Listen to radar echoes from satellites and meteors, live on listener-supported Space Weather Radio.
FRIDAY IS PI DAY: Mark your calendar. This Friday, March 14th (3.14), is day. It's an occasion to celebrate one of the most compelling and mysterious constants of Nature. Pi appears in equations describing the orbits of planets, the colors of auroras, the structure of DNA. The value of is woven into the fabric of life, the universe and ... everything.
Humans have struggled to calculate for thousands of years. Divide the circumference of a circle by its diameter; the ratio is . Sounds simple, but the devil is in the digits. While the value of is finite (a smidgen more than 3), the decimal number is infinitely long:
Supercomputers have succeeded in calculating more than 2700 billion digits and they're still crunching. The weirdest way to compute : throw needles at a table or frozen hot dogs on the floor. Party time!
GROWING CHANCE OF FLARES: Sunspot AR2002 poses a growing threat for solar flares. Since the week began, the active region has more than tripled in size. It now has more than a dozen dark cores and sprawls across 100,000 km of solar terrain. Karzaman Ahmad sends this picture from the Langkawi National Observatory in Malaysia:
"AR2002 is so large," says Ahmad, "that I was able to photograph it using an ordinary 11-inch Celestron telescope capped with a Thousand Oaks Glass Filter." The exceptionally crisp image shows thousands of boiling granules surrounding the sunspot's dark cores. Each granule is about the size of Texas.
A 48-hour movie from NASA's Solar Dynamics Observatory shows the sunspot's development:
The rapid growth of AR2002 has destabilized its magnetic field, which makes it more likely to erupt. NOAA forecasters estimate a 70% chance of M-class flares and a 15% chance of X-class flares during the next 24 hours. Solar flare alerts: text, voice
Space Weather Photo Gallery
HELIOPHYSICS SUMMER SCHOOL: Are you an undergraduate physics or astronomy instructor? There might be a seat waiting for you at the 2014 Heliophysics Summer School. The program's sponsor, UCAR, is looking for a number of qualified instructors to attend with most expenses paid. Apply here. The deadline has been extended to March 22nd.
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 Mar. 10, 2014, the network reported 3 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.
March 12, 2014 there were
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