Robert Coontz discusses this year's Breakthrough and letting readers have their say. Online news editor David Grimm brings the top news stories of 2014 and takes an audio news quiz. Hosted by Sarah Crespi.

Justin Reich discusses the brief history of MOOCs and their impact on teaching online and offline. [Img: GARY WATERS/GETTYIMAGES]

Vanessa Ezenwa discusses the complex relationship between parasitic infections and tuberculosis in African buffalo and what it can tell us about human health. Online news editor David Grimm dicusses coloration in lizards, weighing earth-like planets, and how bears help meadows by eating ants. Hosted by Sarah Crespi. [Img: Mark Jordahl/Flickr/CC-BY-2.0]

Charles Bishop discusses the "roller-coaster" flight strategy of bar-headed geese as they migrate across the Himalayas between their breeding and wintering grounds. Online news editor David Grimm discusses daily news stories. Hosted by Sarah Crespi. [Img: © Nyambayar Batbayar]

Myrtha Hässig discusses variability and heterogeneity of the coma of comet 67P as part of Science's special issue on the Rosetta spacecraft. Meghna Sachdev discusses daily news stories. Hosted by Susanne Bard. [Img: European Space Agency/Rosetta/NAVCAM]

John Bohannon discusses the growing rift between mathematicians and the National Security Agency following Edward Snowden's 2013 revelations of massive eavesdropping on U.S. citizens. David Grimm discusses daily news stories. Hosted by Susanne Bard. [Img: Amos Frumkin/Hebrew University Cave Research Center]

Gyorgy Buzsáki discusses how two types of neurons in the brain's hippocampus work together to map an animal's environment. David Grimm discusses daily news stories. Hosted by Susanne Bard. [Img: © Isaac Planas-Sitjà]

Will Steffen discusses the processes that define the planetary boundaries framework: a safe operating space within which humanity can still thrive on earth. Jenna Jambeck examines the factors influencing how much plastic debris a nation contributes to the ocean. David Grimm discusses daily news stories. Hosted by Susanne Bard. [Img: Bo Eide Creative Commons License BY-NC-ND 2.0]

Renée Duckworth discusses the role of maternal effects on species replacement in ecological communities shaped by forest fires. David Grimm discusses daily news stories. Hosted by Susanne Bard. [Img: © Alex Badyaev]

Sara Mitchell discusses the co-evolution of sexual traits in mosquitoes and their influence on malaria transmission. David Grimm discusses daily news stories. Hosted by Susanne Bard. [Img: © Sam Cotton]

Stephen Baker discusses the challenges faced by lower-income countries when fighting antimicrobial resistant infections. Emily Conover discusses daily news stories. Hosted by Susanne Bard. [Img: Merton Wilton/flickr/CC BY-NC 2.0]

Sean Wojcik discusses the relationship between happiness and political ideology. Emily Conover discusses daily news stories. Hosted by Susanne Bard. [Img: Erik Hersman/flickr/CC BY 2.0]

Nikolaus Correll discusses the future of robotic materials inspired by nature. Emily Conover discusses daily news stories. Hosted by Susanne Bard. [Img: Nick Dragotta]

Cathy Spatz Widom discusses whether child abuse is transmitted across generations. Angela Colmone has a round-up of advances in immunotherapy from Science Translational Medicine, and David Grimm discusses daily news stories. Hosted by Susanne Bard. [Img: Luigi Mengato/flickr/Creative Commons]

5th Anniversary of the Deepwater Horizon disaster: Marcia McNutt discusses the role of science in responding to the Deepwater Horizon oil spill in the Gulf of Mexico. Warren Cornwall examines the state of ecological recovery 5 years later. Hosted by Susanne Bard. [Img: © Bryan Tarnowski/Science Magazine]

Chris Tyler-Smith discusses what whole genome sequencing reveals about the genetic diversity and evolutionary history of endangered mountain gorillas, and David Grimm discusses daily news stories. Hosted by Susanne Bard. [Img: Berzerker/flickr/Creative Commons License BY-NC-ND 2.0]

Evan MacLean discusses the role of oxytocin in mediating the relationship between dogs and people, and David Grimm discusses daily news stories. Hosted by Susanne Bard. [Img: Teresa Alexander-Arab/flickr/Creative Commons BY-ND 2.0]

Hubble at 25: Daniel Clery discusses the contributions of the Hubble Space Telescope to our understanding of the universe, and David Grimm discusses daily news stories. Hosted by Susanne Bard. [Img: NASA]

James Sanchirico discusses the challenges of creating sustainable fisheries in developing countries, and David Grimm discusses daily news stories. Hosted by Susanne Bard. [Img: © Simon Bush]

Michael Mina discusses how measles destroys immunity to other infectious diseases and why the measles vaccine has led to disproportionate reductions in childhood mortality since its introduction 50 years ago, and David Grimm discusses daily news stories. Hosted by Susanne Bard. [Img: UNICEF Ethiopia/Creative Commons License BY-NC-ND 2.0, via flickr]

Richard Stone discusses science in Cuba: isolation, innovation, and future partnerships, and David Grimm discusses daily news stories. Hosted by Susanne Bard. [Img: Garry Balding/Creative Commons License CC BY-NC-ND 2.0, via flickr]

Katrina Karkazis discusses the controversial use of testosterone testing by elite sports organizations to determine who can compete as a woman, and David Grimm discusses daily news stories. Hosted by Susanne Bard. [Img: Alexander Hassenstein/Getty Images]

Christina Larson discusses the impact of climate change on China's tea and other globally sensitive crops, and Emily Conover discusses daily news stories with Sarah Crespi. Hosted by Susanne Bard. [Img: Yosomono/Creative Commons License BY 2.0, via flickr]

Alexei Bylinskii discusses friction at the atomic level and Braxton Boren talks about the acoustics of historical spaces, and David Grimm discusses daily news stories with Sarah Crespi. Hosted by Susanne Bard. [Img: Pericles' Funeral Oration by Philipp von Foltz, 1852]

Sara Iverson discusses how telemetry has transformed the study of animal behavior in aquatic ecosystems, and Monita Chatterjee discusses the impact of cochlear implants on the ability to recognize emotion in voices, and David Grimm discusses daily news stories with Sarah Crespi. Hosted by Susanne Bard. [Img: © marinesavers.com]

Samuel Wasser discusses using genetics to track down sources of elephant ivory, Suzanne Boyce talks with Susanne Bard about why it's so hard to say the letter R, and David Grimm brings online news stories about declining devils, keeping dinos out of North America, and the tiniest flea circus. Hosted by Sarah Crespi. [Img: guido da rozze/Flickr CC BY 2.0]

Marcus Knudson discusses making metallic hydrogen and how it can better our understanding of gas giant planets and David Grimm brings online news stories about kid justice, part-time dieting, and bird brains. Hosted by Sarah Crespi. [Img: NASA/ESA]

Silvie Baudino discusses the biosynthesis of the compounds responsible for the scents of roses and David Grimm brings online news stories about hearing fractals, muon detectors, and bobcat burials. Hosted by Sarah Crespi. [Img: liz west/Flickr]

Nick Bartlett discusses the challenges of building a jumping soft robot and David Grimm brings online news stories about drug violence in Mexico, pollution's effect on weather, and drugging away our altruism. Hosted by Sarah Crespi. [Img: Stephen Wolfe/Flickr]

John Bohannon discusses using artificial intelligence in the psychologist's chair and David Grimm brings online news stories about the age of human hands, deadly weather, and biological GPS. Hosted by Sarah Crespi. [Img:Nils Rinaldi/Flickr]

Elizabeth Culotta discusses the ancient DNA revolution and David Grimm brings online news stories about rising autism numbers, shark safety, and tiny cloudmakers. Hosted by Sarah Crespi. [Img: Alexander Maklakov]

Fred Goesmann discusses Philae's bumpy landing on Comet 67P, and the organic compounds it detected there, and Hanae Armitage talks with Sarah Crespi about this week’s online news stories. Hosted by Susanne Bard. [Img: NAVCAM/ESA/Rosetta]

Andrea Marzi discusses a vaccine that is effective against Ebola in monkeys and David Grimm talks about weigh-loss surgery, carbon suckers, and sexist HVAC. Hosted by Sarah Crespi. [Img: NIAID]

Asif Ghazanfar discusses how marmoset parents influence their babies' vocal development and Hanae Armitage talks with Sarah Crespi about the influence of livestock on biodiversity hotspots, trusting internet search results, and ant-like robots. Hosted by Susanne Bard. [Img: Carmem A. Busko, CC BY-2.5]

Chris Darimont discusses the impact of humans' unique predatory behavior on the planet and Catherine Matacic talks with Sarah Crespi about whistled languages, Neolithic massacres, and too many gas giants. Hosted by Sarah Crespi. [Image credit: Andrew S Wright]

Brian Nosek discusses the reproducibility of science, Lizzie Wade delves into the origin of religions with moralizing gods. David Grimm talks about debunking the young Earth, a universal flu vaccine, and short, sweet paper titles. Hosted by Sarah Crespi. [Image credit: DIPTENDU DUTTA/AFP/GETTY IMAGES]

Rich Stone discusses science in Iran in the face of economic sanctions. David Grimm brings stories on sleep deprivation and the common cold, plastic in birds, and counting trees. Hosted by Sarah Crespi. [Image credit: Credit: Alessandro Marongiu / Demotix /Corbis]

Seth Bordenstein discusses how our genes affect the composition of our microbiome, influencing our health, and David Grimm talks with Sarah Crespi about the origins of the Basque language, the benefits of being raised in a barn, and how some flying ants lost their wings. Hosted by Susanne Bard. [Image credit: Decaseconds/CC BY-NC 2.0, via flickr

Daniel Markovits discusses the preferences for fairness and equiality among potential future US leaders and David Grimm talks about finding fluorine's origins, persistant lone wolves, and the domestiction of the chicken. Hosted by Sarah Crespi. [Image credit: Philip Pikart/CC BY-SA 4.0]

Kimberly Dunham-Snary discusses the long-term health considerations of gene therapy for mitochondrial diseases and David Grimm talks about the smell of death, Mercury crashing, and animal IQ. Hosted by Susanne Bard. [Image credit: Ben Gracewood CC BY-NC 2.0, via flickr]

Julia Kornfield discusses the design of safer jet fuel additives using polymer theory to control misting and prevent fires, David Grimm talks about building a better sunscreen, cultures that don't count past four, and does empathy mean feeling literal pain. Hosted by Susanne Bard. [Image credit: Eduard Marmet/CC BY-SA-3.0]

Talia Berkowitz discusses the use of a math app at home to boost math achievement at school, Catherine Matacic talks about the fate of animals near Chernobyl, a potential kitty contraceptive, and where spiders got their knees. Hosted by Sarah Crespi.

Alan Stern discusses the first scientific results from the New Horizons July 14 flyby of Pluto, which revealed details about the dwarf planet's geology, surface composition, and atmosphere; Catherine Matacic talks about dino temps, Paleo-sleeping, and editing pig organs. Hosted by Sarah Crespi.

Rhitu Chatterjee discusses Project Prakash and the neuroscience behind reversing blindness in children, teenagers, and adults in rural India; David Grimm talks about where dogs came from, when life first evolved, and holes in the brain. Hosted by Susanne Bard. [Img: Francois de Halleux CC BY-NC-ND 2.0]

Lizzie Wade discusses whether the amazing biodiversity of the Amazon Basin was the result of massive flooding, or the uplift of the Andes mountain range. David Grimm talks about microbes aboard the International Space Station, the fate of juvenile giant ground sloths during the Pleistocene, and singing classes as social glue. Hosted by Susanne Bard. [Img: ©Jason Houston]

Bruce Jakosky discusses where Mars' once-thick, CO2-ish atmosphere went and the first data from the MAVEN mission to study the Red Planet; David Grimm talks about worm allergies, fake fingerprints, and toilets for all. Hosted by Sarah Crespi. [Img: NASA]

Lauren Sallan discusses the consequences of a mass extinction event 359 million years ago on vertebrate body size; David Grimm talks about grandma's immune system, gambling on studies, and killer genes. Hosted by Sarah Crespi. [Img: Robert Nicholls]

Jennifer Long explains how scientists have engineered human vocal cords; Catherine Matacic talks about vanquishing a deadly amphibian fungus, pigeons that spot cancer, and more. Hosted by Susanne Bard. [Img: Jaime Bosch MNCN-CSIC]

Joshua Blumenstock discusses patterns of mobile phone use as a source of "big data" about wealth and poverty in developing countries; David Grimm talks about gene drives, helpful parasites, and electric roses. Hosted by Sarah Crespi. [Img: A.A. JAMES]

Paul O'Toole discusses what happens to our gut microbes as we age; David Grimm talks about competent grandmas, our tilted moon, and gender in the brain. Hosted by Susanne Bard. [Img: Dhinakaran Gajavarathan CC BY 2.0, via flickr]