Marianne's Heaven On Earth Aurora Chaser Tours Chasethelighttours.co.uk invites you to join them in their quest to find and photograph the Aurora Borealis. Experience the winter wonderland in the Tromsø Area.
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QUIET SUN: Solar activity is very low. No sunspots are actively flaring, and the sun's X-ray output is flatlining. NOAA forecasters say the odds of a strong flare on Oct. 9th is no more than 1%. Solar flare alerts: text or voice
BLUE SKIES ON PLUTO: Earth isn't the only planet with blue skies. Pluto has them, too. The first color images of Pluto's atmosphere were beamed back to Earth by NASA's New Horizons spacecraft just last week, and the sky looks a lot like home:
New Horizons took the picture just after it sped by Pluto on July 14, 2015. The spacecraft's cameras were looking back at Pluto's nightside as sunlight illuminated the fringe of blue around Pluto's circumference.
"Who would have expected a blue sky in the Kuiper Belt?" says Alan Stern, principal investigator of the New Horizons mission. "It's gorgeous."
Carly Howett of the New Horizons science team explains the phenomenon: "A blue sky often results from scattering of sunlight by very small particles. On Earth, those particles are nitrogen molecules. On Pluto they appear to be soot-like particles we call tholins."
The term "tholin" was coined by Carl Sagan and Bishun Khare to describe organic substances they obtained in Miller-Urey experiments on gas mixtures akin to atmosphere of Saturn's moon Titan. On Pluto, tholins form high in the atmosphere where UV sunlight breaks apart nitrogen and methane molecules. The fragments re-combine to form complex macromolecules. These macromolecules continue to combine and grow until they become "tholins."
Ironically, tholins themselves are not blue. They merely scatter blue light. When tholins fall to the ground they show their true colors: gray or red. At least some of Pluto's patchy red coloring is thought to result from a gentle rain of these particles from the planet's atmosphere.
Realtime Space Weather Photo Gallery
GREEN SKIES ON EARTH: Sky watchers around the Arctic Circle have experienced three straight nights of auroras that some veteran observers say is "the strongest" they've ever seen. "Mother Earth gave us a massive display of lights," reports Johnny Henriksen, who photographed this outburst over Harstad, Norway:
The lights were not restricted to the Arctic Circle, however. Auroras spilled into the United States as far south as Virginia. Sightings were also made in the Dakotas, Maine, Michigan, Wisconsin, Wyoming and Minnesota. Subscribers to our Space Weather Alert service received wake-up calls during the storm.
Most displays of this magnitude are caused by CMEs, billion-ton clouds of gas from the sun. This event, however, was caused by a CIR (co-rotating interaction region). CIRs are boundary zones between slow- and fast-moving solar wind streams. Solar wind plasma piles up in these regions, producing density gradients and shock waves that do a good job of sparking auroras. A CIR hit Earth's magnetic field during the early hours of Oct. 7th, amplifying a storm already in progress. A solar wind stream arriving in the wake of the CIR has kept the storm going through Oct. 8th.
More auroras are in the offing tonight, albeit not as strong. NOAA forecasters estimate a 60% chance of minor geomagnetic storms on Oct. 9th as Earth slowly exits the stream of solar wind. Aurora alerts: text or voice
Realtime Aurora Photo Gallery
Realtime Eclipse Photo Gallery
Realtime Sprite Photo Gallery
| ||Cosmic Rays in the Atmosphere |
These measurements are based on space weather balloon flights, described below.
|Situation Report -- Oct. 8, 2015 ||Stratospheric Radiation (+37o N) |
|Cosmic ray levels are elevated (+6.2% above the Space Age median). The trend is flat. Cosmic ray levels have increased +0% in the past month. |
|Sept. 06: 414 uRad/hr |
|Sept. 12: 409 uRad/hr |
|Sept. 23: 412 uRad/hr |
|Sept. 25: 416 uRad/hr |
|Sept. 27: 413 uRad/hr |
Introduction: Once a week, and sometimes more often, Spaceweather.com and the students of Earth to Sky Calculus fly "space weather balloons" to the stratosphere. These balloons are equipped with radiation sensors that detect cosmic rays, a form of space weather important to people on Earth. Cosmic rays can alter the chemistry of the upper atmosphere, seed clouds, spark exotic forms of lightning, and penetrate commercial airplanes. This last point is of special interest to the traveling public. 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. From now on we will present the results of our regular weekly balloon flights in this section of our web site. Here is the radiation profile from our latest flight:
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 nearly 100x 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 Sept. 27th measurements, a plane flying at 45,000 feet is exposed to 288 uRads/hr. At that rate, a passenger would absorb about one dental X-ray's worth of radiation in 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.
Stay tuned for improvements to this section in the days and weeks ahead as we develop a glossary and better plain language strategies for communicating this information. Suggestions are welcomed.
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 Oct. 9, 2015, the network reported 12 fireballs.
(11 sporadics, 1 Southern Taurid)
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 October 9, 2015 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.
| ||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 |
| ||Web-based high school science course with free enrollment |