“If I learn one new thing, it makes my night,” Cheryl Haberman, a Waltham kindergarten teacher, said on the roof of the Harvard College Observatory Thursday night (Jan. 17). “I’ve never walked away disappointed.”
Welcome to Observatory Nights, a community outreach program sponsored by the Harvard-Smithsonian Center for Astrophysics (CfA) that is revved up after a yearlong hiatus, drawing packed houses month after month.
“Attendance is fantastic. We at times have had standing room only, well over 200 people,” said David Aguilar, event organizer and the center’s manager of public affairs.
The events, held on the third Thursday of each month, begin with a 45-minute lecture on a topic that is both of current interest in astronomy and that has relevance to a community audience. Thursday’s “Solar Storms and Space Weather,” presented by John Kohl, senior astrophysicist at the CfA and lecturer in Harvard’s Astronomy Department, talked about both what happens on the sun during solar eruptions called “coronal mass ejections” and what their impact is on Earth.
That impact can be great and is likely to grow, Kohl said, largely due to the potential for disruptions of our increasingly wireless and electronics-dependent society.
Despite the enthusiasm with which the 120 or so jammed into Phillips Auditorium for Kohl’s talk, the planets were the stars of the show.
After the lecture, the group trooped to the roof and stood in the frosty night air to view Jupiter, Saturn, and the Orion Nebula through the observatory’s 9-inch Clark refractor telescope, as well as through two portable telescopes, an 8-inch reflector and an 8-inch dobsonian telescope.
“It is fascinating,” said Erin McCafferty, of Lynn, who was visiting the Center for Astrophysics – and seeing Jupiter through a telescope – for the first time. Then she echoed a comment by Aguilar at the end of the lecture. “It really does exist, it’s not just a joke they’re playing on us.”
The crowd’s enthusiasm was reflected in the CfA staff organizing the event. Christine Lafon was ushering people past the reflector pointed at Jupiter and commenting on her good fortune to be able to educate people about something they’re already interested in.
“We’re so lucky to be involved in astronomy. It’s not as difficult to explain as physics,” Lafon said.
Though the recent incarnation of Observatory Nights comes after a yearlong layoff, Aguilar said the event has been a regular staple at the center for almost three decades.
“It’s kind of a heritage event here at the CfA,” Aguilar said.
Aguilar said he tweaked the format a bit, shifting from somewhat academic presentations of papers and findings to more accessible topics that would be attractive to the enthusiastic but lay audience that the event draws.
Kohl’s presentation kept the audience so interested that questions had to be cut off so the rooftop observing session could begin. Using large, false-color images – many taken from the CfA’s own instruments on the SOHO (Solar and Heliospheric Observatory) satellite – Kohl’s presentation illustrated several recent and dramatic explosions on the sun’s surface, drawing some oohs and aahs from the crowd.
“Even if you’ve been doing this for a while, everybody lights up with this one,” Kohl said as he showed a short video image of the largest solar flare ever observed, recorded just weeks ago, on Jan. 4. “It’s really an incredible event. Luckily it was pointing away from Earth.”
Though the particles from such eruptions speed through space and can enter the Earth’s atmosphere, it isn’t the particles that are disruptive, Kohl said. The real problem is the associated magnetic field. That magnetic field can disrupt television and radio broadcasts, interrupt satellite and cell phone conversations, and, by stimulating electric currents in wires, damage sensitive equipment.
In fact, Kohl said, as wireless devices such as cell phones and pagers become smaller, lighter, and use less power, the amount of damage a coronal mass ejection can cause rises, as the smaller circuitry can be more easily damaged by a surge of electricity. Satellites and space-walking astronauts can also be harmed by the solar explosions.
Sharing discoveries, excitement
Along the way, the crowd learned about the sun’s structure, including its relatively cool – 5,000 degrees – surface, contrasting with 10 million to 15 million of degrees in its core and 2 million degrees in the gas surrounding the surface. They also learned of the immense size of the coronal mass ejections, 10,000,000,000,000,000 grams, which travel away from the sun at speeds of 100 to 1,500 kilometers per second.
“This shares with the community the excitement of the discoveries here,” Aguilar said. “It’s an opportunity for the astronomers to do something they don’t do every day of their lives. It humanizes a science that can seem so cold and inhuman because the distances out there are so vast.”