THE FIRST INTERPLANETARY PHOTOBOMB ALIEN CUPCAKES AURORAS OVER YELLOWSTONE:

THE FIRST INTERPLANETARY PHOTOBOMB: On Friday, July 19th, the Cassini spacecraft will photograph Earth through the rings of Saturn--and NASA wants you to jump into the shot.

ALIEN CUPCAKES: Yesterday, the students of Earth to Sky Calculus flew a space weather balloon to measure the height of the tropopause. It's part of a project to monitor the effects of solar storms on the upper atmosphere. To support their project, they let a pair of Alien Cupcakes hitch a ride to the edge of space.

AURORAS OVER YELLOWSTONE: A CME swept past Earth on July 13th. The impact was gentle and did not spark a geomagnetic storm. However, south-pointing magnetic fields in the CME's wake had greater effect. The "negative Bz" opened a crack in Earth's magnetosphere, allowing solar wind to pour in and fuel high-latitude auroras. Zack Clothier photographed these over Yellowstone National Park on July 15th:

"At about midnight on July 15th, just as the moon was setting, the lights came alive over White Dome Geyser in the Lower Geyser Basin of Yellowstone National Park," says Clothier. "While I was standing there in the darkness a coyote started howling nearby, adding to the already eeriness of the scene. If you look closely you can see a meteor streaking down towards the geyser, to the left of the Milky Way."

More scenes like this are possible on July 18th when a solar wind stream is expected to hit Earth's magnetic field. NOAA forecasters estimate a 50% chance of geomagnetic storms.