MORE ASTRONOMY PICS 8/2015

This is Puppis A, a supernova remnant seen through a gap in a large foreground nebula, the Vela Super Nova Remnant. If you're a longtime reader of the astronomy posts here then you probably realize that this is not the way nova remnants are supposed to look.

Look how fragmented the red clouds are, as if they were torn to pieces by an angry giant. Not only that but the blue pieces of the cloud are long and fibrous, and the pieces are parallel...not the shape you'd expect in a conventional explosion. One of the red clouds on the right has a corkscrew shape. So what gives here? I don't know. 

Do you suppose there was one big explosion then ejected fragments blew up in secondary explosions the way some fireworks do? I'm probably wrong. 

For context, here's a much wider shot of the foreground cloud we were peeking through in the topmost photo. Look at the number of stars in the background. This is somewhere in the star-dense middle region of the galaxy. Stars are born and die quickly there.

It's a violent place with (I'm guessing) cumulative solar winds of an intensity that's hard to imagine. Maybe we should be surprised when any remnants have a normal shape in a rough neighborhood like this one.

Back in our neighborhood, here's (above) the familiar Crab Nebula, looking better than you've ever seen it before. The star that created it went nova in 1054 AD. When I was a kid a local science museum sold black and white glossies of this object and I bought one. It looked like a simple doughnut with slightly fuzzy edges and a star in the middle. Now,   with aid of the Hubble, it looks like an explosion in a cat fur warehouse.

The rapidly enlarging cloud is now 10 light years across.

Above, a color enhanced Pluto as seen by the New Horizons spacecraft in July. The probe is now headed for an asteroid in the Keiper Belt. It's a billion miles more remote than Pluto.

THE LATEST ASTRONOMY PICTURES

I never tire of looking at pictures of the Milky Way taken from the surface of the Earth. This one (above) was taken from Reunion Island in the Southern Indian Ocean. 

What we call the Milky Way is actually a spiral arm of our own galaxy which is closer to the galactic center than we are. 

One of the biggest fears of space scientists is that Earth might might one day find itself looking down the polar axis of a nearby star which is about to go supernova. Until now no star fit the description but one has recently been discovered and we appear to be looking right down the barrel of the gun. 

That star (possibly a double star) is Wolf-Rayett 104, about 8,000 light years distant. Sometime in the next million years this star (above) will explode and the remaining core will fire a massive gamma ray jet in our direction. We don't know enough yet to predict whether the jet will hit us directly or score a near miss.

It's unlikely but we can't rule out the possibility that the star has already exploded thousands of years ago and the gamma rays simply haven't arrived yet. They could be here tomorrow.

 Above. the rings of Neptune. 

Above, a heat map of the sky taken by the COBE satellite. It shows that one side of the sky is warm and another relatively cold. By measuring the difference scientists can calculate how fast the Earth is moving through the universe relative to the background radiation. Our speed it turns out, is an unexpected 600 kilometers per second. That's very fast. No one knows why we should be moving at that speed. 

What you see here (above) is a recent imrovement on the deep field picture we all saw on the news a couple of years ago.  These are some of the most distant stellar objects it's possible to see. The galaxies shown here are all very young, only a few hundred million years old. 

It's puzzling because you'd think that stars would form first then clump together into galaxies, but that doesn't seem to be the case here. Maybe stars were abundant but were too small for the Hubble to resolve, but it's also possible that galaxies of some sort precede stars.