2015 TB145 discovered. Flyby Oct 31 at 15:14 UT. Dist: 1.26 LD. Size: 210-650 m.

originally posted by: Trillium
From itelescope.net

Always use the latest possible orbital elements and ephemeris. Note that at the moment the JPL and MPEC ephemeris do not converge between the 29th and 1st Nov, reflecting how current orbital uncertainties feed into their orbit models, you you will need to keep checking until they substantially converge.

JPL ephemeris for astronomical twilight 31st 06 10 13.22 +32 21 01.1
MPEC ephemeris for astronomical twilight 31st 05 44 46.8 +26 28 06

Now a pretty big difference ???? why

It says why right in your quote, due to the current uncertainty in the orbit.

JPL page has now appeared: ssd.jpl.nasa.gov...

Despite the condition code 9, I'm certain that the asteroid will pass safely past both Earth and the Moon. You will need a telescope to even spot it.

originally posted by: wildespace
JPL page has now appeared: ssd.jpl.nasa.gov...

Despite the condition code 9, I'm certain that the asteroid will pass safely past both Earth and the Moon. You will need a telescope to even spot it.

Provided the weather allows, I will be webcasting it live via youtube.

a reply to: UnBreakable

I do remember all the people who laughed at the Sept. 23 asteroid prediction. It was always, always a real long shot, but considering how short the notice is on this, it was never exactly something you could laugh at as an absolute impossibility either.

Is this going to do anything? Almost certainly not, but it carries a slender risk, and we're learning about it only about 15 days before its window of possibility.

a reply to: ketsuko
No, we know this one carries NO risk of impact to either earth or the moon on this orbit. The trouble is that we don't get much warning on asteroids of this size class, yet they can wipe entire cities off the map.

originally posted by: ketsuko
a reply to: UnBreakable

I do remember all the people who laughed at the Sept. 23 asteroid prediction. It was always, always a real long shot, but considering how short the notice is on this, it was never exactly something you could laugh at as an absolute impossibility either.

Is this going to do anything? Almost certainly not, but it carries a slender risk, and we're learning about it only about 15 days before its window of possibility.

The reason those (and many other past) predictions were laughed at, is because they had nothing to do with the real astronomy, you know, astronomers photographing the sky and detecting something new, observing it over the course of time, and calculating its trajectory.

And with the discovery date being Oct 10th versus the close approach date being Oct 31st, we've found it 21 days before any theoretical damage.

Any object in the size range of 210-650 metres would do a LOT more than wipe out a single city.

originally posted by: Mogget
Any object in the size range of 210-650 metres would do a LOT more than wipe out a single city.

I think it's a good time to load up the good old impact calculator and plug the numbers in.

Let's give it a 440 meter diameter, the density of dense rock, and impact velocity of 35 km/s, striking the ground at an angle of 45 degrees.

The results are:

Energy:
Energy before atmospheric entry: 8.20 x 10^19 Joules = 1.96 x 10^4 MegaTons TNT
The average interval between impacts of this size somewhere on Earth during the last 4 billion years is 2.2 x 10^5years

Major Global Changes:
The Earth is not strongly disturbed by the impact and loses negligible mass.
The impact does not make a noticeable change in the tilt of Earth's axis (< 5 hundreths of a degree).
The impact does not shift the Earth's orbit noticeably.

Atmospheric Entry:
The projectile begins to breakup at an altitude of 65600 meters = 215000 ft
The projectile reaches the ground in a broken condition. The mass of projectile strikes the surface at velocity 34.2 km/s = 21.2 miles/s
The impact energy is 7.82 x 10^19 Joules = 1.87 x 10^4MegaTons.
The broken projectile fragments strike the ground in an ellipse of dimension 1.02 km by 0.724 km

Crater Dimensions:
Crater shape is normal in spite of atmospheric crushing; fragments are not significantly dispersed.

Transient Crater Diameter: 7.58 km ( = 4.71 miles )
Transient Crater Depth: 2.68 km ( = 1.67 miles )

Final Crater Diameter: 9.93 km ( = 6.16 miles )
Final Crater Depth: 591 meters ( = 1940 feet )
The crater formed is a complex crater.
The volume of the target melted or vaporized is 0.492 km3 = 0.118 miles3
Roughly half the melt remains in the crater, where its average thickness is 10.9 meters ( = 35.7 feet ).

Ok found this on Face book interesting
does not look too close so far

2015 TB145 Orbit

Better then mine attempt

originally posted by: Trillium
Ok found this on Face book interesting
does not look too close so far

2015 TB145 Orbit

Better then mine attempt

A very nice, and safe, passage past the Moon and the Earth. Astronomers know what they're doing when calculating and anouncing this sort of thing, and ATS members would be wise to trust them, as opposed to sensationalist MSM articles or crank Youtube videos.

This close approach will present a good opportunity to observe and study a NEO asteroid. Rest assured, when an object is calculated to impact the earth, it will be made known by the astronomy community, such as was the case with the 2008 TC3.

As you might guess from the post that opened this thread, your first point of stop for such matters is the Minor Planet Center.

There's no hiding of the night sky from amateur (and professional) astronomers; they systematically scan the skies in search of anything new. Rest assured, a large potential impactor would get spotted by them and anounced to the world.

originally posted by: Mogget
Any object in the size range of 210-650 metres would do a LOT more than wipe out a single city.

Not just for it's size, but it's velocity. This is a real speedy one, 34.97Km/s. One of the fastest CPA's of any NEO this year or next.

Although it was only discovered 7 days ago, it is not a threat at just over 1.3 lunar distances, and the sigma they will have closer to the 31'st of the month will really not significantly change the prediction.

On another note, this is scary because of it's discovery date and that it has an orbit highly inclined to the solar system orbital plane, which means the Sun did not interfere with earlier observations. Very little time to prepare any kind of intercept, if we even could.

Here are charts of the path of this asteroid from several locations in the US on the night of October 30th/morning of the 31st when it will be most visible. All times shown in the videos are local times at their respective locations.
Miami:

Denver:

Los Angeles:

And it might actually be a spent comet: www.cbsnews.com...

WOW in just two day it will pass and 598 observation and it still
a condition code 6 and 20 up-date later

Facebook vid

more on here

a reply to: Trillium

Time itself is a necessary factor for reducing the long term uncertainty, which is what drives the condition code. You guys aren't patient enough. It literally does not matter how many observations are collected if there isn't enough time between them. There will be a ton of observations of this asteroid since it's making the news and since it's relatively bright and easy to observe with powerful amateur telescopes.

a reply to: Trillium

There's a possible connection with all the recent blue fireballs. Scary how it was underreported

originally posted by: PapagiorgioCZ
a reply to: Trillium

There's a possible connection with all the recent blue fireballs. Scary how it was underreported

What connection? Sources/quotes please.

The bluish fireballs and meteors might have been part of the Orionids meteor shower. www.abovetopsecret.com...