Comments on: Astronomers: Potentially dangerous asteroid 2024 YR4 originally came from main asteroid belt

By: john hare

john hare — Thu, 10 Apr 2025 08:11:55 +0000

Ray Van Dune
April 9, 2025 at 7:20 am
“””For years I have wondered whether Earth / Lunar orbiting asteroids could be used for planetary defense. Small deflections could be made by onboard rockets that might allow them to be steered into the path of incoming threats.”””

Obviously I agree.

https://selenianboondocks.com/2013/03/dinokiller-eight-ball/

By: Don C.

Don C. — Wed, 09 Apr 2025 20:38:46 +0000

The paper referenced here only theorizes where in the asteroid belt that 2024YR4 originated. Although it does have all of the orbital elements listed in Table 1, plus three other constants that are calculated for orbit..

This paper (arXiv:2504.04003v1 by Elango & Loeb) estimates parallax corrections for the orbit at the Dec 22, 2032 date. It also shows all six of the orbital elements.

Both papers ended with an appeal for telescopes at all five Lagrange points:
“…NEO-specific telescopes positioned at all Lagrange points thereby eliminating existing NEO blindspots.” I smell more cash for scopes.

I could not locate a paper that actually calculates the estimated “hit” percentages. Most of the folks are using the JPL Horizons system (https://ssd.jpl.nasa.gov/horizons/) for calculating the orbits of earth-moon-YR4, and may not have the time to write formal papers about their findings. But there is a tutorial for using the Horizons program yourself, with all of its 1,444,807 asteroids et al. Yeah, and here I thought there were only 1,443,500 of them!

By: Ray Van Dune

Ray Van Dune — Wed, 09 Apr 2025 17:17:55 +0000

And yes, obviously capturing such a guardian asteroid would require enormous energy, at least a nuclear powered rocket firing for months or even years!

By: wayne

wayne — Wed, 09 Apr 2025 16:47:01 +0000

Popcorn in Bed
Cassie; First Time Watching…
“Starship Troopers” (1997)
https://youtu.be/ls7aa_GRoOQ
42:05

By: Ray Van Dune

Ray Van Dune — Wed, 09 Apr 2025 14:20:23 +0000

For years I have wondered whether Earth / Lunar orbiting asteroids could be used for planetary defense. Small deflections could be made by onboard rockets that might allow them to be steered into the path of incoming threats.

By: Jeff Wright

Jeff Wright — Wed, 09 Apr 2025 02:46:53 +0000

Some have suggested burying inflatable based in rubble piles for shielding –but a nice solid rock has its charms as well.