The "Transit of Venus" celebration will be held from 4 to 7 p.m. at the southeast side of the MSU football stadium, said organizer Joey Shapiro Key, education specialist for the Montana Space Grant Consortium. Gate 8 on the southeast side of the stadium will open at 3:30 p.m. The party is free and open to the public.
Venus will appear at the edge of the sun slightly after 4:05 p.m. It will be halfway across the sun around 7:27 p.m. and won't be visible in the night sky after sunset, Key said. Safe viewing glasses and telescopes with filters will be available at the stadium. NASA images showing the transit from space will be shown continually on the stadium's scoreboard screen.
MSU President Waded Cruzado will give opening remarks at 4 p.m. MSU undergraduate Lincoln Gulley, a member of MSU's Space Public Outreach Team (SPOT), will speak at 4:30 p.m. about the sun-Earth connection. MSU solar physicist David McKenzie will speak at 5:30 p.m. about the transit of Venus.
Hours of sun-themed songs will play during the event, which will also include children's activities, educational booths and concessions.
"In a person's lifetime, there are at most two opportunities to see Venus go across the face of the sun. We only have one left," McKenzie said. "The last chance we had was in 2004. The next one will be long after we are dust.
"I'm pretty excited. I can't wait," McKenzie said.
Venus is the second planet away from the sun, and Earth is the third. Since the planets orbit at different angles and different speeds, it's highly unusual to see Venus cross in front of the sun, McKenzie said. The transit generally occurs in pairs eight years apart. Between those pairs are 105 to 121 years.
"There wasn't any transit in the 1900s," McKenzie said. "The last pair was in the late 1800s before Montana was a state. That was when Jesse James was still terrorizing the West. Barbed wire had just been patented."
The transit before that occurred in 1761 and 1769. The first pair of transits to be predicted occurred in the 1600s. The 2004 and 2012 transits are only the second pair to happen during the space age. The next pair will occur in 2117 and 2125.
"This doesn't happen often. It's a chance to really see first-hand in person the relationship between the planets and our solar system," McKenzie said. "You can look at images and computers, but it's not the same as seeing it in real life."
Because the transit occurs so infrequently, the transit provides a unique opportunity for scientists to study Venus and answer questions about the solar system, McKenzie said.
Two solar missions that involve MSU faculty members - the Solar Dynamics Observatory and Hinode --will both make images of the June 5 transit, McKenzie said. The SDO will make images from several different ultraviolet wavelengths. Hinode will make images in visible light and X-rays.
McKenzie was part of the team that made observations in 2004 from the space-based telescope called TRACE, or the Transition Region and Coronal Observatory. Scientists in the past discovered that Venus had an atmosphere when they watched Venus pass in front of the sun. They also determined from the transit that the Earth was almost 93 million miles from the sun.
"Knowing the scale and size of the solar system was a key discovery," McKenzie said.
Venus is the planet most like the Earth up to a point, McKenzie said. Its diameter is five percent smaller than the Earth's, and its mass is over 20 percent smaller than the Earth's. Someone who weighs 100 pounds on Earth would weigh 88 pounds on Venus.
Venus and the Earth are dramatically different in other ways, McKenzie said. The daytime temperature on Venus is about 750 degrees Fahrenheit. The air on Venus is almost completely carbon dioxide except for fluffy clouds of sulfuric acid. The atmospheric pressure on Venus is 90 times the pressure on Earth.
Those conditions would be deadly for astronauts, McKenzie said. If they happened to land on Venus and stepped outside their spacecraft, they would feel a little lighter than on Earth. "But then they would be crushed, melted and dissolved."
The Transit of Venus party is sponsored by MSU's Museum of the Rockies, the Southwest Montana Astronomical Society, MSU Solar Physics, the Montana Space Grant Consortium, the College of Letters and Science and the College of Engineering.
For more information and a schedule of events for the viewing party, go to www.montana.edu/lettersandscience/venus
Evelyn Boswell, (406) 994-5135 or email@example.com