Detecting asteroids that might smite us

[Mr. Bill]

My brother happens to be an astrophysicist, and he has released the first 3 parts of an educational video series about asteroids that might impact Earth, and how they are detected.  This is pretty nerdy stuff, but it explains the technical issues visually, and doesn't require an advanced degree to understand.  (Possibly also of interest to you folks who are home-schooling.)

Asteroid Hazards, Part 1: What Makes an Asteroid a Hazard? -- 6 min -- The basics: what's an asteroid?, what's an orbit?, etc.

Asteroid Hazards, Part 2: The Challenge of Detection -- 7 min -- Why was it impossible to get advance warning of the house-sized asteroid that exploded over Chelyabinsk in Feb 2013?

Asteroid Hazards, Part 3: Finding the Path -- 6 min -- How is the orbit of an asteroid calculated?  Definitely nerdier than parts 1 and 2, but explains the observations that are needed.

Asteroid Hazards, Part 4: Predicting the Impact Risk -- should be available in late 2015 early 2016(?)

[FreeLancer]

I love that word, smite. So Old Testament.

[David in MN]

Utterly fascinating...

[Mr. Bill]

NASA: Small Asteroid to Pass Close to Earth March 5

...During the upcoming March 5 flyby, asteroid 2013 TX68 could fly past Earth as far out as 9 million miles (14 million kilometers) or as close as 11,000 miles (17,000 kilometers). The variation in possible closest approach distances is due to the wide range of possible trajectories for this object, since it was tracked for only a short time after discovery. ...

Refer to my bro's videos linked above to understand why the range is so wide.

[Mr. Bill]

NPR, 4/29/19: This Week, NASA Is Pretending An Asteroid Is On Its Way To Smack The Earth

The giant asteroid is in a horrible orbit and has a 1% chance of striking the Earth in just eight years. And — thank goodness — it doesn't really exist.

It's a fictitious asteroid that's the focus of a realistic exercise devised for scientists and engineers from around the world who are attending the 2019 Planetary Defense Conference being held this week outside of Washington, D.C.

A real asteroid of this size, should it ever hit the planet, could wipe out an entire city. ...

This time around, the pretend asteroid is around 300 to 1,000 feet across, and was spotted around 35 million miles away. What's known about its fake trajectory indicates that it has a 1 percent chance of hitting our planet in 2027. ...

"The asteroid is not in a convenient orbit at all. ... It's not like one of these asteroids that we go to with our science missions, where you get to pick a nice asteroid that's easy to get to. In planetary defense, the asteroid picks you."...

[Gamer]

I found these anti-asteroid suggestions on the net, can forum members think of any more?

1- KINETIC IMPACTOR:  a spacecraft that would deliberately crash into an asteroid at high velocity in an effort to alter its trajectory.

2- GRAVITY TRACTOR: a spacecraft that will fly alongside the asteroid for a period and exert a gravitational effect on it.

3-  LASER KETTLE: a spacecraft flies alongside an asteroid and uses lasers to heat its surface generating a plume of gas and debris that gives the asteroid a subtle push.

4- ATTACHING ROCKET: attaching a low impulse rocket to the asteroid to deflect it..

5- SHREDDER: placing an automated “mass ejector” system on the surface of the asteroid that would extract mass from the rock and eject it into space, again giving the object a steady push.

6- NUKE BOMB SHOCK WAVE: a nuclear charge is detonated at a certain distance from the object causing a flow of radiation that will vaporise the asteroid’s surface and push it into a different orbit.

7- NUKE BOMB IMPLANT: as used by Bruce Willis in the film Armageddon by burying a giant bomb beneath the surface and blasting the asteroid to smithereens.

https://www.theengineer.co.uk/protecting-planet-large-meteor-strikes/

[Mr. Bill]

"2019 OK" missed us by 45,000 miles a few days ago.

Astronomy, 7/25/29: A large asteroid just zipped between Earth and the Moon

...Because it’s such a newcomer, there’s still a lot astronomers aren’t sure about, from its orbit to its size, which ranges between 187 to 426 feet (57 to 130 meters) across. 

While Earth gets a few asteroid visitors that buzz closer than the Moon every year, this one is the largest so far in 2019. ...

For reference, the asteroid purported to have killed the dinosaurs 66 million years ago was about 10 miles (16 km) across, if not larger, while the meteor that flew over Chelyabinsk, Russia in 2013 was only 66 feet (20 m) across.

So if 2019 OK had struck Earth, it could have delivered quite the blow to any city it struck, but would not have been a world-wide event. ...