March 20: School Visit

Over spring break, Professor Kathryn Johnston hosted a group of 30 high-school students from the New York Harbor School. Prof. Johnston discussed her research on "galatic cannibalism" which focuses on how the Milky Way has evolved over time by gravitational interactions with other galaxies, i.e., capturing and accreting them. Prof. Johnston also spoke with the students about various career paths into science. Following the talk, the students toured the Rutherfurd Observatory with undergraduate Doug Thornhill.

March 15: Cosmic Candles

Last week, Ashley Pagnotta, a post-doc at the American Museum of Natural History, gave a talk entitled, "Supernovae: Cosmic Candles of the Universe." Ashely's research focuses on stellar explosions known as supernovae which occur toward the end of a star's life. Different phenomena give rise to different types of supernovae and by understanding the nature of these explosions, astronomers can better constrain the parameters that help us describe the behavior of our Universe. 

It was less than a hundred years ago that astronomers even discovered that the Universe wasn't static, i.e., "standing still". Using the doppler effect to measure the speed at which galaxies were moving away from Earth and cepheid variable stars to measure distance, Edwin Hubble made a plot of of these two variables and discovered that the farther a galaxy was from Earth, the faster it was moving a way from us. Today, we call this plot the Hubble Diagram in his honor and continue to update it as we make better and better measurements. You can make you own Hubble Diagram using data from the Sloan Digital Sky Survey here. 

While Hubble's work showed that Universe is expanding, it said nothing about the future of this expansion. To investigate this, two teams of astronomers proposed using Type 1a supernovae to probe the Universe out to greater distances, and therefore farther back in time. They used Type 1a supernovae instead of cepheid variables as these supernovae have a characteristic explosion that allows astronomers to use them as a standard candle of sorts; astronomers know how bright they are at a given distance so they can observe them at various distances and extrapolate their true distance based on their observed brightness. Both teams ended up discovering that the expansion of the Universe was *accelerating*, giving rise to the theory of dark energy, and as a result we awarded the Nobel Prize for Physics in 2011. 

Ashely went on to explain how studying how Type 1a supernovae form in more detail can help astronomers minimize errors associated with their distance measurements and thereby improve our understanding of dark energy. You can view the slides from Ashely's talk here. 

Unfortunately, the skies were cloudy again so after the lecture, the 120+ audience members toured the roof with the help of graduate student Adrian Price-Whelan, viewed 3D movies with undergraduate Jose Montelongo, and learned about Comet PANSTARRS with Director of Outreach, Summer Ash, and graduate student Yong Zheng. 

Please come see us on April 5th when graduate student, Ximena Fernandez, will present highlights from lesser known space telescopes that are providing astronomers with great glimpses of the Universe. 

--Summer Ash (Director of Outreach)

March 1: Martian Summer

We hosted author, Andrew Kessler, and approximately 80 members of the general public on Friday, March 1st to hear all about the people and the science behind NASA's Phoenix Mars mission. Kessler spent a year with the engineers and scientists who worked on Phoenix to learn what it takes to launch a spacecraft from Earth and safely place it on the surface of another planet. Phoenix landed near the north pole on Mars, the first craft to ever land in the polar regions of the red planet. It's mission was to study the history of water in the ice-rich boundary of the Martian arctic. To do this, the Phoenix lander was equipped with a robot arm that could scoop up soil samples for analysis by an array of instruments including a mass spectrometer, a wet chemistry lab, and a high resolution imager. Not only did Phoenix discover subsurface water ice, but it also found that Martian soil contained high concentrations of chloride which converts to perchlorate in the presence of sunlight. You can read all about the Phoenix mission and Kessler's experience in mission control in his book, "Martian Summer: Robot Arms, Cowboy Spacemen, and My 90 Days with the Phoenix Mars Mission" and you can follow him on Twitter here.

After the talk, audience members toured our rooftop observatory (with the help of graduate students Jennifer Weston and Yong Zheng and undergraduate Jose Montelongo), viewed 3D movies (with undergraduate Bryan Terrazas), and listened to graduate student Steph Douglas explain the myriad of motions experienced by the Earth from our rotation around the Sun all the way out to the expansion of the Universe.

Join us for our next event on Friday, March 15th when post-doc Ashely Pagnotta explains how supernovae are used to understand the mysterious force known as dark energy.

--Summer Ash (Director of Outreach)

March 2: Grumpy Bert

On Saturday night, graduate student Munier Salem and Director of Outreach Summer Ash helped kick off the opening of a spectacular photography exhibit at Grumpy Bert in Brooklyn. The exhibition entitled "The Universe in Color" runs through the end of the month and features 22 large format images of the Universe taken by astrophotographer (and physician) Robert Gendler.

Munier opened the evening with an informal talk on light and how astronomers make use of the entire electromagnetic spectrum in order to learn as much as possible about the Universe. Then the 40+ audience members asked some very astute questions ranging from the expansion of the Universe to extraterrestrial life. The event culminated in a lively reception which allowed everyone to examine Gendler's amazing works up close and personal.

Additional photos from the event can be found here.

February 15: My Life as a Higgs Boson

Friday, February 15th, Gladys Velez Caicedo had the very difficult task of explaining what exactly the Higgs Boson is and how its existence is necessitated by the Standard Model of Physics. The Standard Model explains all the particles we know, such as protons, neutrons, and electrons, along with their interactions. Gladys is a second year undergraduate at Barnard College studying Astrophysics and Literature and is a researcher at Nevis Laboratories working with the Very Energetic Radiation Imaging Telescope Array System (VERITAS) and the Fermi Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope. If you missed the talk or if you just want to immerse yourself in some hard-core physics, you can view the slides from Gladys's talk here.

Over 175 people came out for the event, and we were lucky to have the roof available for star-gazing for an hour after the lecture despite the encroaching cloud cover. The 3D wall was manned by Bryan Terrazas.

After the lecture, I led a small discussion in which we talked about the recent meteorite impact in Russia, along with the near-Earth asteroid that came within 17,200 miles of us, closer than orbiting equatorial geosynchronous satellites! In comparison, the moon is between 220,000 to 250,000 miles away. The discussion was slightly free-form due to the recent nature of the event, and it included us watching some internet videos from Russia. The discussion also focused on efforts humans are undertaking to detect future near-Earth asteroids and possible collisions. Thanks to all who came and participated in this Friday’s outreach program!

Meteor and asteroid videos:
Russia Meteorite Compilation
Another Meteorite Video
Asteroid 2012 DA14 Close Approach
Asteroid Discoveries

--Emir Karamehmetoglu (undergraduate student)

February 1: Saving Hubble

On Friday, February 1st, we kicked off our spring Public Lecture & Stargazing series with not a lecture, but a film. Saving Hubble is a documentary that chronicles NASA's decision to cancel the Hubble Space Telescope in 2004 and the subsequent public outcry. Filmmaker David Gaynes interviewed people far and wide on their thoughts about the pioneering space telescope that became a household name, from scientists and engineers who worked on Hubble to amateur astronomers, cabdrivers, and kids who are self-proclaimed "Hubble Huggers." After the screening, Summer Ash led Q&A with David and Ph.D. candidate, Christine Simpson.

If you missed the film, you can see a clip of it here and find out about upcoming screenings here.

The event attracted a sizable audiences of over 200 people who got to see some great sights from the rooftop telescopes after the film, thanks to the clouds that decided to clear out. Graduate students Jeff Andrews, Lauren Corlies, Ximena Fernandez, and David Hendel had telescopes trained on Jupiter and the Orion Nebula, both wonderful offerings of the winter sky. We also had the 3D wall up and running.

Join us on Feb. 15th for our next event: My Life as a Higgs Boson.

 --Summer Ash (Director of Outreach)

November 30: Galactic Neighborhoods

On November 30th, about 100 people joined us to hear Columbia Astronomy Professor Jacqueline van Gorkom talk about how galaxies are influenced by their surroundings. Professor van Gorkom is a radio astronomer and does extensive research on galaxies. She showed us how strikingly different galaxies look in dense clusters of galaxies compared with fields. She explained that when a galaxy enters a galaxy cluster filled with hot intra-cluster gas, the cold gas inside the galaxy gets stripped out of it and thus star formation is quenched, which changes the color of the galaxy from blue to red. The audience raised a lot of interesting questions about galaxies and gravity.

After the talk, some people went to see the 3D movies on the 13th floor shown by Columbia undergraduate student Gladys Velez-Caicedo. Unfortunately, the sky was not clear on Friday, but Columbia Astronomy graduate students Adrian Price-Whelan and Jenna Lemonias gave a telescope tour to a group of people on the roof of Pupin. In the lecture hall, graduate student Yuan Li presented a slide show on spiral galaxies and Dr. Jana Grcevich talked about the Big Bang and the expansion of the universe.

Join us on December 14th for the last event of this semester: a panel discussion on Life, the Universe, and Everything!

--Yuan