Help - Search - Members - Calendar
Full Version: INCOMING!
Unmanned > Other Missions > Cometary and Asteroid Missions
Pages: 1, 2, 3, 4, 5, 6, 7, 8
no sone seems to have noticed this yet
Too much info kill the info! Where do we have to look? I've seen something will hit the atmosphere tonigth over Sudan, correct?
Whoa! Any chance of organizing a crash observing campain from ground or even orbit?
Holder of the Two Leashes
An asteroid... well, really a meteor, is now predicted to hit the atmosphere.

First time I know we have had advanced warning on a single natural object.

MPEC report

Quote: "Steve Chesley (JPL) reports that atmospheric entry will occur on 2008
Oct 07 0246 UTC over northern Sudan."
Any idea how big is this rock?
The absolute magnitude indicates that the
object will not survive passage through the atmosphere.

Steve Chesley (JPL) reports that atmospheric entry will occur on 2008
Oct 07 0246 UTC over northern Sudan.

Don't sell all your stocks yet, looks like we'll live to see another day....

Is this the first time a fireball's been predicted in advance? I was very interested in meteor observing for a few years and read a lot of stuff (it seems so in retrospect, anyway) but I don't recall ever hearing of an event like this.

For those of us who can't interpret the MPEC data or ephemerides, what does the absolute magnitude mentioned tell us about the size of this object?
Hey guys, don't just tear your swimming suits apart. laugh.gif

The link says that it will disintegrate in the atmosphere, as Juramike already pointed in the duplicate thread.

Why do you scare us with no reason ? huh.gif


You 're welcome !
Holder of the Two Leashes
There have been at least three revisions in the last hour, a lot of people are looking at this object.

Hard to say, but now it looks like it may be a near miss, by about a thousand miles. The latest Mpec
doesn't state whether an impact is still expected.

The absolute magnitude indicates a size of two to seven meters.

Gosh, I just mixed english and metric units in the same post.

Edit: Five meters big at most, more likely two to three. Absolute magnitude of 30.4
30.4!!! Gona be visible over the horizont!
Holder of the Two Leashes is now reporting the story, and says atmospheric entry is expected.


The report also emphatically states that it will be destroyed at altitude, and doesn't pose a significant danger.

True enough... if it's not a nickle-iron.
I wonder if it can be imaged from orbit during entry a la Mars Phoenix? Probably too much uncertainty.
From TPS:

The meteor is expected to be visible from eastern Africa as an extremely bright fireball traveling rapidly across the sky from northeast to southwest. The object is expected to enter the atmosphere over northern Sudan at a shallow angle.

"We're eager for observations from astronomers near the asteroid's approach path. We really hope that someone will manage to photograph it," said Williams.

My SR71 is in maintenance, or I'd be over there like a shot.

It may be small and harmless, but for me knowing it is on the way represents a huge psychological milestone. It is a great achievement by those watchers of the skies who search for these objects that the fall of a meteorite need no longer take us by surprise. It feels as though in one more small way we have 'grown up' as a species. If it had been a bit larger and aimed at a suburb near you, you would already have heard when to head for the cellar (and felt quite safe out of doors until a few seconds beforehand).
I guess once LSST and PanSTARRS come online we'll get these kind of alerts fairly regularly. I imagine it will change the public perception of 'asteroid impact predicted!' headlines a lot. People will go from thinking of the end of the world to thinking of photo ops + a mad scramble for very valuable rocks.
Holder of the Two Leashes
Man, I've never seen anything quite like this. Twenty observatories have turned in collectively nearly 200 observations of this object, and the Minor Planet Center is issuing updates about every fifteen minutes. This little rock is definitely getting it's share of attention.

A fair number of professional observatories seem to be poised to follow this thing almost into the ground.
LINKS, man! Give us links, HTL!
Holder of the Two Leashes

Anything with 2008 TC3. Most recent on top.

BTW: "HTL"? Whazzat?
I guess they won't be seeing it from here (bad luck!): Haboob sandstorm in Sudan
If this thing is coming in shallow from NE to SW then it should be visible in Alexandria, Cairo, Egyptian tourist destinations, maybe as far down as Khartoum ... so there is some chance to get it on film. If I get my timzones right, it will be night then. Anybody's got a groundtrack?
hmm, I think my Celestia copy needs fixing. Using the most up-to-date orbital parameters, I get a miss distance of 5,850 km over North Africa.
Fran Ontanaya
The NEO Program lists it as a close approach at 0.02 LD. That's under 8000 km.

It was briefly in the Recently Observed list of Impact Risk, with dates beyond 2080, but it isn't anymore.
Holder of the Two Leashes
Used a reliable horizon calculator to come up with some figures. Provided you have a clear horizon.

When it is at 20 miles altitude (32 km), under perfect seeing, it should be visible for over 400 miles (640 km) in every direction. It will probably survive down to this far.

It should also be glowing brightly at 50 miles altitude (80 km), and at that point be seen for at least 650 miles (1000 km).
Emily pointed to a beautiful simulation of the event at
By the way, discussion on Minor Planets Mailing List (which is where I got the link to that simulation) indicates that the press release wasn't correct when it described the flight direction -- it's not coming in from northeast, it's coming in more from the west, basically over the Sahara.

I agree, that's the direction I got from my simulation in Celestia.
Holder of the Two Leashes
QUOTE (Shaka @ Oct 6 2008, 06:48 PM) *
Er.. thanks, HTL. (If I wrote Holder of the Two Leashes every time, my posts would get trashed for wasting bandwidth.)
When you referred to loads of observatories, I sort of anticipated a CometCam live picture.
Ephemera are nice, but not very sexy. blink.gif

My bad. I'm one of the very few people who could even get a little excited over watching raw positional information pouring in.

Here is one real picture: Sky and Telescope

I'm pretty sure just about every other pic of 2008 TC3 looks like that at this point.

In a couple of hours, we may be getting some much more spectacular shots.

A lot of people will shorten my title to "Holder", and I'll answer to that. The dogs don't mind, either. Actually, they don't have a clue.
"Major Bolide Forecast Tonight; No Damage Expected" (S&T from Holder's link.)

What a headline!!! What a time to be alive!!! Nigel is absolutely right; this is marvelous, this is an expansion of our general situational awareness. We've always grown thereby through such things.
If I did the math right, just a few more minutes until impact.

Two ways to look at it.

-> Small asteroid hits planet. No damage done.
-> Comparatively HUGE freaking Planet hits an asteroid, obliterating it. Owned.

Either way, the asteroid will be one with the planet. I look forward to pictures (I hope we get some).
Here's a Celestia simulation of 2008 TC3's entry into Earth's atmopshere:

The green circle indicates the region where the asteroid is visible over the horizon. The trajectory of 2008 TC3 was taken from HORIZONS (about an hour ago.)

QUOTE (claurel @ Oct 7 2008, 11:44 AM) *
Here's a Celestia simulation of 2008 TC3's entry into Earth's atmopshere:

Judging from that clip, 2008TC3 is gonna come down at / explode over the Nubian Desert, somewhere in the center of the triangle made up by the cities Wadi Halfa, Atbara & Port Sudan. Man, I flew over there some years ago!

EDIT: The Horizons system is very slow ... must have a lot of traffic!
Going to? Has it already? Or did I again get my math wrong with time conversions? Lol. sad.gif
QUOTE (Hungry4info @ Oct 7 2008, 03:00 AM) *
Going to? Has it already? Or did I again get my math wrong with time conversions? Lol. sad.gif

The time given was 10:46 EDT (my time zone). It is now 10:19 EDT. I plan to go outside....we are far too far away, but I figure that just in case it has some smaller cousins, it couldn't hurt to go take a look.
Here's a Celestia simulation of 2008 TC3's entry into Earth's atmopshere:

The green circle indicates the region where the asteroid is visible over the horizon. The trajectory of 2008 TC3 was taken from HORIZONS (about an hour ago.)

This video gives the view from 2008 TC3:
(Itokawa is standing in for 2008 TC3.)

The Celestia add-on used for both simulations is here:
It requires a very recent version of Celestia, however; I'll make a more widely usable available post-impact.

Holder of the Two Leashes
I will take the liberty of posting this quote from Emily's blog over at

"Thanks to Ron Baalke for posting the following, from JPL asteroid scientist Paul Chodas, on the Minor Planets Mailing List:
Update - 6:45 PM PDT (1 hour prior to atmospheric entry)

Since its discovery barely a day ago, 2008 TC3 has been observed extensively by astronomers around the world, and as a result, our orbit predictions have become very precise. We estimate that this object will enter the Earth's atmosphere at around 2:45:28 UTC and reach maximum deceleration around 2:45:54 UTC at an altitude of about 14 km. These times are uncertain by +/- 15 seconds or so. The time at which any fragments might reach the ground depends a great deal on the physical properties of the object, but should be around 2:46:20 UTC +/- 40 seconds."

Well, the asteroid has passed into the earth's shadow, so telescope observations are at an end now.

Just waiting for the fireworks ...
As 2008 TC3 passes over Niger, let's us have a moment of silence for this little asteroid that could. 2008 TC3 started life when it was freed from sub-surface of a larger asteroid. For millions of years it wondered. Unloved. Uncared for. Unnoticed. Now, as it's end approachs, in a fiery burst of light, people care for this little guy.

God speed little doodle. sad.gif

Now at 1,900 km above north africa.
And the earth emits a contented belch. wink.gif
Well that was would seem. Looks like we're all still here! smile.gif I doubt anyone caught it. It hit news outlets so late in the day and it's almost 3am there. Even with seemingly everybody these days having a cameraphone on them... still doubtful.
At last check, Earth still here.

2008 TC3...not so much
my mistake, nearly 5am local time rather than 3 UTC.
I can confirm that Australia is still here as well at 1:55 PM Sydney summer time rolleyes.gif ... and I couldnt even put up a realtime simulation (I was 4 minutes late) [at least the decision whether to use Earth Received Time or Space Object Event Time would have been easy this time around]. Just imagine this had been a very dark 'biggie' - the stock markets wouldn't even had time to crash further
Any Videos or Photos of the event yet???
here you go!


is breathtaking, no? laugh.gif
QUOTE (volcanopele @ Oct 7 2008, 04:40 AM) *
As 2008 TC3 passes over Niger, let's us have a moment of silence for this little asteroid that could. 2008 TC3 started life when it was freed from sub-surface of a larger asteroid.

hope mother-asteroid is not chasing her daughter.... laugh.gif
ugordan has news about a possibly positive sighting (from a plane at roughly 750 nm away) of a flash at around the expected time of impact.
Well we can at least say that it wasn't CATASTROPHICALLY larger than predicted! smile.gif Also the nearest ISS pass over the area is way off at the time of expected entry so there was no chance of observation from there...;satid=25544
Surprised I haven't seen any word of this from Aswan or Abu Simbel in southern Egypt. These would seem like the likeliest places where word/images/movies would have been returned and posted on the net.
Fran Ontanaya
A small piece of info about spectra:
That series of 10s exposures showing the thing 'speeding up' as it were - that's one of those rare astronomical observations that puts the Earth, the solar system, and the things flying around it into sharp '3d' context.

Maybe an indirect sighting of a webcam at El Grouna (middle east in Egypt):

In a German meteorite forum had someone contact to people in Egypt and they say it was great (more will be come I guess - the guy in the forum is sleeping now). Sadly Sadly their camera went off in waiting of the event and it was too late to start it again sad.gif
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.
Invision Power Board © 2001-2018 Invision Power Services, Inc.