Our Favorite Things: Big Dipper

On the third floor of the main MOSI building, just to the right of the High Wire Bike there are seven small white balls that hang from the ceiling. When viewed from near the elevator or the balcony where you can enter Science Works Theater, this group of white globes goes mostly unnoticed and does not contain a familiar shape. Interestingly, this collection of orbs has a unique history at MOSI, which makes it one of our favorite things.

In 1995 MOSI opened its doors and contained exhibits on Florida, health and space. The 3rd floor space exhibit eventually became timeworn and the information out-dated so it was removed in 2010 to make way for our new high-tech health exhibit called The Amazing You. Portions of the exhibit, like a model Apollo capsule were relocated to other parts of the museum and the outdated pieces of the exhibit were scrapped. This cluster of suspended globes is the last exhibit remaining in place from our selection of space science exhibits.

When viewed straight on from just to the right of the High Wire Bike, these orbs resolve into the familiar shape of the well known constellation the Big Dipper. These seven orbs represent the stars in the constellation and their relative distance to Earth:

Star	Magnitude	Distance (L yrs)
Dubhe	1.8	124
Merak	2.4	79
Phecda	2.4	84
Megrez	3.3	81
Alioth	1.8	81
Mizar	2.1	78
Alkaid	1.9	101

When viewed straight on from the 3rd floor, the shape of the Big Dipper is the same as it appears in our night sky, viewed straight on from earth. A walk down the balcony beside Science Works Theater shows us the distance of the stars from one another, especially the star Dubhe which is quite distant from many of the stars in the constellation. Also known as The Great Bear or Ursa Major this constellation has been referenced throughout history including in the Bible as “the seven stars” (Amos 5.8) and in Homer’s Iliad as “the Bear”.

Although there are no longer signs to reference this display, the stars remain in place and are a great talking point for MOSI interactors and a great bit of trivia for our members and guests. The Big Dipper display was the first permanent exhibit installed at MOSI and is the favorite exhibit of long-time MOSI staffer Brian Albury.

Brian is the Director of Facility Operations and Information Technology for MOSI and has been with the museum for 16 years.

International Observe the Moon Night

On Saturday, September the 18th we invite you to join us at MOSI as we turn our eyes towards the heavens and a waxing gibbous moon on International Observe the Moon Night.

This is the second annual event of this name that celebrates exploration and observation of the moon. Started last year in celebration of the Lunar Reconnaissance Orbiter (LRO) and the Lunar Crater Observation and Sensing Satellite (LCROSS), International Observe the Moon Night brings an international community together for a single night of moon observation.

The Lunar Reconnaissance Orbiter (LRO) orbits just 50km above the surface of the moon. This robotic spacecraft is engaged in a 3D mapping mission that will help NASA identify potential moon landing sites for upcoming missions and locate formerly unknown resources on the lunar surface. The LRO has also brought us some of the first photographs of Apollo equipment that was left on the lunar surface.

Lunar Crater Observation and Sensing Satellite (LCROSS) was intentionally crashed into the Cabeus crater on the lunar surface near the moon’s south pole on October 9, 2009. The Centaur module of the LCROSS impacted the lunar surface and the Shepherding Spacecraft fallowed four minutes behind to analyze the plume of debris shot upward by the impact. LCROSS achieved its objective and discovered proof of water ice on the moon

This year MOSI is hosting an official International Observe the Moon Night event that will begin at 7:30pm on September the 18th. We will have binoculars and telescopes available for lunar observation, talks by lunar experts, activities and a show in the Saunder’s Planetarium.

Program fee: $12 per person
MOSI member: $9 per person
Call (813) 987-6000 to register; advance reservations are recommended. Limited seating is available for the lunar shows in The Saunder’s Planetarium.

Summer Solstice Science

The Summer Solstice is the day of the year in which we have the longest period of daylight. Today in Tampa the sun rose at 6:34am and will not set until 8:29pm.

The Summer Solstice occurs exactly when the Earth's axial tilt or obliquity is most inclined towards the sun at its maximum of 23° 26'. In the Northern Hemisphere this generally happens at a point between June 20th and June 21st when the Northern Hemisphere is tilted closest to the sun. In the Southern Hemisphere this is reversed. Today the Southern Hemisphere is tilted furthest away from the sun and is currently experiencing the Winter Solstice or longest period of night. In the Southern Hemisphere the Summer Solstice occurs in late December. The cumulative cooling and warming that result from the tilt of the planet become most pronounced after the solstices, leading to the custom of using these days to mark the traditional beginning of summer and winter.

Since Neolithic times, cultures have celebrated the longest days and nights of each year. In Roman times the Summer Solstice was celebrated each summer on June 24th. In fact, the word solstice derives from the Latin words sol (sun) and sistere (to stand still). In ancient Europe pagans lit great bonfires on the night of the Summer Solstice and the holiday was often connected with healing and the first fruits of the seasons. With the advent of Christianity the date of the solstice became connected with the birth of St. John the Baptist and is still celebrated as St. John’s Day in many countries.

Have a fantastic longest day of the year and a happy summer!

On this Day in Astronomy in 1610

Hello again fellow SkyWatchers.

Just an interesting astronomy history tidbit this time – On this day 399 years ago, January 13, 1610, Galileo Galilei discovered Ganymede, Jupiter’s largest moon and the largest moon in our solar system. 

Ganymede is 5268 kilometers (3273 miles ) in diameter, which makes it much larger than both Mercury (4880 km) or Pluto (2300 km), and huge compared to our Moon (3476 km). 

 

Steve Nipper

Manager of Planetarium & Senior Programs