A telescope and screen used to spot galaxies and a cluster of stars was stolen in a Christmas Day raid on a Wearside group's base.
Sunderland Astronomical Society has two observatories within the grounds of WWT Washington site on the banks of the River Wear, with the facilities used to run education sessions for visitors and to host members as they look out into space.
Its leaders were then called on Boxing Day to say staff had discovered one of the sheds bad been broken into when they arrived to open up for the day, after closing up the site at 4pm on Christmas Day.
The group found a telescope - a 3ft Meade 127 refractor - and a large screen Samsung television had been taken, with extensive damaged caused to the rear of the observatory building.
The cost of replacement kit and repairs has been put at between £400 and £500, with a section of the base set up with access for disabled people so they can also enjoy discovering the stars and planets.
Paul Meade, the group's vice chairman, said: "To us, it's worth more than their value, because it's equipment we need to be able to host groups of kids and visitors and we can use this to look at different areas, so this helps us see wide field objects.
"We have used it to see the Seven Sisters Cluster and the near by Galaxies, so the Andromeda Galaxy.
"It was really bad when we heard about what had happened, especially because this happened on Christmas Day.
"We don't know if they came to target us, or they were just looking to see if they could grab what they could.
"It looks like they used a crowbar to try and get through the door and when that didn't work, they then just ripped the back off and then stolen the telescope and television.
"It will have a knock on affect because we need it to host sessions.
"But to use the telescope you need a tripod and a mount to get the scope working and it's a hefty piece of kit."
Northumbria Police has been called in to investigate the theft and damage.
The area is covered by CCTV and the society does use security marking on its kit, with members bumping up crime prevention measures in the wake of the incident.
The observatory targeted in the vandalism and theft attack is the newer of the two set up at the WWT site by the society.
More details about the sessions run by the society can be found via its Facebook page.
Northumbria Police has been contacted for comment.
Anyone with information about the break in can call the force on 101 or Crimestoppers anonymously on 0800 555 111.