2. The Earth’s Crust
8. Phases of Matter
10. Simple Machines
11. The Moon
15. Earth’s Seasons
16. Light and Colour
19. Outer Space
3. Blood and Circulation
4. Chemical Reactions
5. Static Electricity
6. Food Web
7. Light Optics
8. Bones and Muscles
9. Ocean Currents
13. The Sun
14. The Brain
1. Planets and Moon
4. Rocks and Soil
7. Water Cycle
12. Ocean Life
14. Spinning Things
16. Human Transportation
20. Animal Locomotion
1. Rivers and Streams
3. Marine Mammals
5. NTV Top 11 Video Countdown
7. Pollution Solutions
2. Space Exploration
6. Life Cycles
7. Do-It-Yourself Science
8. Atoms and Molecules
9. Ocean Exploration
10. Lakes and Ponds
15. Comets and Meteors
19. Science of Music
Early developmental stages of Xenopus laevis embryos. This is a frog commonly used in biological labs, and the favorite amphibian of Nobel Prize winner John Gurdon, whose work on these embryos led to this week’s announcement of human embryonic stem cells made from somatic cell nuclear transfer.
Half a century apart, it’s all connected.
A hedgehog in Bude, Cornwall, England, was taken to the vet because he was so big and round that he couldn’t walk or curl up. Veterinary staff were puzzled, because the huge hedgehog was of normal weight. An x-ray revealed that the animal was, indeed, inflated. Veterinary surgeon Adam Revitt said he had never seen a case of “balloon syndrome” before. It occurs when bacteria get into a wound and create gas that lifts the skin from the animal. Revitt used a syringe to slowly deflate the hedgehog over about five minutes. The animal is now on antibiotics and is recovering nicely.
Dinoflagellate Protoperidinium latistriatum
SEM by Fiona Scott
Armored Dinoflagellate Protoperidinium pellucidum - can produce dangerous toxins that lead to so-called red tides.
Census of Marine Life E&O (http://bit.ly/181nxUd)
Epithelial cell in anaphase (stage of cell division) (100x) | Nasser M. Rusan
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.
Made rebloggable by request.
NASA’s Hubble Space Telescope Finds Dead Stars ‘Polluted with Planet Debris
This is an artist’s impression of a white dwarf (burned-out) star accreting rocky debris left behind by the star’s surviving planetary system. It was observed by Hubble in the Hyades star cluster. At lower right, an asteroid can be seen falling toward a Saturn-like disk of dust that is encircling the dead star. Infalling asteroids pollute the white dwarf’s atmosphere with silicon. Credit: NASA, ESA, and G. Bacon (STScI)
Galaxies fed by funnels of fuel
Computer simulations of galaxies growing over billions of years have revealed a likely scenario for how they feed: a cosmic version of swirly straws.
The results show that cold gas — fuel for stars — spirals into the cores of galaxies along filaments, rapidly making its way to their “guts.” Once there, the gas is converted into new stars, and the galaxies bulk up in mass.
“Galaxy formation is really chaotic,” said Kyle Stewart, lead author of the new study appearing in the May 20th issue of the Astrophysical Journal. “It took us several hundred computer processors, over months of time, to simulate and learn more about how this process works.”
In the early universe, galaxies formed out of clumps of matter, connected by filaments in a giant cosmic web. Within the galaxies, nuggets of gas cooled and condensed, becoming dense enough to trigger the birth of stars. Our Milky Way spiral galaxy and its billions of stars took shape in this way.
Recent research has contradicted the former scenario in smaller galaxies, showing that the gas is not heated. An alternate “cold-mode” theory of galaxy formation was proposed instead, suggesting the cold gas might funnel along filaments into galaxy centers. Stewart and his colleagues set out to test this theory and address the mysteries about how the cold gas gets into galaxies, as well as the rate at which it spirals in.
Since it would take billions of years to watch a galaxy grow, the team simulated the process using supercomputers at JPL. The simulations began with the starting ingredients for galaxies — hydrogen, helium and dark matter — and then let the laws of physics take over to create their galactic masterpieces.
When the galaxy concoctions were ready, the researchers inspected the data, finding new clues about how cold gas sinks into the galaxy centers. The new results confirm that cold gas flows along filaments and show, for the first time, that the gas is spinning around faster than previously believed. The simulations also revealed that the gas is making its way down to the centers of galaxies more quickly than what occurs in the “hot-mode” of galaxy formation, in about 1 billion years.
The researchers looked at dark matter too — an invisible substance making up about 85 percent of matter in the universe. Galaxies form out of lumps of regular matter, so-called baryonic matter that is composed of atoms, and dark matter. The simulations showed that dark matter is also spinning at a faster rate along the filaments, spiraling into the galaxy centers.
Image credit: N-Body Shop at University of Washington
Exploring the Structure of the Ring Nebula
What is a Hypernova?
Nova, “new star”; supernova, a “super” nova; hypernova, a super-duper, or super super, nova!
This word appeared in the astronomical literature at least as early as 1982, and refers to a kind of core-collapse supernova far brighter (>100 times) than usual; its meaning has changed somewhat, and today generally refers to the core collapse of particularly massive stars (>100 sols), whether or not they are spectacularly brighter than other core-collapse supernovae (though they are that too).
Most times you’ll come across hypernovae in material on gamma ray bursts (GRBs), many of which seem to involve emission of electromagnetic radiation with total energy many times that from ordinary supernovae (whether core collapse or Type Ia). Long-duration GRBs have jets, presumably from the poles of the temporary accretion disk which forms around the new black hole at the heart of the collapsed core of the progenitor (short-duration GRBs, which also produce jets, are thought to be the merger of two neutron stars, or a neutron star and a stellar-mass black hole), but even when viewed side-on (i.e. not looking into one of the jets), these GRBs are intrinsically much brighter than other core collapse supernovae.1
Eta Carinae (pictured below) is considered a good candidate for a future hypernova event.
Betelguese (pictured below) is another good candidate for a hypernova event.3
SN2007bi is the biggest such event observed to date.5
Hunting for Alien Megastructures
It’s a big galaxy out there. Even the most skeptical scientist has to accept that if a civilisation like our own exists, then there’s a good chance we’re not the only one to have ever done so. When most people think about SETI (the search for extraterrestrial intelligence), they imagine someone like Ellie Arroway searching the skies for radio transmissions. But what about looking in other ways? Perhaps a highly advanced alien civilisation might build structures large enough for us to see.
Vast structures, constructed on astronomical scales by advanced civilisations, is what the field of astroengineering is all about. This, admittedly, sounds audacious – and for the human race right now, it is. For us, astroengineering is still very much the realm of thought experiments, theoretical calculations, and science fiction. So it may be surprising to know that certain astronomers have made some quite serious attempts to look for astroengineered artifacts around other stars. With telescopes becoming ever more sensitive, and images being taken of exoplanets, the idea is starting to captivate imaginations once more.
Icy, impact-riddled Mimas (396 kilometers, 246 miles across) slips briefly in front of the moon Janus (179 kilometers, 111 miles across) in this movie from Cassini.
The movie was created from 37 original images taken over the course of 20 minutes as the spacecraft’s narrow angle camera remained pointed toward Janus. Although Mimas moves a greater distance across the field of view, Janus also moved perceptibly during this time. The images were aligned to keep Janus close to the center of the scene. Additional frames were inserted between the 37 Cassini images in order to smooth the appearance of Mimas’ movement – a scheme called interpolation. Close-up images from the few minutes surrounding the occultation are arranged into a strip along the bottom of the GIF.
The terrain on Mimas seen here is about 80 degrees to the west of that visible in a previously released movie, which showed the little moon appearing to cross Saturn’s ring plane from Cassini’s vantage point. In that previous movie, the rim of the large impact crater Herschel (130 kilometers, 80 miles wide) was visible as a flattening of the moon’s eastern limb. In the new movie, Herschel is almost at dead center.
Contrast on Janus was mildly enhanced to aid the visibility of its surface. The right side of Mimas appears bright because the moon was partly overexposed in this image sequence.
Credit: NASA/JPL/Space Science Institute
10 Astronauts Who Became Pop Icons
Being an astronaut may not sound like such a dream job nowadays as it has done in the past—but there was once a time when almost every child dreamed of shuttling into space.
The space race between the USSR and the USA—not to mention countless blockbuster space films—created a popular conception of astronauts as some of the most heroic, intrepid, and glamorous people in the world. This list will attempt to rank the ten most famous, inspirational, and influential astronauts of all time, who each changed the course of history by breaking down one or another of humankind’s barriers.
How Bilinguals Switch Between Languages
May 20, 2013 — Individuals who learn two languages at an early age seem to switch back and forth between separate “sound systems” for each language, according to new research conducted at the University of Arizona.
Army Ant Bivouac
Army ants are nomads; their ferocious appetite means that they must move to new regions every few days in order not to starve. As a result, they make a temporary nest constructed out of individual ants.
Depending on the colony size, 150,000 - 700,000 worker ants link onto each other to form a structure 1m in diameter. The queen and larvae are protected near the center of the protective mass.
Geoff Gallice on Flickr