Talk:V-type asteroid

Section about Near-Earth V-type asteroids

I have blanked the section about V-type Near Earth asteroids. It previously said, per the version written on 21 February 2018:

V-type NEAS (or V-NEAs) are near-Earth asteroids with a V spectral type. Impacts of V-NEAs on the Earth, according to the known sample (data taken in 2016), occur once in about 12 million years and have the potential to cause disastrous effects on regional to global scale, producing craters as large as 30 km in diameter and releasing kinetic energy of as much as 3 Mt. This energy is almost 6 million times greater than the energy released during the Chelyabinsk event in 2013. Venus, Mars and the Moon will experience impacts with V-NEAs every 22 Myr, 125 Myr and 168 Myr, respectively. Two craters with confirmed basaltic impactor which fits with the impact rate found from V-type NEAs are the Strangways crater (24 km diameter) in Australia, the Nicholson crater (12.5 km diameter) in Canada. Some V-NEAs have orbits similar to that of the Bunburra Rockhole meteorite.

There are multiple problems with that, all of which can be traced back to the source. The most obvious is that the math doesn't add up: The Chelyabinsk meteor didn't release an energy of 0.5 tons of TNT. The paper also gives a comparison to the atomic bomb at Hiroshima, which would imply that it had an energy of 15 grams of TNT. It is obvious that the word "million" is missing (not just in our article, but in the source itself).

The rest of the paper is riddled with equally dubious claims. For instance, their main result are the impact rates of V-type asteroids on the terrestrial planets, deriving a rate of one per 12 million years for the Earth (together with rates for the other planets). No size limits, just any V-type asteroid. They take the sample of V-type asteroids known at the time of publication (2016) and completely disregard the question of completeness. By their methodology, the rate of impact will rise continuously as we discover more objects. It is true that, among the 49 asteroids they looked at (which is a very outdated sample by 2025), an impact with Earth is expected once every 12 million years, but that's an almost meaningless statement, considering the wide range of sizes of these objects. For comparison, HED meteorites, which are believed to originate from Vesta, have 70 documented falls over the past 220 years.[1] Impacts of V-type NEAs large enough to leave meteorites (around a meter in diameter) occur at least once every few years. Known falls of small V-type NEAs were completely disregarded by that paper, which would be fine if the paper put a size limit on the objects they studied. But their sample of 49 objects does include some small asteroids, ranging from several km down to a few tens of meters.

I'm not exactly sure what to do? The source is peer-reviewed, and was published in a reputable journal. Still, their numbers and methodology are so obviously nonsensical that I think we should just disregard the paper entirely. Which leaves us with a section that needs to be rewritten from scratch... Renerpho (talk) 11:24, 8 April 2025 (UTC)

References