The darkness of the moon

Above: three phases of a lunar eclipse

If you hang around after work today, you’ll have a chance to see the moon darken and turn a shade of red during the lunar eclipse. Drop by York’s brand new observing facility, located on the top of the southeast corner of Arboretum Parking Structure 2, to watch the eclipse, beginning at 9pm. Even if clouds prevent a good view, the facility itself may be worth the visit.

Explaining the eclipse, senior lecturer in the Department of Physics & Astronomy Paul Delaney said, “There are two main shadows that Earth projects; one is called the umbra, which is the complete shadow where all direct light is blocked out, the other is the penumbra, which is a partial shadow. The effect is similar to standing in front of a light source and seeing both a dark shadow in the middle (the umbra) and a lighter shadow on the outer edge (the penumbra). During this eclipse the moon will pass through both shadows.” Delaney is in the Faculty of Pure & Applied Science and is master of Bethune College.


The following is a list of times when the Moon will be passing through each stage.

  • Penumbral contact: 9:05pm
  • Partial Eclipse (umbral contact): 10:03pm
  • Total Umbral eclipse begins: 11:14pm
  • Time of Greatest eclipse: 11:40pm
  • End of Total Phase: 12:07am (May 16)
  • End of Partial Phase: 1:17am
  • Leaves Penumbral: 2:15am

This occasion marks the grand opening of the observatory’s viewing platform and “warm room” to house telescopes and computers. The familiar, white-domed observatory, built in 1969 and stationed behind the Petrie Building, remains where it is.

The new viewing facility came about primarily through the need to accommodate York’s astronomy program, which expanded to include three sections of the first-year course.

“There was an urgent need for a multi-telescope site. It became apparent that the ability of the existing observatory wasn’t up to the task of accommodating such a large throughput of students,” said Delaney (right), “and still be able to support second and fourth-year course commitments and the increasingly popular public education program.”

Delaney was delighted with suggestions from Tom Arnold, executive director of York’s Security, Parking & Transportation Services, that the new parking structure could provide space for a “larger, open-area observing facility for such special events as watching eclipses, comets etc.

“Tom felt he could guarantee the rooftop for these events and kill lights as needed – so the marriage was made.”

The new facility has a warm room for computer networking and general operation-control of telescopes, seven permanent piers for telescopes and a securable environment. It is fully accessible by elevators.

“The location at the southeast corner of the parking garage gives a great view of the southern horizon and the ecliptic – planets, moon, sun. When it’s fully operational, the area will be used for class demonstrations, solar observing and school-group tours,” said Delaney.

“The Faculty was very supportive of this initiative and, with the great cooperation of the parking division, we see this areas as being a huge asset for York’s public education program in astronomy.”

thaYork’s observatory welcomes public interest and promotes astronomy to those who are interested. The observatory public viewing program, popular with the local and visiting communities, runs all year round. Check out the schedule for public viewing nights: