ATMOSPHERIC COSMIC RAYS ARE INCREASING: So you thought Solar Minimum was boring? Think again. High-altitude balloon flights show that atmospheric radiation is intensifying from coast to coast over the USA--a direct result of low solar activity. Get the full story.
A NEW SPACE WEATHER METRIC: The Thermosphere Climate Index (TCI) is now on Spaceweather.com. TCI is a relatively new space weather metric that tells us how the top of Earth's atmosphere (or "thermosphere") is responding to solar activity. During Solar Max the top of our atmosphere heats up and expands. Right now the opposite is happening. Solar minimum is here and the thermosphere is cooling off:
TCI was invented by Martin Mlynczak of the Langley Research Center along with other NASA and university colleagues. For the past 17 years they have been using the SABER instrument onboard NASA's TIMED satellite to monitor the wattage of infrared emissions from the top of the atmosphere. Recently, they realized that these measurements could be used to summarize the state of the thermosphere in a single daily number–the TCI. Moreover, they learned to calculate TCI going back in time all the way to the 1940s, thus placing current conditions in a historical context.
So where do we stand? Right now TCI=4.6x1010 W. That means the top of Earth's atmosphere is approximately 10 times cooler than it was during the record-setting Solar Max of 1957-58 (TCI=49.4x1010 W). The current record low, TCI=2.1x1010 W, was set in 2009 less than ten years ago during the previous Solar Minimum. We're not quite there yet, but were getting close.
You can monitor daily values of TCI right here on SpaceWeather.com. TCI not only tracks the slow progression of the 11-year solar cycle, but also it can change suddenly in response to solar flares and geomagnetic storms. As these events occur, we'll be writing about them to raise awareness of the many ways the sun can dump energy into Earth's atmosphere. Stay tuned!
Realtime Space Weather Photo Gallery
A MOONSTONE IN THE STRATOSPHERE: Are you looking for a far-out gift? Nothing says "I love you" like a moonstone from the edge of space. On June 12th, the students of Earth to Sky Calculus flew this moonstone wrapped in a sterling silver Celtic love knot 34.1 km (111,877 feet) above Earth's surface:
You can have it for $149.95. The students are selling these pendants to support their cosmic ray ballooning program. Each one comes with a greeting card showing the item 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 sales support hands-on STEM education
AFRICAN ICE HALO: You never know what you might see when you go on safari. "Earlier this week I was riding through Choose National Park in Botswana," says George Kourounis. "While the rest of the people in the vehicle were scanning the bushes, looking for lions and leopards, I was looking up in the sky at this complex solar halo."
"It was almost like a giant eye in the sky looking down at us," says Kourounis. "I've never seen anything like it."
Halos like this are caused ice crystals in high cirrus clouds. Shaped like pencils, long and thin with 6 sides, the crystals bend and refract sunlight into a variety of shapes. Shown above is a 22-degree circular halo, a circumscribed halo, and a fraction of a full parhelic circle.
Some people think ice halos are rare in Africa--but they are not. The air 10 km high is freezing over Africa just like everywhere else. Safari-goers should definitely look up, from time to time.
INFERIOR CONJUNCTION OF VENUS: Today, Oct. 26th, Venus is at inferior solar conjunction. In other words, Venus is passing almost directly between Earth and the sun. Shahrin Ahmad photographed Venus in broad daylight from Kuala Lumpur, Malaysia:
"Venus was a mere 6 deg 24 min from the sun!" says Ahmad. "The sky around it was super blue and clear."
During inferior conjunction, Venus turns its night side toward Earth, showing itself only by dint of sunlight scattered in a thin crescent around the edge of its atmosphere. When Venus is very close to the sun, that crescent can close upon itself, making a complete circle. "The horns or cusps of Venus have already gone beyond 180º, but they have not completely closed," notes Ahmad.
This is arguably the most beautiful time to observe Venus, but also the most perilous. The glare of the nearby sun magnified by a telescope can damage the eyes of anyone looking through the eyepiece.
Anthony J. Cook of the Griffith Observatory has some advice for observers: "I have observed Venus at conjunction, but only from within the shadow of a building, or by adding a mask to the front end of the telescope to fully shadow the optics from direct sunlight. This is tricky with a refractor or a catadioptric, because the optics start at the front end of the tube. Here at Griffith Observatory, I rotate the telescope dome to make sure the lens of the telescope is shaded from direct sunlight, even through it means that the lens will be partially blocked when aimed at Venus. With our Newtonian telescope, I add a curved cardboard mask at the front end of the tube to shadow the primary mirror."