Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 



Forgot your password?
typodupeerror
×

Submission + - How astronauts took the most important photo in space history

The Bad Astronomer writes: On December 24, 1968, the Apollo 8 astronauts saw the Earth rising over the limb of the Moon. The photo they took of this moment — dubbed Earthrise —has become an icon of our need to explore, and to protect our home world. NASA has just released a video explaining how the astronauts were able to capture this unique moment, which included a dash of both coincidence and fast teamwork.

Comment headline isn't quite correct (Score 5, Informative) 129

The headline as submitted isn't really correct. The planet is not the biggest found; there are several whose mass may be larger, like the exoplanets announced just last week (and this planet has 11 times the mass of Jupiter; we don't know its actual size). The real issue with HD 106906 b is that it is so far out from its parent star, much farther out than planets with that ass should form. Either it formed farther in and got tossed out (which is unlikely) or it formed where it was, which current theories say is difficult; usually objects forming that far out have much higher mass. I explain all this in my own blog post about it.

Submission + - Three new exoplanets seen in direct photographs

The Bad Astronomer writes: Planets orbiting other stars are usually found indirectly (by blocking their stars' light or inducing a Doppler shift in the light as they orbit, for example), but direct images of exoplanets are extremely rare. However, using the 10-meter Keck telescope in Hawaii, astronomers have taken photographs of three nearby exoplanets, all young, massive, and hot. One may be massive enough to count as a brown dwarf, but the other two are more likely in the planet-mass range. All three are very far from their stars, which means they may have formed differently than the planets in our solar system.

Comment Re:They should upgrade the warning ... (Score 1) 526

The difference is that the batteries can ignite without an external heat source.

That doesn't necessarily make them more dangerous. I have a friend who lost a home to a fire that started in the engine compartment of a car in the garage. It was probably a leaky fuel line dripping onto a hot engine component. In your reconing is that an internal or an external heat source? Of order half a dozen car fires happen during a typical commute day on SF bay area freeways, and that's not counting the fires that start because of collisions.

It doesn't seem that likely that Teslas are any more fire prone than any other car. The rates for gasoline cars have about one serious (i.e. reported to police) fire per 18 million miles. If the average car goes 180K miles, that's about 1% that go up in flames at some point. The average Tesla hasn't gone that far, and I don't know what the fleet mileage is, but I'll be surprised if they are that flammable.

Submission + - Chelyabinsk-sized asteroid impacts may be more common than we thought

The Bad Astronomer writes: Using data from the Feb. 15, 2013 asteroid impact over Russia, scientists have determined that we may be hit by objects in this size range (10 — 50 meters across) more often than we previously thought, something like once every 20 years. They also found the Chelyabinsk asteroid was likely a single rock about 19 meters (60 feet) across, had a mass of 12,000 tons, and was criss-crossed with internal fractures which aided in its breakup as it rammed through the Earth's atmosphere.

Submission + - One in five Sun-like stars may have an Earth-like planet

The Bad Astronomer writes: A new study, looking at over 40,000 stars viewed by the Kepler spacecraft, indicates that 22% of stars like the Sun should have Earth-like planets orbiting them — planets that are similar in size to our home world and with a surface temperature hospitable for liquid water. There are some caveats (they don't include atmospheric issues like the greenhouse effect, which may reduce the overall number, or at cooler stars where there may be many more such planets) but their numbers indicate there could be several billion planets similar to Earth in the Milky Way alone.

Comment Math. Sigh. (Score 5, Informative) 142

Folks- Please note a couple of math errors in the article (and in the headline I submitted here at /.). 1) The chance of it missing is 99.998%, and not 99.99998%. I misplaced a parenthesis when I did the math and wound up essentially getting 100 - 1/63000 instead of 1 - 1/63000. D'oh. 2) Also, the original circle I drew in the article was too big. This one makes me smile wryly: I first drew up the analogy as the circular cross-sectional area of a target region in space versus the cross-section of the Earth. Both are circles. However, a pixel is square! So my circle was too wide by a factor of the square root of pi, since the radius of the circle is the sqrt(area/pi). Put in 63,000 pixels for the area and the radius is 141. I corrected the article, sent a note to TPTB at Slashdot, and beg the forgiveness of math pedants everywhere. :)

Submission + - No, the Earth (almost certainly) won't be hit by an asteroid in 2032

The Bad Astronomer writes: Last week, astronomers discovered 2013 TV135, a 400-meter wide asteroid that will swing by the Earth in 2032. The odds of an impact at that time are incredibly low — in fact, the chance it will glide safely past us is 99.99998%! But that hasn't stopped some venues from playing up the apocalypse angle. Bottom line: we do not have a good orbit for this rock yet, and as observations get better the chance of an impact will certainly drop. We can breathe easy over this particular asteroid.

Submission + - Saturn in all its glory

The Bad Astronomer writes: On Oct. 10, 2013, the Cassini spacecraft took a series of wide-angle pictures of Saturn from well above the plane of the rings. Croatian software developer and amateur astronomical image processor Gordan Ugarkovic assembled them into a stunning mosaic (mirrored on Flickr), showing the planet from a high angle not usually seen. There's a lot to see in this image, including the rings (and the gaps therein), moons, and the planet itself, including the remnants of a monstrous northern hemisphere storm that kicked off in 2010. It's truly wondrous.

Submission + - Russian missile test seen and photographed by ISS astronauts

The Bad Astronomer writes: It sounds like a scene from "Gravity": Astronauts aboard the International Space Station Thursday saw a weird, glowing cloud of light in the distance, most likely caused by a fuel dump or leaking fuel from a Russian missile launch. The extended life of a Topol missile was being tested in a ballistic launch to a test target in Kazakhstan, and the astronauts were able to take pictures of both the launch vapor trail and the glowing cloud. This event is similar to the eerie spiral lights seen over Norway in 2009 caused by a Russian missile launch as well.

Submission + - Can a 4K TV fool people into thinking they're about to get hit by an asteroid? 3

The Bad Astronomer writes: A video is going viral showing people in a job interview. What they think is a window in the room is actually a new 4K (3840x2160 pixel) TV, and when it shows an asteroid screaming in over the city and impacting nearby, hilarity (more or less) ensues. It may seem unlikely, but it turns out the TV pixels really are small enough that from a short distance away, they can fool people into thinking they're seeing reality and not a video on a TV.

Submission + - Watch the Crab Nebula expand over a 13 year period

The Bad Astronomer writes: A thousand years ago, the light from the explosion of a massive star reached the Earth. We now call this supernova remnant the Crab Nebula, and a new image of the Crab taken by astronomer Adam Block shows the physical expansion of the debris, made obvious in a short video comparing his 2012 observations with some taken in 1999. The outward motion of filaments and knots in the material can be easily traced even over this relatively short time baseline.

Comment Re:Science? (Score 1) 440

When I drop a ball, and show that it follows the path predicted by gravitation, what more must I do to "show" that gravity caused the ball to fall.

When the atmospheric CO2 content increases and the global average temperature goes up about the amount Arrhenius said it would back in 1906 due to basic physical principles, and then I show that is in fact human emissions that caused the CO2 increase, what more must I do to "show" that global warming cause the temperature increase.

Slashdot Top Deals

Top Ten Things Overheard At The ANSI C Draft Committee Meetings: (5) All right, who's the wiseguy who stuck this trigraph stuff in here?

Working...