MOON-SATURN CONJUNCTION: Have you been looking for Saturn? Let the Moon be your guide. Tonight, the Moon will pass by the ringed planet, forming a loose but beautiful conjunction in the constellation Sagittarius. Look south after midnight: sky map.
COLORFUL CLOUDS PILE UP ABOVE ALBERTO: Yesterday, May 30th, tropical depression Alberto was spending the last of its strength over Illinois when Chris Moore in the town of Streator looked up at the sky. "I caught these spectacular rainbow-colored rings swirling around a cloud bank on the western edge of the storm," he says. "The setting sun lit up the wispy clouds from behind."
These are pileus clouds, and while they may resemble rainbows, they form in a completely different way. To make a pileus cloud, a cumulus cloud must first boil upward, pushing layers of moist air above it where the layers cool and condense to form cloud caps ('pileus'). Because pileus clouds form very quickly, their internal water droplets tend to be all the same size--the perfect condition for iridescence. Uniform droplets diffract passing sunlight into vivid pastel hues.
Normally pileus clouds appear on warm summer afternoons when the landscape is festooned with rising cumulous towers. In this case, however, Alberto created the conditions for a late-spring display.
Realtime Space Weather Photo Gallery
SOLAR WIND ALERT: NOAA forecasters say there is a 60% chance of G1-class geomagnetic storms on June 1st when a solar wind stream is expected to hit Earth's magnetic field. The gaseous material is flowing from an equatorial hole in the sun's atmosphere:
This is a coronal hole--a region where the sun's magnetic field has opened up, allowing solar wind to escape. It looks dark in this extreme UV image from NASA's Solar Dynamics Observatory because the hot gas normally contained there is missing. Soon it will be at Earth.
This coronal hole has been lashing Earth with streams of solar wind approximately once a month since February. It faces us every ~27 days as the sun spins on its axis. On previous occasions, the solar wind speed topped 700 km/s, exciting hot currents of gas in Earth's upper atmosphere. These currents, in turn, caused apparitions of STEVE seen as far south as the USA. Stay tuned for updates. Free: Aurora Alerts.
BASEBALLS IN THE STRATOSPHERE: Some home runs begin with the crack of a bat. This one began with a countdown: "10, 9, 8, 7...." On May 23, 2018, the students of Earth to Sky Calculus launched this World Series Champion Houston Astros ball to the stratosphere on a cosmic ray balloon:
You can have it for $149.95. The students are selling these balls as a fundraiser for their cosmic ray ballooning. Each baseball comes with a greeting card showing the ball in flight and telling the story of its journey to the stratosphere. They make great Father's Day gifts.
Are you a fan of a different team? We also have "space balls" for the Red Sox, Angels, Dodgers, Giants, and Padres. Coming soon: Royals, Cubs, Yankees. If your home team is not on the list, let us know and we will fly it for you on an upcoming flight.
Far Out Gifts: Earth to Sky Store
All proceeds support hands-on STEM education