sagansense:

Neil deGrasse Tyson Explains The Origins Of Atomic Elements In Our Bodies

What’s the human body made of? Ninety-nine percent consists of atoms of just six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus, with the remaining one percent consisting of trace elements like magnesium, sulfur, and iron.

But where did those elements come from? That question long presented a puzzle to scientists. At least it did until the publication of a now-obscure scientific paper in the middle of the twentieth century, as celebrated astrophysicist Neil deGrasse Tyson explains in a new video (above).

“There was a seminal paper — one of the most important research papers ever published — that gave us the description of the origin of the elements,” Tyson says in the video.

The paper is entitled “Synthesis of the Elements in Stars” but is sometimes referred to as the B2FH paper, after the authors’ initials. It was published in Reviews of Modern Physics in 1957. Before its publication, the prevailing theory held that all elements were products of the Big Bang 15 billion years ago. But this theory accounted only for light elements like hydrogen and helium.

So where did the heavy elements found in nature come from?

The B2FH paper argued that all heavy elements were created within stars via nuclear fusion — a process known as stellar nucleosynthesis. As stars cool and “die,” they release the heavy elements into space. Ultimately, some of this material is incorporated into planets and even our bodies.

If the paper was so important, why do so few nonscientists know about it? According to Tyson, it’s because the paper’s origins don’t fit conventional notions of scientific discovery.

“There was no lone scientist burning the midnight oil making the eureka discovery,” Tyson says. “It was a little messier than that. But the consequences of it are profound.”

Stay Curious! Watch The Extended Interview With NDT

Both dippers are considered asterisms, actually. So you’re initial guess is correct! 

For those who don’t know what an asterism is, here’s the definition, “A prominent pattern or group of stars, typically having a popular name but smaller than a constellation.” Surprisingly enough, it’s rather uncommon knowledge that many of the star-patterns seen in the night skies that we call constellations are actually asterisms. Such as Orion’s belt; it’s an asterism inside the constellation of Orion. 

I’m sure some of you are wondering what’s the difference between a constellation and an asterism?

Well the differences aren’t too striking, but enough so that they have different names.Constellations are recognizable parts of the sky with “patterned” stars that are part of our celestial sphere. Asterisms are either subsets of star groups within constellations, or stars from many different constellations that create recognizable patterns, and may not always appear as “fixed” in the sky as certain constellations.

Some asterisms, such as the Big Dipper, are a subset of stars that are part of a larger constellation, with Ursa Major [Great Bear[ being it’s respective constellation. The same goes for the Little Dipper, as you mentioned, which is part of the larger constellation Ursa Minor [Little Bear]. Other types of asterisms are a grouping of stars from many different official constellations. An example of this would be the Summer Triangle [shown below], which is composed of the three brightest stars, Vega, Deneb, and Altair, that are respectively the brightest stars in the constellations Vega, Cyngus and Aquila. Another example of an asterism would be the ever-popular Pleiades, found within the constellation of Taurus.  

[Image credit via Astro Bob.]

Below is a list of asterisms and their respective constellations via BrightHub:

• Winter Triangle – Canis Major, also known as the Great Dog, and the star Betelgeuse.
• Great Square – Pegasus, which may be referred to as the the Winged Horse.
• Water Jug – Aquarius or the Water Bearer.
• Teapot/Teaspoon – Sagittarius; also called the Archer.
• The Northern Cross – Cygnus the Swan.
• Medusa’s Head – Perseus, who was a mythological figure
• Circlet – Pisces, or the Fish.
• Job’s Coffin – Delphinius, which is sometimes called the Dolphin.
• Keystone – Hercules, the mythological hero.
• Lozenge – Draco, or the Dragon, and Hercules.
• Sickle – Leo, or the Lion.
• Fish Hook – Scorpius, or the Scorpion.

I hope this helped answer your question, and thank you for asking! If you’d like to do a little extra reading on the differences between asterisms and constellations you can do so here, and here.

Made rebloggable by request. 

(Source: thescienceofreality)

(via atomstargazer)

knowledgethroughscience:

Attention stargazers - Mercury, Jupiter and Venus appear very close together in the sky, May 24-26, 2013.

Three planets are coming together in the evening sky at the moment, putting on a celestial show that won’t be seen again for more than a decade.

“The view should be best about 30 to 45 minutes after sunset,” said Alan MacRobert, a senior editor at Sky & Telescope magazine. Find out how to spot Jupiter, Venus and Mercury.

(via thescienceblog)

Nope, but I did make one just for you! [Well really for all my readers, but you made it happen, my little anon!] 

Meteor showers that have already occurred in 2013:

• January 3, 2013 Quadrantids
• April 22, 2013 Lyrids
• May 5, 2013 Eta Aquarids

You can learn more about the exact times to view each of the upcoming meteor showers, and where they are visible from Earth here.

Also check out some useful stargazing tips below:

• A word about moonlight
• Most important: a dark sky
• Know your dates and times
• Where to go to watch a meteor shower
• What to bring with you
• Are the predictions reliable?
• Remember …
• Easily locate stars and constellations during any day and time with EarthSky’s Planisphere.

Enjoy, and happy skywatching to all!

(Source: thescienceofreality)

Dark Energy & Dark Matter via Chandra X-ray Observatory (Illustration: NASA/CXC/M.Weiss)

spaceplasma:

Hawc gamma-ray telescope captures its first image

A new set of “eyes” to capture the Universe’s highest-energy particles and light has snapped its first image.

The High-Altitude Water Cherenkov Observatory or Hawc, high on a Mexican plain, now holds the record for the highest-energy light it can capture.

The image - of the shadow cast by the Moon as it blocks the light and particles - was shown off at a meeting of the American Physical Society.

Hawc is currently made of 30 detectors, but by 2014 will comprise some 300.

Each one is a 7.3m-diameter, 4m-high tank filled with pure water.

They dot the landscape at an altitude of 4,100m in a national park near the Mexican city of Puebla.

But they do not capture the cosmic rays and gamma rays directly.

When the cosmic rays and gamma rays smash into molecules in the Earth’s atmosphere, they set off a cascade of other fast-moving particles.

It is these that the “Cherenkov” detectors actually track.

Faster than light

While the speed of light in a vacuum cannot be exceeded, the speed in matter can be much slower.

When the fast-moving particles created in the atmosphere break this speed limit inside the water of the Hawc tanks, they give off flashes of light that detectors at the tanks’ bottoms can catch.

Cherenkov telescopes such as the Hess array in Namibia or the Magic facility in the Canary Islands catch this process directly from the atmosphere when the particles first arrive at Earth.

But while Hawc catches fewer of these events high in the atmosphere, it can survey more in a given night - or day, said Hawc collaboration member Tom Weisgarber of the University of Wisconsin-Madison.

“We’re very complementary to these other instruments - but we see a very large fraction of the sky,” he told BBC News.

“Hawc doesn’t need to point in one location, and it’s unaffected by the Sun, the Moon, the weather or anything - it just depends on the atmosphere being there.”

It also claims the crown for highest-energy light we can detect - up to 100 TeV, or tens of trillions of times more energetic than the visible light we can see.

Particles and light with these blistering energies give insights into the most violent processes the cosmos hosts, from the leftovers of supernovas to supermassive black holes eating matter.

Only by catching them can we understand just how these regions create them.

But Hawc is just starting its mission, and to make sure that its first 30 detectors are working as expected, the team snapped an image exactly where it did not expect any cosmic rays - the Moon’s shadow.

A fuller array of 100 detectors should be up and running by August.

“That’s when we’ll really be able to start doing some really interesting science,” Mr Weisgarber said.

Credit: Jason Palmer

sagansense:

Hey, I’m having a dilemma and I need some advise.
Astrophysics fascinate me, and I really want to major in it, I took all the classes that relate in my HS (AP physics, advanced math…etc) I’m still a junior but I’m pretty determined. Except this semester I found out that my music teacher is actually an astrophysicist, he told me that there are practically no jobs for astrophysicists, and the closest thing he could find was working in a weapon factory. I really wanna follow my dream, but I feel like this country doesn’t value science, and I’ll end up in debt and out of work when I graduate college. Do you have any advise?
— billkaulitzisunf

First off, let me tell you that your music teacher, although an astrophysicist, is a bit of a douche. Follow your dream. Look toward any & all space advocacy-related sources for openings, what the positions require in terms of educational background, email & communicate with ACTUAL, WORKING, astrophysicists & do not limit yourself just to the astrophysics field. There are a multitude of fields continually being expanded around the world in all areas of science. You’ll figure it out as you press on, especially since you still have a little way to go before even getting through the most basic preliminary courses for astronomy/astrophysics in general.

Second, watch/listen to this. While you do, take notes and jot down these fields and memorize them. Subscribe to this podcast as well. I intend on doing this exact thing myself, along with publishing a post on here about the list of fields unbeknownst to the science-loving community at large.

Third, keep asking questions. Hang out with others who share your passion. Join your local astronomy club & stay curious. Much love & respect to you, friend. Hope to hear more back from you in the upcoming years to see where this journey has taken you, as science and technology will not be forever ignored or disregarded, as they are the keys to our survival & evolution. Ad astra.
- sagansense

thenewenlightenmentage:

Charted: Extraterrestrial Driving Records

NASA has just released this cute chart depicting the various distances traveled by wheeled machines on other worlds (click to enlarge).

The comparison was put out in honor of the agency’s Opportunity rover, which has been on Mars since 2004, beating NASA’s previous distance record-holder, the Apollo 17 moon buggy. During its nine years of operations, Opportunity has roved 35.760 kilometers, edging out the Apollo astronaut’s 35.744-kilometer drive.

The champion for driving on another surface still goes to the Soviet Lunokhod 2 rover, which traveled 37 kilometers across the moon in 1973. Of course, Opportunity still has the *ahem* opportunity to overtake the international record holder since it’s continuing to rove around the rim of Endeavour crater on Mars. The little robot has been exploring that area since 2011 and has uncovered some of the most unambiguous evidence for water on ancient Mars. Though NASA’s celebrated Curiosity rover has only gone less than one kilometer since landing in August, it has nuclear batteries that could last 14 years at minimum — ample time to beat all competitors.

Image: NASA/JPL-Caltech

ikenbot:

When Supermassive Supergiants Go Superboom

Article by Phil Plait via Slate

I have long been fascinated by gamma-ray bursts (or GRBs). These are incredibly violent events: It’s like taking the Sun’s entire lifetime energy output and cramming into a single event that lasts for mere seconds! The energy emitted is so intense, so bright, we can see GRBs from a distance of billions of light years.

Gamma rays themselves are just a form of light, like the kind we see, but with huge energy; each photon is packed with millions or billions of times the energy in a single photon of visible light. Only the most energetic events in the Universe can make them, so if we detect a burst of them coming from the sky, we know something literally disastrous has happened.

We know GRBs come in many flavors. Some last literally for milliseconds, while others stretch on for minutes. We also know different events can cause them, too. Short ones seem to come from merging neutron stars, ultra dense compact objects left over after stars explode. The longer ones occur when massive stars explode, leaving their cores to collapse. In both cases, the huge blast of high-energy gamma rays signals the birth of a black hole.

But astronomers were recently surprised to find a third type of GRB, one that lasts not for minutes, but for hours. Whatever these objects are, they don’t just flash with light, they linger, blasting out far, far more gamma rays for far, far longer than was previously thought. What could do such a thing?

Several ideas were put forth, but new observations provided the linchpin: an ultra-long-duration GRB occurred on Christmas Day in 2010, and its distance was found to be a soul-crushing 7 billion light years away, about halfway across the visible Universe! This left only one possible candidate for the progenitor: a hugely massive star, one so big it dwarfs the Sun into insignificance.

Continue to Full Article..

Balancing Rocks in Central Oregon

“Geologists explain that the formations are the result of the aging, tilting and erosion of two layers of consolidated volcanic ash, known as tuff.

These ash flows originated from the Cascade volcanoes to the west many thousands of years ago. The top layer of tuff was tougher so to speak than the bottom layer, so as the ground tilted and cracked and the softer bottom layer was eroded by wind and water, top-heavy rock pedestals remained.

Discovered by surveyors way back in the 1850s, the unusual rocks were known to only a handful of people for many decades. They remained hidden in a forest of pine and juniper until a forest fire in 2002 denuded the area. Visible now from Forest Service roads and from boats on the popular Lake Billy Chinook below, the rocks are visited more frequently. Sadly, the formations pose an irresistible temptation to immature vandals and a few of the pedestals have been toppled. Fortunately, most are far more massive, stable and durable than they appear.”— Brad Goldpaint

(Source: ikenbot)

ikenbot:

SN 1006: New X-Ray View of A Thousand-Year-Old Cosmic Tapestry

Over a millenia ago Earth witnessed an explosion in the heavens, that explosion was later discovered to be a supernova. Now, new data from NASA’s Chandra X-ray observatory adds to the awesome factor of SN 1006 and supernovae like it, which provides new details about the remains of this exploded star. As noted in Chandra’s official site:

“The Chandra data provides the best map to date of the debris field including information on important elements expanding into space.”

A new image of SN 1006 from NASA’s Chandra X-ray Observatory reveals this supernova remnant in exquisite detail. By overlapping ten different pointings of Chandra’s field-of-view, astronomers have stitched together a cosmic tapestry of the debris field that was created when a white dwarf star exploded, sending its material hurtling into space. In this new Chandra image, low, medium, and higher-energy X-rays are colored red, green, and blue respectively.

The Chandra image provides new insight into the nature of SN1006, which is the remnant of a so-called Type Ia supernova . This class of supernova is caused when a white dwarf pulls too much mass from a companion star and explodes, or when two white dwarfs merge and explode. Understanding Type Ia supernovas is especially important because astronomers use observations of these explosions in distant galaxies as mileposts to mark the expansion of the Universe.

Further Details on The Newly Discovered Data

pappubahry:

Jupiter’s moon Io, photographed by Voyager 2, 10 July 1979.

The end of this blog’s Io-thon follows on from yesterday’s post.  The photos used in this gif were taken with longer exposures than yesterday’s, so there is a better contrast between Io and the background.  Two volcanic eruptions are clearly visible in the top-left: I think that they are from Amirani and Maui.  There’s also an eruption on the right-hand side, but as its only lit by reflected light from Jupiter, it requires a lot of brightening to see (NASA’s photojournal shows it here).

You can also see a volcano in the south, tall enough to stay in sunlight even as the surrounding areas fall into darkness.

Yesterday I mentioned the bright spot glinting near the equator.  I asked Jason Perry (who used to write an Io blog) about it on Twitter and he said that it “looks like specular reflection off of glassy, cooled lava near Hi’iaka Patera.”  So there you go.

The rate of evolution and the ultimate fate of a star depends on its mass. (Illustration: NASA/CXC/M.Weiss)

More on stellar evolution here.