Learn to photograph Northern Lights like a pro. Sign up for Peter Rosen's Aurora Photo Courses in Abisko National Park.
CHANCE OF STORMS: NOAA forecasters estimate a 45% to 65% chance of polar geomagnetic storms during the next 24 to 48 hours. A solar wind stream and a CME are expected to hit Earth's magnetic field in quick succession, sparking G1-class disturbances on April 21st and 22nd. Aurora alerts: text, voice.
SUNSET SKY SHOW: When the sun goes down tonight, step outside and face west. Venus and the crescent Moon are beaming through the twilight side by side. Last night in Bergen, Norway, photographer Ronny Tertnes caught the Moon approaching Venus from below:
"It was an awesome sight to end the day with Venus and the Moon setting after a beautiful sunset," says Tertnes.
That was Monday. Tuesday will be even better as the distance between Venus and the crescent Moon shrinks to less than 10o. Try to catch them before the sky fades to black. Framed by twilight blue, Venus and the Moon have a special beauty that late-night conjunctions lack. Check it out.
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.
LYRID METEOR SHOWER: Earth is entering a stream of debris from Comet Thatcher, source of the annual Lyrid meteor shower. If forecasters are correct, the shower will peak on April 22-23 with 10 to 20 meteors per hour. Sky watchers are already seeing some early arrivals. Dan Bush photographed this Lyrid fireball over Albany, Missouri, before sunrise on April 20th:
"I captured an early Lyrid meteor in two of my all sky cameras," reports Bush. "This is a 1 minute image stack. The brighter streak in the east from behind the tree is the trail of an airplane."
Reports of Lyrids have also been received from Mexico and Washington state.
The Lyrid meteor shower is usually mild, and this year may be no exception. Nevertheless, these early sightings could herald a nice display. The best time to look is between about 11 pm on April 22nd and sunrise on April 23rd. [sky map]
Observing tips: Dress warmly. Bring a reclining chair, or spread a thick blanket over a flat spot of ground. Lie down and look up. Meteors can appear in any part of the sky, although their trails will tend to point back toward the constellation Lyra, from which the meteors get their name. The hours before dawn are best, because that is when Lyra is highest in the sky.
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. 20, 2015, the network reported 51 fireballs.
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 21, 2015 there were 1574
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