Space Weather

[Jherrith]

Intriguing

[Aelin]

Something about the center of the Milky Way

https://www.sciencealert.com/wild-new-paper-proposes-the-center-of-the-milky-way-might-not-be-a-black-hole

[Jherrith]

SOLAR FLARE FRENZY AND CME: Yesterday, May 22nd, sunspot AR2824 unleashed a sequence of solar flares unlike anything we've seen in years. In only 24 hours, NASA's Solar Dynamics Observatory recorded 10 C-flares and 2 M-flares:

movie

The rapid fire explosions hurled multiple overlapping CMEs into space. According to NOAA models, at least one of them will graze Earth's magnetic field on May 26th. The impact of the CME's dense flank could spark G1-class geomagnetic storms and auroras.

[Jherrith]

THE SODIUM TAIL OF MERCURY: The biggest comet in the Solar System is actually a planet. It's Mercury. Researchers have known for years that Mercury has an enormous tail. Last week, Andrea Alessandrini photographed it from the balcony of his house in Veroli, Italy:



"I took the picture on May 5th using a 66 mm (2.5 inch) refracting telescope and a Pentax K3-II camera," says Alessandrini, an amateur astronomer who works by day as an aerospace engineer. "This is a 7 minute exposure @ ISO 1000."

First predicted in the 1980s, Mercury's tail was discovered in 2001. Its source is Mercury's super-thin atmosphere. Mercury is so close to the sun, pressure from sunlight itself can push atoms out of the atmosphere and into space. The escaping gas forms a tail more than 24 million km long.

The key to detecting Mercury's tail is sodium. There are many elements in Mercury's tail; sodium is only one. But because sodium is so good at scattering yellow light, it is the best element for tracing the long plume of gas. "I use a special 589 nm filter tuned to the yellow glow of sodium," says Alessandrini. "Without that filter, Mercury's tail would be invisible."

NASA's MESSENGER spacecraft spent years observing Mercury's tail often from close range. This movie shows how the brightness of the tail varies as Mercury orbits the sun:



For reasons having to do with the Doppler shift of sodium absorption lines in the solar spectrum, Mercury's tail is brightest when the planet is ±16 days from perihelion (closest approach to the sun). Read the research here.

That special date is this week: On May 13th, Mercury will be 16 days past perihelion and the tail could be as much as 10 times brighter than Alessandrini saw last week. Coincidentally, on that same day the crescent Moon will pass by Mercury in the evening sky.

[Jherrith]

THE SUN SWALLOWS A COMET: Today, the sun swallowed a comet. SOHO coronagraphs spotted the dirty snowball making a headlong plunge into our star. One comet went in; none came out:



The comet was a member of the Kreutz family. Kreutz sungrazers are fragments from the breakup of a single giant comet many centuries ago. They get their name from 19th century German astronomer Heinrich Kreutz, who studied them. Every day, several Kreutz fragments pass by the sun and disintegrate. Most, measuring less than a few meters across, are too small to see, but occasionally a bigger fragment like this one (~10 to 30 meters wide) attracts attention.

The dusty remains of this comet have mostly disintegrated into individual atoms, and are now being blown back into the Solar System by the solar wind. R.I.P. sungrazer.

[Jherrith]

A CME IS APPROACHING EARTH: A coronal mass ejection (CME) is expected to hit Earth on May 12th or 13th, according to NOAA forecasters. It was hurled toward us yesterday by an erupting filament of magnetism on the sun. This is not an especially fast or powerful CME, but it could spark G1-class geomagnetic storms when it arrives later this week.

[thelufias]

That was pretty darn cool....thanks.  I haven't got to my E Mail yet so probably missed it.

[Jherrith]

STRONG SOLAR FLARE AND RADIO BURST: New sunspot AR2822 exploded on May 7th @ 1904 UT, producing an M3.9-class solar flare--one of the strongest flares of young Solar Cycle 25. NASA's Solar Dynamics Observatory recorded the explosion near the sun's northeastern limb:



A pulse of ultraviolet and X-radiation from the flare ionized the top of Earth's atmosphere. This, in turn, caused a shortwave radio blackout over the Americas. Areas and frequencies affected are shown in this map. Ham radio operators and mariners may have noticed strange propagation effects at frequencies below 20 MHz, with some transmissions below 10 MHz completely extinquished.

While the radio blackout was underway, the sun, ironically, produced a strong shortwave radio burst. Astronomer Thomas Ashcraft heard a roar of static emerge from the loudspeaker of his radio telescope in rural New Mexico. Click on the dynamic spectrum to listen:






"After a long quiet solar minimum, I am happy to have captured the M3.9 solar flare today," says Ashcraft. "It generated complex and dynamic Type II, Type V and Type III radio emissions." These natural emissions are caused by shock waves ripppling through the sun's atmosphere in the aftermath of the explosion.

The explosion also hurled a CME into space. Coronagraph images from the Solar and Heliospheric Observatory (SOHO) will reveal if there is an Earth-directed component. We're still waiting for those data to arrive, so stay tuned for updates.

[thelufias]

Geee.....who would think a Chinese Space Station would set a course to fly over the Americas LOL....

But that is pretty cool...

Just be sure to wear a helmet...

[Jherrith]

CHINA'S SPACE STATION IS VISIBLE FROM EARTH: China's new space station is just getting started, but it's already putting on a good show. "I've seen it twice this week," reports Mark A. Brown of Marion, Iowa. "The space station's Tianhe-1 module has been making brilliant passes across Middle America." Here it is rivaling the star Vega on May 4th:




"In the photo, I also caught the tumbling Long March 5B booster, which helped loft the module into orbit," says Brown. "The booster flares brilliantly (visual magnitude -1) in reflected sunlight as it tumbles along Tianhe-1's path. Both objects are easily seen with the naked eye."
China launched the Tianhe-1 module on April 29th. It is the first of three modules that will eventually join to create the Chinese Space Station (CSS), serving as living quarters for a three person crew. When the CSS is finished, it will be about as big as Russia's old Mir space station, roughly a quarter of the mass of the ISS.

On May 5th, Tianhe-1 flew over Manorville, New York, where Philip Smith photographed it through a 14-inch telescope:



"I was lucky to get this image," says Smith. "The module was already 56 degrees above the horizon when it popped out of Earth's shadow--so I didn't have much time. Less than a minute later it was at its maximum altitude of 76 degrees, and that's when I caught it."