One proposed theory is that the incident was a hoax.
The BBC reported that a former U.S. security policeman, Kevin Conde, claimed responsibility for creating strange lights in the forest by driving around in a police vehicle whose lights he had modified.
However, there is no evidence that this prank took place on the nights in question.

Other explanations for the incident have included a downed Soviet spy satellite, but no evidence has been produced to support this.

The most plausible sceptical explanation is that the sightings were due to a combination of three main factors.
The initial sighting at 03.00 on 26 December, when the airmen saw something apparently descending into the forest, coincided with the appearance of a bright fireball over southern England, and such fireballs are a common source of UFO reports.
The supposed landing marks were identified by police and foresters as rabbit diggings.
No evidence has emerged to confirm that anything actually came down in the forest.

According to the witness statements from 26 December the flashing light seen from the forest lay in the same direction as the Orfordness Lighthouse.
When the eyewitnesses attempted to approach the light they realised it was further off than they thought.
One of the witnesses, Ed Cabansag, described it as “a beacon light off in the distance” while another, John Burroughs, said it was “a lighthouse” (see Statements from eyewitnesses on 26 December, above).

Timings on Halt’s tape recording during his sighting on 28 December indicate that the light he saw, which lay in the same direction as the light seen two nights earlier, flashed every five seconds, which was the flash rate of the Orfordness Lighthouse.

The star-like objects that Halt reported hovering low to the north and south are thought by some sceptics to have been misinterpretations of bright stars distorted by atmospheric and optical effects, another common source of UFO reports.
The brightest of them, to the south, matched the position of Sirius, the brightest star in the night sky.

In his 6 January 2009 Skeptoid podcast episode titled "The Rendlesham Forest UFO," scientific sceptic author Brian Dunning evaluated the original eye-witness reports and audio recordings, as well as the resulting media reporting of this incident.
After a lengthy analysis Dunning concluded:
Col.
Halt's thoroughness was commendable, but even he can be mistaken.
Without exception, everything he reported on his audiotape and in his written memo has a perfectly rational and unremarkable explanation... All that remains is the tale that the men were debriefed and ordered never to mention the event, and warned that "bullets are cheap".
Well, as we've seen on television, the men all talk quite freely about it, and even Col.
Halt says that to this day nobody has ever debriefed him.
So this appears to be just another dramatic invention for television, perhaps from one of the men who have expanded their stories over the years.

When you examine each piece of evidence separately on its own merit, you avoid the trap of pattern matching and finding correlations where none exist.
The meteors had nothing to do with the lighthouse or the rabbit diggings, but when you hear all three stories told together, it's easy to conclude (as did the airmen) that the light overhead became an alien spacecraft in the forest.
Always remember: Separate pieces of poor evidence don't aggregate together into a single piece of good evidence.
You can stack cowpies as high as you want, but they won't turn into a bar of gold.
One proposed theory is that the incident was a hoax. The BBC reported that a former U.S. security policeman, Kevin Conde, claimed responsibility for creating strange lights in the forest by driving around in a police vehicle whose lights he had modified. However, there is no evidence that this prank took place on the nights in question.
Other explanations for the incident have included a downed Soviet spy satellite, but no evidence has been produced to support this.
The most plausible sceptical explanation is that the sightings were due to a combination of three main factors. The initial sighting at 03.00 on 26 December, when the airmen saw something apparently descending into the forest, coincided with the appearance of a bright fireball over southern England, and such fireballs are a common source of UFO reports. The supposed landing marks were identified by police and foresters as rabbit diggings. No evidence has emerged to confirm that anything actually came down in the forest.
According to the witness statements from 26 December the flashing light seen from the forest lay in the same direction as the Orfordness Lighthouse. When the eyewitnesses attempted to approach the light they realised it was further off than they thought. One of the witnesses, Ed Cabansag, described it as “a beacon light off in the distance” while another, John Burroughs, said it was “a lighthouse” (see Statements from eyewitnesses on 26 December, above).
Timings on Halt’s tape recording during his sighting on 28 December indicate that the light he saw, which lay in the same direction as the light seen two nights earlier, flashed every five seconds, which was the flash rate of the Orfordness Lighthouse.
The star-like objects that Halt reported hovering low to the north and south are thought by some sceptics to have been misinterpretations of bright stars distorted by atmospheric and optical effects, another common source of UFO reports. The brightest of them, to the south, matched the position of Sirius, the brightest star in the night sky.
In his 6 January 2009 Skeptoid podcast episode titled "The Rendlesham Forest UFO," scientific sceptic author Brian Dunning evaluated the original eye-witness reports and audio recordings, as well as the resulting media reporting of this incident. After a lengthy analysis Dunning concluded:
Col. Halt's thoroughness was commendable, but even he can be mistaken. Without exception, everything he reported on his audiotape and in his written memo has a perfectly rational and unremarkable explanation... All that remains is the tale that the men were debriefed and ordered never to mention the event, and warned that "bullets are cheap". Well, as we've seen on television, the men all talk quite freely about it, and even Col. Halt says that to this day nobody has ever debriefed him. So this appears to be just another dramatic invention for television, perhaps from one of the men who have expanded their stories over the years.
When you examine each piece of evidence separately on its own merit, you avoid the trap of pattern matching and finding correlations where none exist. The meteors had nothing to do with the lighthouse or the rabbit diggings, but when you hear all three stories told together, it's easy to conclude (as did the airmen) that the light overhead became an alien spacecraft in the forest. Always remember: Separate pieces of poor evidence don't aggregate together into a single piece of good evidence. You can stack cowpies as high as you want, but they won't turn into a bar of gold.
Rendlesham Forest incident