It appears that New Zealand is under a meteor war. Astronomers and scientists aim to recover them, but they are particular because they have a green color.
A meteorite bombardment is hitting New Zealand . This came after a huge meteor exploded above the sea near Wellington on 7 July. A sonic boom was created and after two weeks a smaller fireball was caught over Canterbury. Astronomers and citizens have teamed up to recover fallen meteorites. The peculiarity is that they are of a bright green color similar to that of the auroras .
Meteors announce the arrival of a piece of nickel and iron asteroid which then hit the atmosphere at a speed of 60 km per second. This releases heat really quickly, so the iron and nickel produce a green light. Is it the same bright green as the aurora? The answer is not that simple. The green light of the aurora is caused by oxygen ions in the upper atmosphere. They are created by collisions between atmospheric oxygen molecules and particles eliminated by the sun.
Oxygen ions recombine with electrons to make oxygen atoms. Electrons can last in the excitation phase for several seconds. In this phase there is a “forbidden” transition with which they radiate auroral green light at 557 nm of wavelength. Here is that the meteor , when compared with an aurora, can shine like this, but only if it is really fast. Very fast meteors warm up over 100 km where the auroras stop.
For the recovery of fallen meteorites, an attempt was made to sensitize citizen scientists to build meteoric cameras to immortalize such events. They not only allow you to find the rock, but also to know which part of the solar system the meteorite came from. Meteoric cameras are populating Tagus and the South Island. The North Island has yet to be completed.
- Bright Green Meteors Seem to Be Raining Down on New Zealand, But Why? (sciencealert.com)