Astro Bulletin

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.

The Curiosity rover is seeking environments on Mars that could support life—or could have in the past. Earlier Mars missions found signs of water, but not organic carbon—life’s essential building block. Watch the Curiosity team prepare to hunt for carbon at Mount Sharp, which holds a geologic record hundreds of millions of years old.

In the nearby Hyades star cluster, a pair of dead stars is surrounded by dust particles that resemble the building blocks of rocky planets. These particles allow astronomers to study the chemical makeup of planetary building material, and suggest that planet formation may take place even around burnt-out or failed stars.

A new study uses thousands of infrared photographs of the Saturn system to reveal that the planet’s moons and rings are older than expected. A surface dusting of dark minerals helped conceal their age, but distributed underneath is an abundance of water ice—a telltale leftover from the earliest days of the Solar System, billions of years ago.

For the first time, scientists have calculated the rotation speed of a supermassive black hole, and they found that it is spinning at nearly the speed of light, the limit of what is possible, according to Einstein’s Theory of Relativity. Measuring the spin rate of black holes provides valuable clues about their formation.

Saturn’s largest moon, Titan, is the only moon or planet in our Solar System other than Earth with stable liquid on its surface. The Cassini spacecraft recently imaged a river valley on Titan that looks much like Earth’s Nile River valley. Titan’s hydrocarbon river follows a relatively straight path before emptying into a large lake in the north.

A telescope searching for interplanetary systems has detected a large gap in the dust disk around a young star, which could indicate the presence of multiple planets. The star is similar in size to our own Sun. Studying early-stage extrasolar planets and their host stars helps scientists to understand the formation of solar systems—including our own.

NASA's GRAIL mission is mapping the Moon's gravity field, but it has a second purpose. Cameras mounted on the paired satellites serve an education program created by late astronaut Sally Ride. MoonKAM offers students a unique opportunity to interact directly with the space program. By controlling the satellite's eight cameras, they capture thousands of pictures of the lunar surface.

The icy South Pole desert is a harsh and desolate landscape in which few life-forms can flourish. But the extreme cold and isolation are perfect for astronomical observations. Taking advantage of the severe conditions, scientists are using the new South Pole Telescope—the largest ever deployed in Antarctica—to observe the oldest light in the Universe, the cosmic microwave background (CMB).

An international team of astronomers has discovered an enormous galaxy cluster producing stars at a fantastic pace. Galaxy clusters, the Universe’s largest structures, are groups of galaxies bound by gravity with a supermassive black hole at the center. Most galaxy clusters produce few stars. But the newly described Phoenix Cluster is experiencing a period of rapid star formation.

In early August 2012, the Mars Science Laboratory Curiosity rover was safely delivered to its Mars landing site in Gale Crater. In addition to the rover’s science instrument payload for atmosphere and soil analysis, Curiosity carries 17 cameras that are capturing the Martian landscape in unprecedented detail. Scientists anticipate that the geological diversity of the landing site and nearby areas will yield a rich variety of samples, informing their understanding of Mars’s past and present habitability.

For a handful of hours in June 2012, Venus’s orbit carried it directly across the face of the Sun, providing a spectacular backlit view visible from Earth. Only six transits of Venus have been recorded since the possibility for such events was first discovered in 1639. During the four transits occurring in the 18th and 19th centuries, hundreds of astronomers worldwide coordinated their efforts, using their observation data to calculate the size of the solar system. The 2012 transit was viewed by thousands using telescopes, binoculars, and solar glasses, and was photographed by satellites and astronauts on board the International Space Station.

SpaceX achieved a milestone in space travel last month, becoming the first private company in the United States to successfully launch a cargo capsule, attach it to the International Space Station, and safely return it to Earth. Their Falcon 9 rocket and Dragon spacecraft were developed with NASA engineers to supply the ISS following the termination of NASA’s space shuttle program. Dragon is designed to carry both cargo and astronauts, and future missions may include in-space technology demonstrations, instruments tests, and experiments.

By sending an infrared telescope to altitudes of 12,000 meters (40,000 feet) and higher, NASA and the German Aerospace Center (DLR) conduct astronomical research that would be impossible using telescopes based on Earth. The Stratospheric Observatory for Infrared Astronomy—SOFIA—is the only airborne telescope in the world. Infrared imaging of stars and planets is difficult from ground-based observatories, because water vapor in Earth’s lower atmosphere blocks most infrared radiation. SOFIA operates from a modified Boeing 747, soaring high above occluding vapor to capture infrared emissions from distant galaxies. Using instruments that include a high-speed imager and a sensitive far-infrared spectrometer, SOFIA will provide insights into distant star formation, the chemical composition of deep space, and the atmospheres of planets within our own solar system.

Journey to the heights of Mauna Kea in Hawaii where astronomers search for brown dwarfs, cosmic bodies that are not quite stars and not quite planets. These long-sought objects are still elusive and visible largely with advanced technologies such as the adaptive optics tools on the Keck II telescope.

On September 30, 2010, a NASA space telescope called the Wide-field Infrared Survey Explorer, or WISE, completed its sweeping goal: to record observations of the entire sky in infrared light. The WISE science team is now sifting through the telescope’s two million images to spot objects that no astronomer has ever seen before. WISE’s most intriguing finds will include mysterious objects called brown dwarfs, blacker-than-coal asteroids, and the Universe’s brightest galaxies. All told, WISE’s data will yield a new picture of the Universe, from our local region to the remotest reaches, and from the distant past to the present. In this Astro Bulletin, watch the WISE team launch and focus this unique eye on the sky.

The Known Universe takes viewers from the Himalayas through our atmosphere and the inky black of space to the afterglow of the Big Bang. It is a short flight through the world's most complete four-dimensional map of the Universe, the Digital Universe Atlas, which is maintained and updated by astrophysicists at the American Museum of Natural History.

In 1998, two independent teams of astrophysicists discovered a baffling phenomenon: the Universe is expanding at an ever-faster rate. The current understanding of gravity can’t explain this cosmic acceleration. Scientists think that either a mysterious force called dark energy is to blame or a reworking of gravitational theory is in order. Travel to the University of California’s Lick Observatory to learn how astrophysicists use distant stellar explosions to observe the expansion of space. Then watch a team at Fermilab assemble the Dark Energy Camera, a new device researchers hope will find compelling evidence of what’s propelling the Universe to expand at an increasing pace.

The history of cosmic ray research is a story of scientific adventure. For nearly a century, cosmic ray researchers have climbed mountains, soared in hot air balloons, and traveled to the far corners of the Earth in the quest to understand these energetic particles from space. They have solved some scientific mysteries—and revealed many more. With each passing decade, scientists have discovered higher-energy and increasingly more rare cosmic rays. The Pierre Auger Project is the largest scientific enterprise ever conducted to search for the unknown sources of the highest-energy cosmic rays ever observed.

When South Africa decided to build a new telescope, it went big. As in rival-the-world's-best big. With the participation of astronomy groups from all over the world, the Southern African Large Telescope, or SALT, is casting a wide eye on the southern sky. Moreover, it's inspiring future astronomers in the region. This Science Bulletins feature takes you behind the scenes as this bold new telescope brings world-class astronomy to a developing nation.

The MESSENGER orbiter’s January 2008 flyby of the planet Mercury was historic. The last time a spacecraft visited was 1975, and it only mapped half the planet. MESSENGER is now sending back a complete picture of Mercury, shedding light on its geological history. But the ongoing mission will return much more than images. Its data on the planet’s core, magnetic field, composition, and other attributes will help scientists answer pressing questions about the evolution of the terrestrial planets and even the Solar System itself. In the feature video, watch the MESSENGER science team react as the orbiter’s first images of Mercury roll in. To explore the images in detail, click on the slide show at left. Find out more on the mission by clicking on the essay "First Planet Finishes Last."

Gamma-ray bursts—flashes of intense radiation in space that are often just seconds long—were accidentally discovered in the 1960's by satellites built to monitor nuclear bomb explosions. They’ve been one of the leading astrophysical mysteries ever since. This Astro Bulletin introduces you to the scientists and instruments working to unravel the origins of gamma-ray bursts. It highlights Swift, NASA’s burst-detecting satellite, and PAIRITEL, one of a fleet of ground-based telescopes that point toward a gamma-ray burst in response to Swift’s alert to capture the afterglow before it fades. Astrophysicists at Penn State and other institutions are analyzing these afterglows to understand what causes the most powerful explosions known.

The peaceful glow of the moonlight in our sky belies a violent history. Evidence suggests that the Moon formed when a Mars-sized object collided with the young Earth, and detailed computer models show us how such an impact could form our lunar companion in just one month.

If technology, cost, and terrain permitted, scientists seeking key data on stars in our galaxy would have loved to construct a behemoth 330 m wide telescope atop Mount Wilson, just northeast of Los Angeles. Instead, they arranged six smaller telescopes over an identical area, synchronizing the light to achieve an equally superlative resolution. Called the Center for High Angular Resolution Astronomy (CHARA), the array uses the technique of interferometry to spot details the size of a nickel seen from 16,000 km away. Hear from project astronomers why the labyrinthine engineering required for CHARA’s renowned precision is a small sacrifice for the valuable data it gleans on the properties and life cycles of stars.

Since its discovery in 1930, we’ve looked at Pluto as our solar system’s ninth planet. But residing in the icy realm of the outer solar system, where the sun’s brightness is less than 1/1000 of the brightness here on Earth, Pluto is nothing like the other planets of our solar system. It differs tremendously from the gas giants Jupiter, Saturn, Uranus, and Neptune, but does not resemble the rocky terrestrial worlds Mercury, Venus, Earth, and Mars.

Taking a census of all the luminous objects in one-quarter of the visible cosmos is a hefty accounting job. It takes a specially-built telescope on task every clear night for eight years, wielding one of the biggest digital cameras on the planet. Over a hundred million stars, galaxies, and quasars have been tallied so far. Meet the astronomical observers and theorists set on divining the three-dimensional structure and origins of the Universe from these unprecedented scores of data.

The Milky Way and the Andromeda Galaxy are on a collision course. A computer model developed by scientists at the Museum shows that the pair is bound to crash in about three billion years and merge into a single elliptical galaxy. This video shows the result of that computer model, called a simulation.

Collisions between space objects are a vital part of the evolution of our Solar System. Most of Earth's impact craters have been wiped away due to plate tectonics, but evidence of such cosmic catastrophes, such as Arizona's 50,000-year-old meteor crater, do remain. When is Earth due for another major blast? Meet the professional and amateur astronomers who may be the first to know: first at LINEAR, a near-earth asteroid detection facility in New Mexico, and then at the Smithsonian's Minor Planet Center, where orbits of near-earth objects are tracked for possible hits and misses.

Gravity may seem elementary. But proving Einstein's theories about it is quite hard. To do so, scientists are struggling to capture gravity's most elusive hallmark: the gravitational wave. This Astro Feature focuses on research at the Laser Interferometer Gravitational-Wave Observatory (LIGO) in Livingston, LA, where scientists have constructed a sprawling facility dedicated to the detection of minute changes in spacetime caused by gravitational waves traveling from energetic events in space.

In March 2004, two NASA explorers discovered firm evidence that water once flowed on Mars—perhaps enough water to harbor life.

Astrophysicists are discovering new extrasolar planets—those outside our Solar System—almost daily. NASA’s Spitzer Space Telescope (originally called SIRTF, or the Space Infrared Telescope Facility) and AMNH’s Lyot Project Coronograph are two of the many technologies uncovering the attributes and evolution of these faraway worlds. The techniques employed by these instruments may one day help answer one of astronomy’s reigning mysteries: do any extrasolar planets host life? The feature video relates scientists’ hopes for the Spitzer Space Telescope before its launch in 2003. It also gives a firsthand look into the making of the Lyot Project. The feature essays share how these two remarkable technologies are making progress in their goals to seek and understand extrasolar planets.

The Cosmic Microwave Background (CMB) is a vast curtain of energy left over from the Big Bang. It is the oldest, most distant feature of the observable Universe. Since the discovery of the CMB in the mid-1960s, cosmology—the study of the origin and evolution of the Universe—has experienced an explosion of activity. The field has changed from a purely theoretical enterprise to the empirical study of what populates the physical Universe. "Cosmologists are right at the cusp," says the University of Chicago's Michael Turner. "We have these fantastic ideas about the Universe, and we now have the technology and the instruments to test them." This feature travels to the U.S. Amundsen-Scott South Pole Station in Antarctica, where an instrument called DASI measures the CMB, and to the University of Chicago, where DASI’s results are analyzed.