Chicken Asteroid #WrongWay #

99.99% of objects in the solar system orbit the Sun in the same direction – counter-clockwise as viewed from above the up above the Earth’s North pole. But, as always, there is always the odd exception to prove the rule. This newly discovered asteroid is in a giant game of chicken with Jupiter

As just published in Nature

http://www.nature.com/nature/journal/v543/n7647/full/nature22029.html

and discussed on Space.com

Wrong-Way, Daredevil Asteroid Plays ‘Chicken’ with Jupiter

Astronomers have found a bizarre asteroid orbiting the sun in the wrong direction while playing a risky game of “chicken” with the largest planet in the solar system.

The unnamed asteroid shares Jupiter’s orbital space while moving in the opposite direction as the planet, which looks like a recipe for a collision, astronomers said. Yet somehow, the asteroid has managed to safely dodge Jupiter for at least tens of thousands of laps around the sun

 

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Asteroid day #Armageddon #

Celebrate Asteroid day.

On this day, back in 1908, a large explosion wiped out an area of forest in Siberia about the same size as London. Newspaper clippings from 30 years later attest to the fact that few people were actually affected, but many people saw it
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The effect of the collision was also felt in Britain, with a reader writing to the Times newspaper inquiring why the sky was so bright at night. She didn’t receive an answer in 1908, but a 1991 Guardian Notes and Queries offered the hypothesis that the amount of dust thrown up by the blast diffracted the sun’s rays, leading to “someone [playing] a round of golf at St Andrews at 2.30 in the morning.”

So where does a ‘Death by asteroid’ scenario rank on a list of end-of-the-world possibilities. This defintely isn’t the biggest threat to the future existence of mankind (we’re much more likely to destroy each other) but it is a serious concern. There are sizable asteroids on collision courses with Earth and we don’t know about them all. In 2013, this small-ish asteroid hit a much more populated part of Russia.
Screen Shot 2015-06-30 at 3.44.46 PM https://www.youtube.com/watch?v=dpmXyJrs7iU

As reported by the Guardian newspaper in UK,

The aim of Asteroid Day is to inform the public and raise awareness about the possibility that asteroids can collide with the Earth in the future. Today was chosen to highlight the risk because on the same day in 1908, a 30m object entered the atmosphere over a forested region in Siberia and exploded in mid­-air.

In contrast to other natural disasters, such as earthquakes, an asteroid impact is predictable. Shortly after an asteroid is discovered, its impact probability and time can be calculated to the hour, even if the potential impact is tens of years in the future. In addition, the impact location can be predicted to lie within a so­-called “impact corridor”, as shown in the image below. Because of uncertainty in the observations of asteroids, the impact prediction does not produce a point but a corridor that typically stretches across half the globe.

In essence you are unlikely to be in the immediate vicinity of the strike. However, the resulting global effects of a big impact would be Tsunami, fireballs and earthquakes. This would be followed by a dust cloud entering the atmosphere, blocking out sunlight, global climate change and a distinct genetic wipe-out effect. In short, better off to be right at the impact zone – less pain.

So what are we doing, well Space-based telescopes, such as the Sentinel mission proposed by the B612 Foundation, or Nasa’s proposed NeoCam mission, would be able to discover most of the remaining asteroids within 10 years. Such telescopes would also help reduce uncertainty in the observational data. Less uncertainty means that we can make a clearer statement about whether or not an asteroid is likely to strike Earth. Similarly, better observations narrow the impact corridors, and allow us to make better predictions about where a potential impact might occur. So don’t stress too much.

Close call

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Great NASA video on the close call asteroid which will buzz the Earth next week.

http://www.telegraph.co.uk/science/space/9856539/Nasa-2012-DA14-asteroid-will-not-impact-Earth.html

It may sound unsettling to hear that a potential killer known as asteroid 2012 DA14 will be coming closer to Earth than telecommunication satellites on Feb. 15, but don’t panic: Earth’s gravitational field will give it such a kick that we’ll never have to worry about it again. It has been getting closer to Earth for quite a while, but this is the closest predicted flyby for this object both in the past and in the future. NASA’s calculations show that Earth’s gravity will perturb the 150-foot-wide (45-meter-wide) asteroid’s orbital period, which had been getting close to Earth’s own one-year orbit. Earth is going to actually put this one in an orbit that is considerably safer than the orbit it has been in. There is an extremely remote chance that 2012 DA14 could hit a satellite on its way in or out of Earth’s neighborhood, and that satellite operators were being given orbital tracking data as a precaution. That makes 2012 DA14 nothing more than one of the universe’s most vivid reminders that we live in a cosmic shooting gallery.

Death by asteroid!

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This is a great topic for astro101 classes. We can talk about reality compared to hollywood, about big numbers, big space, and how long odds can act up over long period of time. Two new articles add to the debate.

http://www.scientificamerican.com/podcast/episode.cfm?id=earth-was-longtime-asteroid-punchin-12-05-01

This first one shows that there has been far more asteroid collisions on Earth than previously accepted, seemingly mostly from one orbital location. Best to keep any eye on these ones then.

http://www.nytimes.com/2012/05/01/science/new-studies-of-permian-extinction-shed-light-on-the-great-dying.html?_r=1&ref=science

This second one talks about a species ending event long before the time of the dinosaurs. This one knocked off 95% of species on the Earth. This one was not an asteroid collision, instead a sudden release of CO2, probably from a volcano. The scary thing about this second one is the rise of CO2 in the last 60 years or so is paralleling this situation. Perhaps we should worry more about the risks we are doing to ourselves than about big bits of rock in space.