FLIGHT ATTENDANTS AT HIGHER RISK OF CANCER: According to a new study of more than 5,000 flight attendants, the crews of aircraft have higher rates of cancer than the general population. This includes cancers of the breast, cervix, skin, thyroid and uterus, as well as gastrointestinal cancers. What's happening? The researchers, led by Irina Mordukhovich of Harvard University, listed cosmic rays, poor sleep habits, and chemical contaminants as likely risk factors. Read the original research here.
THE BEST NIGHT OF THE YEAR TO SEE SATURN'S RINGS: Tonight, Saturn is "at opposition"--bigger, brighter and closer to Earth than at any other time in 2018. To find the ringed planet, look due south at midnight. You'll see it shining like a golden star right beside the full Strawberry Moon in the constellation Sagittarius. [sky map]
This is also the best night of the year to see Saturn's rings. Even a small telescope will show them. Christopher Go sends this picture taken last night from Cebu City in the Philippines:
"Saturn's rings are surging in brightness," he reports. "This is because of the Seeliger Effect."
Named after the German astronomer Hugo van Seeliger who first described it in the 19th century, the Seeliger Effect happens when sunlit objects hide their own shadows. At opposition, the icy particles in Saturn's rings do this, causing the whole ring system to brighten. A process called coherent backscattering may also contribute to the extra luminosity.
Bonus: Remarkably, Saturn is not the brightest planet out tonight. Look to the left and right of the conjunction. Jupiter and Mars are there, too.
Realtime Space Weather Photo Gallery
NOCTILUCENT TORNADO: In recent nights, noctilucent clouds (NLCs) have rippled across Europe from Scandinavia to the south of France. "We have been observing NLCs every night here in N. Ireland," reports Martin McKenna of Maghera in Co. Derry. "Their brightness and complexity have been getting more advanced since the solstice, with whirls and knots glowing electric blue above a yellow midnight sunset horizon." He observed this 'noctilucent tornado' on June 25th:
"It was amazing to watch," he says. "This area then morphed into an succession of dynamic shapes--a wedge, a funnel, angel wings, an electrified smoke ring, then a long rope tornado which reached towards the horizon."
What creates these forms? The answer is "gravity waves."
Gravity waves are, essentially, waves of pressure and temperature spawned by powerful storm systems. Gravity does not vary inside the waves; they get their name from the fact that gravity acts as a restoring force that tries to restore equilibrium to up-and-down moving air. Gravity waves can propagate all the way from Earth's surface up to the mesosphere, where they imprint themselves on the the forms of noctilucent clouds. When a sufficient number of gravity waves meet, they can interfere to produce all of the structures McKenna saw--plus many more.
Summer is the season for NLCs. Summertime wisps of water vapor rise to the top of Earth's atmosphere where they wrap themselves around specks of meteor smoke. Mesospheric winds gather the resulting ice crystals into noctilucent clouds
Realtime Noctilucent Cloud Photo Gallery
ONE RING TO RULE THE STRATOSPHERE: This week, the students of Earth to Sky Calculus are in New Zealand launching cosmic ray balloons over Earth's 8th continent. To pay for the helium, they launched a ring of power to the stratosphere. Here it is floating 33 km above the Sierra Nevada mountains of central California:
You can have one for $119.95. The students are selling these rings as a fundraiser for their trip. They are made of golden-colored tungsten and inscribed with the authentic Mordor script of the One Ring.
Buy one now, and we will fly it again for you over Hobbiton, located in the North Island of New Zealand where our cosmic ray balloons will be released. Just note "Please fly it again!" in the comments section at checkout.
Each golden ring comes with a greeting card showing the ring in flight and telling the story of its journey to the edge of space. Sales support the Earth to Sky Calculus cosmic ray ballooning program and hands-on STEM research.
Far Out Gifts: Earth to Sky Store
All proceeds support hands-on STEM education