Warning: Snow Falling Off Dome!

Today is the Winter Solstice and yes, we are still closed to the public due to snow.

When we are open to the public we do ask that visitors read and obey all signs. They are posted for everyone's safety.


During and immediately after a snowfall there is always a danger at the observatory. One that most visitors do not think about--snow and ice falling off of the Hale Telescope's dome. The dome is 135 feet high. A slump of snow falling from that height carries a lot of energy--energy that could cause great damage, injury or even death.

When we are open to the public and the potential is there for snow to fall off of the dome the observatory staff does its best to warn visitors by posting signs like the one below.

Many people don't pay any attention to the signs as they are really focused only on the snow.

On Friday of this week we had a slump of snow slide off of the dome on to a Manzanita tree growing between the dome and the visitors path next to it. The impact of snow, yes snow, to the tree makes it look like the tree had exploded.

Notice that the trees in the background have already lost their snow. We keep the dome at nighttime temperatures (you get better images of the stars that way) which keeps the snow and ice on the dome far longer than it stays in the surrounding trees. As a result, most people wouldn't expect to have anything fall onto them, because they can see that all the snow has already fallen from the trees.

Thankfully no one was hit by this. Imagine what it would have done.


In February 1998 the observatory had just acquired a new car (one week before) when a visiting astronomer had parked it right next to the dome early in the morning, before the staff had the chance to up the signs warning of snow falling off of the dome. The result could have been deadly. Thankfully the observer was not in the car when the snow fell. The impact of snow falling off of the dome crushed the roof of the vehicle.

When visiting the observatory for snow, be careful out there and pay attention to all signs. They are posted for everyone's safety. And when we are closed because of snow that's for everyone's safety too.

Thanks to Steve Kunsman for providing me with the photos for this post.