Earth Is Safe From Menacing Asteroid—but Our Moon Might Take the Hit

Gizmodo ^ | Published April 1, 2025 | Passant Rabie

[BenLurkin]

Ground-based telescopes from the International Asteroid Warning Network have been tracking the asteroid, but it will be too faint to observe until June 2028...That’s why Webb was called in for the job, measuring the asteroid’s brightness across a range of infrared wavelengths to better determine its size.

In late January, a team of scientists proposed using the mid-infrared instrument on Webb to observe the asteroid and better understand its damage potential. The team recently released the preliminary results of Webb’s observations of asteroid 2024 YR4, suggesting that, while the asteroid is larger and rockier than previous observations, it has nearly a 0% chance of hitting Earth during its upcoming flyby...

Webb first spotted the asteroid on March 26, observing it as it rotated every 20 minutes over a five-hour-long period. [T]he researchers determined that the asteroid was slightly larger than previously believed. Initial estimates suggested that the asteroid measures between 130 and 300 feet wide (40 and 90 meters) based on its reflected light. Webb’s observations, however, measure the asteroid at 200 feet (60 meters) wide.

...[T]he results suggest that the asteroid “continues to have a non-zero probability of impacting the Moon at this time,” the researchers concluded. The Moon has likely endured thousands of asteroid impacts during its 4.5-billion-year history, but it’s not yet clear what would happen if asteroid 2024 YR4 strikes our natural satellite. At its current size estimate, the asteroid would likely release about 8 megatons of energy during impact...comparable to the energy released in the Tunguska blast of 1908, according to NASA.

The potential Moon impact would allow scientists the rare opportunity to observe a lunar crater being formed right before their eyes (assuming it hits within our view from Earth), and gain a better understanding of the violent history of the solar system.

[monkeyshine]

Hopefully it won’t send the moon out of our orbit.
See, me and that man up there have history.

[sit-rep]

the moon gets knocked out of orbit just a smidge, its gonna play hell on our ocean’s tides...

[Openurmind]

Great... So instead of a bullet we will get a secondary shotgun blast from the Moon. Has anyone though about how much physical influence the Moon has on the Earth? If it is slowed down or knocked even slightly off from normal orbit it would have drastic secondary residual effects on us too.

[Carry_Okie]

...[T]he results suggest that the asteroid “continues to have a non-zero probability of impacting the Moon at this time,” the researchers concluded.

Now that would be awesome video! I'm sure someone knows the probability if the impact would be in sun or shade. Getting a profile shot of the dust cloud would be amazing. Do we have instruments there to detect tremors?

[Openurmind]

“the moon gets knocked out of orbit just a smidge, its gonna play hell on our ocean’s tides...”

Oh much more than that... Our Barycenter could change. That could affect gravity influences on Tectonic plates and could eventually even affect our own orbit and axial pitch. It could affect the Magnetosphere and in turn Atmospheric Cells and weather. It could literally even change how we keep time... there are a whole slue of things that could happen if the Moon was changed from it’s normal...

[wildcard_redneck]

The Moon is smaller than the Earth but it is still a massive object and the little asteroid cannot and will not affect its orbit in any significant way if it impacts the Moon. The only danger to Earth is some of the material ejected from the impact may fall to Earth and hit an old lady in the head.

[BipolarBob]

[Carry_Okie]

Bonk

[Qwapisking]

anything is better than trouble with Uranus.

[HartleyMBaldwin]

Exactly. The moon has about 200 trillion times the mass of a 60-meter asteroid. You’d see more effect if you shot a battleship with a BB gun.

[Diana in Wisconsin]

Rover's Fault?

[Diana in Wisconsin]

It’ll do my heart some good to not have to see the ‘Death Star’ every night! ;)

[Teacher317]

The Moon is smaller than the Earth but it is still a massive object and the little asteroid cannot and will not affect its orbit in any significant way if it impacts the Moon.

F = ma

Even a small object can have a big impact, if it is moving fast enough.

[DouglasKC]

it has nearly a 0% chance of hitting Earth during its upcoming flyby

Reminds me of those memes that say things like "Your odds of being killed by a hamster are low but never zero".

[Tell It Right]

I've often thought of the moon as an example of God's design. The moon is just large enough and moves just fast enough in the orbit circling the Earth to attract asteroid/meteorites that would otherwise hit the Earth. Almost like a sentry protecting the Earth.

But the moon is not so incredibly large or moving too fast to wreak havoc on Earth (like if Jupiter's moon Ganymede orbited the Earth).

[Teacher317]

The moon has about 200 trillion times the mass of a 60-meter asteroid.

"Size matters not. Judge me by my size, do you?"

It is mass that "matters" (lame pun intended!). If it had the density of a neutron star, then we would all be done for.

[joshua c]

moon for the block

way to go moon

[Lee N. Field]

The Moon has likely endured thousands of asteroid impacts during its 4.5-billion-year history,

Ya think?

"True, by inspection."

The potential Moon impact would allow scientists the rare opportunity to observe a lunar crater being formed right before their eyes

Zehr cool if it happens.

[Teacher317]

It is also the exact size and distance from us to allow us to observe the sun’s corona during an eclipse. That’s either an amazing coincidence, or just another small indicator that there was intent there.