Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Explanation: This shadowy landscape of majestic mountains and icy plains stretches toward the horizon of a small, distant world. It was captured from a range of about 18,000 kilometers whenNew Horizons looked back toward Pluto, 15 minutes after the spacecraft’s closest approach on July 14. The dramatic, low-angle, near-twilight scene follows rugged mountains still popularly known as Norgay Montes from foreground left, and Hillary Montes along the horizon, giving way to smooth Sputnik Planum at right. Layers of Pluto’s tenuous atmosphere are also revealed in the backlit view. With a strangely familiar appearance, the frigid terrain likely includes ices of nitrogen and carbon monoxide with water-ice mountains rising up to 3,500 meters (11,000 feet). That’s comparable in height to the majestic mountains of planet Earth. This Plutonian landscape is 380 kilometers (230 miles) across.
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Explanation: From where do these neutrinos come? The IceCube Neutrino Observatory near the South Pole of the Earth has begun to detect nearly invisible particles of very high energy. Although these rarely-interacting neutrinos pass through much of the Earth just before being detected, where they started remains a mystery. Pictured here is IceCube’s Antarctic lab accompanied by a cartoon depicting long strands of detectors frozen into the crystal clear ice below. Candidate origins for these cosmic neutrinos include the violent surroundings of supermassive black holes at the centers of distant galaxies, and tremendous stellar explosions culminating in supernovas and gamma ray bursts far across the universe. As IceCube detects increasingly more high energy neutrinos, correlations with known objects may resolve this cosmic conundrum — or we may never know.
In his exploration of the wonders of the universe, Professor Brian Cox goes in search of humanity’s very essence to answer the biggest questions of all: what are we? And where do we come from? This film is the story of matter – the stuff of which we are all made.
Brian reveals how our origins are entwined with the life cycle of the stars. But he begins his journey here on Earth. In Nepal, he observes a Hindu cremation. Hindu philosophy is based on an eternal cycle of creation and destruction, where the physical elements of the body are recycled on to the next stage. Brian draws a parallel with the life cycle of the stars that led to our own creation.
Next, he explains how the Earth’s resources have been recycled through the ages. How every atom that makes up everything we see, was at some time a part of something else. Our world is made up of just 92 elements, and these same 92 elements are found throughout the entire universe. We are part of the universe because we are made of the same stuff as the universe. -Wonders of the Universe 2011: Episode 2
This graphic presents a view of Pluto and Charon as they would appear if placed slightly above Earth’s surface and viewed from a great distance. Recent measurements obtained by New Horizons indicate that Pluto has a diameter of 2370 km, 18.5% that of Earth’s, while Charon has a diameter of 1208 km, 9.5% that of Earth’s.
“Which was the right one? I tried to figure it out but had no success. It worried me. The different Gods – Catholic, Jewish, Protestant, Mohammedan – seemed all very particular in the way in which they expected me to keep on good terms with them. I couldn’t please one without offending the others. One kind soul solved my problem by taking me on my first trip to the planetarium. I contemplated the insignificant flyspeck called Earth, the millions of suns and solar systems, and concluded that whoever was in charge of all this would not throw a fit if I ate ham, or meat on Friday, or did not fast in the daytime during Ramadan. I felt much better after this and was, for a while, keenly interested in astronomy.” ― Richard Erdoes, Lame Deer – Seeker of Visions
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Explanation: Often imaged but rarely mentioned, Messier 43 is a large star forming region in its own right. It’s just part of the star forming complex of gas and dust that includes the larger, more famous neighboring Messier 42, the Great Orion Nebula. In fact, the Great Orion Nebula itself lies off the lower edge of this scene. The close-up of Messier 43 was made while testing the capabilities of a near-infrared instrument with one of the twin 6.5 meter Magellan telescopes at Las Campanas Observatory in the Chilean Andes. The composite image shifts the otherwise invisible infrared wavelengths to blue, green, and red colors. Peering into caverns of interstellar dust hidden from visible light, the near-infrared view can also be used to study cool, brown dwarf stars in the complex region. Along with its celebrity neighbor, Messier 43 lies about 1,500 light-years away, at the edge of Orion’s giant molecular cloud. At that distance, this field of view spans about 5 light-years.
An image taken on July 7, 2012 by the Wide Field Camera 3 on the Hubble Space Telescope shows the recently discovered fifth moon of Pluto. Moons P4 and P5 are now known as Kerberos and Styx, respectively. NASA, ESA, M. SHOWALTER (SETI INSTITUTE) AND L. FRATTARE (STSCI)
NEW HORIZONS IS practically knocking on Pluto’s door. The spacecraft is less than six weeks away from its razor-close flyby of the dwarf planet. In anticipation, Pluto research has gone into overdrive, as astronomers and planetary scientists rack up questions to ask of the coming data. Fortunately, the little-known underdog of the solar system continues to surprise—especially when it comes to the weird configuration of its five motley moons.
Pluto is so far away that astronomers only discovered four of those orbiting bodies in the last decade (the largest, Charon, was discovered in 1978). New analysis of Pluto’s system, gleaned from Hubble Space Telescope images, suggests that three of the small moons—Styx, Nix and Hydra—are locked in close rotation. That keeps them from colliding as they circle the “binary planet” formed by Pluto and Charon. But that alignment can be thrown into chaos thanks to interactions with those larger bodies and the recently discovered moon Kerberos. Astronomers Mark Showalter and Douglas Hamilton hope their findings, published in Nature today, will help explain how planets and their satellites form.
Chaotic interactions between moons and their orbitees are uncommon, but not unknown, says Showalter, of the SETI Institute in Mountain View, Calif. Saturn’s cratered, potato-shaped moon Hyperion also has a wobbly rotation, one that is impossible to forecast in advance, unlike the majority of well-behaved, synchronously rotating moons in the solar system.
More curious than that, however, may be Pluto’s moons’ orbital configuration. The ratios of their orbital periods (the amount of time they take to complete their orbit around the Pluto-Charon pair) are very close to 1:3:4:5:6. That simple integer ratio is called the Laplace resonance—a gravitational relationship seen in Jupiter’s moons Io, Europa, and Ganymede, which have a period ratio of 1:2:4.
Aside from being mathematically cool, the Laplace-like resonances seen around Pluto narrows down some of the possibilities for how the system formed. In the past, the relationships between the moons’ movements may have been more perfectly aligned, until they were knocked slightly out of place by some unknown force, speculates Scott Kenyon, an astrophysicist at the Smithsonian and author of an accompanying Nature article commenting on Showalter and Hamilton’s study. The probability that this relationship developed by chance, he says, is very slight (about 1 percent).
Kerberos, the most recently discovered member of the Pluto-moon family, continues to add to the system’s mystery. Observations suggest that its mass is about one third of the mass of Nix and Hydra. Yet it reflects so little sunlight (about 5 percent as much as Nix and Hydra) that it is probably made of a different material. “We expect it is about as black as coal,” says Showalter.
We won’t have to wait long to find out, says Alan Stern, principal investigator of NASA’s New Horizons mission. When the spacecraft reaches Pluto, in less than a month and a half, it will be able to send images of the planet and its moons back, confirming if Kerberos really is composed of a different material. If true, that would also be extremely rare.
The majority of planetary systems have moons that seem to be made of the same material as the planet and each other. If Kerberos is made of something dramatically different it may be the relic of a body that crashed into Pluto, sprayed the region with debris, and contributed to the formation of its fellow moons. New Horizons will clarify how likely that is to be true.
Keep tuned in, dear reader. Pluto’s story is just beginning to be told.
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Explanation: What’s that rising from the clouds? The space shuttle. Sometimes, if you looked out the window of an airplane at just the right place and time, you could have seen something very unusual — a space shuttle launching to orbit. Images of the rising shuttle and its plume became widely circulated over the web shortly after Endeavour’s final launch in 2011 May. The above image was taken from a shuttle training aircraft by NASA and is not copyrighted. Taken well above the clouds, the image can be matched with similar images of the same shuttle plume taken below the clouds. Hot glowing gasses expelled by the engines are visible near the rising shuttle, as well as a long smoke plume. A shadow of the plume appears on the cloud deck, indicating the direction of the Sun. The US Space Shuttle program concluded in 2011, and Endeavour can now be visited at the California Science Center.
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Explanation: A long solar filament stretches across the relatively calm surface of the Sun in this telescopic snap shot from April 27. The negative or inverted narrowband image was made in the light of ionized hydrogen atoms. Seen at the upper left, the magnificent curtain of magnetized plasma towers above surface and actually reaches beyond the Sun’s edge. How long is the solar filament? About as long as the distance from Earth to Moon, illustrated by the scale insert at the left. Tracking toward the right across the solar disk a day later the long filament erupted, lifting away from the Sun’s surface. Monitored by Sun staring satellites, a coronal mass ejection was also blasted from the site but is expected to swing wide of our fair planet.
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Explanation: How will cows survive on the Moon? One of the most vexing questions asked about space, scientists have spent decades debating this key issue. Finally, after extensive computer modeling and over a dozen midnight milkings, engineers have designed, built, and now tested the new Lunar Grazing Module (LGM), a multi-purpose celestial bovine containment system. By now, many of you will not be surprised to be wished a Happy April Fool’s Day from APOD. To the best of our knowledge, there are no current plans to launch cows into space. For one reason, cows tend to be large animals that don’t launch easily or cheaply. As friendly as cows may be, head-to-head comparisons show that robotic rovers are usually more effective as scientific explorers. The featured image is of a thought-provoking work of art named “Mooooonwalk” which really is on display at a popular science museum.
Findings Led by Rensselaer Polytechnic Institute Researchers Published in the Astrophysical Journal
The Milky Way galaxy is at least 50 percent larger than is commonly estimated, according to new findings that reveal that the galactic disk is contoured into several concentric ripples. The research, conducted by an international team led by Rensselaer Polytechnic Institute Professor Heidi Jo Newberg, revisits astronomical data from the Sloan Digital Sky Survey which, in 2002, established the presence of a bulging ring of stars beyond the known plane of the Milky Way.
“In essence, what we found is that the disk of the Milky Way isn’t just a disk of stars in a flat plane—it’s corrugated,” said Heidi Newberg, professor of physics, applied physics, and astronomy in the Rensselaer School of Science. “As it radiates outward from the sun, we see at least four ripples in the disk of the Milky Way. While we can only look at part of the galaxy with this data, we assume that this pattern is going to be found throughout the disk.”
Importantly, the findings show that the features previously identified as rings are actually part of the galactic disk, extending the known width of the Milky Way from 100,000 light years across to 150,000 light years, said Yan Xu, a scientist at the National Astronomical Observatories of China (which is part of the Chinese Academy of Science in Beijing), former visiting scientist at Rensselaer, and lead author of the paper.
“Going into the research, astronomers had observed that the number of Milky Way stars diminishes rapidly about 50,000 light years from the center of the galaxy, and then a ring of stars appears at about 60,000 light years from the center,” said Xu. “What we see now is that this apparent ring is actually a ripple in the disk. And it may well be that there are more ripples further out which we have not yet seen.” Read more
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Explanation: What dark structures arise from the Pelican Nebula? Visible as a bird-shaped nebula toward the constellation of a bird (Cygnus, the Swan), the Pelican Nebula is a place dotted with newly formed stars but fouled with dark dust. These smoke-sized dust grains formed in the cool atmospheres of young stars and were dispersed by stellar winds and explosions. Impressive Herbig-Harojets are seen emitted by a star on the right that is helping to destroy the light year-long dust pillar that contains it. The featured image was scientifically-colored to emphasize light emitted by small amounts of ionizednitrogen, oxygen, and sulfur in the nebula made predominantly of hydrogen and helium. The Pelican Nebula (IC 5067 and IC 5070) is about 2,000 light-years away and can be found with a small telescope to the northeast of the bright star Deneb.
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Explanation: Palomar 12 was not born here. The stars of the globular cluster, first identified in the Palomar Sky Survey, are younger than those in other globular star clusters that roam the halo of our Milky Way Galaxy. Palomar 12’s position in our galaxy and measured motion suggest its home was once the Sagittarius Dwarf Elliptical Galaxy, a small satellite of the Milky Way. Disrupted by gravitational tides during close encounters the satellite galaxy has lost its stars to the larger Milky Way. Now part of the Milky Way’s halo, the tidal capture of Palomar 12 likely took place some 1.7 billion years ago. Seen behind spiky foreground stars in the sharp Hubble image, Palomar 12 spans nearly 60 light-years. Still much closer than the faint, fuzzy, background galaxies scattered throughout the field of view, it lies about 60,000 light-years away, toward the constellation Capricornus.
From year to year, the moon never seems to change. Craters and other formations appear to be permanent now, but the moon didn’t always look like this. Thanks to NASA’s Lunar Reconnaissance Orbiter, we now have a better look at some of the moon’s history.
On it, everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives.
The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every superstar, every supreme leader, every saint and sinner in the history of our species, lived there… on a mote of dust suspended… in a sunbeam.
The Earth is a very small stage in a vast, cosmic arena.
Think of the rivers of blood spilled by all those generals and emperors so that in glory and triumph they could become the momentary masters of a fraction… of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner. How frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. Our posturings, our imagined self-importance, the delusion that we have some privileged position in the universe, are challenged by this point of pale light.
Our planet… is a lonely speck in the great, enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves. The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate.
Visit, yes. Settle, not yet. Like it or not, for the moment, the Earth is where we make our stand. It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image.
To me, it underscores our responsibility to deal more kindly with one another and to preserve and cherish the pale blue dot, the only home we’ve ever known.” Carl Sagan – The Pale Blue Dot – Cosmos: A Space Time Odyssey
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Explanation: Where did all the stars go? What used to be considered a hole in the sky is now known to astronomers as a dark molecular cloud. Here, a high concentration of dust and molecular gas absorb practically all the visible light emitted from background stars. The eerily dark surroundings help make the interiors of molecular clouds some of the coldest and most isolated places in the universe. One of the most notable of thesedark absorption nebulae is a cloud toward the constellation Ophiuchus known as Barnard 68, pictured above. That no stars are visible in the center indicates that Barnard 68 is relatively nearby, with measurements placing it about 500 light-years away and half a light-year across. It is not known exactly how molecular clouds like Barnard 68 form, but it is known that these clouds are themselves likely places for new stars to form. In fact, Barnard 68 itself has been found likely to collapse and form a new star system. It is possible to look right through the cloud in infrared light.
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Explanation: Solar active region AR2192 was the largest recorded sunspot group of the last 24 years. Before rotating off the Earth-facing side of the Sun at the end of October, it produced a whopping six energetic X-class flares. Its most intense flare was captured on October 24 in this stunning view from the orbiting Solar Dynamics Observatory. The scene is a color combination of images made at three different wavelengths of extreme ultraviolet light; 193 angstroms shown in blue, 171 angstroms in white, and 304 angstroms in red. The emission, from highly ionized Iron and Helium atoms, traces magnetic field lines looping through the hotplasma of the Sun’s outer chromosphere and corona. Beneath, the cooler solar photosphere appears dark at extreme ultraviolet wavelengths. The exceptionally sharp composite image has been processed with a new mathematical algorithm (NAFE) that adapts to noise and brightness in extreme ultraviolet image data to reliably enhance small details.
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2014 October 28
Moving the cursor over the image will bring up an annotated version. Clicking on the image will bring up the highest resolution version available.
Explanation: Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth’s sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun. During the most recent such pass starting late last year, Mars as usual, loomed large and bright. Also during this time, Mars appeared to move backwards in the sky, a phenomenon called retrograde motion. Featured here is a series of images digitally stacked so that all of the stars coincide. Here, Mars appears to trace out a narrow loop in the sky. At the center of the loop, Earth passed Mars and the retrograde motion was the highest. Retrograde motion can also be seen for other Solar System planets.
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Explanation: What’s that in front of the Sun? The closest object is an airplane, visible just below the Sun’s center and caught purely by chance. Next out are numerous clouds in Earth’s atmosphere, creating a series of darkened horizontal streaks. Farther out is Earth’s Moon, seen as the large dark circular bite on the upper right. Just above the airplane and just below the Sun’s surface are sunspots. The main sunspot group captured here, AR 2192, is one of the largest ever recorded and has been crackling and bursting with flares since it came around the edge of the Sun early last week. Taken last Thursday, this show of solar silhouettes was unfortunately short-lived. Within a few seconds the plane flew away. Within a few minutes the clouds drifted off. Within a few hours the partial solar eclipse of the Sun by the Moon was over. Only the sunspot group remains, but within a few more days even AR 2192 will disappear around the edge of the Sun. Fortunately, when it comes to the Sun, even unexpected alignments are surprisingly frequent.
![Mooooonwalk_rjn_960[1]](https://www.mcha.nl/wp-content/uploads/2015/04/Mooooonwalk_rjn_9601.jpg)
![IC5067_vanvleet_960[1]](https://www.mcha.nl/wp-content/uploads/2015/03/IC5067_vanvleet_9601.jpg)
![barnard68v2_vlt_960[1]](https://www.mcha.nl/wp-content/uploads/2014/12/barnard68v2_vlt_9601.jpg)
![SDO_AIA-2014_10_24-21_42UT1024[1]](https://www.mcha.nl/wp-content/uploads/2014/11/SDO_AIA-2014_10_24-21_42UT10241-800x584.jpg)
