Near Earth Objects

[Harpo]

I searched, and was very surprised to find we don’t have a Near Earth Objects topic. So let this be it.

A second Earth Trojan has just been found.

| EarthSky

earthsky.org

Orbital stability analysis and photometric characterization of the second Earth Trojan asteroid 2020 XL5 - Nature Communications

Although Trojan asteroids have been known for decades in other Solar System planets, only one Earth Trojan asteroid was detected. Here, the authors show that recently discovered 2020 XL5 is the second transient Earth Trojan asteroid.

www.nature.com

 

[Harpo]

I’ve just found this old thread on the subject:

Can you describe an effective method to deflect a comet or asteroid headed for Earth?

Asteroid deflection strategies are methods by which near-Earth objects could be diverted, preventing potentially catastrophic impact events. See also Asteroid deflection strategies - Wikipedia, the free encyclopedia In particular 2 Popular strategies 2.1 Nuclear weapons 2.2 Kinetic Impact 2.3...

www.sffchronicles.com

 

[CupofJoe]

I feel safer that someone is looking for things that might come a bit too close...

Asteroid Watch

NASA's Jet Propulsion Laboratory, the leading center for robotic exploration of the solar system.

www.jpl.nasa.gov

 

[StilLearning]

I'm fascinated by the teeny 'temporarily captured objects' that occasionally get caught in unstable orbits around Earth for a few years at a time - I wonder if they m ight be a good 'low hanging fruit' for a small private mission to investigate. Hell, they're small enough to tow into LEO and study at leisure: | EarthSky

 

[BAYLOR]

I'm fascinated by the teeny 'temporarily captured objects' that occasionally get caught in unstable orbits around Earth for a few years at a time - I wonder if they m ight be a good 'low hanging fruit' for a small private mission to investigate. Hell, they're small enough to tow into LEO and study at leisure: | EarthSky

.02 miles in diameter . It would do some damage if it hit the earth

 

[StilLearning]

That's...about 30 meters (tries to pretend he doesn't have calculator pulled up on the desktop). That's comparable to the impact that made Barringer / Meteor crater in Arizona. Coming down at typical meteorite speeds that's equivalent to a 5-20 megaton nuke...ish? Depending what it's made of. But no fallout - I have been worrying for a while about what will happen when someone realises the potential (no pun intended) of all those rocks out there...

Edit: For once my memory is on point: Barringer was 30 meters, and detonated at around 20-40 megatons Barringer Meteor Crater and Its Environmental Effects

 

[BAYLOR]

That's...about 30 meters (tries to pretend he doesn't have calculator pulled up on the desktop). That's comparable to the impact that made Barringer / Meteor crater in Arizona. Coming down at typical meteorite speeds that's equivalent to a 5-20 megaton nuke...ish? Depending what it's made of. But no fallout - I have been worrying for a while about what will happen when someone realises the potential (no pun intended) of all those rocks out there...

Or like , Tunguska, an atmospheric burst and devastate a wide area.

Near earth objects are a very scary proposition

 

[StilLearning]

For natural impacts that depends on composition (iron is best for ground strike, cometary material best for airburst) and re-entry angle (steep angle for ground strike, shallow for airburst) - if anyone reading this urgently needs this knowledge I really hope it's relating to a tight deadline on a sci-fi novel.