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Significant auroras predicted for tonight

View larger. | Colin Chatfield near Saskatoon, SK, Canada captured this aurora Friday morning.  Taken with a Canon 7D and Tokina 10-17mm fisheye lens at 10mm, f/3.5, 20 sec exp, ISO 800.  Visit Colin Chatfield on Facebook.

View larger. | Colin Chatfield near Saskatoon, SK, Canada captured this aurora Friday morning.

Due to two recent events on the sun – including an X-flare from Active Region 2158 on the sun on Wednesday – reports from NOAA and elsewhere predict good chances for significant auroral displays. Auroras will be possibly observable at latitudes as far south as the northern U.S. states including, for example, Wisconsin, Michigan, and New York, and maybe even farther south. Spaceweather.com reports:

The first of two CMEs expected to hit Earth’s magnetic field on Sept. 12 has arrived, and a minor (G1-class) geomagnetic storm is underway as a result of the impact. The second and potentially more powerful CME is still en route. NOAA forecasters say geomagnetic storming could become strong (G3-class) during the late hours of Sept. 12 and Sept 13 after the second CME arrives.

Rosetta spacecraft selfie with comet

Via ESA/Rosetta/Philae/CIVA.

Rosetta spacecraft ‘selfie’ with comet 67P/Churyumov–Gerasimenko, imaged Sunday, September 7, 2014. Image via ESA/Rosetta/Philae/CIVA.

Here is a Rosetta ‘selfie’ with comet 67P/Churyumov–Gerasimenko in background. It was taken by the CIVA camera onboard the Philae Lander. This is the same camera that will be acquiring images from the surface of the comet itself, when the Philae lander sets down on the comet in November.

What are cloud streets?

cloud-streets-bering-sea-20jan2006-540

Cloud streets over the Bering Sea on January 20, 2006. Image Credit: Jesse Allen, NASA.

Your Friday FAQ. Find out what they are and how they form. And check out these cool images!

Lifeform of the week: Skunks

Image Credit: Don DeBold

Image Credit: Don DeBold

Evolutionary biology can explain skunks’ striking appearance, but only chemistry can get rid of the smell.

Why our Milky Way galaxy has fewer satellites than expected

Two models of the dark matter distribution in the halo of a galaxy like the Milky Way, separated by the white line. The colours represent the density of dark matter, with red indicating high-density and blue indicating low-density. On the left is a simulation of how non-interacting cold dark matter produces an abundance of smaller satellite galaxies. On the right the simulation shows the situation when the interaction of dark matter with other particles reduces the number of satellite galaxies we expect to observe around the Milky Way.  image via Durham University.

Notice the white line. It separates two models of dark matter distribution in the halo of a galaxy like our Milky Way. Left: a standard simulation of cold dark matter produces many smaller satellite galaxies. Right: the new simulation, which lets dark matter interact with elementary particles in the early universe. You can see that the number of satellite galaxies is smaller in the new simulation. The colors represent the density of dark matter; red indicates high-density, and blue indicates low-density. Image via Durham University.

European cosmologists and particle physicists, working together, have a new theory of how cold dark matter interacts with elementary particles – such as photons and neutrinos – in the early universe. Their work shows that the particles act to “scatter” the dark matter. If this model is correct, then it accounts for fact that our own Milky Way galaxy has fewer satellites than scientists expect it to have. If it’s correct, then it must have far-reaching implications about the formation of structures throughout our universe.

A preliminary map of different regions on Rosetta’s comet

Several morphologically different regions are indicated in this preliminary map, which is oriented with the comet’s ‘body’ in the foreground and the ‘head’ in the background.  Image via ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

Morphologically different regions are indicated in this preliminary map of Comet 67P/Churyumov-Gerasimenko. Image via ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

A preliminary map of morphologically different regions on the surface of Comet 67P/Churyumov-Gerasimenko – as revealed by the Rosetta spacecraft – shows the comet to be a unique, multifaceted world. We now know that comets can have cliffs, depressions, craters, boulders or even parallel grooves.

In 2014, China’s Mid-Autumn Festival on September 8

Sky lanterns at the Mid-Autumn Festival in Vietnam, where the festival is called Tet-Trung-Thu. Image via OhMyAsian! on Tumblr

Many Asian friends will be wishing each other a happy Mid-Autumn Festival today. For us in the U.S. and elsewhere in the Northern Hemisphere, this week’s Harvest Moon and autumnal equinox are signs that autumn is here. Meanwhile, in China, Taiwan, Vietnam and other parts of Asia, the focus is on the annual Mid-Autumn Festival, which by tradition also carries a strong connection to the full moon coming later this week. It’s sometimes called the Moon Festival in honor of this moon. It’s also called the Mooncake Festival for a traditional baked delicacy exchanged among family and friends.

Lifeform of the week: Hoatzin

Image Credit: Geoff Gallice

Image Credit: Geoff Gallice

Next time someone asks you, “If you could be any animal, what would you be?” , considering putting aside the conventionally popular animals and aligning yourself instead with zoological individuality, a bizarre tropical South American bird that can’t fly very well and smells like cow manure.

Stand your ground and answer, “I would be a hoatzin, because they’re freakin’ cool.”

Is the October 8, 2014 full moon a supermoon?

The moon's apparent size in our sky depends on its distance from Earth.  The supermoon of March 19, 2011 (right), compared to an average moon of December 20, 2010 (left).  Image by Marco Langbroek of the Netherlands via Wikimedia Commons.

The moon’s apparent size in our sky depends on its distance from Earth. The supermoon of March 19, 2011 (right), compared to an average moon of December 20, 2010 (left). Image by Marco Langbroek of the Netherlands via Wikimedia Commons.

The astrologer Richard Nolle is credited for coining the term supermoon, which he defines as:

… a new or full moon which occurs with the moon at or near (within 90% of) its closest approach to Earth in a given orbit.

Based on this definition, should the October 8, 2014 full moon be regarded as a supermoon? Experts disagree. Follow the links inside to learn more.

What if you could see the sound of a nightingale?

Andy Thomas of Australia is a multimedia artist, who makes 3D animations of bird songs. He calls them “audio life forms.”