Is it possible for a meteorite to start a fire on the ground?

Question

Just came across this video (which has already been debunked) where it is claimed that a meteorite caused a house fire. (Turns out the meteorite actually landed about 200 miles away.)

Most of the video is filled with the information most of us are probably familiar with stating that meteorites are generally at ambient temperature when they reach the ground. But a quick search for Meteorite causes house fire shows a lot of people took this seriously.

Are there any known instances of a meteorite causing a fire? Or even theoretical analysis to say it's possible?

Answer 1

Obviously an asteroid impact can sometimes start fires on the ground.

The Tunguska Event in 1908 probably caused fires on the ground. When investigating in 1927:

Kulik led a scientific expedition to the Tunguska blast site in 1927. He hired local Evenki hunters to guide his team to the centre of the blast area, where they expected to find an impact crater. To their surprise, there was no crater to be found at ground zero. Instead they found a zone, roughly 8 kilometres (5.0 mi) across, where the trees were scorched and devoid of branches, but still standing upright.[24] Trees more distant from the centre had been partly scorched and knocked down in a direction away from the centre, creating a large radial pattern of downed trees.

https://en.wikipedia.org/wiki/Tunguska_event#:~:text=The%20explosion%20over%20the%20sparsely,have%20died%20in%20the%20event.

The scorchig of the trees may have caused by fires on the ground as well as by the heat of the blast.

The Chicxulub Impact is believed to have caused fires over most of the planet.

A cloud of hot dust, ash and steam would have spread from the crater, with as much as 25 trillion metric tons of excavated material being ejected into the atmosphere by the blast. Some of this material escaped orbit, dispersing throughout the Solar System,4 while some of it fell back to Earth, heated to incandescence upon re-entry. The rock heated Earth's surface and ignited wildfires, estimated to have enveloped nearly 70% of the planet's forests

https://en.wikipedia.org/wiki/Chicxulub_crater#Effects

The Tunguska impactor was:

The explosion is generally attributed to a meteor air burst: the atmospheric explosion of a stony asteroid about 50–60 metres (160–200 feet) in size.[2][8]: p. 178

And the Chicxulub impactor:

It was formed slightly over 66 million years ago when a large asteroid, about ten kilometers (six miles) in diameter, struck Earth.

So asteroids wich are about 50 to 60 metes, and about 10 kilometers, in diameter can cause fires on Earth. Do such large aseroids count as meteorites?

Remember that a meteoroid is a space object which enters the atmosphere and leaves a trail of glowing gas which is a meteor as seen from the ground. And if a meteoroid survives passing thorugh the atmosphere and reaches the ground it is a meteorite.

Meteoroids are defined as objects significantly smaller than asteroids, ranging in size from grains to objects up to a meter wide.3 Objects smaller than this are classified as micrometeoroids or space dust.24 Most are fragments from comets or asteroids, whereas others are collision impact debris ejected from bodies such as the Moon or Mars.[5][6][7]

In 1961, the International Astronomical Union (IAU) defined a meteoroid as "a solid object moving in interplanetary space, of a size considerably smaller than an asteroid and considerably larger than an atom".[10][11] In 1995, Beech and Steel, writing in the Quarterly Journal of the Royal Astronomical Society, proposed a new definition where a meteoroid would be between 100 µm and 10 m (33 ft) across.[12] In 2010, following the discovery of asteroids below 10 m in size, Rubin and Grossman proposed a revision of the previous definition of meteoroid to objects between 10 µm and one meter (3 ft 3 in) in diameter in order to maintain the distinction.2 According to Rubin and Grossman, the minimum size of an asteroid is given by what can be discovered from Earth-bound telescopes, so the distinction between meteoroid and asteroid is fuzzy. Some of the smallest asteroids discovered (based on absolute magnitude H) are 2008 TS26 with H = 33.2[13] and 2011 CQ1 with H = 32.1[14] both with an estimated size of one m (3 ft 3 in).[15] In April 2017, the IAU adopted an official revision of its definition, limiting size to between 30 µm and one meter in diameter, but allowing for a deviation for any object causing a meteor.[16]

https://en.wikipedia.org/wiki/Meteoroid

so meteoroids are less than 1 meter in diameter, and meteorites are meteoroids which survive passing though the atmosphere to hit the ground.

And there is a exception to the size defintion of a meteoroid:

In the context of meteor observations, any object causing a meteor can be termed a meteoroid, irrespective of size.

https://www.imo.net/definitions-of-terms-in-meteor-astronomy-iau/

So if someone wants to they can claim that any impacting asteroid or comet large enough to start fires on the ground would count as being a meteoroid, since it wold certainly be large enough to make a meteor passing through the atmosphere, and thus that any frgament which reached the ground would be a meteorite.

And I don't know if any any ordinary sized meteorites have caused fires on the ground.

Answer 2

As mentioned already in M.A.Golding's answer that ordinary meteorites are unlikely to cause any forest fire but it is the big asteroids capable of causing a catastrophe can cause a huge forest fire (e.g. Chicxulub impactor, Tunguska meteor), it was actually discussed when a forest fire happened in Hampshire. People linked the forest fire with a meteorite. On 3 October 2017, a passerby saw a meteor streak through the sky and crash on the forest area. The blaze in the area later spread to between 22 to 25 surrounding acres of forest. While there is a possibility that the meteorite is the reason for the forest fire, scientist debunked it. Most of the meteorites that enters the Earth's atmosphere disintegrates almost completely leaving behind a chunk of rock; the atmosphere sucking away any frictional heat caused. This process is called ablation. Quoting from the article:

The ablation process, which occurs over the majority of the meteorite’s path, is a very efficient heat removal method, and was effectively copied for use during the early manned space flights for re-entry into the atmosphere. During the final free-fall portion of their flight, meteorites undergo very little frictional heating, and probably reach the ground at only slightly above ambient temperature.

While "big" meteorites are capable of transferring their kinetic energy to thermal energy that can heat up and cause fire, the "small" ones are not capable of doing it and probably quite cold at the time of impact (note that the rock is ice cold at space, so there is not much temperature increase). The rocks itself are poor conductors of heat and although it is hot enough to singe grass, it is highly unlikely to cause a huge forest fire. You can watch this video for more details.

Moreover, the forest fire of 1871 which many believed to be due to meteorite was also debunked.