2009 FD - an asteroid that could cause trouble for future generations.

A large Near-Earth Asteroid 2009 FD (approx 470 meters in diameter) has just been placed back on the JPL Sentry Risk Table, at Palermo Scale of -0.40 (with 0 being a certain impact) and the Torino Scale not identified.

Earth Impact Risk Summary: neo.jpl.nasa.gov...

It gives the 1 in 345 cumulative chance of impact between 2185 and 2196, which I think is pretty high (we usually hear of one in hundreds of thousands or millions chance for close approaches). Out of all possible asteroid worries, I think this one takes the cake. In fact, the 2185 close approach is calculated to happen closer to the Moon than the Earth, so even if it doesn't impact us, it may impact the Moon.

An impact by 2009 FD would cause severe devastation to a large region or tsunamis of significant size. I wonder if we will develop technology to prevent this catastrophe by then.

What do amateur astronomers here think, should we start to worry for our kids and grandkids?

Nah, I think we're fine. They usually refine down the risk factors when they get more accurate readings from what I've seen. That 1 in 345 will probably be refined down to 1 in 10,000 or something pretty soon.

a reply to: wildespace

If we are still here by then ( Yes, I'm having one of my "optimistic" days. )
I'm sure they will come up with a solution.

We already have the technology to blast asteroids.
We just need better technology on detecting them in time, but they are also working on that since the Russian meteor impact happened last year.

Further, the U.S. Congress held several hearings about planetary defense in the aftermath of Chelyabinsk, and the Obama adminstration asked Congress to double NASA's asteroid-hunting budget, to $40 million.

Fragments of Chelyabinsk (C2-C6)Pin It Fragments of Chelyabinsk (C2 - C6) analyzed in this study. Find locations are marked. C2 is an oriented meteorite; it travelled with its flat side forward. Its backside is shown. Image released Nov. 6, 2013.

Finally, last June, NASA announced that it was launching an asteroid "Grand Challenge," which would solicit ideas from industry, academia and the general public about the best ways to detect potentially hazardous asteroids and prevent them from hitting Earth.

The extra attention could help new instruments such as the privately funded Sentinel Space Telescope get off the ground. The nonprofit B612 Foundation is developing the infrared Sentinel, which it plans to launch to a Venus-like orbit in 2018. From there, the scope should be able to spot 500,000 new asteroids in less than six years of operation, officials say.

"We have the technology to deflect asteroids, but we cannot do anything about the objects we don’t know exist," B612 Foundation chairman and CEO Ed Lu, a former NASA astronaut, wrote in a blog post.

www.space.com...

a reply to: AnIntellectualRedneck

Don't be too sure, it's been observed over a period of 5 years now, plenty of time to get the calculations close.

originally posted by: AnIntellectualRedneck
Nah, I think we're fine. They usually refine down the risk factors when they get more accurate readings from what I've seen. That 1 in 345 will probably be refined down to 1 in 10,000 or something pretty soon.

Thing is, the chance of impact for this asteroid had been reduced in the past. But the more recent observations suggest that this asteroid is much larger than thought previously, and that gravitational perturbations from Mars and Venus, as well as the Yarkovsky effect, make this asteroid's orbit much less certain over time.

Due to 2009 FD's size, and its interactions with Mars and Venus, which increase its orbital uncertainty over time, it is rated −0.40 on the Palermo Scale, placing it high on the Sentry Risk Table.

In January 2011, near-Earth asteroid 2009 FD (with observations through 7 December 2010) was listed on the JPL Sentry Risk Table with a 1 in 435 chance of impacting Earth on 29 March 2185. In 2014 (with observations through 5 February 2014 creating an observation arc of 1807 days) the potential 2185 impact was ruled out. Using the 2014 observations, the Yarkovsky effect has become more significant than the position uncertainties. The Yarkovsky effect has resulted in the 2185 virtual impactor returning.

(emphasis mine)

Seems like the Yarkovsky effect is very dominant for this asteroid, because it is very dark, having albedo of 0.01 which is darker than coal or fresh asphalt.

By the way, we have Amy Mainzer to thank for the new findings.

a reply to: wildespace

I hope this goes away because if it went too close to our moon and affected the delicate balanced we interplay with it, the impact on water on this planet would be huge and we may not go back to our balancing stability -which is a horrible situation to contemplate.

Surely we should have some kind of deterrent already up in the satellite sphere that all nations should contribute to and be operated by some form of international council, in case of asteroids suddenly popping up. We shouldn't have to have countries, as Russia having to face this threat which we all know is very real.

I have always felt that were we threatened by something not of this planet it would reunite the world and then we would move forward with terrific speed, instead of the in fighting and greed mongering that splits up our best resources and only ends up in private pockets/bunkers.

I SH*T YOU NOT, I just had a dream last night about some sort of big earth impact from space.

I don't remember much detail but a few things stand out. I was with a group of people and it was at night and we heard a loud rumble. I looked out across the horizon and seen a huge fireball bellowing out black smoke heading to towards the ground. I seen a huge flash followed a few seconds later by what seemed like a massive gush of wind and an earthquake. I fell down and then I remember calling my wife. I remember verbatim her exact words. "They said it hit near Memphis" and then she was gone. Then the ground started getting extremely hot and i was scrambling trying to get off the ground. Then I woke up.

a reply to: wildespace

The Yarkovsky effect is not only a problem because the asteroid is dark but because we're trying to predict precisely where it will be some 170+ years in the future. That's a lot of time for small order effects to become significant in ways that wouldn't normally matter as much for relatively short term predictions. It's hard to predict the exact effect it will have on the asteroid's orbit due to the impact of albedo and shape and orientation variations. It seems like we do have a radar return on the object so that should give us some information about the shape and rotation rate. Clearly we need more info, but it's hard to get terribly worried about a potential impact that is almost two centuries away. Even a very small amount of delta-V administered today (probably on the order of centimeters per second or less) could avert an impact that far in the future. To do so would require first knowing what the smaller order effects like Yarkovsky and solar radiation pressure will have over the next two centuries, otherwise you would need a larger amount of delta-V to push it off course far enough that the smaller order effects are too small to matter even over the long time span involved.

a reply to: wildespace

Asteroids? They will soon be the least of your worry, believe it or not. Plus i doubt everything is random in the universe. There are invisible strings you know.