Buzzed, by #2014 JO25

The name is terribly mundane, but the consequences of the close pass of asteroid 2014 JO25 last week are anything but. This peanut-shaped, 1400-yards, asteroid whizzed past Earth at a distance of about 1 million miles. At 4 time the Earth-Moon distance, that seems pretty safe, but in astronomy sizes that is a buzz call.

From

https://www.washingtonpost.com/news/capital-weather-gang/wp/2017/04/19/an-asteroid-will-not-destroy-earth-today-but-lets-consider-that-for-a-moment/?utm_term=.d5d5239cf6e0

Good news: Wednesday was the closest this asteroid has been in 400 years, and it won’t get this close again for at least 500 years. It’s not going to hit Earth, and if it were, we’d know it by now.

Somewhat disconcerting news: When the radar at Arecibo Observatory in Puerto Rico spotted it, astronomers realized the space rock was larger than they had thought. Today’s estimate is about 0.8 miles wide.

Let us, for a moment, consider a scenario in which a 0.8-mile-wide asteroid strikes Earth. First, the magic number for total apocalypse is 60 miles. That’s how big an asteroid would need to be to wipe out human life. At six miles wide, even the asteroid that led to dinosaur extinction was much smaller than the Earth-obliterating scenario.

When physics tells me an asteroid this large would release 1031 Joules of kinetic energy, I take note. That’s how much energy the sun releases in a day. Think about that for a minute. But don’t dwell! Breathe easy.

Luckily, there’s nothing that large orbiting in our neighborhood. Instead, we’re plagued by articles like this that pop up every other month when little space rocks pass our planet 1 million miles away.

 

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

 

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.

The Earth, Moon and Comet 67/P showing how they would appear in the same light conditions (Not to correct size scale)

BOGOF? For asteroids? #rosetta #DuckComet

7 papers in the free special edition of Science magazine yesterday with results from the Rosetta mission. The duck-shaped comet 67P/Churyumov-Gerasimenko,is giving up its secrets one by one. And its biggest secret may be BOGOF.

Recall this great mission had a long journey to its target and then even landed on the surface of the asteroid.

http://news.discovery.com/space/videos/rosettas-10-year-gravity-fling-to-catch-a-comet-video-141112.htm

These set of initial results present new light on many different topics.

First up, the type of water on the comet is not the same type of water we have on Earth. So while comets may still have brought water to Earth, this comet is not an example of one that could have done so.

Second, the comet is spitting out gas in very strange and complex manned. It is a weird comet, after all – it looks more like two comets stuck together, which leads is nicely onto the next finding – maybe it is 2 comets stuck together.It may well turn out that the two blobs of the comet are different material, so this may have started out as two bodies, coallesed into one. So, Buy One Get One Free

Finally, it density is similar to that in the insoles of your new shoes – that aerogel that gives you a nice smooth walk. This is much lighter than anticipated, so the scientific models will have to adapt.

More to come as the comet gets closer to the Sun over the next 8 months.

An astronomical stepping stone? #ceres #amacrojot

Ceres has never quite decided exactly what is should be when it grows up. Originally declared a planet when it was found in the nineteenth century, it was quickly demoted to being ‘star-like’ – asteroid. But it has always stood out from its fellow asteroid. For a start it, by itself, accounts for 1/3 the mass of the entire asteroid belt. Then when Pluto got demoted, Ceres got promoted to the status of dwarf planet. It is important enough to have it’s own mission, called Dawn. Now the big suppose is how much water it might have.

From The Verge

Scientists have speculated for decades that Ceres — the planet-like heavenly body embedded in our solar system’s asteroid belt — might contain water, still considered a rarity in our solar system. They haven’t been sure, though, until now: researchers at the European Space Agency and the Observatoire de Paris (Paris Observatory) have used the Herschel space telescope to detect two “geysers” on Ceres’ surface, blasting plumes of water vapor into the void. Further analysis indicated that some of the water ends up falling back onto the dwarf planet’s surface.

What’s less clear, though, is where the water is coming from. Scientists involved in the research speculate that an ocean could lie beneath Ceres’ surface, or there could just be isolated zones of liquid fueling each of the geysers. Fortunately, help is on the way: NASA’s Dawn spacecraft arrives at Ceres in February of next year after studying asteroid Vesta, which should provide the high-resolution images researchers need to decode the mysteries of the largest object between Mars and Jupiter.

NASA grand challenge

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( Reuters) – NASA called on backyard astronomers and other citizen-scientists on Tuesday to help track asteroids that could create havoc on Earth.

http://www.youtube.com/watch?v=f5rsJwsyni4

The U.S. space agency has already identified 95 percent of the potentially planet-killing NEOs – near Earth objects – with a diameter of .62 miles or more, a size comparable to the space rock many scientists believe wiped out the dinosaurs some 65 million years ago.

Now NASA wants to work with individuals, government agencies, international partners and academia to “find all asteroid threats to human populations and know what to do about them.” Between 50 and 100 amateur astronomers are doing what is called light-curve analysis on space rocks, making repeated images of the astronomical bodies to help determine their characteristics, said Jason Kessler, program executive for what NASA calls Astroid Grand Challenge.

“We’re certainly going to need more help with that as our detection rate goes up,” Kessler said by telephone. He acknowledged that what NASA aims to do, at least in part, is to crowd-source asteroid detection.

Even smaller space rocks can be dangerous, whether or not they hit the Earth. In February, a meteorite about 19 yards in diameter exploded over central Russia, shattering windows, damaging buildings and injuring 1,200 people.

Earlier this month, an asteroid the size of a small truck zoomed past the Earth four times closer than the moon, crossing within about 65,000 miles over the Southern Ocean south of Tasmania, Australia.

Spectacular cosmic coincidence

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A 10 tonne asteroid has crashed into Russia early this morning. The large piece of space rock probably shattered 20 miles above the ground, it enough fragments made it all the way down to Earth to cause significant damage. The small crater in the ice above is the result of one of the fragments. At least 950 people were injured as the resulting shockwave blew out windows and shook buildings in the Ural Mountains.

“It was quite extraordinary,” Chelyabinsk resident Polina Zolotarevskaya told BBC News. “We saw a very bright light and then there was a kind of a track, white and yellow in the sky.” “The explosion was so strong that some windows in our building and in the buildings that are across the road and in the city in general, the windows broke.”

Your can see it for yourself here

http://www.telegraph.co.uk/news/newsvideo/9872507/The-science-behind-Russian-meteor-strike.html

Asteroids this size strike the Earth several hundred times a year, but are mostly over sea or desolate places and mostly burn up. But this event shows that when the trajectory is right, it can cause a lot of damage. Scientists have played down suggestions that there is any link between the event in the Urals and 2012 DA14, an asteroid expected to race past the Earth on Friday at a distance of just 27,700km (17,200 miles) – the closest ever predicted for an object of that size. The two asteroids approached from different directions, so it appears to be a cosmic coincidence.

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.

8th century radiation blast.

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http://www.nature.com/nature/journal/v486/n7402/full/nature11123.html

http://mnras.oxfordjournals.org/content/early/2013/01/08/mnras.sts378.full

A real mystery is developing. In 2012 researchers found evidence that our planet had been struck by a blast of radiation during the Middle Ages, but there was debate over what kind of cosmic event could have caused this. Either a rare solar flare or an even bigger explosion, a gamma-ray burst seems to be the culprit. Last year, a team of researchers found that some ancient cedar trees in Japan had an unusual level of a radioactive type of carbon known as carbon-14. In Antarctica, too, there was a spike in levels of a form of beryllium – beryllium-10 – in the ice. These isotopes are created when intense radiation hits the atoms in the upper atmosphere, suggesting that a blast of energy had once hit our planet from space. Using tree rings and ice-core data, researchers were able to pinpoint that this would have occurred between the years AD 774 and AD 775, but the cause of the event was a puzzle.

Observations of deep space suggest that gamma ray-bursts are rare. They are thought to happen at the most every 10,000 years per galaxy, and at the least every million years per galaxy. If a cosmic explosion happened at the same distance as the 8th Century event, it could knock out our satellites. But if it occurred even closer – just a few hundred light-years away – it would destroy our ozone layer, with devastating effects for life on Earth.

Two teams of scientists, two different conclusions! That’s the way science works. Either more data, or a better developed theory will show which one is right. Until then, may the debate continue.