5M asteroid passing by tomorrow closer than the Moon

[Delta4Embassy]

Just saw this this morning during my rounds of various sites.

SpaceWeather.com -- News and information about meteor showers, solar flares, auroras, and near-Earth asteroids

"2015 TC25
Oct 13

0.3 LD

5 m"

Still about 130,000KM away, but just one-third the distance from Earth to Moon. That's REALLY close as these things go. These 5M ones hit the planet about once a month. Most splashing down in the ocean where we may not even notice them.

 

[waltky]

Big ol' asteroid hit earth long ago...

Tantalizing Remains of an Ancient Earth-Shaking Asteroid
May 16, 2016 - Tiny glass beads scientists have discovered on what used to be ocean floor tell the tale of a giant asteroid that hit the earth billions of years ago.

The beads are called spherules and scientists from the Australian National University found them in far Northwestern Australia. The asteroid 20 to 30 kilometers across would have left a crater hundreds of kilometers wide when it hit.

That's a big asteroid

A rock that size would also, have triggered "earthquakes orders of magnitude greater than terrestrial earthquakes," according scientist Andrew Glikson. "It would have caused huge tsunamis and would have made cliffs crumble." The debris from such a huge impact Glikson says would also have spread around the world. But the constant movement and volcanic activity of our home planet would have obliterated any clues to where it hit.

Marble Bar sediments, a microcrystalline silicone-rich chert​

The oceans of the moon, called mare are the remains of similar sized rocks that hit our lunar companion between 3.8 and 3.9 billion years ago, so it makes sense that a few would have been pulled to earth. So instead of looking for craters, the scientists looked for the vaporized materials that would have been thrown into the atmosphere and coated the planet.

What they found were these tiny spherules of glass, heavy with metals like platinum, nickel and chromium that match up with the elements we find inside most asteroids. Scientific dating methods put the impact date at about 3.46 billion years ago. Glikson has been looking for impacts like these for 20 years and he has found about 17, but he thinks there could have been hundreds, some strong enough to change the way the earth evolved.

Tantalizing Remains of an Ancient Earth-Shaking Asteroid

See also:

Scientists Find Traces of Early Earth in Volcanic Rock
May 13th, 2016 - According to most scientists, Earth was formed between 4.5 and 4.6 billion years ago after gravity forced gas and dust left over from the creation of the Sun accreted into an object called a planetesimal.

Over time, the planetesimal continued to gather more and more material and eventually became a planet. Scientists say heat produced by this formation process caused our early planet to melt. The heat separated Earth’s material into layers with heavy matter such as iron sinking down to the center of planet to form its core. Lighter and less dense material such as silicates floated above the core, subsequently forming what would become the Earth’s mantle and crust. As the planet evolved, the mantle continued this process of melting and separating with heavier remnants sinking downwards and lighter material rising toward the top to form the Earth’s crust.

It’s thought this process, over the years, changed the chemical composition of the mantle to a point where any of the original ancient mantle material dating back to the core’s formation may have completely disappeared. Now a consortium of US and Canadian research institutions say they have found two ‘birthmarks’ of silicate material from Earth’s mantle that may have formed when our planet was a mere 50 million years old. Writing in the journal Science, the researchers say they’ve found clear signatures of this unique silicate material in comparatively young rocks from two locations that are a long distance from each other.

One of the samples of the ancient material came from Baffin Island, which is located off the coast of northern Canada, while the other was found in the Ontong-Java Plateau just north of the Solomon Islands in the Pacific Ocean. The volcanic rock containing the primitive mantle signatures are known as flood basalts and were created about 60 to 120 million years ago by massive lava eruptions. What led the researchers to detect the primordial mantle material in the volcanic rock was a profusion of an isotope of tungsten called tungsten-182.

Scientists say this tungsten isotope is created when an isotope of the element hafnium (hafnium-182) undergoes radioactive decay – changes in its elemental composition as it gives off radiation. According to the researchers, the radioactive decay of hafnium-182 into tungsten-182 takes place so quickly – about 9 million years – that differences in the amounts of tungsten-182 compared to other tungsten isotopes can only be due to processes that took place very early in the history of our Solar System.

Scientists Find Traces of Early Earth in Volcanic Rock « Science World

 

[MarathonMike]

I still say NASA needs to get funding for a moon-based asteroid intercept system. We have existing ICBM intercept technology that can readily be adapted for asteroid intercept.

 

[idb]

I still say NASA needs to get funding for a moon-based asteroid intercept system. We have existing ICBM intercept technology that can readily be adapted for asteroid intercept.

I can imagine the headlines in the Russian media now...

 

[waltky]

Granny wishes dem space aliens would stop flingin' dem rocks at us...

... one o' these days dey gonna hit somebody...

... or town.

 

[MarathonMike]

When the big one with our name on it shows up, it might be nice to have a fighting chance, no?