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Why do we scream?

Despite our fascination with screams, science knows relatively little about them.

Harold Gouzoules is one of the few scientists researching human screams. He collects them and analyzes their tone, pitch, and frequency to try and uncover the hidden patterns and complexities carried in one of the most intense human sounds.

Algol is the Demon Star

Via Wikimedia and Caravaggio

What’s the scariest star in all the heavens?

If you were one of the early stargazers, you might have chosen Algol in the constellation Perseus. Early astronomers nicknamed Algol the Demon Star. Bwahaha!

Halloween derived from ancient Celtic cross-quarter day

Equinoxes, solstices and cross-quarter days are all hallmarks of Earth's orbit around the sun.  Halloween is the fourth cross-quarter day of the year.  Illustration via NASA

Equinoxes, solstices and cross-quarter days are all hallmarks of Earth’s orbit around the sun. Halloween is the fourth cross-quarter day of the year. Illustration via NASA

Halloween is an astronomical holiday. Sure, it’s the modern-day descendant from Samhain, a sacred festival of the ancient Celts and Druids in the British Isles. But it’s also a cross-quarter day, which is probably why the ancient Celtic and Druidic festival occurred when it did. The ancients were keen observers of the sky. A cross-quarter day is a day more or less midway between an equinox (when the sun sets due west) and a solstice (when the sun sets at its most northern or southern point on the horizon). Our American Halloween – October 31 – is approximately midway point between the autumn equinox and winter solstice, for us in the Northern Hemisphere.

Ghost light from dead galaxies

Massive galaxy cluster Abell 2744, nicknamed Pandora's Cluster, takes on a ghostly look where total starlight has been artificially colored blue in this Hubble view.  Image via NASA/ESA/IAC/HFF Team, STScI

The total starlight has been artificially colored blue in this Hubble view of the galaxy cluster Abell 2744, also known as Pandora’s Cluster. Hubble Space Telescope image via NASA/ESA/IAC/HFF Team, STScI

Witness the faint, ghostly glow of stars ejected from their galaxies. This is the galaxy cluster Abell 2744, also known as Pandora’s Cluster, whose history is now known to be both complex and violent. It’s thought that at least six galaxies in this cluster were gravitationally ripped apart several billion years ago. As a result, many stars here aren’t bound to any one galaxy. Instead, they drift freely between galaxies in the cluster.

Arcturus is a Halloween ghost of the summer sun

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Every Halloween – and a few days before and after – the brilliant star Arcturus sets at the same time and on the same spot on the western horizon as the summer sun. What’s more, this star rises at the same time and at the same place on the eastern horizon as the sun does during the dog days of summer.

The weird walk of a bizarre dinosaur

Computer animation of Deinocheirus mirificus walking. The bizarre-looking dinosaur had unusually large forearms and features that seem cobbled together from other dinosaurs.

Ghost lights: Believe if you dare

Marfa lights – or not – from papiblogger.com.

Ghost lights used to be called will-o-the-wisps. They were a weird glow over swamps or bogs. Nowadays, people report strange lights in the sky in all sorts of places. Some are more famous than others. The ghost lights closest to me are in the desert-like Davis Mountains near Marfa, Texas, but you can also see them in the Brown Mountains of North Carolina, and other places in North America. There are modern, very ordinary explanations for these lights. Yet people still love to try to spot them. Follow the links inside to some samples of North American ghost lights.

Night spider

Photo: Guy Livesay

Photo: Guy Livesay

“She waits patiently through the night on her invisible web, stars dimly glowing in the background…” A spooky way to launch your Halloween celebration.

Find the Ghoul Star of Perseus. Plus see moon and Mars

If you can locate the M- or W-shaped constellation Cassiopeia, you can find Perseus.  Then notice Algol, the Ghoul Star!

If you can locate the M- or W-shaped constellation Cassiopeia, you can find Perseus. Then notice Algol, the Ghoul Star!

Two sky tips for today. First, as Halloween approaches, try looking for the star Beta Persei, otherwise known as Algol in the constellation Perseus. This star’s proper name comes from the Arabic for head of the ghoul, or head of the demon. That’s why Algol is sometimes called the Ghoul Star. Second, have you been watching the moon lately? Find it near Mars again tonight!

Star system like a wheel within a wheel

View larger. |  This artist’s impression shows the dust and gas around the double star system GG Tauri-A. Researchers using ALMA have detected gas in the region between two discs in this binary system. This may allow planets to form in the gravitationally perturbed environment of the binary. Half of Sun-like stars are born in binary systems, meaning that these findings will have major consequences for the hunt for exoplanets.  Image via ESO/L. Calçada

Artist’s concept of dust and gas in multiple star system GG Tauri-A. Image via ESO/L. Calçada

Astronomers using the ALMA telescope in Chile have peered 460 light-years away – in the direction of our constellation Taurus – to discover a young multiple star system they say appears as a wheel within a wheel. In other words, there appear to be two disks, one within the other, and the astronomers have found gas flowing in the region between the two disks. They say this gas might let planets form in the gravitationally perturbed environment of this system.