The Coronal Mass Ejection (CME) resulting from the big X-class solar flare on 10 June 2014 as seen through the LASCO C2 instrument of the ESA/NASA Solar and Heliospheric Observatory (SOHO).
LASCO (Large Angle Spectrometric Coronagraph) is able to take images of the solar corona by blocking the light coming directly from the Sun with an occulter disk, creating an artificial eclipse within the instrument itself.
Back in 1998, the Sun was behaving as expected. The approximately 11-year cycle of activity was proceeding smoothly, heading towards a peak in 2001.
The Solar and Heliospheric Observatory (SOHO) captured this image on 9 November 1998 through its ultraviolet telescope, showing radiation from iron atoms bathed in a gas of around a million degrees Celsius.
This textbook image of solar activity shows two brighter bands circling the Sun at the same latitude in each hemisphere.
At visible wavelengths these bright loops and patches are associated with dark smudges known as sunspots. They are produced when loops of magnetism become buoyant and rise from inside the Sun into the atmosphere.
When the cycle begins, the active regions appear at high latitudes in sparse numbers, disappearing after a few weeks or so. As the cycle proceeds, new and often larger active regions appear more frequently at successively lower latitudes. Many can be larger than Earth, and they sometimes persist for months.
This activity takes place in both hemispheres simultaneously, and about five or six years into the cycle sunspots reach lower latitudes closer to the equator. This is known as solar maximum.
After this, the number of spots begins to decline until they virtually disappear and the cycle starts again at high latitudes. It is one of the enduring mysteries of the Sun why this cycle happens. Certainly, it is linked to the way the Sun generates magnetism deep inside its gaseous layers but the details remain elusive.
In recent years, the Sun has deviated from this textbook behavior. The current cycle was about two years late in starting, the hemispheres are behaving differently and the peak of activity is relatively modest. The next cycle is expected to continue in this new vein. It may even be weaker than the current cycle.
The building blocks of comets, and apparently Saturn's largest moon, Titan, formed under similar conditions in the disk of gas and dust that formed the sun.
NASA's Spitzer Space Telescope observed a fledgling solar system like the one depicted in this artist's concept, and discovered deep within it enough water vapor to fill the oceans on Earth five times. This water vapor starts out in the form of ice in a cloudy cocoon (not pictured) that surrounds the embryonic star, called NGC 1333-IRAS 4B (buried in center of image). Material from the cocoon, including ice, falls toward the center of the cloud. The ice then smacks down onto a dusty pre-planetary disk circling the stellar embryo (doughnut-shaped cloud) and vaporizes. Eventually, this water might make its way into developing planets.
A new study of the Perseus galaxy cluster, shown in this image, and others using Chandra and XMM-Newton has revealed a mysterious X-ray signal in the data. The signal is also seen in over 70 other galaxy clusters using XMM-Newton. This unidentified signal requires further investigation to confirm both its existence and nature, but one possibility is that it represents the decay of ‘sterile neutrinos’, one proposed candidate to explain dark matter.
Just as children are sorted into age groups at school, so the seeds of new stars can also be found in ‘classes’ of others of similar ages. This is especially true when the birth of stars in a cloud of gas and dust is triggered by an external event, like the explosion of a nearby supernova.
This image from ESA’s Herschel space observatory shows a sequence of star-forming regions in the molecular cloud W48, some 10,000 light-years away in the constellation Aquila (the Eagle).
The blue, jellyfish-shaped cloud at the lower left is the oldest stellar nursery in the image. Young and massive stars embedded within it have shaped it into a bubble and heated the diffuse gas, making it shine at the longest wavelengths probed by Herschel.
To its right, another glowing cloud conceals clumps that will evolve into massive stars. These clumps, some of which are visible as bright blotches of light, are also lined up by their age: the older ones at the lower-left and the younger ones to the upper-right. The youngest in this sequence is the small cyan lump at the center of the image, harboring the seeds of future massive stars.
Astronomers believe that this sequence of stellar birth is the result of dozens of supernovas that exploded over 10 million years ago in a region called Aquila Supershell, beyond the left edge of this image. Compressing the surrounding material, these supernovas may have initiated a wave of star formation that sparked, one by one, these stellar cribs.
The image is a composite of the wavelengths of 70 microns (blue), 160 microns (green) and 250 microns (red) and spans about one degree on the long side. North is to the upper-left and east is to the lower left. The data were acquired with Herschel’s PACS and SPIRE instruments in September 2010, as part of a larger map of the W48 molecular complex in the HOBYS Key Programme. This was first published in a paper by Q. Nguyen Luong, et al. 2011. A more detailed study of the star-forming regions shown in this image is presented in a paper by K.L.J. Rygl, et al. 2014.
This animation shows changes in Earth’s magnetic field from January to June 2014 as measured by ESA’s Swarm trio of satellites.
The magnetic field protects us from cosmic radiation and charged particles that bombard Earth, but it is in a permanent state of flux. Magnetic north wanders, and every few hundred thousand years the polarity flips so that a compass would point south instead of north. Moreover, the strength of the magnetic field constantly changes – and it is currently showing signs of significant weakening.
The field is particularly weak over the South Atlantic Ocean – known as the South Atlantic Anomaly. This weak field has indirectly caused many temporary satellite ‘hiccups’ (called Single Event Upsets) as the satellites are exposed to strong radiation over this area.
This image shows a region of space containing a sample of dwarf galaxies studied by the NASA/ESA Hubble Space Telescope to unlock the secrets of star formation in the early Universe.
Hiding amongst these thousands of galaxies are faint dwarf galaxies that reside in the early Universe, between two and six billion years after the Big Bang, an important time period when most of the stars in the Universe were formed. Some of these galaxies are undergoing starbursts and have been studied by astronomers to deduce their contribution to star formation in this crucial era of the Universe's history.
The image is part of the Great Observatories Origins Deep Survey (GOODS), and this image shows only one section that the survey covered.
This is the galaxy known as NGC 5548. At its heart, though not visible here, is a supermassive black hole behaving in a strange and unexpected manner. Researchers detected a clumpy gas stream flowing quickly outwards and blocking 90 percent of the X-rays emitted by the black hole. This activity could provide insights into how supermassive black holes interact with their host galaxies.
This image of asteroid 2011 MD was taken by NASA's Spitzer Space Telescope in February 2014, over a period of 20 hours. The long observation, taken in infrared light, was needed to pick up the faint signature of the small asteroid (center of frame). The Spitzer observations helped narrow down the size of the space rock to roughly 20 feet (6 meters), making it one of a few candidates for NASA's proposed Asteroid Redirect Mission for which sizes are approximately known.
This image was taken by Spitzer's Infrared Array Camera at a wavelength of 4.5 microns.
The Ring Nebula at optical wavelengths as seen by the Hubble Space Telescope, with Herschel data acquired with SPIRE and PACS over a wavelength range of 51–672 micrometers for the region identified. The spectra have been cropped and the scales stretched in order to show the OH+ emission, a molecular ion important for the formation of water. ESA’s Herschel space observatory is the first to detect this molecule in planetary nebulas – the product of dying Sun-like stars.
Massive stars end their lives with a bang: exploding as spectacular supernovas, they release huge amounts of mass and energy into space. These explosions sweep up any surrounding material, creating bubble remnants that expand into interstellar space. At the heart of bubbles like these are small, dense neutron stars or black holes, the remains of what once shone brightly as a star.
Since supernova-carved bubbles shine for only a few tens of thousands of years before dissolving, it is rare to come across neutron stars or black holes that are still enclosed within their expanding shell. This image captures such an unusual scene, featuring both a strongly magnetized, rotating neutron star – known as a pulsar – and its cosmic cloak, the remains of the explosion that generated it.
This pulsar, named SXP 1062, lies in the outskirts of the Small Magellanic Cloud, one of the satellite galaxies of our Milky Way galaxy. It is an object known as an X-ray pulsar: it hungrily gobbles up material from a nearby companion star and burps off X-rays as it does so. In the future, this scene may become even more dramatic, as SXP 1062 has a massive companion star that has not yet exploded as a supernova.
Most pulsars whirl around incredibly quickly, spinning many times per second. However, by exploring the expanding bubble around this pulsar and estimating its age, astronomers have noticed something intriguing: SXP 1062 seems to be rotating far too slowly for its age. It is actually one of the slowest pulsars known.
While the cause of this weird sluggishness is still a mystery, one explanation may be that the pulsar has an unusually strong magnetic field, which would slow the rotation.
The diffuse blue glow at the center of the bubble in this image represents X-ray emission from both the pulsar and the hot gas that fills the expanding bubble. The other fuzzy blue objects visible in the background are extragalactic X-ray sources.
This image combines X-ray data from ESA’s XMM-Newton (shown in blue) with optical observations from the Cerro Tololo Inter-American Observatory in Chile. The optical data were obtained using two special filters that reveal the glow of oxygen (shown in green) and hydrogen (shown in red). The size of the image is equivalent to a distance of 457 light-years on a side.
This image was first published on ESA’s Science and Technology website in 2011. It is based on data from the paper “Discovery of a Be/X-ray pulsar binary and associated supernova remnant in the Wing of the Small Magellanic Cloud” by V. Hénault-Brunet, et al. 2012.
A class M1.3 flare can be observed from the Central-East active region on 3 June 2014 (~13 seconds into the movie), and a large prominence eruption followed by a spectacular expanding flare ribbon can be seen located to the South East, on 4 June 2014 (~33 sec into the movie). Note that on the Sun, East and West are reversed.
NASA scientists used Earth-based radar to produce these sharp views -- an image montage and a movie sequence -- of the asteroid designated "2014 HQ124" on June 8, 2014.
2014 HQ124 is what scientists call a "contact binary": an asteroid that consists of two lobes that are in contact and that could have once been separate objects. About one in six asteroids in the near-Earth population has this type of elongated, "peanut" shape.
The asteroid is about 1,300 feet (400 meters) long and about half as wide. The radar images reveal a wealth of interesting features, including a large depression or concavity on the larger lobe as well as two blocky, sharp-edged features at the bottom on the radar echo. Scientists suspect that some of the bright features that persist from frame to frame could be surface boulders.
The 21 radar images were taken over a span of four hours. During that interval, the asteroid rotated a few degrees per frame, suggesting its rotation period is slightly less than 24 hours.
At its closest approach to Earth on June 8, the asteroid came within 776,000 miles (1.25 million kilometers), or slightly more than three times the distance to the moon. Scientists began radar observations of 2014 HQ124 shortly after the closest approach, when the asteroid was between about 864,000 miles (1.39 million kilometers) and 902,000 miles (1.45 million kilometers) from Earth.
The new views show features as small as about 12 feet (3.75 meters) wide. This is the highest resolution currently possible using scientific radar antennas to produce images. Such sharp views were made possible for this asteroid by linking together two giant radio telescopes to enhance their capabilities.
To obtain the new views, researchers paired the 230-foot (70-meter) Deep Space Network antenna at Goldstone, California, with two other radio telescopes, one at a time. Using this technique, the Goldstone antenna beams a radar signal at an asteroid and the other antenna receives the reflections. The technique dramatically improves the amount of detail that can be seen in radar images.
To image 2014 HQ124, the researchers first paired the large Goldstone antenna with the 1000-foot (305-meter) Arecibo radio telescope in Puerto Rico. They later paired the large Goldstone dish with a smaller companion, a 112-foot (34-meter) antenna, located about 20 miles (32 kilometers) away.
The first five images in the sequence -- the top row in the montage -- represent the data collected by Arecibo, and demonstrate that these data are 30 times brighter than what Goldstone can produce observing on its own. There is a gap of about 35 minutes between the first and second rows in the montage, or between the fifth and sixth frames in the video. The gap represents the time needed to switch from receiving at Arecibo to receiving at the smaller Goldstone station.
Each image in the montage and movie represents 10 minutes of data. Each frame has the same orientation, delay-Doppler dimensions and resolution (3.75 meters by 0.0125 Hertz).
For asteroids, as well as comets, radar is a powerful tool for studying the objects' size, shape, rotation, surface features and orbits. Radar measurements of asteroid distances and velocities enable researchers to compute orbits much further into the future than if radar observations were not available.
This animated blink comparison shows five different versions of observations that NASA's Curiosity made about one hour apart while Mercury was passing in front of the Sun on June 3, 2014. Two sunspots, each about the diameter of Earth, also appear in the images, moving much less during the hour than Mercury's movement.
This is the first observation of any planet's transit of the Sun observed from any planet other than Earth. It is also the first observation of Mercury from Mars.
With precise information about when the transit would occur, the rover team planned this observation using the telephoto-lens (right-eye) camera of Curiosity's Mast Camera (Mastcam) instrument. The camera has solar filters for routine observations of the Sun used for assessing the dustiness of the atmosphere. Mercury appears as a faint darkening that moves across the face of the Sun. It is about one-sixth the size of a right-Mastcam pixel at the interplanetary distance from which these images were taken, so it does it does not appear as a distinct shape, but its position follows Mercury's known path.
Each of the five versions of the image presented here blinks back and forth between two views recorded at different times during the transit. North is up. The version on the left is minimally enhanced, for a natural looking image of the Sun with two sunspots barely visible. The second version has limb darkening removed, the edges masked. The third has enhanced contrast. The fourth has a line added to indicate the calculated path of Mercury during the transit. The fifth adds annotation to point out which spot is Mercury (in the cross hairs) and to identify two sunspots.
For a video presentation of these images, see http://www.jpl.nasa.gov/video/?id=1309.
Transits of the Sun by Mercury and Venus, as seen from Earth, have significant history. Observations of Venus transits were used to measure the size of the solar system, and Mercury transits were used to measure the size of the Sun.
Taking center stage in this new NASA/ESA Hubble Space Telescope image is a galaxy known as NGC 3081, set against an assortment of glittering galaxies in the distance. Located in the constellation of Hydra (The Sea Serpent), NGC 3081 is located over 86 million light-years from us. It is known as a type II Seyfert galaxy, characterized by its dazzling nucleus.
NGC 3081 is seen here nearly face-on. Compared to other spiral galaxies, it looks a little different. The galaxy's barred spiral center is surrounded by a bright loop known as a resonance ring. This ring is full of bright clusters and bursts of new star formation, and frames the supermassive black hole thought to be lurking within NGC 3081 — which glows brightly as it hungrily gobbles up infalling material.
These rings form in particular locations known as resonances, where gravitational effects throughout a galaxy cause gas to pile up and accumulate in certain positions. These can be caused by the presence of a "bar" within the galaxy, as with NGC 3081, or by interactions with other nearby objects. It is not unusual for rings like this to be seen in barred galaxies, as the bars are very effective at gathering gas into these resonance regions, causing pile-ups which lead to active and very well-organized star formation.
Hubble snapped this magnificent face-on image of the galaxy using the Wide Field Planetary Camera 2. This image is made up of a combination of ultraviolet, optical, and infrared observations, allowing distinctive features of the galaxy to be observed across a wide range of wavelengths.
The Herschel Space Observatory has uncovered a weird ring of dusty material while obtaining one of the sharpest scans to date of a huge cloud of gas and dust, called NGC 7538. The gigantic ring structure is situated at the center-top of this image. The odd ovoid possesses the mass of 500 suns, with its long axis spanning about 35 light-years and its short axis about 25 light-years.
Astronomers often see ring and bubble-like structures in cosmic dust clouds. The strong winds cast out by the most massive stars, called O-type stars, can generate these expanding puffs, as can their explosive deaths as supernovas. But no energetic source or remnant of a deceased O-type star, such as a neutron star, is apparent within the center of the ring. It is possible that a big star blew the bubble and, because stars are all in motion, subsequently left the scene, escaping detection.
Astronomers study stellar nurseries such as NGC 7538 to better learn how stars come into being. The Herschel observations have revealed numerous clumps of material in NGC 7538, a baker's dozen of which may evolve into O-type stars. Early in the star-formation process, these clumps remain quite cold, just a few tens of degrees above absolute zero. At these temperatures, the clumps emit the bulk of their radiation in the low-energy, sub-millimeter and infrared light that Herschel was specifically designed to detect.
Finding the mysterious ring came as an unexpected bonus during the Herschel observing run.
The blue and green colors in this image represent 70- and 160-micron data, respectively, from Herschel's Photoconductor Array Camera and Spectrometer (PACS) instrument. The red colors are 250-micron observations obtained from Herschel's Spectral and Photometric Imaging Receiver (SPIRE) instrument.
An artist’s conception of the environment around GRB 020819B based on ALMA observations.
ESA’s Herschel space observatory has observed 132 of the known 1400 cold worlds that inhabit a region of the Solar System beyond the orbit of Neptune, some 4.5–7.5 billion km from the Sun.
These ‘trans-Neptunian objects’, or TNOs, include worlds such as Pluto, Eris, Haumea and Makemake, and make up a vast population of such objects thought to occupy these far-flung reaches of the Solar System.
TNOs are particularly cold, at around –230ºC, but these low temperatures lend themselves to observations by Herschel, which observes at far-infrared to sub-millimeter wavelengths. Indeed, the space observatory observed the thermal emission from 132 such objects during its nearly four-year lifetime.
These measurements provided their sizes and albedos (the fraction of visible light reflected from the surface), properties that are not otherwise easily accessible. The graphic presented here shows a sample of the population of TNOs observed with Herschel, arranged to showcase these properties.
What is most striking is their diversity. They range from just below 50 km to almost 2400 km in diameter; Pluto and Eris are the largest. Two worlds have distinctly elongated shapes: Haumea (seen in white) and Varuna (brown). Some even host their own moons (not shown).
The albedo measurement implies a variety of surface compositions: low albedo (brown) is an indication of dark surface materials, such as organic material, while higher albedo (white) suggests pure ices.
TNOs are thought to be some of the most primitive remnants of the planet-forming era. Thus the results of the Herschel “TNOs are cool: A survey of the trans-Neptunian region” open key time program are being used to test different models of Solar System formation and evolution.
Prometheus is caught in the act of creating gores and streamers in the F ring. Scientists believe that Prometheus and its partner-moon Pandora are responsible for much of the structure in the F ring.
The orbit of Prometheus (53 miles, or 86 kilometers across) regularly brings it into the F ring. When this happens, it creates gores, or channels, in the ring where it entered. Prometheus then draws ring material with it as it exits the ring, leaving streamers in its wake. This process creates the pattern of structures seen in this image. This process is described in detail, along with a movie of Prometheus creating one of the streamer/channel features, in PIA08397.
This view looks toward the sunlit side of the rings from about 8.6 degrees above the ringplane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on February 11, 2014.
The view was acquired at a distance of approximately 1.3 million miles (2.1 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 147 degrees. Image scale is 8 miles (13 kilometers) per pixel.
This infrared image from NASA's Spitzer Space Telescope shows N103B -- all that remains from a supernova that exploded a millennium ago in the Large Magellanic Cloud, a satellite galaxy 160,000 light-years away from our own Milky Way.
Spitzer's instruments pick up infrared light emitted by dust in both the remnant and the surrounding interstellar medium. The infrared light has been translated to colors we see in this image, allowing astronomers to dissect the scene. In this image, dust associated with the remnant appears red, while dust in the ambient background of the galaxy appears yellow and green. Stars in the field appear blue.
By studying the infrared light emitted from this supernova remnant, astronomers have determined that the density of the gas surrounding the supernova is much higher than is typical for a 'Type Ia' supernova, which are those that occur when dead stars called white dwarfs explode. Astronomers believe that this dense material was expelled prior to the supernova explosion, possibly by a companion to the white dwarf -- an aging star that shed the material.
Most Type Ia supernovas do not show evidence for this process occurring, making N103B an example of a rare subclass of Type Ia explosions. In fact, only one other remnant of a Type Ia explosion shows evidence for this: the remnant of Kepler's supernova in our own galaxy, the remains of the explosion of a star witnessed on Earth in 1604 A.D.
The clump of blue stars seen at the lower right is the cluster known as NGC 1850. Also a resident of the Large Magellanic Cloud, this cluster is made up of young stars yet has the appearance of globular clusters in the Milky Way, which are much older.
The red data shows infrared light with wavelengths of 16 and 24 microns, while shorter-wavelength infrared light of 3.6, 4.5, and 8 microns is shown as blue, cyan and green, respectively.
Whirlpool Galaxy: A spiral galaxy located about 30 million light years from Earth.
This image contains nearly a million seconds worth of Chandra observing time (purple) along with optical data from the Hubble Space Telescope (red, green, and blue). The X-ray data reveal hundreds of point-like sources, most of which are X-ray binary systems (XRBs) containing a neutron star or black hole in orbit with a star like the Sun. Researchers are studying the XRBs in M51, a.k.a. the "Whirlpool Galaxy," to better understand the role they play in the evolution of the galaxy.
Scale: Image is 6 x 10 arcmin (About 52,000 x 87,000 light years).
This image shows the Bullet Group, a group of galaxies also known as SL2S J08544-0121.
The galaxies belonging to the group are visible in the central part of the image, embedded in the diffuse dark matter (shown in blue). Hot gas, which fills the space between galaxies and comprises the bulk of ordinary (baryonic) matter in the group, is shown in pink, as imaged by ESA's XMM-Newton X-ray observatory.
The light from galaxies and hot gas belonging to the group, which lies at a redshift of z=0.351, has been traveling for almost four billion years before reaching us. Other galaxies, either in the foreground or background of the Bullet Group, are sprinkled across the image, as well as bright foreground stars that belong to our Galaxy.
The group's components appear to be clearly separated, with the hot gas partitioned from the rest of the mass within the group. This is the smallest object ever found to show such an effect, which was caused by a merger in the group's past.
Astronomers were able to map the extent of the Bullet Group's dark matter through its gravitational lensing of background galaxies. This effect is particularly evident in the center-right part of this image, where a round, bright galaxy that belongs to the Bullet Group is circled by curious arcs of light – the distorted image of another galaxy lying much farther away.
By exploring the contents of these cosmic wrecks, astronomers can learn more about the properties of dark matter. In particular, from the split between the dark matter and the hot gas, they can constrain how much dark matter does – or does not – interact with normal matter.
This image is a composite of an X-ray image (shown in pink) from ESA's XMM-Newton observatory, a three-color (red, green, blue) optical image from the Canada-France-Hawaii Telescope (CFHT), and a dark matter overlay (indicated in blue) based on data from CFHT, the NASA/ESA Hubble Space Telescope, and the W. M. Keck Observatory.
Astronomers using the Hubble Space Telescope have captured the most comprehensive picture ever assembled of the evolving Universe – and one of the most colorful. The study is called the Ultraviolet Coverage of the Hubble Ultra Deep Field (UVUDF) project.
This infrared image shows the dust ring around the nearby star HR 4796A in the southern constellation of Centaurus. It was one of the first produced by the SPHERE instrument soon after it was installed on ESO’s Very Large Telescope in May 2014. It shows not only the ring itself with great clarity, but also reveals the power of SPHERE to reduce the glare from the very bright star — the key to finding and studying exoplanets in future.
X-ray emission from the B-type star Xi1 Canis Majoris (Xi1 CMa) – seen in the center of this image - has been measured using ESA's XMM-Newton observatory.
Xi1 CMa was observed continuously with XMM-Newton in October 2012 for almost 29 hours. These observations resulted in the first detection of pulsed X-ray emission from a non-degenerate, massive star.
Xi1 CMa is an extremely bright star with a surface temperature of approximately 27,500K, and a mass of approximately 15 times that of the Sun. It lies some 1400 light years away in the constellation Canis Major. The star has a notably strong magnetic field, about 5000 times stronger than our Sun's.
This 3-colour image of the field was made by mapping 0.2-1.0 keV emission to red, 1.0-2.5 keV emission to green, and 2.5-10.0 keV emission to blue. The field of view of this image is 19 arcmin × 19 arcmin (approximately 7.6 light years × 7.6 light years).
An artist's conception shows the Kepler-10 system, home to two rocky planets. In the foreground is Kepler-10c, a planet that weighs 17 times as much as Earth and is more than twice as large in size. Planet formation theorists are challenged to explain how such a massive world could have formed.
