Saw this article on Discover.com earlier this month and thought it was really interesting: The Solar System’s Lost Planet.
Nesvorny, who runs computer simulations to study how the solar system evolved over time, kept encountering the same problem: The four giant gas planets, whose orbits are comfortably far apart from each other today, kept violently jostling with each other in his models of the early solar system. Jupiter would end up tugging on Uranus or Neptune and casting one of them out into interstellar space. Obviously, that never happened. So Nesvorny came up with a clever explanation: He proposed that a fifth gas giant emerged from the planet-birthing cloud 4.5 billion years ago. Suddenly his simulations started matching reality. The outer planets still jockeyed for position, but this time Jupiter spared Uranus and Neptune and ejected the extra planet instead.
Not that we’d ever be able to know if this is correct (probably), but it certainly sounds logical. I just hope the Planet X/Nibiru nuts don’t jump all over this as proof of pending doom.
I realized I missed posting in April entirely(!), and I don’t like the look of the gap in the archive calendar, so I’m back-dating this entry.
And you need to check this out, a Flash-animated Scale of the Universe that is simply mind-boggling. From the smallest structures known (quantum foam, the Planck length) to the largest (the size of the observable universe), that you can zoom in and out on, and it’s all to scale (relative to the zoom level). The coolest thing I’ve seen online lately.
Tomorrow, April 12th, is a pretty momentous date: it is the 50th anniversary of the first human being to launch into space (which took place on April 12, 1961) by Russian Cosmonaut Yuri Gagarin. Appropriately enough, the 12th is also when Yuri’s Night is celebrated, a sort of unofficial holiday “world space party” that commemorates that first flight.
As someone who grew up with a deep interest in space and astronomy (not to mention science and science fiction) I love the idea of Yuri’s Night and I love what the website is doing: presenting a registry of events that are taking place around the world for the event, and letting people register more at no cost. Mostly it seems entirely fitting to celebrate the occasion; it would be neat to have a Yuri’s Night event here in Bend, but it seems the nearest is Portland.
50 years of manned spaceflight. That’s something to think about.
The February issue of Discover Magazine has an interesting article about Project Orion: a project that was developed during the ’50s and ’60s to build a spaceship that was as big as a skyscraper, weighed eight million pounds, and was propelled by—get this—nuclear bombs.
While Discover’s article was good, focusing more on the people and policies involved, Wikipedia’s Project Orion page is excellent, and delves much more into the hard science. It sounds on the one hand totally insane and on the other hand perfectly logical and obvious. But you gotta wonder at the audacity of a design that would have required 800 (or more) nuclear explosions just to lift the ship into Earth orbit 300 miles up…
Interestingly, an Orion ship is a major plot point in one of my all-time favorite science fiction books, Footfall by Larry Niven and Jerry Pournelle. A great book, probably the best alien invasion story out there, period—Niven and Pournelle simply rock. What else can I say? I totally recommend it. It would make a perfect movie, done right, but if nothing else, read the book.
One for the weekend: tomorrow, July 31, (er, rather, today now I guess) is a blue moon. One definition of it, anyway. Enjoy!
Forgot to point to this the other day: Opportunity finds evidence of water in Mars’ past. Probably you’ve all heard this by now, but it’s still incredible.
“Liquid water once flowed through these rocks. It changed their texture, and it changed their chemistry,” said Dr. Steve Squyres of Cornell University, Ithaca, N.Y., principal investigator for the science instruments on Opportunity and its twin, Spirit. “We’ve been able to read the tell-tale clues the water left behind, giving us confidence in that conclusion,” he said.
In case you live in a cave somewhere and don’t look up into the night sky, there was a total lunar eclipse tonight. Unfortunately, here on the west coast we missed most of the show; by the time the moon rose over the cloudy horizon, it was just past totality and starting to emerge from the Earth’s shadow.
Still totally cool.
Took some pictures with our digital camera, on the night mode setting. This is about the best one, I think:
click to view larger image
Pretty neat, eh?