Potentially Hazardous Asteroids - (...does this make you feel any better?)

Palomar · 2004-02-09 07:56:11

*Spaceweather.com updates the PHA count daily!

"Potentially Hazardous Asteroids (PHAs) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs are on a collision course with our planet, although astronomers are finding new ones all the time.

On 9 Feb 2004 there were 569 known Potentially
Hazardous Asteroids..."

*Also includes updated bimonthly grid of "Earth-asteroid encounters" (February-March 2004, etc.)

--Cindy :laugh:

Yang Liwei Rocket · 2004-07-18 15:38:50

space weather is a cool website

GCNRevenger · 2004-07-18 15:51:54

Not really, its all about statistics...

It is statisticly unlikly that an asteroid will survive the gauntlet of Jupiter and the Sun and the Moon and hit Earth

Its even more unlikly that such an asteroid will be big enough to obliterate the planet

So the chances of it happening in a given amount of time is pretty slim... you've got better chances of being hit by lightning or terrorist attack.

Yang Liwei Rocket · 2004-07-18 16:13:28

I think PHAs are a great thing to study
some will say 'so what that will never happen'
so much for any of those fossils stuck in the Earth or any one who happened to be near any of those "Tunguska" events , the people in British Guyana got a big whack in 1935

Palomar · 2004-08-27 08:35:29

http://www.astronomy.com/asy/default.as … 411]Missed Earth "by a whisker"

*2004 FU162 skimmed past us in March, a mere 4000 miles away. Was 15 to 30 feet in diameter. Would have disintegrated in the atmosphere if it'd been drawn in.

It "produced the closest miss of any asteroid known."

"'It would have produced a nice fireworks show." He continues: 'Objects this size hit Earth every several years.'"

We had another close encounter in March as well. That one (2004 FH) zipped by at a distance of 27,000 miles and was 100 feet across (I think I posted about this one in a different thread...not sure). It too would have disintegrated in our atmosphere.

Thank goodness for our thick atmosphere.

--Cindy

SpaceNut · 2004-08-27 10:16:36

Depending on the close encounter of these near Earth objects what is the distance relationship to Earth that would allow for it to be deflected by gravity either to be directed on a collision course or to be captured. Any references?

Mad Grad Student · 2004-08-27 19:37:32

There must be something flawed with one of Zubrin's arguments for asteroid hunting in Entering Space (Another great space exploration advocacy book, though less read than The Case for Mars). According to his data, an asteroid producing around 100 megatons of force when it hits the atmosphere hits around once a decade. If that's true, it seems that some populated area should have been hit in the last thousand years or so. I understand that the odds are very slim, but on a long enough timeline someplace ought to be hit.

Just in case that comment got you feeling safe and secure again, take heart that an asteroid carrying about 2,000 megatons of explosive force hits about every hundred years or so. The last one that big exploded over Tunguska in 1908. Pleasent dreams. :bars3:

PS. Oh, save me a spot under the bed, will you?

Euler · 2004-08-27 20:33:26

Just in case that comment got you feeling safe and secure again, take heart that an asteroid carrying about 2,000 megatons of explosive force hits about every hundred years or so. The last one that big exploded over Tunguska in 1908. Pleasent dreams.

I think that should be 2,000 kilotons, rather than 2,000 megatons.

Mad Grad Student · 2004-08-27 22:07:56

Just in case that comment got you feeling safe and secure again, take heart that an asteroid carrying about 2,000 megatons of explosive force hits about every hundred years or so. The last one that big exploded over Tunguska in 1908. Pleasent dreams.
I think that should be 2,000 kilotons, rather than 2,000 megatons.

Nope, that wasn't an order-o-magnitude error, I had thought that the Tunguska "event" was something like 2 gigatons of fireworks, but it turns out it's more like 30 or 40 megatons. Whoops.

SpaceNut · 2004-12-23 06:31:41

Well our satellites just missed a visitor thou it was only about 16 feet (5 meters) wide.
This space rock was relatively small and posed little of any danger had it plunged into the atmosphere.

Small Asteroid Passes Between Satellites and Earth

Palomar · 2004-12-24 08:54:33

http://www.spaceref.com/news/viewsr.html?pid=14887]Here comes your 19th nervous breakdown!

*This one is going to be close. Will occur on 13 April 2029 (well, we've still got a bit of time!). Impact odds are 1:300, and this thing -- named 2004 MN4 -- is getting special monitoring from astronomers. The odds of impact will change based on day-to-day observations.

Includes illustration and animation.

Highest score to date on the hazard scale.

--Cindy

Shaun Barrett · 2004-12-25 04:53:55

Yeah, could be nasty if it hits.
It's supposed to be about 400 metres across. The meteorite that dug Barringer Crater in Arizona 50,000 years ago was only about 50 metres across.

Admittedly, the object which struck Arizona was made of iron, whereas this new potential threat may not be as dense. But still, 400 metres is 400 metres and I think it would make quite a splash!

:: EDIT ::
It occurred to me that this meteor, if it proves to be on a collision course with Earth, could be just what we need to get the world focused on space.
It's relatively slow-moving, has a long lead-time, and is the kind of mass we might be able to deflect with present or near-term technology.
And, as they say, the prospect of imminent death concentrates the mind wonderfully! :;):

Soyuz · 2004-12-25 13:35:37

http://www.spaceref.com/news/viewsr.html?pid=14887]Here comes your 19th nervous breakdown!
*This one is going to be close. Will occur on 13 April 2029 (well, we've still got a bit of time!). Impact odds are 1:300, and this thing -- named 2004 MN4 -- is getting special monitoring from astronomers. The odds of impact will change based on day-to-day observations.
Includes illustration and animation.
Highest score to date on the hazard scale.
--Cindy

Get ready for your 20th nervous breakdown. The impact odds have gone up from 1.6% to 2.4%.
http://neo.jpl.nasa.gov/risk/2004mn4.html]2004 MN4 impact risk

Mars_B4_Moon · 2022-07-01 17:35:51

Bernese researchers simulate defense of the Earth
https://www.spacedaily.com/reports/Bern … h_999.html
NASA's Double Asteroid Redirection Test (DART) mission is the world's first full-scale planetary defense test against potential asteroid impacts on Earth. Researchers of the University of Bern and the National Centre of Competence in Research (NCCR) PlanetS now show that instead of leaving behind a relatively small crater, the impact of the DART spacecraft on its target could leave the asteroid near unrecognizable.

Mars_B4_Moon · 2022-07-12 06:43:49

China to target near-Earth object 2020 PN1 for asteroid deflection mission

https://spacenews.com/china-to-target-n … n-mission/

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#1 2004-02-09 07:56:11

Re: Potentially Hazardous Asteroids - (...does this make you feel any better?)

#2 2004-07-18 15:38:50

Re: Potentially Hazardous Asteroids - (...does this make you feel any better?)

#3 2004-07-18 15:51:54

Re: Potentially Hazardous Asteroids - (...does this make you feel any better?)

#4 2004-07-18 16:13:28

Re: Potentially Hazardous Asteroids - (...does this make you feel any better?)

#5 2004-08-27 08:35:29

Re: Potentially Hazardous Asteroids - (...does this make you feel any better?)

#6 2004-08-27 10:16:36

Re: Potentially Hazardous Asteroids - (...does this make you feel any better?)

#7 2004-08-27 19:37:32

Re: Potentially Hazardous Asteroids - (...does this make you feel any better?)

#8 2004-08-27 20:33:26

Re: Potentially Hazardous Asteroids - (...does this make you feel any better?)

#9 2004-08-27 22:07:56

Re: Potentially Hazardous Asteroids - (...does this make you feel any better?)

#10 2004-12-23 06:31:41

Re: Potentially Hazardous Asteroids - (...does this make you feel any better?)

#11 2004-12-24 08:54:33

Re: Potentially Hazardous Asteroids - (...does this make you feel any better?)

#12 2004-12-25 04:53:55

Re: Potentially Hazardous Asteroids - (...does this make you feel any better?)

#13 2004-12-25 13:35:37

Re: Potentially Hazardous Asteroids - (...does this make you feel any better?)

#14 2022-07-01 17:35:51

Re: Potentially Hazardous Asteroids - (...does this make you feel any better?)

#15 2022-07-12 06:43:49

Re: Potentially Hazardous Asteroids - (...does this make you feel any better?)

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