerp” post I’ve had my eye open for more cosmic mysteries. There’s a fair number of them actually, I also covered the Axis of Evil and Dark Flow as well. And there’s many more to be found no doubt. The Universe is a big place, and the Hubble Telescope has only examined a tiny tiny amount of it in detail. Just like in any photography, long exposures are needed to take pictures of very faint objects, and some of the things Hubble has photographed are very far away dim objects indeed. Then when one realizes that visible light is just a tiny part of the picture, and, well, we will be finding new things in the Universe for decades or centuries to come. Yes, an age of exploration that will last for centuries at the very least, and forever if we start to venture forth among the stars. In fact we better venture forth to the stars or we face extinction according to Steven Hawking. Of course he previously warned us about the dangers of running into hostile aliens, so if I understand this right, according to Steven Hawking, we’re damned if we do and damned if we don’t. I don’t like the sound of that at all.
Moving right along, Ira’s Ghost. (nebula IRAS 05437+2502) Imaged above, a refection nebula in the constellation Taurus. I’m not sure exactly how far away it is, but it is inside our galaxy. It’s a very small faint nebula, and only got photographed because it got lucky, there was some spare time on the Hubble and this was on the list of “bonus” targets. A nebula means it’s a cloud of gas, and a reflection nebula means it is lit up by some external source of light. This is opposed to an emission nebula that is glowing of its own accord. It may look like thick gas too, but in actuality it’s not. The gas in a typical nebula is about 100 to 10,000 particles per cubic centimetre. The Earth’s atmosphere contains 2.5 × 1019 particles per cubic centimetre. In other words we call it a gas, but for all practical purposes a nebula is just a slightly dirty vacuum. Granted brand new planetary nebulae have higher densities, but still nowhere near the density of gas in Earth’s atmosphere. Still this is the stuff from which stars were made, in fact every atom in our bodies was once part of nebula in space billions of years ago. Yes, we’ve all been galactic tourists so to speak. Maybe that’s behind our drive to explore space … we’re homesick on an atomic level.
So what’s the mystery? It’s just a pile of dust in space glowing by reflected light. There’s thousands of reflection nebula in the galaxy, why is this one mysterious? It’s mysterious because we don’t know what is illuminating this dust! The bright arc near the top is especially mysterious, there should be a bright star (or something!) nearby lighting it up … but there isn’t. Kinda like the situation with the aforementioned Hanny’s Voorwerp, though that’s a vastly larger object.
Fortunately scientists have a theory. They’re good that way, scientists are always coming up with a helpful theory. In this case scientists hypothesize that there was a massive star lighting up the nebula that somehow attained a high velocity and left the nebula. Brilliant. OK, I’m being unfair here for artistic licence. It is however both a singularly obvious theory … and one that poses as many questions as it answers. Theories like that are a good place to start, but not really bringing us any closer to a solution. Will scientists ever solve this mystery? Maybe. As astronomical mysteries go though, this one is kind of unimportant in the greater scheme of things. Solving it would likely require more Hubble time, and the Hubble is booked solid so to speak.
No real lessons or insight here. Just one of many examples that there’s all sorts of stuff out there that we don’t understand. And likely always will be, one of the things that gets me most excited about space exploration is that we are always finding things that no one ever dreamt of. One looks back at humanity’s SciFi the truth of it is, it’s been pretty unimaginative when it comes right down to it. Simply humans projecting their own selves and viewpoints on the Universe. Like say a recently very popular movie involving smurfs on steroids. A Bat Durston if there ever was was.
(I believe the image above is Public Domain under all sorts of copyright laws as it it was put together by a variety of government agencies. And it’s not being used for profit or to endorse any product. Credit: ESA, Hubble, R. Sahai (JPL), NASA My next post is going to be about another space mystery, or very bad things in Afghanistan. Reader’s choice.)