10 Incredible Images from NASA
1. Psychedelic Pluto
New Horizons scientists made this false color image of Pluto using a technique called principal component analysis to highlight the many subtle color differences between Pluto’s distinct regions. The image data were collected by the spacecraft’s Ralph/MVIC color camera on July 14 at 11:11 AM UTC, from a range of 22,000 miles (35,000 kilometers). This image was presented by Will Grundy of the New Horizons’ surface composition team on Nov. 9 at the Division for Planetary Sciences (DPS) meeting of the American Astronomical Society (AAS) in National Harbor, Maryland.
2. Hubble Spies a Rebel
Most galaxies possess a majestic spiral or elliptical structure. About a quarter of galaxies, though, defy such conventional, rounded aesthetics, instead sporting a messy, indefinable shape. Known as irregular galaxies, this group includes NGC 5408, the galaxy that has been snapped here by the NASA/ESA Hubble Space Telescope.
John Herschel recorded the existence of NGC 5408 in June 1834. Astronomers had long mistaken NGC 5408 for a planetary nebula, an expelled cloud of material from an aging star. Instead, bucking labels, NGC 5408 turned out to be an entire galaxy, located about 16 million light-years from Earth in the constellation of Centaurus (The Centaur).
In yet another sign of NGC 5408 breaking convention, the galaxy is associated with an object known as an ultraluminous X-ray source, dubbed NGC 5408 X-1, one of the best studied of its class. These rare objects beam out prodigious amounts of energetic X-rays. Astrophysicists believe these sources to be strong candidates for intermediate-mass black holes. This hypothetical type of black hole has significantly less mass than the supermassive black holes found in galactic centers, which can have billions of times the mass of the sun, but have a good deal more mass than the black holes formed when giant stars collapse.
European Space Agency
3. The ‘Serpent’ Star-Forming Cloud Spawns Stars
Within the swaddling dust of the Serpens Cloud Core, astronomers are studying one of the youngest collections of stars ever seen in our galaxy. This infrared image combines data from NASA’s Spitzer Space Telescope with shorter-wavelength observations from the Two Micron All Sky Survey (2MASS), letting us peer into the clouds of dust wrapped around this stellar nursery.
At a distance of around 750 light-years, these young stars reside within the confines of the constellation Serpens, or the “Serpent.” This collection contains stars of only relatively low to moderate mass, lacking any of the massive and incredibly bright stars found in larger star-forming regions like the Orion nebula. Our sun is a star of moderate mass. Whether it formed in a low-mass stellar region like Serpens, or a high-mass stellar region like Orion, is an ongoing mystery.
The stellar “hatchlings” in the Serpens Cloud Core represent the very youngest stages of stellar development. They appear as red, orange and yellow points clustered near the center of the image. Other red features include jets of material ejected from these young stars. Some mature stars that are not in the nebula appear yellowish due to dust obscuring our view at shorter, bluer wavelengths.
This region also includes a population of prenatal stars that are so deeply enshrouded in their dusty cocoons to be completely hidden in this view. They only become detectable at much longer wavelengths of light.
The inner Serpens Cloud Core is remarkably detailed in this image, as it was assembled from 82 separate snapshots totaling a whopping 16.2 hours of Spitzer observing time. Serpens is one of several star-forming regions targeted by the Young Stellar Object Variability (YSOVAR) project, which conducted repeated observations in each area to look for changes in brightness in the baby stars. Such fluctuations can provide valuable clues to how stars gobble up gas and dust as they grow and mature.
4. Aurora and the Pacific Northwest
NASA astronaut Scott Kelly and ESA astronaut Tim Peake shared a series of aurora photographs taken from the International Space Station on Jan. 20, 2016. Kelly (@StationCDRKelly) wrote, “#goodmorning #aurora and the Pacific Northwest! #YearInSpace” and Peake (@astro_timpeake) followed up with, “Getting a photo masterclass from @StationCDRKelly – magical #aurora”
The dancing lights of the aurora provide spectacular views on the ground, but also capture the imagination of scientists who study incoming energy and particles from the sun. Aurora are one effect of such energetic particles, which can speed out from the sun both in a steady stream called the solar wind and due to giant eruptions known as coronal mass ejections or CMEs.
5. Flying Through an Aurora
European Space Agency astronaut Alexander Gerst posted this photograph taken from the International Space Station to social media on Aug. 29, 2014, writing, “words can’t describe how it feels flying through an #aurora. I wouldn’t even know where to begin….”
Crewmembers on the space station photograph the Earth from their unique point of view located 200 miles above the surface. Photographs record how the planet is changing over time, from human-caused changes like urban growth and reservoir construction, to natural dynamic events such as hurricanes, floods and volcanic eruptions. Crewmembers have been photographing Earth from space since the early Mercury missions beginning in 1961. The continuous images taken from the space station ensure this record remains unbroken.
6. Curiosity Self-Portrait at Martian Sand Dune
This self-portrait of NASA’s Curiosity Mars rover shows the vehicle at “Namib Dune,” where the rover’s activities included scuffing into the dune with a wheel and scooping samples of sand for laboratory analysis.
The scene combines 57 images taken on Jan. 19, 2016, during the 1,228th Martian day, or sol, of Curiosity’s work on Mars. The camera used for this is the Mars Hand Lens Imager (MAHLI) at the end of the rover’s robotic arm.
Namib Dune is part of the dark-sand “Bagnold Dune Field” along the northwestern flank of Mount Sharp. Images taken from orbit have shown that dunes in the Bagnold field move as much as about 3 feet (1 meter) per Earth year.
7. Hubble Finds Misbehaving Spiral
Despite its unassuming appearance, the edge-on spiral galaxy captured in the left half of this NASA/ESA Hubble Space Telescope image is actually quite remarkable.
Located about one billion light-years away in the constellation of Eridanus, this striking galaxy — known as LO95 0313-192 — has a spiral shape similar to that of the Milky Way. It has a large central bulge, and arms speckled with brightly glowing gas mottled by thick lanes of dark dust. Its companion, sitting in the right of the frame, is known rather unpoetically as [LOY2001] J031549.8-190623.
Jets, outbursts of superheated gas moving at close to the speed of light, have long been associated with the cores of giant elliptical galaxies, and galaxies in the process of merging. However, in an unexpected discovery, astronomers found LO95 0313-192, even though it is a spiral galaxy, to have intense radio jets spewing out from its center. The galaxy appears to have two more regions that are also strongly emitting in the radio part of the spectrum, making it even rarer still.
The discovery of these giant jets in 2003 — not visible in this image, but indicated in this earlier Hubble composite — has been followed by the unearthing of a further three spiral galaxies containing radio-emitting jets in recent years. This growing class of unusual spirals continues to raise significant questions about how jets are produced within galaxies, and how they are thrown out into the cosmos.
ESA (European Space Agency)
8. Hubble Sees a Youthful Cluster
Shown here in a new image taken with the Advanced Camera for Surveys (ACS) on board the NASA/ESA Hubble Space Telescope is the globular cluster NGC 1783. This is one of the biggest globular clusters in the Large Magellanic Cloud, a satellite galaxy of our own galaxy, the Milky Way, in the southern hemisphere constellation of Dorado.
First observed by John Herschel in 1835, NGC 1783 is nearly 160,000 light-years from Earth, and has a mass around 170,000 times that of the sun.
Globular clusters are dense collections of stars held together by their own gravity, which orbit around galaxies like satellites. The image clearly shows the symmetrical shape of NGC 1783 and the concentration of stars towards the center, both typical features of globular clusters.
By measuring the color and brightness of individual stars, astronomers can deduce an overall age for a cluster and a picture of its star formation history. NGC 1783 is thought to be less than one and a half billion years old — which is very young for globular clusters, which are typically several billion years old. During that time, it is thought to have undergone at least two periods of star formation, separated by 50 to 100 million years.
This ebb and flow of star-forming activity is an indicator of how much gas is available for star formation at any one time. When the most massive stars created in the first burst of formation explode as supernovae they blow away the gas needed to form further stars, but the gas reservoir can later be replenished by less massive stars which last longer and shed their gas less violently. After this gas flows to the dense central regions of the star cluster, a second phase of star formation can take place and once again the short-lived massive stars blow away any leftover gas. This cycle can continue a few times, at which time the remaining gas reservoir is thought to be too small to form any new stars.
European Space Agency
9. Helix Nebula – Unraveling at the Seams
A dying star is throwing a cosmic tantrum in this combined image from NASA’s Spitzer Space Telescope and the Galaxy Evolution Explorer (GALEX), which NASA has lent to the California Institute of Technology in Pasadena. In death, the star’s dusty outer layers are unraveling into space, glowing from the intense ultraviolet radiation being pumped out by the hot stellar core.
This object, called the Helix nebula, lies 650 light-years away, in the constellation of Aquarius. Also known by the catalog number NGC 7293, it is a typical example of a class of objects called planetary nebulae. Discovered in the 18th century, these cosmic works of art were erroneously named for their resemblance to gas-giant planets.
Planetary nebulae are actually the remains of stars that once looked a lot like our sun. These stars spend most of their lives turning hydrogen into helium in massive runaway nuclear fusion reactions in their cores. In fact, this process of fusion provides all the light and heat that we get from our sun. Our sun will blossom into a planetary nebula when it dies in about five billion years.
When the hydrogen fuel for the fusion reaction runs out, the star turns to helium for a fuel source, burning it into an even heavier mix of carbon, nitrogen and oxygen. Eventually, the helium will also be exhausted, and the star dies, puffing off its outer gaseous layers and leaving behind the tiny, hot, dense core, called a white dwarf. The white dwarf is about the size of Earth, but has a mass very close to that of the original star; in fact, a teaspoon of a white dwarf would weigh as much as a few elephants!
The glow from planetary nebulae is particularly intriguing as it appears surprisingly similar across a broad swath of the spectrum, from ultraviolet to infrared. The Helix remains recognizable at any of these wavelengths, but the combination shown here highlights some subtle differences.
The intense ultraviolet radiation from the white dwarf heats up the expelled layers of gas, which shine brightly in the infrared. GALEX has picked out the ultraviolet light pouring out of this system, shown throughout the nebula in blue, while Spitzer has snagged the detailed infrared signature of the dust and gas in yellow A portion of the extended field beyond the nebula, which was not observed by Spitzer, is from NASA’s all-sky Wide-field Infrared Survey Explorer (WISE). The white dwarf star itself is a tiny white pinprick right at the center of the nebula.
The brighter purple circle in the very center is the combined ultraviolet and infrared glow of a dusty disk circling the white dwarf (the disk itself is too small to be resolved). This dust was most likely kicked up by comets that survived the death of their star.
Before the star died, its comets, and possibly planets, would have orbited the star in an orderly fashion. When the star ran out of hydrogen to burn, and blew off its outer layers, the icy bodies and outer planets would have been tossed about and into each other, kicking up an ongoing cosmic dust storm. Any inner planets in the system would have burned up or been swallowed as their dying star expanded.
10. ‘Pacman Nebula’ Lives the High Life
High-mass stars are important because they are responsible for much of the energy pumped into our galaxy over its lifetime. Unfortunately, these stars are poorly understood because they are often found relatively far away and can be obscured by gas and dust. The star cluster NGC 281 is an exception to this rule. It is located about 9,200 light years from Earth and, remarkably, almost 1,000 light years above the plane of the Galaxy, giving astronomers a nearly unfettered view of the star formation within it.
This composite image of NGC 281 contains X-ray data from Chandra (purple) with infrared observations from Spitzer (red, green, blue). The high-mass stars in NGC 281 drive many aspects of their galactic environment through powerful winds flowing from their surfaces and intense radiation that heats surrounding gas, “boiling it away” into interstellar space. This process results in the formation of large columns of gas and dust, as seen on the left side of the image. These structures likely contain newly forming stars. The eventual deaths of massive stars as supernovas will also seed the galaxy with material and energy.
NGC 281 is known informally as the “Pacman Nebula” because of its appearance in optical images. In optical images the “mouth” of the Pacman character appears dark because of obscuration by dust and gas, but in the infrared Spitzer image the dust in this region glows brightly.