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.
SUDDEN SUNSPOTS: On Friday morning, the sun was nearly blank. By the end of the day, two fast-growing sunspots had broken through the stellar surface. See them appear in a 36-hour movie from NASA's Solar Dynamics Observatory. If they continue to grow at this rate, they could soon pose a threat for solar flares. Solar flare alerts: text, voice
SOLAR SECTOR BOUNDARY CROSSING: High-latitude auroras are possible on Feb 28th when Earth crosses through a fold in the heliospheric current sheet. This is called a "solar sector boundary crossing," and NOAA forecasters estimate a 60% chance of polar geomagnetic storms when it occurs. Aurora alerts: text, voice
Boosting the chances of auroras even more is a high-speed solar wind stream waiting on the other side of the heliospheric current sheet. The wind is flowing from a coronal hole on the sun, shown in this extreme UV image from NASA's Solar Dynamics Observatory:
Coronal holes are places in the sun's atmosphere where the sun's magnetic field opens up, allowing hot gas to escape. In the image, above, the magnetic field is traced by curved white lines. Arrows show where the solar wind is escaping along open field lines. Forecasters expect the gassy stream to reach Earth on Feb. 28-March 1. Keep an eye on the realtime photo gallery for aurora sightings this weekend.
Aurora Photo Gallery
WHAT ARE THE ODDS? On Feb.19th, Spaceweather.com and the students of Earth to Sky Calculus launched a helium balloon to the stratosphere. The payload, a cosmic radiation buoy, traveled 112,300 feet above Earth's surface and drifted more than 85 linear miles from the launch site. When it parachuted back to Earth, it landed in a sparsely vegetated stretch of Nevada desert. Getting caught in a tree would seem unlikely, yet that's exactly what happened:
The payload descended into a beautiful forest of Joshua trees, and one of them snagged the parachute. As the student recovery team learned, disentangling the cords of a parachute from the spikey embrace of a Joshua tree is no easy trick. Nevertheless, they persisted and won back their radiation buoy.
The students have been flying radiation buoys to the stratosphere since 2013. Their purpose is to monitor the effect of cosmic rays and solar activity on the upper atmosphere. This buoy carried a pair of ionizing radiation detectors, sensitive to X-rays, gamma-rays and beta particles in the energy range 10 keV to 20 MeV.
A preliminary look at the Feb. 19th data reveals some of the highest radiation levels recorded in the 2-year history of the program. This could be a result of the current spate of low solar activity. Cosmic rays are repelled by CMEs and strong solar magnetic fields. When the sun is quiet, cosmic rays penetrate the solar system in greater numbers--an effect which the students are monitoring with their balloon flights.
Space Weather 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 Feb. 27, 2015, the network reported 1 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.
February 28, 2015 there were 1551
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