Near-Miss Asteroid Breaches Earth's Ring Of Satellites Six Hours After Discovery

[bathroommonkey76]

A previously undetected asteroid passed by Earth on Thursday, hurtling through the ring of satellites that encircle the planet and traveling onward, according to NASA. The space agency said that the asteroid, designated 2017 EA, had been detected only six hours before it whizzed past the planet.

Fortunately (“luckily” was how the Daily Mail phrased it) for Earth and its 7.4 billion people, the asteroid was estimated to be only about 10-feet wide, which, given what is known about prior asteroid/meteor impactors, would have done relatively minor damage had it survived somewhat intact after entry through the Earth’s atmosphere. But it is just that near-miss fly-by that gives experts pause when considering what a space rock just five- to 10-times the size of 2017 EA could do to the Earth if its path were a bit more direct.

Not that anything could have been done with just six hours notice of its arrival.

It is a scenario NASA scientists (and scientists around the world) have confronted for some time, one where NASA scientist Joseph Nuth bluntly told colleagues in San Francisco in December, as reported by the Inquisitr, “The biggest problem, basically, is there’s not a hell of a lot we can do about it at the moment.” He was bemoaning the fact that Earth had inadequate defenses to mitigate the approach of what he referred to as a “dinosaur killer” asteroid (one large enough to alter life on Earth), for which the planet was somewhat overdue.

http://www.inquisitr.com/4031068/near-miss-asteroid-breaches-earths-ring-of-satellites-six-hours-after-discovery/

[bathroommonkey76]

1. Would this have done any damage if it had hit the Earth?

JPL seems to be playing this down on their blog.

A small near-Earth asteroid less than 3 meters (10 feet) across whizzed safely past Earth today at a distance so close that it passed well inside the ring of geosynchronous satellites. Designated 2017 EA, the asteroid made its closest approach to Earth at 6:04 a.m. PST (9:04 a.m. EST / 14:04 UTC) at an altitude of only 14,500 kilometers (9000 miles) above the eastern Pacific Ocean. At its closest point, this asteroid was 20 times closer than the Moon; it then quickly moved into the daytime sky and can no longer be observed by ground-based telescopes.

http://cneos.jpl.nasa.gov/news/news194.html

[muriel_volestrangler]

4. Not a huge amount - the Chelyabinsk meteor was about 7 times more across,300 times more massive

(assuming the same density): https://en.wikipedia.org/wiki/Chelyabinsk_meteor

it then depends on how intact it would be by the time it got to the lower atmosphere or ground. At that size, it would probably break up in the air. You can put in some parameters in a calculator here: http://impact.ese.ic.ac.uk/cgi-bin/crater.cgi?dist=5&diam=3&pdens=8000&pdens_select=0&vel=17&theta=45&tdens=2500&tdens_select=0

For an iron asteroid of that size and a typical 45 degree entry, you get:

The projectile begins to breakup at an altitude of 13200 meters = 43100 ft
The projectile bursts into a cloud of fragments at an altitude of 11200 meters = 36600 ft
The residual velocity of the projectile fragments after the burst is 7.56 km/s = 4.7 miles/s
The energy of the airburst is 1.31 x 1013 Joules = 0.31 x 10-2 MegaTons.
Large fragments strike the surface and may create a crater strewn field.

That should be 3.1 kilotons - the size of the very largest WW2 bombs, and approaching a small nuclear explosion, but in the air (and just an explosion, of course, not a flash of radiation, and no radioactive material). If it is rock, not iron, it would be less - dense rock would be 0.36 kT - just a . For comparison, Chelyabinsk was 400-500 kilotons.

[Bernardo de La Paz]

5. WW2 bombs were NOT in the range of kilotons. Off by a factor of 1000.

The "blockbusters" were about 4,000 lb or 2 tons of explosive. NOT 2,000 tons = 2 kilotons.

[muriel_volestrangler]

6. Oops - how embarrassing. You're right, and I should never have got that wrong

because it would have made atomic bombs just like "very large bombs" (I think my mind was thinking "kilograms to kilotons means dividing by 1000", when it's by a million). The comparison of the asteroids to small atomic bombs does stand.

[bathroommonkey76]

7. Thanks

It's nice to be around people who are way smarter than me. haha

A few years ago (2012, I believe) I witnessed a bolide meteor explosion in NC-- I wasn't sure if an asteroid of this size would be similar to that event. Btw that explosion was very impressive and lasted about 25-30 seconds.

[Throck]

2. The GOP will end the earth first.

[blogslut]

3. Space Junk

She was walking, all alone
Down the street, in the alley
Her name was Sally, I never touched her
She never saw it
When she was hit by, space junk
She was smashed by, space junk
She was killed by, space junk