Deep Impact at Tempel 1: Nought But Dust?

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It seems that Deep Impact‘s impact may not have been as deep as first thought. Recent observations of target comet Tempel 1 show lots of fine powder in the impact plume, and not as much rock and ice as astronomers expected. This most likely means that not a lot of underground comet material was excavated by the collision, and some of our theories about cometary composition and structure will need to be revised.

Given funding and some careful planning, Deep Impact might have a new mission when it’s done with this one; JPL may retarget the craft at Comet 85P/Boethin, which, by the way, was discovered by a priest in the Philippines, Reverend Leo Boethin. With a gravitational assist from Earth, Deep Impact could be at 85P/Boethin by 2008.

Cassini Enceladus Flyby

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While recent manned spaceflight news has been somewhat disappointing, exciting things are still happening with robotic probes in deeper space.

Saturn probe Cassini did its closest pass yet at Enceladus yesterday, one of the stranger moons in the Saturn system. The bright white surface of Enceladus, mostly coated with clean water ice, is smoother and less cratered than most moons like it, with long rifts and valleys wrinkling its face. This would indicate recent geologic activity: tectonics caused by gravitational tidal forces from Saturn, wiping out impact craters and forming cracks and bumps. Enceladus also has a tenuous atmosphere, which might be caused by cryovolcanoes spewing material from underground, covering the moon’s surface with icy particles, and replenishing Saturn’s E ring with new material. This is all theory, of course: no volcanic plumes have been spotted on Cassini yet.

I’m watching the Enceladus Flyby page for updates, but there haven’t been any yet since the scheduled event yesterday. Maybe it was boring. More Enceladus photos by Cassini.

Also check out:

Also posted to Metafilter.

Discovery Launch Scrubbed

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America’s walk-on-eggshells return to manned spaceflight proved to be an anticlimactic disappointment yesterday, with the Space Shuttle Discovery’s launch being scrubbed due to faulty fuel sensors. (No, it was not the falling window cover that did it.) The sensors monitor propellant levels at the bottom of the external fuel tank during launch, signalling the need to shut off the enginges when they detect low levels of fuel. (Liquid hydrogen, in this case.) Engines normally shut off at a predetermined velocity in the launch process, but these fuel sensors act as an emergency backup to prevent the engines from continuing to burn without a continued supply of propellant, which would cause engine damage — a highly unlikely emergency situation, but a consideration important enought to warrant postponing the launch, it seems.

Next earliest possible opportunity for a launch will be Saturday afternoon, though that’s not looking likely. Update: Late next week at the earliest is now the current estimate. Countdown will have to restart at T-43 hours.

Follow the progress of this mission with SpaceflightNow’s STS-114 status page. More from NASA’s Return to Flight section, and Wikipedia’s STS-114 page.

See an overview of the whole space shuttle system in NASA’s Return to Flight section, and if you really feel geeky, go through the 1988 Space Shuttle News Reference Manual.

Shark Mask

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(Shark uploaded by brownpau.)

Amy took this photo of me in the Baltimore Aquarium Shop sometime in early 2004.

“Gloria Resign” Calls Intensifying: Edsa 4?

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(Continued from “Gloria Resign?”)

Gloria not resigning. Recent history continues to repeat itself in the Philippines: an embattled president dogged by scandal and corruption now faces — and refuses — intensifying calls to resign, with various opposition factions now massing in the streets to protest her defiance. She now faces impeachment, which, like the last impeachment, will prove to be more of a political than a factual exercise.

The way it’s going, however, it looks like the mob organizers aren’t even going to give Gloria the time that Edsa II gave Erap: they want her out now. The problem is, if you’re indignant with Gloria for her presidential indiscretions (as I am), and if you really want her out now, look at the people you’ll have to march alongside at Edsa-Timog and Ayala Avenue: Jinggoy and JV, Imee Marcos, far-left socialist groups like Akbayan, Ronald Lumbao. It’s no less distasteful associating with them than it is with the current incumbency.

From other Filipino news sources and weblogs:

Is it to be EDSA 4, then? The way this is going, they should probably institutionalize EDSA rallies as the established Constitutional mode of presidential transition. That way, they can have biennial marches in the streets to force the incumbent president to resign, then install the vice president, or whomever the revolutionaries are clamoring for at any given moment. Advantages: it’s perfectly in keeping with the Filipino “fiesta” spirit, and you won’t even need a COMELEC anymore, just a cleanup crew to pick up the mess on EDSA the next day. Someone pass a bill, and make that the aim of the next Con-Con!

Update: “The meter stopped running.” Heh heh.

Explosions in London

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Terror attacks in London. So far, three Underground trains and a bus have been bombed. It looks like BBC’s being very conservative with the casualty count, and is wisely avoiding the flurry of rumors which always follows an incident such as this. And speaking of rumors, a heretofore unkonwn Al Qaeda group has claimed responsibility.

Londoners, take care. More linkage as the news develops:

Reopened Washington Monument Grounds

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One more thing I did last Monday: As a followup to this, I checked out the reopened Washington Monument area.

The layout of the grounds is much improved over the somewhat haphazard arrangement of asphalt walkways that previously overlaid the area. A circumferential path, bordered on its inward side by the security wall, circles the foot of the hill, with curved paths ascending obliquely through the wall to the Monument, forming an overlapped figure-8 when seen from above. The plaza around the Monument itself — still fenced off to the public when I checked — is no longer paved with asphalt, but with much classier granite, and the standard short wooden benches have been replaced with long, white marble benches. Hopefully it’ll still be skate-friendly.

Here are a few panoramic photos: (Click the thumbs for the Flickr pages, and click ALL SIZES to see the full size panoramas)

(By the way, I do not recommend rollerblading around Washington, DC on the Fourth of July. It’s never a good idea to be on unsteady wheels on bumpy roads in a spot where about half a million tourists are converging. I passed through five different checkpoints and ran into any number of fences and Jersey barriers blocking my regular skating routes. If I’m still in DC next Fourth of July, I’m retreating to the peace of the Rock Creek Park forest trails.)

Update, 07/06/2005: I’ve just jogged down there and back, and the Monument plaza is now open. It’s a much wider circle around the base than it was before, and the new marble benches are great. Much more grandiose, but still friendly to tourists, bikers, and skaters. No pictures right now, though; I don’t normally bring my camera when I run.

Happy Fourth

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Happy Fourth!

My neighbor Scott very nicely shared his Fourth of July tickets to the Department of Labor roofdeck with a few of the neighbors, myself included. The conversation was engaging, the view was grand, the cannons were loud, and the fireworks were fabulous. Click the photos to see them full size:

(View from Department of Labor Roofdeck uploaded by brownpau.)

(Fireworks uploaded by brownpau.)

(Fireworks uploaded by brownpau.)

Full photoset of today’s Fourth of July here.