Category Archives: Space Science

A New Earth?

I’ve been told by someone at NSF that there may be an announcement today of an extrasolar “earth-like” planet (in terms of mass) at 1 PM. We’ll keep an eye out.

[Update at 11:30 AM EDT]

Here’s a link to a webcast on it, coming up in an hour and a half. The person who notified me of this writes:

“I believe, based on the level of media they’re expecting that it will be an earth-size and mass planet outside of the solar system.

Let’s keep our fingers crossed.”

[Update at 2 PM]

OK, it’s “more earth like than anything previously found,” but still not that earth like. It masses several times as much as the earth, at a distance of only a couple million miles from its star, with a year of only two earth days. Sounds more like a large “Mercury-like” planet.

Best.Saturn.Ever

Alan Boyle has the story.

Cassini has been delivering spectacular results, and we can continue to look forward to much more (barring technical disaster, or a collision with a ring particle). I remember when I was in college, and we were just starting to anticipate the pictures that would be coming in from Voyager in a few years. Today, I suspect that most young people take this kind of imagery for granted. It’s just part of the background tapestry of twenty-first century life, like powerful desktop computers, iPods, and affordable air fares.

A Bust

That’s what the eclipse is in Boca Raton. Just as it was starting to really happen, it shyly hid behind a thick cloud, and has yet to emerge.

[Thursday morning update]

It wasn’t a total bust. We got some breaks in the clouds during totality. Our biggest problem was staying up late enough. We gave it up about 11:30, while it was still fully in the umbra. It was a beautiful for a while, though.

Interesting results from cluster spacecraft

Recent results from Cluster shed some light on the mechanism that brings particles from the solar wind into the Earth’s magnetosphere, creating the Aurora and radiation belts. The basic mechanism is vortices generated in the sheared flow region between the magnetosphere and the solar wind. The mechanism behind the vortices is called the Kelvin-Helmholtz instability, and it’s fairly generic to low velocity sheared flows, as the discussed in the article.

The same mechanism will affect any craft powered by mini-magnetospheric plasma propulsion (M2P2), but the particle transport will be the other way – from inside the magnetic bubble to outside (since the inner particle density will be higher than the solar wind particle density, at least in the tail region). This will cause loss of ions from the bubble, and may turn out to be the limiting factor for M2P2.

There is a nice picture of Kelvin-Helmholtz waves in the Earth’s atmosphere here.