Update: Remote solar observatory reopens after mysterious evacuation

*Update, 17 September, 3:55 p.m.: The Sunspot Solar Observatory in New Mexico reopened today. In a statement, the operator of the site, the Association of Universities for Research in Astronomy (AURA), said it has been cooperating with an ongoing law enforcement investigation of criminal activity that occurred on the site. The organization said it evacuated the site because of a concern that a suspect posed a threat to the safety of staff and residents. AURA has not said what the suspected criminal activity is and said it was reluctant to share news during the shutdown because it did not want to alert the suspect and impede the investigation. The original story, published on 14 September, is below.

Nobody is quite sure what’s going on at the Sunspot Solar Observatory in New Mexico, which was quickly and mysteriously evacuated on 6 September amid reports of a Federal Bureau of Investigation (FBI) probe, and has remained closed. The manager of the mountaintop site, the Association of Universities for Research in Astronomy (AURA), today released a statement saying the observatory “will remain closed until further notice due to an ongoing security concern.”

In the wake of the shutdown, Otero County Sheriff Benny House told the Alamogordo Daily News: “The FBI were up there. What their purpose was nobody will say.” Facility employees are similarly in the dark. “We have absolutely no idea what is going on,” says Alisdair Davey, a data center scientist at the National Solar Observatory (NSO). “As in truly nothing, which in itself is just weird.” Messages left with the FBI field office in Albuquerque were not returned.

AURA manages the site for NSO, a National Science Foundation-funded group. New Mexico State University (NMSU) in Las Cruces leads the consortium, including NSO and other universities, that operates the observatory’s Dunn Solar Telescope, which conducts routine observations of the sun used by scientists around the world.

All buildings on the site have been shut down and the staff of approximately 12 have been sent home, says James McAteer, Sunspot director and an NMSU astronomer in Las Cruces. He says shutdown events are not unusual, because remote mountaintop facilities can be closed due to sewage leaks, downed power lines, or snowstorms. But the Apache Point Observatory, located slightly lower down on the same mountain, remains open.

The U.S. Postal Service (USPS), which has a small office on the same site as Sunspot that mostly handles mail deliveries for the observatory, has also been shut down, though spokespeople for the office say the post office being closed is incidental. “Whatever’s occurring there has nothing to do with us,” says Rod Spurgeon, the USPS spokesperson for the New Mexico area. Spurgeon downplayed the idea that the incident could involve any sort of mailed biohazard or bioterror. “I haven’t heard of anything like that going on,” he says. Liz Davis, a public information officer at the U.S. Postal Inspection Service, which handles law enforcement for the USPS, confirms there is “no criminal activity, which is what Postal Inspection Service would be dealing with.”

The Sunspot observatory on Sacramento Peak overlooks Holloman Air Force Base and an observer could potentially see out to the U.S. Army’s White Sands Missile Test range. That has raised questions about possible espionage. “New Mexico is a center of national-security-related science, and for that reason it has also been a prominent venue for foreign espionage,” says Steven Aftergood, director of the Federation of American Scientists’ Project on Government Secrecy. “Spies go where the secrets are, and there are plenty of secrets in New Mexico.”

But, Aftergood says, a solar observatory might not be the best place to conduct such activity. “I imagine most or all of its sensors are directed up.” He wonders if someone at the Sunspot observatory somehow inadvertently spotted a classified satellite or transmission, triggering the shutdown.

That might also explain why the facility has remained closed for so long, Aftergood says; it could take time to interview all relevant personnel, get them to sign nondisclosure agreements, and do background investigations to make sure they are not foreign agents.

While the actual nature of the security issue remains unresolved, the tight-lipped nature of the authorities is only driving more interest. “The mystery is more intriguing than what the ultimate explanation is likely to be,” Aftergood says.