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Astro Bulletin, produced by the Science Bulletins program at the American Museum of Natural History, highlights the scientists, observatories, and technologies that advance our knowledge of the cosmos.
52 Episodes
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How can scientists study a faraway black hole that emits no light? By observing its quasar. As objects get pulled onto the accretion disk orbiting a supermassive black hole, friction creates a bright light known as a quasar. In this video, researchers use a “galaxy-sized lens” to analyze light from a distant quasar—revealing a supermassive black hole with a truly voracious appetite.
AMNH researchers make a discovery about the chemical composition of Type Ia supernovae, which may aid in the understanding of how these stars explode—and become the “standard candles” by which we measure the distance of far-off galaxies.
A large, unseen planet may be lurking in the cold, dim reaches of our solar system. Using a combination of theory and observation, scientists have estimated the mass, distance and orbital period of a proposed “Planet X.”
Phobos, a moon of Mars, is streaked with shallow grooves. Scientists long thought the grooves were caused by meteor impacts. But new computer modeling shows they may be "stretch marks," early signs of Phobos's inevitable demise.
Tiny, faraway Pluto was first spied in 1930. This icy world is one of thousands of rocky bodies that make up the Kuiper Belt, a ring that circles our solar system beyond Neptune. Until recently, the most powerful telescopes on Earth and in space could only capture blurry impressions of Pluto and its moons. But in 2015, New Horizons became the first spacecraft to visit the Pluto system, returning detailed images and data that will bring our distant neighbor’s surface, atmosphere, and internal composition into focus for the first time.
Few of NASA’s telescopes have captured the public imagination like Hubble, with its spectacular views of distant galaxies, supernovas, and nebulas. The first telescope in the world to return visible wavelength images of space from near Earth orbit, Hubble’s photos are more than just pretty pictures. In its twenty-five year mission, Hubble’s discoveries have transformed astronomers’ understanding of cosmic objects, events, and history. Hubble continues to deliver unparalleled images and help scientists solve some of the biggest mysteries about the forces that shape the universe.
Cassiopeia A is the gas cloud left behind after a star exploded, first glimpsed on Earth about 325 years ago. Its youth and proximity to us make it one of the best-studied supernova remnants in our galaxy. Recent observations have made it possible for scientists to create the first map of the star’s interior in 3D. By reconstructing the explosion and its aftermath, astronomers will better understand the death throes of massive stars.
Chandra, the biggest X-ray space telescope to date, detects high-energy emissions from very hot regions of the universe. Since launching in 1999, Chandra has generated hundreds of thousands of images. But X-rays reveal only part of the picture. Researchers are combining Chandra data with other wavelengths to create images that reveal the different types of energy emitted by objects in space.
On November 12, 2014, the European Space Agency’s Rosetta mission landed a probe on the surface of 67P/Churyumov–Gerasimenko, a small comet hundreds of millions of kilometers from the Sun. Comets are time capsules dating back to the earliest days of our solar system, and the data gathered by this mission could reveal the role played by comets in delivering water and organic molecules to an infant Earth.
Jupiter is a planet of extremes—it’s the biggest in our solar system, it spins the fastest, it hosts the most moons, and it has the most turbulent atmosphere. But one of its most recognizable features, an enormous storm known as the Great Red Spot, is coming up short. The storm has been getting smaller for decades, but recent images show that it’s now shrinking even faster.
Astronomers have detected evidence of the young Universe’s formative growth spurt in the moments following the Big Bang. After more than a decade of observations and data analysis with a South Pole telescope called BICEP2, researchers detected distortions left in ancient light, the first direct evidence of the sudden and dramatic change that launched the Universe as we know it.
Dead men tell no tales, but dead stars have plenty to say. Traces of elements left behind after stars explode can inform astronomers about how the star was ripped apart. NuSTAR, the first telescope capable of detecting high-energy X-ray signatures of radioactive elements in supernova remnants, recently captured a picture of a dying star’s last gasp.
When a group of astronomy students gathered for a workshop at the University of London Observatory, little did they know they were about to see something extraordinary—a supernova still so young that it hadn’t yet reached peak brightness. Observers around the world quickly trained their telescopes on the exploded star, the closest of its type in more than 40 years.
Astronomers have located more than 1,000 planets orbiting stars other than our own, and the latest observations are starting to reveal what these planets are like. The AMNH-led Project 1640 is at the forefront of this research. The project’s advanced telescope instrumentation can spot chemical fingerprints that will help characterize how exoplanets form, evolve, and differ from familiar planets closer to home.
Since the first extrasolar planet was discovered in 1995, astronomers have gathered and analyzed telescope data revealing over 1,000 worlds orbiting other stars. Studies that measure and compare atmospheric water, along with recent detection of cloud activity, bring scientists closer than ever to discerning dynamic weather patterns in exoplanets, and determining whether the planets support some form of life.
A massive asteroid impact is thought to be responsible for the extinction of non-avian dinosaurs 65 million years ago. Impacts that destructive are rare, but astronomers have identified thousands of asteroids close enough to Earth to be potentially hazardous. A new plan to coordinate asteroid observations worldwide will help track big objects orbiting close to Earth and determine if they pose a threat.
Jupiter’s enormous size and gravitational attraction increase its vulnerability to comet and asteroid impacts. But collisions flare and fade quickly; unless they’re viewed at the moment of impact, they won’t be seen at all. Thanks to the efforts of amateur astronomers, dramatic impacts on Jupiter were recently captured on video, one of many important scientific contributions made by backyard stargazers.
A recent discovery near the Milky Way’s center sheds light on the inner workings of our galaxy’s supermassive black hole. Astronomers detected a rare type of fast-spinning star, the first of its kind found near the Galactic Center. Its signals reveal previously undetectable activity in the black hole, helping astronomers understand how it feeds and grows.
Every 11 years our Sun’s magnetic north and south reverse positions; after another 11 years they rotate back to their original places. For the first time, this “polar flip” was detected in another star—the slightly bigger and hotter Tau Boo. Its polar rotation took only two years to complete, a magnetic cycle much shorter than the Sun’s. Astronomers suspect that the massive planet orbiting Tau Boo may play a role, hinting that stars’ magnetic fields are linked to the dynamic relationship they share with their planets.
Astronomers have long pondered the origins of enormous elliptical galaxies in the young Universe. An event spotted by the recently ended Herschel mission may help unravel the mystery. Two massive spiral galaxies merged to create a giant elliptical galaxy, which were previously believed to form through the absorption of dwarf galaxies over time.
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