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The Herschel Mission Closes Its Eye | Phil Plait
Bad Astronomy | Monday, April 29, 2013, at 1:39 PM

On May 14, 2009, the European Space Agency launched the infrared astronomical observatory Herschel into space. For very nearly four years, this fantastic telescope observed the Universe and returned high-resolution far-infrared data to scientists on Earth.

Sadly, the mission is now over. Yesterday, engineers reported a temperature spike in all the instruments on board, indicating the supply of liquid helium had finally run out. This ultra-frigid fluid was needed to cool the cameras so they could get clear views of some of the coldest objects in space. Without the helium, the detectors can no longer function optimally.

It’s bittersweet news; liquid helium evaporates, and even though Herschel started with 2300 liters, it had to run out eventually. The lifetime was estimated at just over three years, so we actually got some extra mileage out of it.

And the legacy of Herschel is secure. It took tens of thousands of observations, including some of the most exotic and beautiful images of the sky I’ve seen. Let me show you just a few of my favorites.

Note: These images are all false-colored, since Herschel sees light well beyond what our eyes can see. In general, in the pictures bluer material is warmer, and redder colder. But it’s all cold. Click the pictures to embiggen them. Trust me; you want to.

The Closest Spiral


^ The Andromeda Galaxy, its dusty arms easily seen by Herschel. Photo by ESA/Herschel/PACS & SPIRE Consortium, O. Krause, HSC, H. Linz

This image of the Andromeda Galaxy, our nearest big galactic neighbor, defies adjectives. Stunning. Jaw-dropping. Magnificent. Herschel’s infrared eye sees very cold material; the warmest stuff you see here is at -232°C (-385°F). Frigid dust clouds trace the majestic spiral arms of Andromeda, all the way down into the center of the galaxy. Things get difficult there; a couple of hundred million years ago there was a burst of star formation that mixed things up, and together with the densely-packed stars in the galaxy’s core, the dust itself gets disturbed. This picture is an incredible beauty, but get a good look: In a few billion years, our own galaxy will collide with Andromeda, forming one, much larger, galaxy.

Herschel’s Horsehead


^ The Orion B molecular cloud, including the famous Horsehead Nebula, seen as a small blue spur to the upper right. Photo by ESA/Herschel/PACS, SPIRE/N. Schneider, Ph. André, V. Könyves (CEA Saclay, France) for the "Gould Belt survey" Key Programme

I recently wrote about the famous Horsehead Nebula, a gigantic dark cloud that resembles a brooding cosmic chess piece. That picture was taken by Hubble in infrared light not too far removed from what our eyes can see. Herschel sees much farther into that part of the electromagnetic spectrum, revealing this magnificent vista of gas and dust. The yellow, pink, and white areas are the densest, where stars are actively being born. This complex is only about 1300 light years away, making it the closest large example of a stellar nursery in the sky.

Betelgeuse Hits a Wall


^ The far infrared eye of Betelgeuse, surrounded by thin shells of dust. Photo by ESA/Herschel/PACS/L. Decin et al.

The red supergiant star Betelgeuse—one of the brightest stars in the sky—is dying. In a million years or less it will explode, but in the meantime it episodically blows off thin shells of dust that expand around the star. But Betelgeuse is moving, so the shells become distorted as it rams through the thin material in space. This eerie Herschel image shows those shells, as well as a long, straight “wall” of material on the left toward which Betelgeuse appears to be heading. It may collide with this material in as little as 5000 years. This won’t affect the star at all, but it will interact with the shells, creating beautiful and intricate structures.

The Cold Tendrils of Star Birth


^ IC5146, a long tendril with a star-forming cocoon. Photo by ESA/Herschel/SPIRE/PACS/D. Arzoumanian (CEA Saclay) for the “Gould Belt survey” Key Programme Consortium

Stars sometimes form in dense, thick clots of gas and dust, impenetrable with visible light. But infrared light leaks out, which can be seen by Herschel. This is IC5146, just such a stellar nursery. The part colored blue is where the stars are forming, and the long orange filaments are probably formed by turbulence inside the dust. That material is cold, only a few degrees above absolute zero.

Star Birth in Orion


^ Star formation in the Orion Nebula, seen in a combined image from Herschel and Spitzer. Photo by ESA/NASA/JPL-Caltech/N. Billot (IRAM)

Similar to IC5146, stars are forming in the Orion Nebula, too. This image shows one small part of the nebula, a combination of infrared observations by Herschel and its cousin, Spitzer Space Telescope. The colorful gas and dust is seen by Spitzer, and the knots of intense orange are the locations of stars being born seen by Herschel. Combining data from different telescopes is a powerful way of peering into the Universe, sometimes revealing more science—and more beauty—than a single telescope can do on its on.

A Hole in Space


^ NGC 1999, an apparent hole in space. Photo by ESA/HOPS Consortium

NGC 1999 is a crowded region of gas and dust in Orion. Hubble observations of one section show bright gas with what looks like dark dust seemingly silhouetted in front of it, like a hole in space. That was assumed to be an illusion, just the dust blocking the gas, but when astronomers got this image from Herschel of the region, it came with a surprise: Instead of seeing dust glowing in the infrared, there really was a hole there! You can see it at the top of the picture; the green cloud shows dust, and just to the right of the star is the hole. This is probably a hollow region, carved out by stars that formed inside it.

The Cold Southern Cross


^ The Southern Cross in the far infrared. Photo by ESA/SPIRE/PACS

The iconic constellation of Crux, known as the Southern Cross, lies right in the middle of the disk of our galaxy, and so is strewn with turbulent gas and dust. This Herschel image reveals just how complex and chaotic this region is. Material swirls between the stars, and long thin filaments are dotted with bright knots where individual stars are being born. Some of this chaos is stirred up by the winds of infant stars, some by vast magnetic fields interacting, and some by the heat and fury of powerful exploding stars, dying after their short, fierce lives. And while the Southern Cross is easily seen by even a casual observer—I’ve spotted it myself in my travels south—all this material is invisible to the naked eye. It’s only with orbiting far-infrared observatories like Herschel that it can be seen at all.

Herschel brought us these images, and many more, increasing our knowledge and understanding of the Universe. So it’s sad to see it close its eye, but for the four years we had it, Herschel enriched our grasp of the cosmos immensely. And even better, all that data exists in archives, supplying scientists with data that will be used for decades to come, perhaps even by future generations not even yet born.

My congratulations to the Herschel team for this wonderfully successful mission, and to their contributions to science.

[justdrew]

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^^^ Full Moon Silhouettes! Drew, we got it

Here’s a previous post that includes information with regard to Mark Gee’s gorgeous vimeo production.

~ A.

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Man in (Front of) the Moon | Phil Plait
Bad Astronomy | Wednesday, May 1, 2013, at 8:00 AM

Sometimes, an amazing photograph is a matter of luck. Good timing, happenstance, what-have-you. But most are the results of careful planning, thinking ahead, and knowing exactly what it is you’re trying to do.

That’s what photographer Philipp Schmidli did. He took great pains to map out exactly how he wanted a particular series of photos to go, and I’m really glad he did. The results he got are nothing short of spectacular (click them to embiggen):

[There are three photographs by Philipp Schmidli, all of which have been used by permission and may be viewed in Plait’s original.]

Those are insanely cool shots! For those who want details, he used a Canon EOS 1DX camera equipped with a 600mm lens using a 2X converter for an effective focal length of 1200mm. A telephoto with that much magnification can show a lot of detail on the Moon. Obviously! He had to use a very small aperture, which means the exposure times were a relatively long 1/40th of a second, making this even trickier.

Schmidli planned well in advance for this; in fact he took a series of similar shots in January, so he already had the area mapped out. Knowing exactly where and when the full Moon would rise used to be somewhat difficult, but now there’s a fleet of different apps you can use. You can give this a day before or after the Moon is actually full to get the same effect, but any time outside that window and the phase becomes obvious. That in turn means hoping the weather cooperates, and in fact Schmidli missed a chance one night due to clouds.

The last step was having walkie-talkies to communicate with his friend. Even then, the timing and location had to be precise! Moonrise only takes about two minutes or so, so that’s a tight schedule.

All in all, these pictures took a huge effort, but in the end it was clearly worth it. And who knows? Maybe he’ll get a call from Amblin Entertainment.

Tip o’ the lens cap to io9.

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NGC 6240: Gigantic Hot Gas Cloud Sheaths Colliding Galaxies
Universe Today, Tammy Plotner | May 1, 2013


^ Credit: X-ray (NASA/CXC/SAO/E.Nardini et al); Optical (NASA/STScI)

Looking almost like a cosmic hyacinth, this image is anything but a cool, Spring flower… it’s a portrait of an enormous gas cloud radiating at more than seven million degrees Kelvin and enveloping two merging spiral galaxies. This combined image glows in purple from the Chandra X-ray information and is embellished with optical sets from the Hubble Space Telescope. It flows across 300,000 light years of space and contains the mass of ten billion Suns. Where did it come from? Researchers theorize it was caused by a rush of star formation which may have lasted as long as 200 million years.

What we’re looking at is known in astronomical terms as a “halo” – a glorious crown which is located in a galactic system cataloged as NGC 6240. This is the site of an interacting set of spiral galaxies which have a close resemblance to our own Milky Way – each with a supermassive black hole for a heart. It is surmised the black holes are headed towards each other and may one day combine to create an even more incredible black hole.

However, that’s not all this image reveals. Not only is this pair of galaxies combining, but the very act of their mating has caused the collective gases to be “violently stirred up”. The action has caused an eruption of starbirth which may have stretched across a period of at least 200 million years. This wasn’t a quiet event… During that time, the most massive of the stars fled the stellar nursery, evolving at a rapid pace and blowing out as supernovae events. According to the news release, the astronomers who studied this system argue that the rapid pace of the supernovae may have expelled copious quantities of significant elements such as oxygen, neon, magnesium and silicon into the gaseous envelope created by the galactic interaction. Their findings show this enriched gas may have expanded into and combined with the already present cooler gas.

Now, enter a long time frame. While there was an extensive era of star formation, there may have been more dramatic, shorter bursts of stellar creation. “For example, the most recent burst of star formation lasted for about five million years and occurred about 20 million years ago in Earth’s time frame.” say the paper’s authors. However, they are also quick to point out that the quick thrusts of star formation may not have been the sole producer of the hot gases.

Perhaps one day these two interactive spiral galaxies will finish their performance… ending up as rich, young elliptical galaxy. It’s an act which will take millions of years to complete. Will the gas hang around – or will it be lost in space? No matter what the final answer is, the image gives us a first-hand opportunity to observe an event which dominated the early Universe. It was a time “when galaxies were much closer together and merged more often.”

Original Story Source: Chandra X-Ray Observatory News Release.

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Bright, Long-Lasting GRB Sets Energy Output Record
Universe Today, Nancy Atkinson | May 3, 2013


^ The maps in this animation show how the sky looks at gamma-ray energies above 100 million electron volts (MeV) with a view centered on the north galactic pole. The first frame shows the sky during a three-hour interval prior to GRB 130427A. The second frame shows a three-hour interval starting 2.5 hours before the burst, and ending 30 minutes into the event. The Fermi team chose this interval to demonstrate how bright the burst was relative to the rest of the gamma-ray sky. This burst was bright enough that Fermi autonomously left its normal surveying mode to give the LAT instrument a better view, so the three-hour exposure following the burst does not cover the whole sky in the usual way. Credit: NASA/DOE/Fermi LAT Collaboration. (Click on image if the animation is not working)

Last weekend (April 27, 2013), the Fermi and Swift spacecraft witnessed a “shockingly” bright burst of gamma rays from a dying star. Named GRB 130427A, it produced one of the longest lasting and brightest GRBs ever detected.

Because Swift was able to rapidly determine the GRB’s position in the sky, and also because of the duration and brightness of the burst, the GRB was able to be detected in optical, infrared and radio wavelengths by ground-based observatories. Astronomers quickly learned that the GRB had one other near-record breaking quality: it was relatively close, as it took place just 3.6 billion light-years away.

“This GRB is in the closest 5 percent of bursts, so the big push now is to find an emerging supernova, which accompanies nearly all long GRBs at this distance,” said Neil Gehrels, principal investigator for Swift.


^ Swift’s X-Ray Telescope took this 0.1-second exposure of GRB 130427A at 3:50 a.m. EDT on April 27, just moments after Swift and Fermi triggered on the outburst. The image is 6.5 arcminutes across. Credit: NASA/Swift/Stefan Immler.

“We have waited a long time for a gamma-ray burst this shockingly, eye-wateringly bright,” said Julie McEnery, project scientist for the Fermi Gamma-ray Space Telescope. “The GRB lasted so long that a record number of telescopes on the ground were able to catch it while space-based observations were still ongoing.”

No two GRBs are the same, but they are usually classified as either long or short depending on the burst’s duration. Long bursts are more common and last for between 2 seconds and several minutes; short bursts last less than 2 seconds, meaning the action can all over in only milliseconds.

This recent event started just after 3:47 a.m. EDT on April 27. Fermi’s Gamma-ray Burst Monitor (GBM) triggered on the eruption of high-energy light in the constellation Leo. The burst occurred as NASA’s Swift satellite was slewing between targets, which delayed its Burst Alert Telescope’s detection by a few seconds.

Fermi’s Large Area Telescope (LAT) recorded one gamma ray with an energy of at least 94 billion electron volts (GeV), or some 35 billion times the energy of visible light, and about three times greater than the LAT’s previous record. The GeV emission from the burst lasted for hours, and it remained detectable by the LAT for the better part of a day, setting a new record for the longest gamma-ray emission from a GRB.


^ The Swift BAT light curve. Credit: NASA/Swift team.

As far as the optical brightness of this event, according to a note posted on the BAUT Forum (the Universe Today and Bad Astronomy forum) data from the SARA-North 1-meter telescope at at Kitt Peak in Arizona at about 04:00 UT on April 29 showed a relative magnitude of about 18.5.

Gamma-ray bursts are the universe’s most luminous explosions, and come from the explosion of massive stars or the collision between two pulsars. Colliding pulsars are usually of short duration, so astronomers can rule out a pulsar collision as causing this event.

If the GRB is near enough, astronomers usually discover a supernova at the site a week or so after the outburst.

NASA said that ground-based observatories are monitoring the location of GRB 130427A and expect to find an underlying supernova by midmonth.

Sources: NASA, BAUTForum

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Twisting Solar Eruption | Phil Plait
Bad Astronomy | Saturday, May 4, 2013, at 8:00 AM


^ The Sun had a bit of a hissy fit on May 3, 2013. See that blue dot above the prominence? That's about how big the Earth is. Click to enhelionate. Photo by NASA/SDO.

Yesterday, May 3, 2013, a sunspot was pushed past its limit. The colossal energy stored in its magnetic field erupted, blasting out a relatively weak solar flare. But it was enough to trigger a magnificent, towering spire of plasma that reached the dizzying height of roughly 200,000 kilometers (120,000 miles) over the surface of the Sun before the material thinned out too much to see.

The image above is a combination of three different shots taken by NASA’s Solar Dynamics Observatory, each in the ultraviolet where such magnetic activity is easiest to see (I added the blue dot, which is roughly how big the Earth is, just to give you a sense of scale and to crush your brain). I also created a video of the event using Helioviewer.org; it shows about three hours of solar activity compressed into 19 seconds:



Cooooool.

What you just saw is a pretty typical event for the Sun. Rising plasma (gas stripped of one or more electrons, giving it an electric field) inside the Sun has a magnetic field embedded in it. When it gets to the Sun’s surface, the magnetic field lines go up and down, piercing the surface. There can be quite a few of them, looping high over the surface, each storing more energy than all the nuclear weapons on Earth. The lines can get tangled, and if one of these loops crosses another, they can connect, like a short circuit. It releases its energy, which then twangs another loop, which snaps, and releases its energy…

< Kablam! The solar flare that triggered the prominence. Click to embiggen. Photo by NASA/SDO

…and you get a sudden and explosive release of all that fury. That’s a solar flare (the flare itself from May 3 can be seen in the inset image). It perturbs everything around it, shaking the solar surface and the magnetic fields of other regions. In this case, it triggered an eruptive prominence, that huge tower of plasma. As the prominence rose, the magnetic field lines inside of it still hold sway, and you can see the top of it apparently twisting as it rises, flowing along those magnetic field lines (I’ve explained all this in more detail in an earlier post, too).

The Sun goes through a magnetic cycle, with its activity increasing from a minimum to a maximum over the course of about 5.5 years. It’s recently stalled a bit, with fewer sunspots and fewer flares than expected. It’s not at all clear if it’ll start to ramp up again, or if we’ve already passed the peak. The Sun is a bit like climate and weather; over long periods we can predict its climate, but over short periods its weather is a bit dicier to foretell. We’ll just have to wait and see what the future brings.

Tip o’ the welder’s goggles to Little SDO.

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Collision Course! How A Cold War SpySat Nearly Took Out a NASA Observatory | Phil Plait
Bad Astronomy | Friday, May 3, 2013, at 12:23 PM


^ ”There she is! There she is! Ah… not so wounded as we were led to believe. So much the better!” Photo by NASA’s Goddard Space Flight Center

Fermi is a NASA astronomical observatory orbiting the Earth about 560 kilometers (350 miles) above the surface. This is called low-Earth orbit, and is very popular; a lot of satellites are at roughly the same altitude. However, space is big, and satellites small, so a collision is very, very rare.

But not impossible. And it turns out that in April 2012, Fermi nearly had a very disastrous blind date with Cosmos 1805, an old Soviet spysat. NASA just put out a video describing the tense week after the discovery was made that the two satellites were on a collision course.



A lot of that story amazes me. First, that I didn’t hear about this when it happened! I used to work on Fermi before it launched (when it was still called GLAST) and I try to keep up with it. I guess that since the disaster was avoided, it wasn’t that big a deal…afterwards.

Second, the part where they say the two objects would come within 30 milliseconds of each other made my neck hair stand on end. Fermi orbits the Earth at about 8 km/sec, so in 0.03 seconds it travels about 250 meters—800 feet or so. Fermi is a cube about three meters on a side (not counting the solar arrays, which stick out), so it’s small compared to that distance. But it’s hard to get perfect predictions of orbital positions, especially several days in advance, and 250 meters is a very, very close shave.

Mind you, the Soviet spy satellite was on an orbit perpendicular to Fermi’s. The math works out that the collision speed would be about the square root of two (about 1.4) times Fermi’s orbital speed, or roughly 11 km/sec (27,000 mph). At that speed, both satellites would’ve been wiped out. To say the least. The explosion would’ve been pretty big, and would have created a hazard for other satellites in similar orbits for years to come.

Amazingly, a short one-second burn of the thrusters on Fermi was enough to prevent collision. Because the possible collision was still days in the future, the velocity of Fermi didn’t need to change much to prevent it. Even one centimeter per second change in speed (say) changes Fermi’s position by nearly a kilometer over just a single day, so over a few days even a small kick can be enough to avoid a massive, and disastrous, collision.

Also, once the burn was done, Fermi was back in operation in an hour. That’s pretty cool. Its mission is to continuously scan the sky, looking for high-energy gamma rays that come from black holes, exploding stars, and other mind-bogglingly violent events. I’m glad that its own potentially violent demise didn’t distract it from its duty for very long.

I’m also glad there are so many talented and dedicated people watching out for space collisions. We launch more material into space all the time, and this job will only get more important in the future.

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A Microscopic Bloom from Space | Phil Plait
Bad Astronomy | Friday, May 3, 2013, at 8:00 AM

One of the great ironies of space exploration is that by leaving the Earth, we sometimes get a better view of it. It shouldn’t be too surprising; a change of perspective is generally good for context, and since we live on the Earth we only see a small piece of it at any one time.

Getting above the Earth and looking back provides perspective, context, and a large-scale picture that supplements both. It’s not just geology and geography that benefit from this, either; it’s also biology and microbiology. And, if I may, it can also be art.

To wit, a phytoplankton bloom swirls off the coast of France in this lovely shot taken from NASA’s Aqua Earth-observing satellite:


^ Phytoplankton going forth and multiplying, as seen from space. Click to autotrophenate. Photo by NASA/GSFC

Phytoplankton are algae, microscopic plants. The name is fairly generic; there are a lot of different kinds of phytoplankton. They live in water all over the planet, and in some places, when the temperature rises and food is plentiful, they undergo explosive reproduction. Called a bloom, the area can be so big it can be seen from space. Obviously.

The color is due to various pigments in the phytoplankton; in this case, blue. I think the greenish milky swirls closer to the coast are from sediments. It can actually be difficult to separate out the two in some images, and in cases like that samples of the water can be physically examined to distinguish them.

I’ve written about various blooms seen from space before (like here, here, here, and here, and yeah, you really want to click those), because they are always incredibly beautiful. I’ve also written that scientists keep an eye on them because these blooms can rob the water of oxygen and nutrients, which affects the ecology of the area, and that they also produce some toxins that can be problematic for other life.

< An electron microphotograph of Coccolithus pelagicus, a fairly common coccholithophore. Photo by Richard Lampitt, Jeremy Young, The Natural History Museum, London, via wikipedia

This prompted an email from Dr. Adrian Burd, a biology oceanographer at the University of Georgia. He noted that toxins released by phytoplankton are generally limited to dinoflagellates—a subpopulation of phytoplankton, and probably not seen in the blooms I’ve posted. Given the color, he thinks it’s more likely these are from coccholithophores, an entirely different kind of phytoplankton.

I’ll note that dinoflagellates sometimes glow when disturbed. I recently took a night kayak excursion in Mosquito Bay on Vieques, an island near Puerto Rico (we were doing a site visit for a possible future Science Getaway), and every time the paddle hit the water the dinoflagellates would glow; it was a surreal and amazing experience. Needle fish plowing through the water left sparks and trails like a meteor underwater. Astonishing.

Dr. Burd also noted that the oxygen depletion sometimes seen with phytoplankton blooms is not from the algae itself, which actually produce oxygen. However, the plankton sink and are consumed by bacteria which do use up the oxygen. So these dead zones are due to the phytoplankton, but only indirectly.

Sometimes I really love my job. I get to look at gorgeous pictures, find the science in them, tell you about it, and then hear from scientists who tell me more. Even if they’re correcting me, I don’t mind—that’s another chance to learn, and a chance to be even more amazed about how all the millions upon millions of pieces of our world fit together. Science, like the world and like life itself, is a tapestry; interconnected and interwoven, with each piece affecting every other piece in some way. From the microscopic to the macroscopic to the truly cosmic, it all holds together to create an astonishing and wondrous whole.

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The Rosy Remains of a Star’s Final Days
Universe Today, Jason Major | May 3, 2013


^ Hubble image of SNR 0519, the remains of a Type Ia supernova in the Large Magellanic Cloud

Stars like our Sun can last for a very long time (in human terms, anyway!) somewhere in the neighborhood of 10-12 billion years. Already over 4.6 billion years old, the Sun is entering middle age and will keep on happily fusing hydrogen into helium for quite some time. But eventually even stars come to the end of their lives, and their deaths are some of the most powerful — and beautiful — events in the Universe.

The wispy, glowing red structures above are the remains of a white dwarf in the neighboring Large Magellanic Cloud 150,000 light-years away. Supernova remnant SNR 0519 was created about 600 years ago (by our time) when a star like the Sun, in the final stages of its life, gathered enough material from a companion to reach a critical mass and then explode, casting its outer layers far out into space to create the cosmic rose we see today.

As the hydrogen material from the star plows outwards through interstellar space it becomes ionized, glowing bright red.

SNR 0519 is the result of a Type Ia supernova, which are the result of one white dwarf within a binary pair drawing material onto itself from the other until it undergoes a core-collapse and blows apart violently. The binary pair can be two white dwarfs or a white dwarf and another type of star, such as a red giant, but at least one white dwarf is thought to always be the progenitor.

Read more: A New Species of Type Ia Supernova?

A recent search into the heart of the remnant found no surviving post-main sequence stars, suggesting that SNR 0519 was created by two white dwarfs rather than a mismatched pair. Both stars were likely destroyed in the explosion, as any non-degenerate partner would have remained.

Read more here.

This image was chosen as ESA/Hubble’s Picture of the Week. See the full-sized version here.

Credit: ESA/Hubble & NASA. Acknowledgement: Claude Cornen

[justdrew]

The interior of a Eukaryotic Cell, from the outer membrane through the cytosol to the nucleus. All molecular structures are colored by their function; the cytoskeleton is blue, membranes are green, ribosomes are purple, RNA and spliceosomes are pink, DNA and nucleosomes are yellow. This cell is producing antibodies, all steps of the process are visualized in order from the bottom to the top of the image.

First DNA is transcribed to RNA, and the RNA is spliced before leaving the nucleus through a nuclear pore. Translation begins when the RNA becomes bound to a ribosome, which converts the genetic sequence to a linear protein. The proteins are folded and sorted inside the Golgi Complex, and then packaged into vesicles by the geodesic Clathrin Assembly. These vesicles are pulled along microtubules by kinesin motors. The vesicles then fuse with the outer membrane, and the antibodies are released into the bloodstream.

Illustration by David Goodsell

http://mgl.scripps.edu/people/goodsell/illustration/

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Beautiful Time-Lapse Earth | Phil Plait
Bad Astronomy | Monday, May 6, 2013, at 12:02 PM


^ Look out above! A 2009 eruption of the Russian volcano Sarychev sends a plume towering into the sky, as seen from the International Space Station. Mesmerizing footage of this event is in the video below. Photo by NASA

I will never get tired of time-lapse videos made from all the amazing still photos taken by astronauts on the International Space Station. Here’s one, called simply “Time-Lapse | Earth”, that’s quite lovely and serene:



The video was put together by Bruce W. Berry, Jr., using photos from The Gateway to Astronaut Photography, public-domain pictures hosted by NASA. One of my favorite things to do is try to figure out what part of the Earth I’m seeing in the clips; sometimes it’s easy, and sometimes it’s not.

One in particular, though, is worth noting. The volcanic plume punching through the cloud layer at the beginning of the video is from the June 12, 2009 eruption of Sarychev, in the Russian Kuril Islands chain to the northeast of Japan. The space station happened to fly almost directly above the volcano when it let loose, so they got quite a few pictures of it. I’ve seen video of it before, but it’s usually just the pictures strung together, so it’s a bit jumpy. Berry stabilized the video, keeping the shot smooth by shifting the frames to a common center, while retaining the motion of the station in the shot. The result is an amazing perspective view of the plume and mushroom cloud that gives a stomach-dropping sense of depth.

In just a few days, on May 13, 2013, Commander Chris Hadfield is set to make a fiery return Earth with two his crewmates Tom Marshburn and Roman Romanenko in a Soviet capsule. Hadfield has been taking and tweeting phenomenal images of our home planet nearly every day, many of which I’ve featured here on the blog. I hope that future astronauts will continue in the tradition of keeping us flatlanders in thrall with phenomenal pictures of Earth… and I hope others continue to create fantastic time-lapse videos from them, too.

Tip o’ the lens cap to my astronomer friend Amanda Bauer. If you’re not following her blog, you’re missing out.

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A Different Angle on the Sun | Phil Plait
Bad Astronomy | Wednesday, May 8, 2013, at 12:01 PM


^ The Sun blows off little steam… or a few hundred million tons of plasma, as seen by SDO and SOHO. The bright “star” on the right is actually the planet Mars. Photo by NASA/SDO/SOHO

I’ve written twice in the past few days about the Sun and its incredible power. In a funny coincidence, not long after I posted the beautiful pictures of the “quiet” Sun yesterday, the folks at NASA put out a very, very cool video showing a May 1, 2013 solar eruption as seen from three different spacecraft, showing how well they work together:



I love this! I tend to show images and videos from spacecraft that are isolated; that is, each comes from one observatory. But this video makes it clear why we have so many spacecraft observing the Sun. Solar Dynamics Observatory zooms in on the Sun’s disk, so we can see features on the surface. The Solar and Heliospheric Observatory (SOHO) takes a wider view, displaying the Sun’s environment. In fact, SOHO has different detectors that show different zoom factors.

Working in cahoots, the two observatories can watch an eruptive prominence blast off the surface and expand into a coronal mass ejection (CME), flinging a billion tons of material into space.

Enter STEREO, a pair of spacecraft in an orbit that is taking them in opposite directions, headed for the far side of the Sun. They literally see this event from the other side, giving us a perspective that is impossible from Earth.

All three together provide a powerful view of our star. Given that it is the anchor of our solar system, the provider of all the light and heat we receive—and can, if it so chooses, blow off a huge flare or CME that could seriously affect our power grid and our satellites—I think studying it every way we can is A Good Idea.

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Ring of Fire Over Australia | Phil Plait
Bad Astronomy | Thursday, May 9, 2013, at 7:30 AM

< The annular eclipse from May 20, 2012, seen through a small telescope. You can see why it’s called a “ring of fire”. Click to ensyzygynate. Photo by wikipedia user Smrgeog

On May 9/10, the Moon will pass directly in front of the Sun for people living in Australia and southeastern Papua New Guinea. This event is called a solar eclipse, but this one’s special: the Moon is nearing apogee, its farthest distance from the Earth in its orbit, so it appears slightly smaller than the Sun. That means it cannot block the Sun completely, leaving a ring or annulus of Sun around the edge. That’s why this is called an annular eclipse; at most about 95 percent of the Sun is covered by the Moon.

That means even if you’re directly in the path of the maximum eclipse, you won’t see the sky go dark, and you won’t see the corona, the Sun’s ethereal outer atmosphere. But an annular or partial eclipse is still pretty nifty, and worth taking a look.

First, let me clear up the timing. The eclipse starts when the edge of the Moon just nicks the edge of the Sun. That happens today, on May 9, around 21:25 UTC (depending on your exact location; see below). But Australia is way ahead of UTC (Greenwich time); for example, Sydney is 10 hours ahead. So for them, the eclipse would start around 07:25 a.m. on May 10. For me, in Boulder Colorado (UTC - 6) it starts at 15:25 (3:25 p.m.) local time on May 9—but I won’t see it from here at all, because the geometry is wrong. It’s only visible in the southern hemisphere (see the map below).

Wikipedia has some good info on the eclipse (including maps), as does, of course, NASA. The NASA site has a cool interactive Google Earth map with timings listed that appear to account not only for time zone difference but for geometry as well: Even in the same time zone, the eclipse will start at different times for different locations due to the viewing angle to the Moon (like two side-by-side observers seeing a nearby car pass a distant tree at two slightly different times). So if you want to catch the exact moment the eclipse starts, check there! My pal and astronomer Astropixie has some links, too.


^ The path of the eclipse over Australia and Papua New Guinea. Click to penumbrenate. Illustration by Michael Zeilik

If you do live in the right area, I suggest checking out astronomer Michael Zeilik’s eclipse-maps.com, which has fantastic and beautiful maps of the eclipse path. He has even more links there for info. I also have a page with lots of links on how to safely observe an eclipse. Seriously, don’t observe it without taking adequate precautions first!

However, if you don’t live Down Under, the eclipse will be live streamed by several places. One of them is the Coca Cola Space Science Center in Georgia (a great hands-on museum; I spoke there once); they have an expedition they’ve sent to Australia equipped with a telescope, and they’ll have it all live online. A web search will turn up other live webcasts, too.

I saw an annular eclipse a great many years ago, and it was pretty cool. I’ve still never seen an actual 100 percent total solar eclipse. It’s one of the very few astronomical events left on my bucket list to see (another being a full-blown aurora). Someday…but for now, I’ll watch this one online.

[Joe Hillshoist]

i dunno if the sun will be over the hills when the eclipse starts, and its got cloudy and rainy tonight, so i'm not 100% hopeful. i guess 7 or 8 hours will tell.