Asteroid to fly past Earth this weekend

CNN blogs ^ | Thursday, March 7th, 2013 | Melissa Gray

[SunkenCiv]

An asteroid the size of a city block will pass by Earth this weekend, but have no fear: There's no danger of it hitting our planet.

The 80-meter (262 feet) wide asteroid makes its closest approach to Earth on Saturday afternoon in the United States. It will be about 975,000 kilometers (604,500 miles) away, said Don Yeomans, a planetary scientist at NASA's Jet Propulsion Laboratory in California. That's about 2 1/2 times the distance from the Earth to the moon.

"It's a pretty good size, but it's not getting that close, at least by recent standards," Yeomans said.

The asteroid was only discovered Sunday because search telescopes can't find objects of that size until they get close.

Now that it's in view, Yeomans said, astronomers can accurately chart its orbit. And they assure us this space rock will only make a fly-by.

The asteroid is already observable in the night sky, even with sophisticated amateur telescopes, he said. But get a good look at it now, because after the close approach, the asteroid will appear in the daytime sky and be harder to see, Yeomans said.

Dubbed 2013ET (which is simply code for when it was discovered), the asteroid is the latest object from space to come near our planet.

A meteor exploded over southwestern Russia last month, injuring more than 1,500 people, Russian authorities said. In what astronomers have said was an unrelated coincidence, a larger asteroid passed by Earth the same day, about 17,100 miles away at its closest.

This Friday, a comet called Pan-STARRS will come into view over the Northern Hemisphere. A second comet, called ISON, may be visible in November. Scientists say neither comet poses a threat to Earth.

[SunkenCiv]

An impactor a mile in diameter would destroy our civilization. Naturally the evacuation of our governing bodies to defended underground bunkers would be a necessity for the continuity of that civilization (such as it is).

Even if everyone knew where they were, the facilities are, er, would be expected to be essentially impregnable. And heavily defended.

What’s the matter, you haven’t been wondering why the gubmint has been buying trainloads of ammo?

;’)

Within a couple of hours, the entire surface of the Earth would be in complete darkness, and the clouds would persist for months to years.

The hydrologic cycle would slow to near-zero, thus all the water (which didn’t freeze at altitude) would over a matter of a week or two (for the longest rivers) run down to the oceans and there would be no rain or snow (give or take an impact on water) for months or years.

Anything unable to find water would be dead in a few days.

CO2 levels would rise (this is not even considering CO2 which might be the immediate result of the impact) due to lack of photosynthesis and fires ignited by both the flash from the impact and hot ejecta. Fires might rage for weeks, months, or in some places could at least smoulder for years.

Plant eaters would devour everything, then start to starve.

Nocturnal animals and predators would be out 24/7.

Dead plant eaters (and anything else that died) would be scavenged, repeatedly.

Every wild thing would be hungry, and so would every human when the stored food, game, and carrion ran out.

By the time the cloud cover finally went away for good, the animal and human populations would probably have dropped by over 90%. Some species would have ceased to exist.

[a fool in paradise]

Not to worry. I've got it covered.

I think.

[John W]

So you’re saying we’ve got a chance?

[LostInBayport]

I’m old enough to remember owning and playing Parsec. Which means I’m old.

[JoeProBono]

[Flag_This]

"I’m old enough to remember owning and playing Parsec. Which means I’m old."

But did you ever play "Tunnels of Doom" on the TI-99? It only took about 30 minutes to load from the cassette tape.

[Fred Hayek]

The one over the Indian Ocean had the double flash that was detected by the “bhangmeter” on one of the Vela satellites. Only an atmospheric nuclear explosion can cause such a double flash - two light intensity spikes, separated by a period of time when the shock wave radius has some opacity blocking out the light of the fireball. The rate of increase in light intensity I (dI/dt) would be much higher than a meteor. The bhangmeter (a special photometer designed to detect such “double flashes”) can tell the difference.
South Africa did acknowledge having a nuclear program (remember, Cubans and Angolans acting as Soviet surrogates where making incursions into South Africa during the Cold War), and has dismantled their program.

[fhayek]

Are you, perhaps, suggesting that the sky is falling?

[BenLurkin]

We should be so lucky.

[BenLurkin]

"It would not be difficult, Mein Führer."
"Nuclear reactors could - heh, I'm sorry, Mr. President - nuclear reactors could provide power almost indefinitely."

[Slings and Arrows]

But did you ever play "Tunnels of Doom" on the TI-99?

My first computer dungeon crawl! Add I had the 32K (that's K, not M) memory expansion, so it rocked.

Good times...

[Rome2000]

This Friday, a comet called Pan-STARRS will come into view over the Northern Hemisphere.

[jmacusa]

If it’s big enough, and there are lots of them that are very big, there won’t be anywhere to hide. The survivors will envy the dead.

[LostInBayport]

But did you ever play "Tunnels of Doom" on the TI-99? It only took about 30 minutes to load from the cassette tape.

Tunnels of Doom! I spent untold hours in those dungeons. But our monitor was black and white.

[familyop]

"...and the clouds would persist for months to years...The hydrologic cycle would slow to near-zero,..."

Hiya, SunkenCiv. I'm interested in this--your comment from earlier this month (march) in regards to more particles (including dry particles) in our atmosphere along with the recent low sun activity. We should be very near solar max now.

Any links or other resources would be helpful. I'm at over 9,000 feet on the Rockies, and here's what I've seen. As you probably know, at this elevation, we can more easily sense particulate atmospheric sun shading that is lighter (we'll call normal from our human-observation-time perspective) or heavier: what I'm seeing this winter.

About -24, F, last night here, just east of some peaks (roughly 25 degrees F lower than normal), BTW. During some of the sunnier days this winter, temperatures under glazed covers (larger covered areas--shed-sized or smaller, with only passive heating) were quite a bit lower with respect to outdoor temperatures than last winter by far (low-tech solar energy experiments here, building some collectors, installing modules, pumps, water tanks and transducers before long).

That's one of the reasons I'm interested in the possibility of cloud or other particulate matter slowing evaporation and precipitation cycles: something I paid too little attention to before. As you know, we're seeing unusually severe drought at this elevation, with recent previous droughts of such severity stopping short of this elevation (stopping, more or less, at around 8,000 feet, about an hour or so to the south of here in the drought of the 1930s). Can't find records of such thin upslope effect or high-altitude vegetation dying so much at this elevation (upslope effect happens only a few miles away on the west side of the top of the Divide. Another year, and we might start seeing thicker sand storms way up here. There are other reasons (other energy issues--e.g., electrical, agriculture, water issues, population movement issues and more). And well...okay, I'm a nerd. And I see some things up close, before people at lower elevations do. ;-)

So, any links or other referrals to information on natural, atmospheric sun blocks or low sun spot activity contributing to drought conditions? Thanks, if you have time. Some interesting recent weather patterns, eh?

I don't know whether we'll see more of these fluctuations from recent increases in volcanism, smoke, etc., but the possibly extended solar minimum situation is also of interest. I wonder what we might see in 3-6 years or so (drops to -50, -60, F, up here, perhaps?).