LONG-DELAY RADIO ECHOES: During the geomagnetic storm of Nov. 27th, a brief but intense G2-class event, amateur radio operator Peter Brogl of Fürth, Germany experienced a strange phenomenon. Forty-six seconds after he transmitted his call sign at 7 MHz, he received an echo of his own transmission. "At first, I thought someone was playing tricks on me," says Brogl, "but I changed frequency, re-keyed my call sign (DK6NP), and got another echo." This went on for more than an hour, enough time for Brogl to make several recordings. First reported in 1927 by Norwegian civil engineer Jørgen Hals, long-delay radio echoes are rare and poorly understood. Unusual propagation conditions linked to solar storms is one of many possible explanations.

NEW SUNSPOT: New sunspot 1130 is rapidly developing near the center of the sun's disk and "it is crackling with activity," reports Michael Borman of Evansville, Indiana. Using a backyard solar telescope, he took this picture of a B-class explosion from the active region on Nov. 28th. So far, the flares have been relatively minor, but if the sunspot's growth continues apace, geo-effective blasts could be in the offing.

COMET HARTLEY 2: Comet Hartley 2 is putting on a show for amateur astronomers. Tonight, the amazing green comet glides midway between two star clusters, M46 and M47, in the southern constellation Puppis. George Ionas of Palmerston North, New Zealand, made a two hour movie of the comet's approach on Nov. 28th. "This is a pretty sight in backyard telescopes as the comet stilll has a fairly bright nucleus," he says. Astrophotographers who wish to monitor the encounter can point their telescopes using this ephemeris and sky map.

more images: from Rolando Ligustri and from J.D. Strikis, both using robotic telescopes in New Mexico

FARSIDE ACTIVITY: The far side of the sun is alive with activity. Today, NASA's twin STEREO spacecraft and the Solar and Heliospheric Observatory (SOHO) have observed two farside coronal mass ejections (CMEs) billowing into space. This one came from old sunspot 1126, located just over the sun's southwestern horizon:

Click to play a 3 MB gif animation

Hours later, a second CME followed, but not from the same blast site. The second CME came from an active region near the sun's anti-Earth point, almost directly opposite our planet on the solar farside.

If Earth were on the other side of the sun, we would be be expecting bright auroras from the impact of these clouds. Instead, the alert is for "all quiet." Nothing major is heading our way.

The farside active regions that produced these eruptions will turn to face Earth in 7 to 14 days. Will they remain active that long? Stay tuned for updates from the farside.

ALIEN COMETS IN THE SOLAR SYSTEM: Some of the comets in our Solar System probably came from other stars, according to new research by NASA-supported scientists. Studying these 'alien' comets, they say, could reveal new information about stellar systems far, far away. Get the full story from Science@NASA.

LEONID RECAP: Earth is exiting a thicket of debris from Comet Tempel-Tuttle, source of the annual Leonid meteor shower. According to international counts, the shower crested on Nov. 17th and 18th with a peak rate of 20 meteors per hour. Compared to, say, the Leonid storms of a decade ago, it was not an impressive display--that is, unless you added it up for five nights in a row:

These are all the Leonid fireballs I recorded from Nov. 13th to Nov. 18th," says Jim Gamble, who operates an all-sky camera in El Paso, Texas. "In total, there were 16 Leonids of magnitude -3 or brighter." Considering that Earth missed the densest part of the Leonid debris stream in 2010, more than a dozen fireballs is a good haul.

A bigger display is coming: In early December, Earth will enter a cloud of debris from extinct comet Phaethon, setting off the annual Geminid meteor shower. On peak night, Dec. 14th, forecasters expect as many as 100 meteors per hour, five times greater than the waning Leonids. Stay tuned!

more images: from Yuichi Takasaka of Gingolx (Kincolith), British Columbia, Canada; from Thomas Kerns of Homer, Alaska; from Yaron Eini of Jerusalem, Israel;

LEONID METEOR SHOWER: The annual Leonid meteor shower peaks this year on Nov. 17th when Earth passes through a thicket of debris from Comet Tempel-Tuttle. Earth is expected to miss the densest swarms of comet dust, making this an off-year for Leonids with a maximum of only 20 meteors per hour.

EARTH-DIRECTED ERUPTION: Active sunspot 1123 erupted during the early hours of Nov. 12th, producing a C4-class solar flare and apparently hurling a filament of material in the general direction of Earth. Click on the image to play a three and a half hour (0000 - 0330 UT) time lapse movie of the event:

ACTIVITY ON JUPITER: Earlier this year when Jupiter's great South Equatorial Belt (SEB) vanished, researchers urged amateur astronomers to be alert for its eventual return. The SEB had come and gone before, they noted, and the revival was something to behold. Alert: It might be happening now. After months of quiet in Jupiter's south equatorial zone, a white spot is rapidly forming where the SEB should be. Christopher Go of the Philippines took this picture on Nov. 9th:

It might not look like much, but this is how a revival of the SEB begins--a small disturbance in the upper atmosphere heralds a sudden profusion of spots and swirls. Amid the confusion, Jupiter's vast brown stripe emerges.

The existence of this spot has reportedly been confirmed by astrophotographer Donald Parker of Coral Gables, Florida, and Go himself saw it again on Nov. 10th. "The 'SEB outbreak spot' is also prominent in ultraviolet and methane band filters," notes Go. "This spot should grow bigger in the coming days."

COMET OUTBURST: Comet Ikeya-Murakami (C/2010 V1) is definitely undergoing an outburst event. Italian astronomers Ernesto Guido and Giovanni Sostero assembled the following animation from images they obtained between Nov. 4th and Nov 9th:

The sequence clearly shows an explosion in progress. "Only Nov. 7th is missing," they say, "because of rare cloudy skies over New Mexico, where the remotely-controlled telescope we used is located."

Another New Mexico observer, Leonid Elenin, estimates the size of comet's expanding atmosphere as 4x6 arcminutes. "There is also some evidence of two symmetrical jets emerging from the nucleus of the comet," he says.

The behavior of this comet reminds many onlookers of exploding Comet Holmes in 2007. Researchers believe Holmes exploded when an icy cavern in the comet's nucleus collapsed. Perhaps something similar has happened to Comet Ikeya-Murakami. The icy visitor from the outer solar system made its closest approach to the Sun in late October, so it has just received a dose of solar heating that could trigger such an event.

Amateur astronomers are encouraged to monitor developments. Various reports put the brightness of the comet between 7th and 9th magnitude, invisible to the naked eye but an easy target for telescopes such as the Comet Hunter. It's easy to find, too, little more than a degree from Saturn in the eastern sky before dawn. Set your alarm and happy hunting! [Sky maps: Nov. 9, 10, 11] [3D orbit] [ephemeris]

more images: from Joseph Brimacombe using a robotic telescope in New Mexico (Nov.8); from Gil Esquerdo of Whipple Observatory, Mt. Hopkins, Arizona (Nov. 8); from Tenho Tuomi of Lucky Lake, SK, Canada (Nov. 7); from Gregg Ruppel of Ellisville, Missouri (Nov. 7); from Feys Filip of Crete, Greece (Nov. 6); from Gregg Ruppel of Ellisville, Missouri (Nov. 6); from Gregg Ruppel of Ellisville, Missouri (Nov. 5); from Luca Buzzi of the G.V. Schiaparelli Astronomical Observatory in Varese, Italy (Nov. 4);

SOLAR ACTIVITY UPDATE: After unleashing one of the brightest X-ray flares in years on Saturday, Nov. 6th, sunspot 1121 took Sunday off. No strong flares were recorded for the rest of the weekend. Nevertheless, the active region's magnetic field is complex and harbors energy for more eruptions. NOAA forecasters estimate an 85% chance of M-flares during the next 24 hours.

NEW COMET IKEYA-MURAKAMI: Newly-discovered comet C/2010 V1 (Ikeya-Murakami) is putting on a good show for anyone with a backyard telescope and an alarm clock. The clock is for getting up before dawn, and the telescope is for seeing this:

Leonid Elenin took the picture on Nov. 7th using a robotic telescope in New Mexico. "The comet is rapidly changing," he reports. "The shape of its atmosphere reminds me of Comet Holmes after it had an outburst in 2007."

Indeed, Comet Ikeya-Murakami might be experiencing a similar event. The icy visitor from the outer solar system made its closest approach to the sun (1.7 AU) in late October, so it has recently received a strong dose of solar heating. Ice pockets could be evaporating, comet-caverns collapsing, who knows?

Amateur astronomers are encouraged to monitor developments. Various reports put the brightness of the comet between 7th and 9th magnitude, invisible to the naked eye but an easy target for telescopes such as the Comet Hunter. It's easy to find, too, little more than a degree from Saturn in the eastern sky before dawn. Set your alarm and happy hunting! [Sky maps: Nov 8, 9, 10, 11] [3D orbit] [ephemeris]

more images: from Gil Esquerdo of Whipple Observatory, Mt. Hopkins, Arizona (Nov. 8); from Tenho Tuomi of Lucky Lake, SK, Canada (Nov. 7); from Gregg Ruppel of Ellisville, Missouri (Nov. 7); from Feys Filip of Crete, Greece (Nov. 6); from Gregg Ruppel of Ellisville, Missouri (Nov. 6); from Gregg Ruppel of Ellisville, Missouri (Nov. 5); from Luca Buzzi of the G.V. Schiaparelli Astronomical Observatory in Varese, Italy (Nov. 4);

Radiation from the flare created a wave of ionization in Earth's upper atmosphere that altered the propagation of low-frequency radio waves. There was, however, no bright CME (plasma cloud) hurled in our direction, so the event is unlikely to produce auroras in the nights ahead. This is the third M-flare in as many days from this increasingly active sunspot. So far none of the eruptions has been squarely Earth-directed, but this could change in the days ahead as the sun's rotation turns the active region toward our planet.

ACTIVE SUNSPOT: NOAA forecasters say there is a 70% chance of M-class solar flares during the next 24 hours. The source of the blast would be active region 1121 emerging over the sun's eastern limb:

Image credit: Solar Dynamics Observatory [larger image]

Indeed, AR1121 is already crackling with an M2-flare on Nov. 4th and an M1-flare on Nov. 5th. So far none of the flares has been geo-effective, but this could change as the sun's rotation turns the blast site toward Earth in the days ahead. Readers with solar telescopes are encouraged to monitor developments.

more images: from Rogerio Marcon of Campinas SP Brasil; from Robert Arnold of Isle of Skye, Scotland; from James Kevin Ty of Manila, the Philippines

FARSIDE FLARE: An active region just over the sun's eastern horizon is crackling with solar flares and hurling material high above the stellar surface. This extreme ultraviolet movie from NASA's Solar Dynamics Observatory shows the strongest blast so far, a C4-class event at 1220 UT on Nov. 3rd: 

movie formats: 3.8 MB mpeg, 0.9 MB iPad, 0.3 MB iPhone

Although the blast site is hidden behind the limb, the eruption nevertheless yielded enough x-radiation to produce a wave of ionization in Earth's upper atmosphere. Researcher Rob Stammes recorded a sudden ionospheric disturbance (SID) when the wave passed over his lab in Laukvik, Norway. Learn more about SIDs here.

The source of this activity is an old friend--a sunspot and magnetic filament jointly known as "active region 1112." The ensemble put on a good show in mid-October when it first crossed the face of the sun. For the past two weeks, however, it has been transiting the far side, out of sight. Today's eruption may be read as "hello, I'm back." The sun's rotation is bringing the region around for a second pass; readers with solar telescopes are encouraged to monitor the eastern limb for its emergence in the days ahead.