Asteroid Apophis Just Got Bigger 182
astroengine writes "As the potentially hazardous asteroid makes closest approach to Earth today, astronomers using the European Herschel Space Observatory have announced something a little unsettling: asteroid 99942 Apophis is actually bigger than we thought. Herschel astronomers have deduced that Apophis is 1,066 feet (325 meters) wide. That's 20 percent larger than the previous estimate of 885 feet (270 meters). 'The 20 percent increase in diameter, from 270 to 325 m, translates into a 75 percent increase in our estimates of the asteroid's volume or mass,' said Thomas Müller of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, and lead scientist of the study. In addition, the space telescope has re-analyzed the albedo of the space rock, providing a valuable heat map of the object's surface — data that will improve orbital trajectory models."
SG-1 (Score:4, Insightful)
Re:So... (Score:5, Insightful)
No, the chances we are all going to die are still 100%. The only question is when.
Re:2029 approach (Score:1, Insightful)
indeed, it's not until the 2029 pass whether we'll know if it will hit the earth or not in 2036. the current probabilities are nonsense and mean nothing. The real probability is either 0 or 100%.
1 Earth Diameter Close Pass (Score:5, Insightful)
"In April 2029 the space rock will still make a very close pass with our planet, coming within 22,364 miles"
Being the skeptical engineer, I would say there is also a chance that on its multihundred million mile trip over the next decade and a half all it would take to nudge the orbit a slight amount to make the close pass a hit would be an encounter with another large object that affected its orbit ever so slightly...the wrong way.
That orbital perturbation is random & would simply not be predictable.
Re:1 Earth Diameter Close Pass (Score:5, Insightful)
That orbital perturbation is random & would simply not be predictable.
Not exactly. It's passing by earth again in another 15 years or so -- and its orbit has to pass through a very small space in order for Earth's gravity to alter it just that tiny smidge so that over the following 15 years, that few thousands of a degree change due to gravitational pull will close that 22,364 mile gap. It has to be spot on -- if the vector is even slightly off, it'll either get slingshot out of the solar system (or into one of the outer planets), or into the Sun.
While you're right that the energy required to move the asteroid into a collision path is low, it has to be the precise amount, and at the precise vector. A random preturbation has a very low chance of being at both the correct energy level, and at the correct vector. And even many such random preturbations still wouldn't alter the orbit enough that if we looked for it on its next approach in a very narrow region of the sky, we couldn't find it. Which means we'll know its coming, and we'll have several years' warning to take action. I just hope they can clone Bruce Willis before then.
Re:Apophis larger than we thought (Score:4, Insightful)
The big problem with Stargate: Universe was the plot induced stupidity in the characters. They were clearly trying to emulate the grim, gritty BSG which had plenty of its own plot-induced stupidity. Trouble is, it gets hard to ignore it when the plot-induced stupidity railroads the characters to irredeemable actions. There were plenty of these. Certainly enough that several main characters should have been relieved of all authority and locked up for the whole trip. The one that got to me the most was when there was a character trapped by the legs after a shuttle crash and, at his request, the commander suffocates him to death. I think euthanasia may be appropriate in certain situations, but not when you can put the minds of a couple of expert trauma surgeons into some of the crew and just cut the patients legs off, or waste some explosives to try and remove the debris, or send the ships robot down to the surface to move the debris, or any of a dozen ideas better than just having a few soldiers try to muscle the debris off. When a patient is in extreme chronic pain that can't be stopped and will last for the rest of their life and begs to die, it's time to consider euthensia. When a patient is in transitory pain, no matter how extreme, but has excellent prospects for survival without pain, you simply shouldn't consider their requests since they're not in their right minds. That kind of nonsense, leaving you with no choice but to either pretend big chunks of the show didn't happen or hate some of the main characters, tends to wreck a show.
Sort of reminds of the first and only episode of Star Trek: Enterprise I watched. It was titled "Dear Doctor". In it, the captain and the ships doctor have a cure for an illness that's killing off the population of a planet who they've agreed to help. They decide, based on some crazy nazi-style eugenics destiny argument (with allusions to the not yet established Prime Directive), that the population is destined to die off in favor of another intelligent species that lives on the planet with them. So they withhold the cure as the "ethical" thing to do, but still present them with a partial treatment, then go on their merry way.
Generally speaking, I don't have a problem with fiction with characters that morally flawed. Humans are often morally flawed. The problem is when the fictional treatment also puts these criminally incompetent characters on a pedestal.
Re:IMPORTANT QUESTION... apk (Score:4, Insightful)
Simulations of nuclear weapons vs. asteroids typically show that the nukes mostly just heat the asteroid up. In space, there's no atmosphere to superheat into an airburst, so a nuclear explosion consists of the vaporised remains of the bomb and the delivery vehicle and a lot of radiation. At the speeds involved, there's only about a 50 millisecond window to even detonate a nuke near enough to an asteroid that's approaching us for it to have any effect. Even if the timing is just right, a maximum of 50% of the energy of the nuke is going to hit the asteroid, and it's really going to be more like 10%. As has been mentioned, we pretty much have to hit the asteroid on approach, because it's going to be a lot harder to catch up to while it's moving away. If we do manage to blow it up, then we go from one large body travelling in a fairly predictable path to a number of objects of varying size travelling on less predictable paths, so if it's not going to hit us, we're better off not blowing it into pieces that might hit us. Also, we might have a lot of nuclear warheads, but we don't have anywhere near as many rockets capable of getting the payload to the asteroid. Nuking it might be cathartic, but there are a lot of problems with the idea.