March 28: Our Hungry Black Hole

This Friday relaunched our lecture series after both spring break and daylight savings time so we now begin at 8pm.  Graduate student Yuan Li gave a lecture on an upcoming galactic event: the closet passing of a gas cloud (called G2) to the supermassive black hole in the center of our galaxy.  After explaining the basics of black holes, Yuan showed proof for the existence of our own, called Sagittarius A*.  She then explained that with our own supermassive black hole being so long dormant, watching the feeding of a black hole up close has implications for most areas of astrophysics.

(Almost) April showers kept us from observing on the roof but roof tours were still available along with our 3D wall.  David Jaimes also gave a presentation on the exoplanets discovered by the Kepler telescope, highlighting a number of resources available on the web for those at home.

Check out this New York Times interactive graphic on different planetary systems.You can toggle between orbital size and discovery as well as hover your mouse over the orbits for various information.

-- Lauren Corlies (graduate student) 

March 7: Brain-gazing

This week we partnered with The Zuckerman Institute to help kick off Brain Awareness Week here in New York. This special event previewed a new visualization tool, Neurodome, designed to allow audiences to discover and explore the inner workings of the brain in a planetarium setting. The lecture was a blend of astronomy and neuroscience tracing the path of light through the Universe and into the brain. 

We started the evening with a fun quiz of "Space or Brain?" in which the audience had to guess if a given image was a picture of an object in space or a picture of part of the brain. Surprisingly most people were stumped at every turn! Next Matt Turk, a post-doc in the Department of Astronomy, spoke about how a particle of light, a photon, can travel from the farthest reaches of the observable universe and all the things that can happen to it along the way such as: reddening, scattering, absorption, and reemission. Matt left us and the light here on Earth and handed off the mic to Jonathan Fisher, a neuroscientist at New York Medical College. Jonathan and his colleagues then walked us through the various levels of the structure in the brain that the photon encounters and how Neurodome is allowing us to see the brain like never before. 

After the lecture, the audience was invited to tour to the rooftop observatories and further explore excerpts from Neurodome on our 3D Wall. 

We hope everyone enjoyed the interdisciplinary fun! 

-- Summer Ash (Director of Outreach)

February 21: Neutral Particle Power

Every second trillions of neutrinos cross our bodies without ever noticing. Graduate student Jia Liu guided the audience through the mysteries of these tiny particles that have puzzled scientists for decades. Neutrinos were suggested by the famous physicist Wolfgang Pauli to account for the missing energy, when a neutron splits into a proton and an electron (a process known as beta decay).

Neutrinos are abundant in nature and are produced through various processes. They are produced in the core of the stars when light nuclei merge to form heavier elements, in nuclear plants when the opposite process (heavier nuclei are divided into lighter) takes place to provide energy, in supernovae explosions and even when energetic particles from outer space interact with the atmosphere.

Neutrinos come in three varieties, have low mass and interact very weakly with matter, making their detection challenging. Next, Jia showed some of the cutting-edge operating detectors like IceCube in the South pole, ANTARES under the Mediterranean sea and Super-K in Japan, that trace neutrinos from astrophysical sources.

Finally, Jia discussed some intriguing potential (fiction-like) uses of neutrinos in the future, as proposed in serious scientific journals. Some of them included the destruction on nuclear weapons, the communication with extraterrestrial civilizations and equity trading.

After the lecture, the audience had the chance to view 3D movies of the universe on the 13th floor, to participate in roof tours and hear more about neutrino flavors from graduate student Andrew Weis. Later, as the sky cleared out and observing was possible, the few who stayed had the chance to look at Jupiter, the Orion Nebula as well as the new Supernova 2014J in nearby galaxy M82, which is the closest type-Ia supernova discovered in the past 42 years.

We hope to see you in our next event, which will entail an exciting collaboration with the neuroscience outreach group!

--Maria Charisi (graduate student)

February 7: Five Billion Years of Solitude

We kicked off a new year of events with the help of local author, Lee Billings, who recently published his book Five Billion Years of Solitude on the search for life beyond our Solar System. The title actually refers to the expected "life span" of life on Earth and what we are going to do with our "moment in the Sun". Contrary to popular belief, life on Earth will end long before the Sun becomes a red giant (excluding anthropogenic factors) - in about 500 million years, in fact, when the carbon cycle comes to a grinding halt. Lee's talk focused on our efforts thus far to discover if we will spend our remaining time in the Universe alone. He presented up to date results from NASA's Kepler mission and discussed what exoplanet properties we can currently deduce from the data. For as much as we like to speculate about habitability, it turns out we are still a ways from being able to confidently tell if the ingredients for life are present yet. 

After the talk, audience members enjoyed the 3D wall run by undergraduates Varad and Claire, as well as an informal talk on gamma-ray bursts by Maria, a graduate student. Due to the harsh winter, only the Big Dome was open on the roof for observing and we instead brought our portable telescopes out on the plaza in front of Pupin for glimpses of Jupiter and the Moon. Thanks to Adrian, Emir, Jingjing, and Andrew for leading the stargazing charge. 

-- Summer Ash (Director of Outreach)

December 6: Comet of the Century?

In the year after Comet ISON's detection in September 2012, many predicted that its close encounter with the Sun would produce a show worthy of the title "comet of the century".  However, as graduate student Erika Hamden showed, Comet ISON's passage was less spectacular than predicted, though no less interesting.  The comet's orbit showed that it came from the Oort cloud, a sphere of small icy bodies surrounding the Solar System.  Objects in the Oort cloud probably spend most of their time around 0.75 lightyears from the Sun, but occasionally a nearby star can perturb the cloud and send comets into the inner solar system.  Since Comet ISON came from the Oort cloud, it hadn't interacted with the Sun before and so it could provide information about the composition of Oort cloud bodies.

Erika played movies like the one above from several space-based solar observatories (i.e., NASA's Solar Dynamics Observatory, NASA's Solar and Heliospheric Observatory, and NASA's Solar Terrestrial Relations Observatory) showing Comet ISON as it approached the Sun and after its closest encounter. Astronomers had predicted that, after it passed by the Sun, Comet ISON would be very bright and spectacular to see. However, the comet broke up when it got close to the Sun.  The movies showed that some bright debris reappeared after Comet ISON passed the Sun, but it faded rapidly, indicating that the comet had fallen apart. Comet ISON was probably a loose ball of ice that was destroyed by the Sun's heat, like a poorly-made snowball that falls apart before reaching its target.  Although it was not the "comet of the century", Comet ISON provided astronomers with plenty of information about Oort Cloud comets and provided everyone with a great show.

Clouds and rain prevented any roof activities, but undergraduate Claire Ding showed 3D movies on the 13th floor, and graduate student Andrew Weis gave a slideshow of highlights of the winter sky in the lecture hall.

--Steph Douglas (graduate student)

November 22: From the Ashes of Cosmic Explosions...

How did we get here?  Jeremiah Murphy, a new faculty member at Florida State University, shared with us the astronomical answer to this age-old question.  Or, rather, he answered the question of how his dog got here.  He traced the history of the elements in his dog's body, starting with the hydrogen and helium that formed in the Big Bang.  Those lighter elements were fused into heavier elements in the cores of massive stars and in supernovae, the explosions of those same stars.  Supernovae occur when iron builds up in the core of a massive star until that iron cannot support its own weight. Jeremiah showed us the results of his simulations showing how the iron core collapses, producing a blast wave and a wave of sub-atomic particles called neutrinos.  Those two waves tear the star apart in under a second.  The energy produced allows the production of all the elements up to uranium.

Although it was cloudy, graduate student volunteers Jeff Andrews and Andrew Emerick gave tours of our rooftop observatory after the lecture.  Other attendees visited the 3D wall, where graduate student Yuan Li showed off 3D movies about the universe.  In the lecture hall, Summer Ash and graduate students Jingjing Chen and myself answered questions and collected survey results about the night's events.  I also gave a short slideshow on supernovae that were seen on Earth and recorded in historical documents.

--Steph Douglas (graduate student)

November 8: Astronomer vs Astronomer

Scientists do not always agree with each other, and many times, scientific progress is made through debates. On Friday, November 8th, graduated student Jennifer Weston gave a public lecture about a few of the greatest arguments in astronomy in the past 150 years, and how they were resolved. One of the biggest debates in the history of astronomy and astrophysics, the 'Great Debate', was about whether the Milky Way, our own galaxy, was the entire universe, or there were other galaxies out there, seen as the "spiral nebulae". The debate was eventually resolved by the work of Edwin Hubble, which shows that the spiral nebulae are not only galaxies outside of our own, but they are also moving away from us at high speeds. 

After the lecture, many people went to the roof where graduate student Adrian Price-Whelan showed off the Moon and Albiero along with Andrew Emerick, Susan Clark, Aleksey Generozov, and David Jaimes. On the 13th floor, visitors enjoyed 3D astronomy movies with Barnard student Gladys Velez-Caicedo. In the lecture hall, graduate student Yuan Li presented a slide show on planets outside the solar system found by NASA's Kepler telescope. 

Join us on November 22 for a lecture by Jeremiah Murphy on supernova explosions.

-- Yuan Li (graduate student)