Come to Tromsø and share Marianne's passion for rural photography: Chasethelighttours.co.uk invites you to experience "Heaven on Earth" with an aurora, fjord, fishing, whale watching, photography or sightseeing tour.
SOLAR SECTOR BOUNDARY CROSSING: High-latitude auroras are possible on April 25th when Earth crosses through a fold in the heliospheric current sheet. This is called a "solar sector boundary crossing," and NOAA forecasters estimate a 30% chance of polar geomagnetic storms when it occurs. Aurora alerts: text, voice.
SPECTACULAR PROMINENCE: A magnificent filament of magnetism is rotating over the northeastern limb of the sun. Amateur astronomer Jett Aguilar sends this picture from Quezon City, the Philippines:
"I was lucky to image this beautiful caterpillar-like structure through a break in the clouds," says Aguilar. That's some caterpillar: As the inset picture of Earth shows, the prominence is large enough to swallow our planet more than 50 times over.
This is a type of prominence more commonly called a "hedgerow prominence." Hot glowing plasma inside the structure is held aloft by unstable solar magnetic fields. NASA and Japanese space telescopes have taken high resolution images of of similar prominences and seen some amazing things such as (1) tadpole-shaped plumes that float up from the base of the prominence; (2) narrow streams of plasma that descend from the top like waterfalls; and (3) swirls and vortices that resemble van Gogh's Starry Night.
Got a solar telescope? Take a look!
VOLCANIC LIGHTNING: For the first time in more than 42 years, the Calbuco volcano in southern Chile has erupted. Two blasts in 24 hours on April 22nd sent plumes of ash and volcanic gases shooting at least 50,000 feet high, well into the altitudes where planes fly. One of the eruptions occured at night and put on a spectacular display of volcanic lightning:
Researchers have long known that volcanic eruptions produce strong lightning. Findings published in a 2012 Eos article reveal that the largest volcanic storms can rival massive supercell thunderstorms in the American midwest. But why? Volcanic lightning is not well understood.
Lightning is nature's way of correcting an imbalance of electric charge. In ordinary thunderstorms, one part of a thundercloud becomes positively charged, and another part becomes negatively charged. This charge comes from collisions between particles: e.g., droplets of water and crystals of ice rub together, creating static electricity in much the same way as woolen socks rubbed against carpet. Lightning arcs between charge-separated regions.
Something similar must be happening inside volcanic plumes. One hypothesis holds that catapulting magma bubbles or volcanic ash are themselves electrically charged, and by their motion create charge-separated areas. Another possibility is that particles of volcanic ash collide with each other and become charged through triboelectric rubbing. In short, no one knows. It is a beautiful and terrifying mystery.
Stay tuned for more images as the eruption of Calbuco continues.
Space Weather Photo Gallery
SPACE YEAST MAKES SPACE BREAD: Thought experiment: Suppose you flew a packet of baker's yeast high above Earth's surface, to the edge of space itself, and exposed the microbes to a blast of cosmic rays. Then you made some bread. How would it taste? "Delicious," reports Eileen Weingram of Highland Lakes, New Jersey, who actually did the experiment:
On March 17th, during the strongest geomagnetic storm of the current solar cycle, the students of Earth to Sky Calculus flew a Space Weather Buoy to the stratosphere. Along with radiation detectors and other sensors, the payload carried packets of brewer's and baker's yeast. En route to the stratosphere, the microbes experienced temperatures as low as -63 C and cosmic ray doses 40x Earth-normal.
To support the students' research, Eileen Weingram bought a packet of the baker's yeast. "It made a huge loaf of bread," she says. "Very yummy."
If this story whets your appetite, you can bake some "space bread" of your own. Packets of yeast are still available for only $49.95. Contact Dr. Tony Phillips to place your order--and let the baking begin! All sales support high altitude balloon flights to measure the effect of solar storms on Earth's atmosphere.
Meteor Photo Gallery
Aurora Photo Gallery
Comet Photo Gallery
Every night, a network
all-sky cameras scans the skies above the United
States for meteoritic fireballs. Automated software
maintained by NASA's Meteoroid Environment Office
calculates their orbits, velocity, penetration depth
in Earth's atmosphere and many other characteristics.
Daily results are presented here on Spaceweather.com.
On Apr. 24, 2015, the network reported 12 fireballs.
(6 sporadics, 6 April Lyrids)
In this diagram of the inner solar system, all of the fireball orbits intersect at a single point--Earth. The orbits are color-coded by velocity, from slow (red) to fast (blue). [Larger image] [movies]
Potentially Hazardous Asteroids (PHAs
are space rocks larger than approximately 100m that
can come closer to Earth than 0.05 AU. None of the
known PHAs is on a collision course with our planet,
although astronomers are finding new
all the time.
April 25, 2015 there were 1575
potentially hazardous asteroids.
Notes: LD means
"Lunar Distance." 1 LD = 384,401 km, the distance
between Earth and the Moon. 1 LD also equals 0.00256
AU. MAG is the visual magnitude of the asteroid on
the date of closest approach.
official U.S. government space weather bureau
first place to look for information about sundogs,
pillars, rainbows and related phenomena.
call it a "Hubble for the sun." SDO
is the most advanced solar observatory ever.
views of the sun from NASA's Solar and Terrestrial
and archival images of the Sun from SOHO.
the NOAA Space Environment Center
underlying science of space weather