They came from outer space--and you can have one! Genuine meteorites are now on sale in the Space Weather Store.
| || |
QUIET SUN: Solar activity is low. None of the sunspots on the Earthside of the sun has the kind of complex magnetic field that harbors energy for strong flares. NOAA forecasters put the odds of an M-class solar flare at 20% on June 26th, waning to 10% on June 27th. Solar flare alerts: text, voice.
NOCTILUCENT CLOUDS--AIR VS AIM: Every day, NASA's AIM spacecraft maps the distribution of noctilucent clouds (NLCs) around Earth's north pole. The results are displayed on spaceweather.com in the form of the "daily daisy." On June 20th, pilot Brian Whittaker flew past a vivid display of NLCs over the North Atlantic Ocean and he decided to compare his own view to that of AIM. Here are the results:
"Once again, AIM's daily daisy-wheel allowed me to see where the northern horizon noctilucent clouds truly were!" says Whittaker. "This display reached a maximum height of about 10 degrees as seen from 37,000 feet at 50N latitude. It was my 4th and best sighting of 2013 so far."
2013 is shaping up to be a good year for NLCs. The clouds surprised researchers by appearing early this year, and many bright displays have already been recorded. Once confined to the Arctic, NLCs have been sighted in recent years as far south as Utah, Colorado, and Nebraska. They might spread even farther south in 2013.
Observing tips: Look west 30 to 60 minutes after sunset when the sun has dipped 6o to 16o below the horizon. If you see luminous blue-white tendrils spreading across the sky, you've probably spotted a noctilucent cloud.
Realtime Noctilucent Cloud Photo Gallery
[previous years: 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2011]
CORONAL HOLE: The biggest thing on the sun today is not a sunspot, it's a coronal hole. The yawning dark gap in the sun's atmosphere is almost directly facing Earth, as shown in this June 25th image from NASA's Solar Dynamics Observatory:
Coronal holes are places where the sun's magnetic field opens up and allows solar wind to escape. A stream of solar wind flowing from this particular coronal hole will reach Earth on June 29-30. Because the coronal hole is straddling the sun's equator, the solar wind it is sending our way should make a direct hit on our planet's magnetic field. The impact could spark geomagnetic storms around the poles. High-latitude sky watchers should be alert for auroras at the end of the month. Aurora alerts: text, voice.
Realtime Space Weather Photo Gallery
PHOTOS OF THE SUPERMOON: The mainstream media called this past weekend's full Moon a "supermoon." On the beach in Halkidiki, Greece, however, it didn't seem so big. Photographer Theodoridis Constantinos found that it fit in the palm of an onlooker's hand:
Appearances notwithstanding, the supermoon was as much as 14% bigger than other full Moons of 2013. It only looks small in this picture because foreground objects affect our perception of size and distance. The human brain can be tricky in that way.
The scientific term for the supermoon phenomenon is "perigee moon." Full Moons vary in size because of the oval shape of the Moon's orbit. The Moon follows an elliptical path around Earth with one side ("perigee") about 50,000 km closer than the other ("apogee"). Full Moons that occur on the perigee side of the Moon's orbit seem extra big and bright. On June 23rd, the Moon became full at 11:34 UT, only 23 minutes after perigee--a near-perfect coincidence that gave us an extra-bright, extra-big lunar orb.
More pictures of the super-perigee Moon may be found in the realtime photo gallery. Browse and enjoy.
Realtime Moon Photo Gallery
Realtime Aurora Photo Gallery
Realtime Comet Photo Gallery