Close Asteroid Pass

[steve_bank]

It was observed only a week ago.

Newly discovered asteroid to pass closer to Earth than the moon Monday

Astronomers didn’t know about the space rock until about a week ago.

www.nbcnews.com

The asteroid was discovered on May 10 by astronomers with the Mount Lemmon Survey, an astronomical project based in Arizona’s Santa Catalina Mountains.


A newly discovered asteroid estimated to be about 62 feet wide will zoom near Earth on Monday, though it is not expected to pose a threat to the planet.

It is rare for an object of this size to make such a close flyby of Earth, though not unprecedented.

 

[Tigers!]

Amazing that even today objects can get so close before we pick them up.

The energy released by a collision would be b-i-g huge. Pity we cannot store it for later.

 

[Loren Pechtel]

It's already missed us. Ballpark of Chelyabinsk size, but there's a lot of uncertainty to that.

 

[Bomb#20]

Amazing that even today objects can get so close before we pick them up.

The energy released by a collision would be b-i-g huge. Pity we cannot store it for later.

It is stored for later.

 

[Loren Pechtel]

Amazing that even today objects can get so close before we pick them up.

The energy released by a collision would be b-i-g huge. Pity we cannot store it for later.

It is stored for later.

And how do you propose we recover it??

 

[Bomb#20]

Amazing that even today objects can get so close before we pick them up.

The energy released by a collision would be b-i-g huge. Pity we cannot store it for later.

It is stored for later.

And how do you propose we recover it??

Just wait for it to come around on the guitar again.

 

[Tigers!]

Amazing that even today objects can get so close before we pick them up.

The energy released by a collision would be b-i-g huge. Pity we cannot store it for later.

It is stored for later.

What is your storage mechanism?

 

[bilby]

Amazing that even today objects can get so close before we pick them up.

The energy released by a collision would be b-i-g huge. Pity we cannot store it for later.

It is stored for later.

What is your storage mechanism?

Curved spacetime.

 

[Elixir]

If such an object hits say the Gobi desert, could it cause more mass to be ejected from the earth-moon system than its mass would add?

 

[DBT]

Doesn't seem big enough to cause a major catastrophe if it hit in an isolated region.

 

[steve_bank]

Dust in the atmosphere. 'nuclear winter'.

Watched a show on this.

Year Without a Summer - Wikipedia

en.wikipedia.org

The year 1816 is known as the Year Without a Summer because of severe climate abnormalities that caused average global temperatures to decrease by 0.4–0.7 °C (0.7–1 °F).[1] Summer temperatures in Europe that year were the coldest of any on record between 1766 and 2000,[2] resulting in crop failures and major food shortages across the Northern Hemisphere.[3]

Evidence suggests that the anomaly was predominantly a volcanic winter event caused by the massive eruption of Mount Tambora in the Dutch East Indies (modern-day Indonesia) in April 1815. This eruption was the largest in at least 1,300 years (after the hypothesized eruption causing the volcanic winter of 536); its effect on the climate may have been exacerbated by the 1814 eruption of Mayon in the Philippines. The significant amount of volcanic ash and gases released into the atmosphere blocked sunlight, leading to global cooling.

Countries such as the United Kingdom of Great Britain and Ireland and Bourbon Restoration France experienced significant hardship, with food riots and famine becoming common. The situation was exacerbated by the fact that Europe was still recovering from the Napoleonic Wars, adding to the socio-economic stress.

 

[Loren Pechtel]

Doesn't seem big enough to cause a major catastrophe if it hit in an isolated region.

This is Chelyabinsk size (with a wide error margin). No ejection.

 

[DBT]

536ad is said to have been worse. I don't know how that would compare with a 62 ft wide asteroid impact.

 

[bilby]

If such an object hits say the Gobi desert, could it cause more mass to be ejected from the earth-moon system than its mass would add?

How fast?

For an object of this size and relative speed, no.

For an object of this size at a speed conversant with a solar orbit, also no.

But there's no theoretical upper limit to the kinetic energy of an impact by an extrasolar object; If it were travelling at a sizable fraction of c, then sure.

Mind you, it wouldn't matter where it hit; Such an impact would reset geography, by melting the planet.

A somewhat less energetic impact by a much larger, but much slower, object is how the Moon is believed to have formed.

At such energies, rock behaves like a fluid. It doesn't shatter, it splashes.

 

[Elixir]

For an object of this size and relative speed, no.

So … curved spacetime was the correct answer!

 

[Loren Pechtel]

But there's no theoretical upper limit to the kinetic energy of an impact by an extrasolar object; If it were travelling at a sizable fraction of c, then sure.

Mind you, it wouldn't matter where it hit; Such an impact would reset geography, by melting the planet.

A somewhat less energetic impact by a much larger, but much slower, object is how the Moon is believed to have formed.

At such energies, rock behaves like a fluid. It doesn't shatter, it splashes.

The dinosaur killer ejected material from the atmosphere, I have seen nothing about whether any escaped. We have found material that must have gone above the atmosphere as it managed to outrace the shockwave by a substantial period of time. And that did not remotely reset geography.

 

[bilby]

But there's no theoretical upper limit to the kinetic energy of an impact by an extrasolar object; If it were travelling at a sizable fraction of c, then sure.

Mind you, it wouldn't matter where it hit; Such an impact would reset geography, by melting the planet.

A somewhat less energetic impact by a much larger, but much slower, object is how the Moon is believed to have formed.

At such energies, rock behaves like a fluid. It doesn't shatter, it splashes.

The dinosaur killer ejected material from the atmosphere, I have seen nothing about whether any escaped. We have found material that must have gone above the atmosphere as it managed to outrace the shockwave by a substantial period of time. And that did not remotely reset geography.

Sure, but the question wasn't about an impact that ejects some mass, it was about an impact sufficient to eject "more mass [...] from the earth-moon system than its mass would add"

 

[steve_bank]

kinetic energy Joules = .5*mass*velocity^2

force Newtons = mass*acceleration
change in velocity acceleration = dv/dt

Asteroid 2026 JH2 has an estimated relative kinetic energy between \(1.8 \times 10^{15}\) and \(2.5 \times 10^{15}\) Joules (approximately equivalent to \(0.44\) to \(0.6\) Megatons of TNT). This relies on its estimated diameter of \(15\) to \(35\) meters and a relative velocity of \(9.1\) to \(10\) kilometers per second.

The atomic bomb dropped on Hiroshima, known as "Little Boy," released approximately \(6.3 \times 10^{13}\) to \(6.7 \times 10^{13}\) joules (about 63 to 67 Terajoules) of energy. This explosive yield is equivalent to roughly 15 kilotons of TNT.

During the iconic 1980 eruption, Mount St. Helens released approximately \(1.0 \times 10^{17}\) joules (100 million billion joules) of total thermal energy, including about \(3 \times 10^{16}\) joules specifically from the initial lateral blast.

This monumental energy output translates to roughly 24 megatons of TNT, which is equivalent to about 1,600 times the force of the atomic bomb dropped on Hiroshima.

Following the massive May 18, 1980 eruption, fine volcanic ash injected into the stratosphere was carried by global wind currents and completely circled the Earth in about 15 days

A tactical nuclear weapon yields between \(42 \text{ gigajoules} (4.2 \times 10^{10} \text{ J})\) and \(1.26 \text{ petajoules} (1.26 \times 10^{15} \text{ J})\) of energy. This is equivalent to an explosive force ranging from 10 tons to 300 kilotons of TNT.

 

[Shadowy Man]

But there's no theoretical upper limit to the kinetic energy of an impact by an extrasolar object; If it were travelling at a sizable fraction of c, then sure.

Mind you, it wouldn't matter where it hit; Such an impact would reset geography, by melting the planet.

A somewhat less energetic impact by a much larger, but much slower, object is how the Moon is believed to have formed.

At such energies, rock behaves like a fluid. It doesn't shatter, it splashes.

The dinosaur killer ejected material from the atmosphere, I have seen nothing about whether any escaped. We have found material that must have gone above the atmosphere as it managed to outrace the shockwave by a substantial period of time. And that did not remotely reset geography.

Sure, but the question wasn't about an impact that ejects some mass, it was about an impact sufficient to eject "more mass [...] from the earth-moon system than its mass would add"

Sounds like a conservation of energy problem. The impactor is bringing in energy equal to its own mass at essentially escape velocity. How will it impart enough energy to make even more mass leave with escape velocity? The answer would be it would have to be going much, much faster than escape velocity and overcome all the other energy losses, like heat and sound, that would occur during the impact.

 

[bilby]