COAST CITIES — It took about six hours for Venus to transit the sun Tuesday, but it’ll take another 105 years before the second planet from the sun will cross it again.
But for those who managed to see the planet arc across the face of the sun, it could only help to stir the imaginations and put into perspective just how large the universe is.
Liana Goldberg, 13, came to view the event with her mother Merryl at Double Peak Park in San Marcos.
“It was really interesting,” Liana said after seeing the small black dot of a planet cross against the sun through a telescope for the first time. It was cool, she said, knowing that she was witness to such a significant event.
One of the event’s significance is in its rarity, explained Dr. Michael Burin, assistant professor of physics at Cal State San Marcos. He and other colleagues from the physics department at Cal State set up several telescopes for the public to safely view the event. Historically, he said, the event carried a lot of significance. “Until this was measured accurately in the 1700s, we didn’t know how far away the sun was from the Earth,” he said.
Using that knowledge gives us a scale of the solar system, Burin said, which helps practically, he added, if you’re going to plan a mission somewhere. “You’re going to have to know the distance.”
Astronomical events still hold a fascination on the old and young; the amateur and professional astronomer based on the turnout at the event’s viewing.
“Because it’s out of this world,” Burin said. “Venus, it’s another planet. There’s nothing in your day-to-day life that you can encounter – everything’s on Earth – and there’s a few things, the stars you see at night and events like this…but astronomy is usually a nighttime thing.”
This was the second astronomical event this year that allowed stargazers to view celestial happenings during the day. In May people in the continental United States were able to view the annual solar eclipse.
One of the ways that astronomers have been able to use the transit event is by studying how light can help detect other planets in the distance.
“One of the Kepler missions is currently looking for exo-planets, planets going around other stars,” Burin said. “So when the planet goes around a star, one of the ways we can detect it is the light from the star dims a little bit because there’s a planet in front of it. And, if it’s on the edge, we can actually see light coming through the atmosphere.
“We know what Venus’ atmosphere is like; studying light going through the Venetian atmosphere tells us a little bit about how this event, a planet going in front of a star, how it works in general. So that when we start seeing planets around very distant stars, we have a prototype.”
Burin added that this is a planet we know well, and it’s a sun we know well, but there are still some mysteries.