If asteroid YR4 hits our Moon, it’s going to trigger a shiny flash and meteors as particles hits Earth, say scientists

If asteroid 2024 YR4 does hit the Moon, it might produce a shiny flash on the lunar floor that might be seen from Earth, and spray particles into our planet’s ambiance.

Such an affect could even produce meteors seen in our evening sky, and generate an infrared glow seen hours after the occasion.

These are a few of the outcomes of a brand new examine wanting into what is going to occur if the massive asteroid does hit our Moon in 2032.

The story to this point

Asteroid 2024 YR4 grew to become one of many large speaking factors in the course of the first half of 2025, when it was reported that there was an opportunity this huge area rock might hit Earth in 2023.

The asteroid was found in December 2024 and initially sparked concern as scientists calculated there was a 3.1% likelihood of it hanging Earth in 2032.

Asteroid 2024 YR4 was travelling away from Earth in the course of the time of those observations, however is about to return in 2032.

Astronomers have been eager to be taught as a lot in regards to the asteroid’s orbital trajectory as they might, earlier than it disappeared, so they might calculate the likelihood of it hitting Earth upon its return.

Further observations and knowledge from the James Webb Space Telescope successfully dominated out a risk to Earth, however as an alternative raised the likelihood it might hit our Moon.

By April 2025, refined measurements narrowed the asteroid’s measurement to about 60 metres throughout and calculated the likelihood of it hitting our Moon as 3.8%.

Although the rock will stay unobservable for a number of years because it orbits the Sun, scientists are nonetheless making ready for its return on 22 December 2032.

Asteroid 2024 YR4’s shiny flash on the Moon

A draft science paper titled ‘Observation Timelines for the Potential Lunar Impact of Asteroid 2024 YR4‘, printed in January 2026, reveals what would occur if asteroid 2024 YR4 did hit the Moon in 2023.

It says the asteroid has a 4.3% likelihood of hitting our Moon.

If this did occur, the paper says, it might produce a roughly 1km-wide (0.6 miles) crater on the lunar floor.

It could be the “most energetic lunar impact event ever recorded in human history,” the paper says.

This could be accompanied by a visible flash on the Moon that might seemingly be seen from Earth.

In reality, the paper says the related flash of 2024 YR4 smashing into the Moon may very well be as shiny as magnitude –3, which is about as shiny as a planet like Mars or Jupiter seems to the bare eye from Earth, after they’re at their greatest.

For context, Sirius, the brightest star within the sky, is about magnitude –1.5.

In the magnitude scale, the brighter an object is, the decrease its magnitude is, so meaning asteroid 2024 YR4’s affect on the Moon could be a lot brighter than Sirius.

Such a flash would final a number of minutes after the affect, and a ensuing infrared afterglow would final a number of hours, the paper says.

What’s extra, the affect would result in a worldwide Moonquake simply detectable by seismometers.

The ensuing particles from the affect would trigger about 108kg of lunar rocks and mud to flee the Moon’s gravity, hit Earth Earth and trigger meteors seen in our sky.

“Despite the associated risk,” the paper says, “this situation provides a uncommon and useful scientific alternative.

Observing 2024 YR4’s affect on the Moon

The paper factors to a window of alternative to watch asteroid 2024 YR4 as early as 2028, which might assist astronomers calculate whether or not the asteroid will certainly hit our Moon in 2032.

Then, within the months main as much as the potential collision, additional observations would have the ability to decide an affect timeline right down to the minute.

Observations might additionally decide the place on the Moon it is going to affect, and the place we must be pointing our telescopes.

“On the Moon, active orbiters and landers should be placed in recording or imaging mode, and seismometers armed for immediate data logging,” the paper says.

Spacecraft across the Moon that may observe the aftermath might embody NASA’s Lunar Reconnaissance Orbiter and India’s Chandrayaan3 orbiter.

The paper says the anticipated affect on 22 December 2023 would happen when the Moon is a waning gibbous, about 70% illuminated.

That implies that, on the time of 2024 YR4’s affect, the Moon would seem large and shiny from Earth, simply days after full Moon.

The examine says one of the best locations to see the affect shall be from the Pacific hemisphere, among the finest ground-based observatories to see will probably be Mauna Kea, which incudes the Keck, Subaru and Gemini North telescopes.

Gemini North is notable as being one of many ground-based telescopes that captured wonderful views of comet 3I/ATLAS, the interstellar physique that appeared in Earth’s skies late in 2025/early 2026.

If asteroid 2024 YR4 did hit the Moon, the examine says the Moon could be seen within the western a part of North America close to daybreak, whereas South America, Europe and Asia would have a daylight or low Moon, making observations tough in these components of the world.

Timeline of the Moon affect

The paper authors produced a timeline displaying what would occur from the second of affect to the times, weeks months and years after affect.

Moment of Impact

The examine says the affect of asteroid 2024 YR4 hitting the Moon would produce a flash with an anticipated brightness of magnitude –3 to –5, doubtlessly making it seen to the bare eye if it hits the un-lit portion of the Moon.

This would give astronomers utilizing skilled telescopes the chance to watch the flash in actual time, and even perhaps determine the chemical signatures of the lunar materials ejected from the floor.

Even if the affect does occur on the lit aspect of the Moon, simply past the ‘terminator’ – the road dividing mild and shadow on the lunar floor – it might nonetheless be highly effective sufficient to mild up the encompassing terrain.

Minutes to hours

Just minutes after the flash, a 1km crater would glow in infrared for a number of hours, based on the paper, which means infrared telescopes would have the ability to observe the glow because it cools.

Enormous Moonquakes might attain seismic stations on the Moon inside about 7–quarter-hour.

The examine authors level to a spread of attainable research of the affect, from infrared observations to seismological detections of the quake and observations of the affect crater by lunar orbiters.

Days to years

Between two to eight days after asteroid 2024 YR4’s affect with the Moon, the paper says, lunar particles reaching Earth might create a visual meteor bathe’.

A small fraction of lunar fragments might even survive plummeting via Earth’s ambiance, land on Earth and be discoverable as lunar meteorites over the approaching years.