Last week an observatory in New Mexico was mysteriously shut down by the FBI, with the Internet going wild with speculation as to why. Yes, lots of people said aliens.

But now the actual reason has been revealed, and it’s… not funny at all. FBI records obtained by Reuters said that the Sunspot Solar Observatory, part of the National Solar Observatory on Sacramento Peak, was shut down due to criminal activity, specifically a child porn investigation.

The report said that the FBI was “investigating the activities of an individual who was utilizing the wireless internet service of the National Solar Observatory in Sunspot, New Mexico, to download and distribute child pornography.”

This person was identified as a janitor contracted to clean the facility whose laptop had been connected to the observatory’s Wi-Fi. Fearing the person might pose a danger, the decision was made to shut the observatory. It re-opened on Monday, September 17.

The Association of Universities for Research in Astronomy (AURA), who runs the facility, said on Monday they had been “cooperating with an on-going law enforcement investigation of criminal activity that occurred at Sacramento Peak.”

According to Gizmodo, the search warrant claimed hundreds of child porn files had been downloaded and distributed on the observatory’s Wi-Fi. Only one person’s activity was found to correlate with the trail of online activity.

Their computer was seized by the FBI, with the janitor protesting his innocence, claiming others had access to it. When he started becoming erratic and potentially dangerous, the FBI took the decision to evacuate the observatory to be on the safe side.

According to the New Mexico news station KRQE, the suspect said it was "only a matter of time before the facility got hit,” and he "believed there was a serial killer in the area" that could execute someone in the facility.

AURA apologized on Sunday, September 16 in a statement for the lack of information at the time. “The decision to vacate was based on the logistical challenges associated with protecting personnel at such a remote location, and the need for an expeditious response to the potential threat,” they said.

“We recognize that the lack of communications while the facility was vacated was concerning and frustrating for some. However, our desire to provide additional information had to be balanced against the risk that, if spread at the time, the news would alert the suspect and impede the law enforcement investigation.”

The janitor has not been named because he has yet to be formally charged, while the observatory has remained open since the unpleasant incident.