Celestial play on shortest day

AMATEUR astronomers and other interested onlookers can come together to witness the June solstice at precisely 1.33pm on Monday, 21 June at the Ballarat Municipal Observatory and Museum.

The gathering will centre around the facility’s curiously named Pipehenge, which Observatory manager Judith Bailey described as “a structure that looks like a climbing frame, but is actually a representation of the celestial sphere that indicates the positions of the earth in space.”

“The angle that Pipehenge is on is based on our latitude, and it’s pointing to a point in the sky called the South celestial pole, which is directly above the South Pole,” Ms Bailey said.

“It’s a bit like a sundial, and the sun’s shadow will fall at a particular position during the Solstice.

“You’ll be able to see the shadow lined up with the ‘shortest day’ ring on the structure. It’s an excellent educational tool.”

Visitors will also have the opportunity to delve into Ms Bailey’s knowledge of all things unearthly, including the related question of why we have seasons, for example.

“It’s all tied in with the axis that the earth rotates on, which is about 23.5 degrees off the perpendicular,” she explained.

“So that’s indicative of how our seasons evolve.

“Just say perchance that the angle was only 22 degrees – then our seasons would be markedly different. So the angle determines the extremes – the heat of our summer, and the extreme cold in our winter.”

Observing the June Solstice takes place from 1.15pm to 2.30pm on Monday, 21 June and bookings can be made via bit.ly/2TSHXkR.