Wednesday, December 01, 2010

Shrugging Off My Cosmology Guilt

Sometimes I put aside a link to an interesting website or a news story with the intention of writing something about it and doing a blog post but then I keep putting off the writing part for one reason or another. Then months can go by and I’ll have this web link or news story around day after day and I’ll feel guilty day after day for not writing something and it really starts to bug me.

I’ve got enough stuff to feel guilty about without feeling guilty about old news so I’m trying to stop putting stuff aside for more than a few days at a time.

So I’ve got one old news story that I’m going to link to today, and one recent news story that I’m going to link to just to get it up.

Someday I hope to come back to both of these news stories, but today I’m just looking forward to deleting these links from my folders of random stuff.

These are both astronomy stories, but they’re about two different astronomical ‘neighborhoods.’

This first story is about galactic space, and the motion of our solar system through our Milky Way galaxy. Scientists recently discovered that the galactic spiral arm our solar system is within has a stronger magnetic field than traditional thinking about astrophysics would predict. This has lots of interesting implications. First of all, there is a comparatively new astronomical paradigm built around plasma physics called the ‘electric universe’ which does expect strong magnetic fields throughout galactic space. Second, if a stronger than expected magnetic field in galactic space does turn out to be an indication that plasma physics plays a larger role than expected in astronomy there are a lot of other predictions the ‘electric universe’ paradigm makes that will be fun to look at in detail.

Holiday tidings come from NASA's Voyager 2 this week, offering a view of deep space beyond our sun's solar system.

Now speeding through space at more than 34,000 miles-per-hour, the 1977 space probe resides more than 8.3. billion miles away from the sun. That is twice as far as Pluto. Two years ago, Voyager 2 passed into the region of space where the sun's solar wind peters out as it plows into the interstellar gases of our Milky Way galaxy. And now it's giving us some news from this region, called the "heliosheath," by astrophysicists.

"This is a magic mission," says space scientist Merav Opher of George Mason University. in Fairfax, Va.. "After all these years, Voyager 2 is still working and sending us first hand (on-site) data."

Voyager 2's vantage, revealed in the Dec. 24 Nature journal in a study led by Opher and colleagues, shows that beyond the solar system, the galaxy's magnetic field is unexpectedly strong, about twice as much as expected, and unexpectedly tilted.


This second story is about solar system space. Astronomers and astrophysicists are always predicting what they suspect might be happening at the outer edge of the solar system. This is the latest prediction. Modern technology makes it possible to study the outer system like never before in history and it must be the greatest feeling in the world to be young and doing post-grad astrophysics work right now because there are a lot of discoveries to be made and lots of interesting mysteries to resolve.

A century of comet data suggests a dark, Jupiter-sized object is lurking at the solar system’s outer edge and hurling chunks of ice and dust toward Earth.

“We’ve accumulated 10 years’ more data, double the comets we viewed to test this hypothesis,” said planetary scientist John Matese of the University of Louisiana at Lafayette. “Only now should we be able to falsify or verify that you could have a Jupiter-mass object out there.”

In 1999, Matese and colleague Daniel Whitmire suggested the sun has a hidden companion that boots icy bodies from the Oort Cloud, a spherical haze of comets at the solar system’s fringes, into the inner solar system where we can see them.

In a new analysis of observations dating back to 1898, Matese and Whitmire confirm their original idea: About 20 percent of the comets visible from Earth were sent by a dark, distant planet.

This idea was a reaction to an earlier notion that a dim brown-dwarf or red-dwarf star, ominously dubbed Nemesis, has pummeled the Earth with deadly comet showers every 30 million years or so. Later research suggested that mass extinctions on Earth don’t line up with the Nemesis predictions, so many astronomers now think that object doesn’t exist.


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