When is the best time to see auroras? Where is the best place to go? And how do you photograph them? These questions and more are answered in a new book, Northern Lights - a Guide, by Pal Brekke & Fredrik Broms. | | |
LEONID METEOR SHOWER: Today, Nov. 19th, Earth is passing through a narrow stream of debris from Comet Tempel-Tuttle, source of the annual Leonid meteor shower. "The Leonids are showing up nicely in our data from the Canadian Meteor Orbit Radar (CMOR)," reports Peter Brown of the University of Western Ontario. "Rates are only about 10 per hour, but the shower is definitely active, if muted due to moonlight this year!" Listen to Space Weather Radio for live Leonid echoes.
X-CLASS SOLAR FLARE (UPDATED): Departing sunspot AR1893 (not AR1897 as previously reported) erupted on Nov. 19th (10:26 UT), producing an X1-class solar flare. NASA's Solar Dynamics Observatory recorded the explosion's extreme ultraviolet flash:
Although the sunspot is not directly facing Earth, the flare did affect our planet. Mainly, the UV flash produced a wave of ionization in the upper atmosphere over Europe, Africa and parts of Asia. A brief blackout of HF radio transmissions around the poles might have also occurred. UPDATE: The explosion hurled a CME into space: movie. But the cloud is not heading toward Earth. Solar flare alerts: text, voice
Realtime Space Weather Photo Gallery
COMET ISON--ANOTHER OUTBURST? Astronomers working with the TRAPPIST telescope at ESO's La Silla Observatory report that Comet ISON's production of gas and dust surged another six-fold during the early hours of Nov. 19th. This marks the second outburst since Nov. 13th. Experienced observers put the comet's rising magnitude near +4.0, well above the threshold of naked-eye visibility. The problem is, ISON is approaching the sun and becoming increasingly difficult to observe. Shahrin Ahmad of Kuala Lumpur, Malaysia, photographed the comet's green core framed by twilight blue on the morning of Nov. 19th:
Amateur photography of the comet will be possible for a few more days. Soon, however, only NASA's fleet of solar observatories will be able to track the sundiver.
At closest approach (perihelion) on Nov. 28th, ISON will be little more than a million kilometers from the sun's fiery surface. Despite the recent outbursts, which could have been caused by a break up of ISON's nucleus, astronomers with NASA's Comet ISON Observing Campaign believe that the comet is still intact. It will need to be to survive next week's hellish plunge through the sun's atmosphere.
Observationally speaking, the next big event in the timeline of Comet ISON's journey comes on Nov. 21st when the comet enters the field of view of STEREO-A. The spacecraft's Heliospheric Imager will pick up the comet just as Earth-bound telescopes begin to lose it. In the days that follow, STEREO-B, SOHO and the Solar Dynamics Observatory will join the hunt, providing continuous views of Comet ISON all the way to perihelion. Stay tuned for some marvelous images.
Realtime Comet ISON Photo Gallery
Ephemerides: Comet ISON, Comet Lovejoy, Comet Encke, Comet LINEAR X1
VENUS AND NUNKI: When the sun goes down tonight, step outside and look southwest. You can't miss Venus shining brightly through the twilight. Got patience? Keep watching until the sky darkens. Venus is not alone:
"Last night, Venus slid past the star Nunki (Sigma Sagittarii) in the Milk Dipper asterism in Sagittarius," says astronomy professor Jimmy Westlake, who took the picture on November 18th from Stagecoach, Colorado. "The two missed each other by a scant 12.75 arc minutes. Venus (magnitude -4.56) shines a whopping 420 times brighter than Nunki (magnitude +2)." The mismatched pair is separating now, but Venus and Nunki are still only a fraction of a degree apart on Nov. 19th. Take a look!
Realtime Space Weather Photo Gallery
Realtime Aurora Photo Gallery
Realtime Comet ISON 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 Nov. 19, 2013, the network reported 31 fireballs.
(21 sporadics, 10 Leonids)
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 November 19, 2013 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 |