Looking for a unique Mother's Day gift? How about Space Roses? Proceeds from the sale of these far-out blooms support student space weather research.
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ALMOST NO CHANCE OF FLARES: Solar activity is very low. There are two sunspots on the solar disk, but neither one has the type of unstable magnetic field that poses a threat for explosions. NOAA forecasters say the chance of a strong flare today is no more than 1%. Solar flare alerts: text or voice
ANTARCTIC AURORAS: A solar wind stream is blowing around Earth. On April 23rd, it sparked a G1-class geomagnetic storm and auroras around the poles. Gabriel Saiquita photographed the display from Argentina's Belgrano II Base in Antarctica:
"We are deep inside the Antarctic Circle at a latitude of -78 degrees," says Saiquita, a member of the research station's winter crew.
Similar auroras danced across Arctic skies, but they were mostly invisible due to the waxing glow of the summer Midnight Sun. As the seasons change, aurora sightings shift from one pole to the other. The winter night at Belgrano II Base is 4 months long, so stay tuned for more aurora australis. Aurora alerts: text or voice
Realtime Aurora Photo Gallery
THE MICRO-MOON: We've all heard of supermoons--full Moons that are extra big and bright because they occur close to Earth. This week's full moon was the opposite--a micro-moon. April's full Moon was as much as 14% smaller than other full Moons of 2016. Marek Nikodem photographed the shrunken orb over a cement factory in Piechcin, Poland:
"Hot smoke rising over the factory distorted the shape of the lunar disk and made it seem that the Moon was being drawn into the smokestack," says Nikodem. Not even a micromoon, however, is small enough to fit inside a chimney. Photos taken moments later reveal the disk floating free.
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 apogee side of the Moon's orbit seem a bit smaller and dimmer than usual. That's what happened on April 22nd. The Moon became full at 05:24 UT only 13 hours after apogee--a coincience that reduced the size of the lunar orb.
The supermoon will return on Nov. 14 when the Moon becomes full at perigee. Stay tuned for that.
Realtime Space Weather Photo Gallery
SPACE WEATHER PROBE TAKES SELFIE: Last December, Joyce and Tad Lhamon of Seattle, Washington, bought their 12-year-old grandson Barrett a far-out Christmas gift--that is, a trip to the edge of space. In exchange for this gift certificate, Barrett could fly any experiment he wanted to the stratosphere onboard an Earth to Sky Calculus helium balloon. He thought about it for months and, after discarding many ideas, Barrett decided to fly a convex mirror. The payload's cameras could look into the mirror and take a new kind of "space selfie." Would it work? On April 17th, we flew Barrett's experiment, and the results were better than anyone dreamed:
"Spaceweather.com and the students of Earth to Sky Calculus have flown more than 150 missions to the edge of space monitoring cosmic rays and stress-testing microbes. We've never seen our payload quite like this before.
A particularly interesting sequence of images shows the balloon exploding above the payload 117,100 feet above Earth. The following video frames are separated by only 1/30th of a second: #1, #2, #3, #4. Note how the payload remains motionless during the explosion. It takes more than a second for the shock wave from the explosion to propagate down the long cord connecting the payload to the balloon.
Congratulations, Barrett, on a very successful experiment!
Realtime Space Weather Photo Gallery
Realtime Comet Photo Gallery
Every night, a network of NASA 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, 2016, the network reported 2 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 ones
all the time.
On April 24, 2016 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.
| ||Cosmic Rays in the Atmosphere |
These measurements are based on regular space weather balloon flights: learn more.
|Situation Report -- Oct. 30, 2015 ||Stratospheric Radiation (+37o N) |
|Cosmic ray levels are elevated (+6.1% above the Space Age median). The trend is flat. Cosmic ray levels have increased +0% in the past month. |
|Sept. 06: 4.14 uSv/hr (414 uRad/hr) |
|Sept. 12: 4.09 uSv/hr (409 uRad/hr) |
|Sept. 23: 4.12 uSv/hr (412 uRad/hr) |
|Sept. 25: 4.16 uSv/hr (416 uRad/hr) |
|Sept. 27: 4.13 uSv/hr (413 uRad/hr) |
|Oct. 11: 4.02 uSv/hr (402 uRad/hr) |
|Oct. 22: 4.11 uSv/hr (411 uRad/hr) |
Approximately once a week, Spaceweather.com and the students of Earth to Sky Calculus fly "space weather balloons" to the stratosphere over California. These balloons are equipped with radiation sensors that detect cosmic rays, a surprisingly "down to Earth" form of space weather. Cosmic rays can seed clouds, trigger lightning, and penetrate commercial airplanes. Our measurements show that someone flying back and forth across the continental USA, just once, can absorb as much ionizing radiation as 2 to 5 dental X-rays. For example, here is the data from a flight on Oct. 22, 2015:
Radiation levels peak at the entrance to the stratosphere in a broad region called the "Pfotzer Maximum." This peak is named after physicist George Pfotzer who discovered it using balloons and Geiger tubes in the 1930s. Radiation levels there are more than 80x sea level.
Note that the bottom of the Pfotzer Maximim is near 55,000 ft. This means that some high-flying aircraft are not far from the zone of maximum radiation. Indeed, according to the Oct 22th measurements, a plane flying at 45,000 feet is exposed to 2.79 uSv/hr. At that rate, a passenger would absorb about one dental X-ray's worth of radiation in about 5 hours.
The radiation sensors onboard our helium balloons detect X-rays and gamma-rays in the energy range 10 keV to 20 MeV. These energies span the range of medical X-ray machines and airport security scanners.
| ||The official U.S. government space weather bureau |
| ||The first place to look for information about sundogs, pillars, rainbows and related phenomena. |
| ||Researchers call it a "Hubble for the sun." SDO is the most advanced solar observatory ever. |
| ||3D views of the sun from NASA's Solar and Terrestrial Relations Observatory |
| ||Realtime and archival images of the Sun from SOHO. |
| ||from the NOAA Space Environment Center |
| ||the underlying science of space weather |