Space Weather

[thelufias]

One never knows nowadays.....the buck is the ruler of the world ..... was a time when people cared about people.....

[Jherrith]

WATCH OUT FOR THE HARVEST MOON:

Tonight's full Moon has a special name--the Harvest Moon. It's the full Moon closest to the northern autumnal equinox (Sept. 23rd). In years past, farmers depended on the light of the Harvest Moon to gather ripening crops late into the night. Post-Edison, we appreciate it mainly for its beauty.

[Jherrith]

SPECTACULAR DOUBLE RAINBOW: Sometimes running out in the rain is a good idea. On the evening of Sept. 12th, Göran Strand of Östersund, Sweden, did just that. Here is what he saw:




"It was the most beautiful double rainbow I've ever seen," says Strand. "I was home when I noticed that there was some very special light outside, so I quickly grabbed my camera and went out in the rain to capture this photo."

Many people don't know it, but all rainbows are double. The bright primary arc is caused by sunlight reflecting once inside raindrops. The tall second rainbow is caused by sunlight reflecting twice. That second rainbow is always there, but often it is too dim to see against the bright background sky. This time, however, it was visible to the naked eye.
"This was a sunset rainbow," adds Strand, "and that made it extra special." Rainbows always appear opposite the sun, so when the sun is low, the rainbow is high. "Because the rainbow was visible at sunset we got the highest possible rainbow, 46° above the horizon."

[Jherrith]

INTERSTELLAR COMET: 'Oumuamua is not alone. Another interstellar visitor appears to be passing through the solar system--and this time it's definitely a comet. Ukrainian amateur astronomer Gennady Borisov discovered the object, now named C/2019 Q4 (Borisov), approaching from beyond the orbit of Mars on Aug. 30th. Click to view a 3D visualization of Comet Borisov's orbit from NASA's Jet Propulsion Lab:

3D visual

Based on observations gathered since Borisov discovered the distant fuzzball, the comet seems to be following a hyperbolic orbit with an eccentricity greater than 3.5. This means the comet is unbound to the sun. Indeed, it is moving some 30.7 km/s (68,700 mph) too fast for the sun's gravity to hang onto it. Comet Borisov is a first time visitor to the inner solar system, and after this flyby it will return to deep space.

Comet Borisov will make its closest approach to the sun (2 AU) around Dec. 7th. Three weeks later, near the end of December, it will make its closest approach to Earth (also 2 AU). At the moment the comet is very dim, around magnitude +18. How bright it may become by December is anyone's guess.


Above: Dim and distant, Comet Borisov was photographed in the constellation Cancer on Sept. 12th by Graziano Ventre using an 11-inch telescope.

The first known interstellar object to visit our solar system, 'Oumuamua, caused a sensation when it was discovered racing away from the sun in late 2017. Speculation about its nature ranged from an alien spacecraft to a fossil exocomet. Astronomers still aren't sure what it was. Comet Borisov, on the other hand, appears to have a fuzzy atmosphere (a "coma") and perhaps a stubby tail--signs that it really is a comet.

Because Comet Borisov is still just entering the solar system, astronomers will have plenty of time to study it in the months ahead. Is it truly interstellar? What are comets from other solar systems made of? Answers to these and many other questions are forthcoming.

[sidherose]

SPECTACULAR DOUBLE RAINBOW: Sometimes running out in the rain is a good idea. On the evening of Sept. 12th, Göran Strand of Östersund, Sweden, did just that. Here is what he saw:




"It was the most beautiful double rainbow I've ever seen," says Strand. "I was home when I noticed that there was some very special light outside, so I quickly grabbed my camera and went out in the rain to capture this photo."

Many people don't know it, but all rainbows are double. The bright primary arc is caused by sunlight reflecting once inside raindrops. The tall second rainbow is caused by sunlight reflecting twice. That second rainbow is always there, but often it is too dim to see against the bright background sky. This time, however, it was visible to the naked eye.
"This was a sunset rainbow," adds Strand, "and that made it extra special." Rainbows always appear opposite the sun, so when the sun is low, the rainbow is high. "Because the rainbow was visible at sunset we got the highest possible rainbow, 46° above the horizon."

That is indeed a gorgeous rainbow. Saw a very nice double one here Sunday night but unfortunately I can't see the whole thing where I am. Thanks for the 'pretty'. 

[sidherose]

INTERSTELLAR COMET: 'Oumuamua is not alone. Another interstellar visitor appears to be passing through the solar system--and this time it's definitely a comet. Ukrainian amateur astronomer Gennady Borisov discovered the object, now named C/2019 Q4 (Borisov), approaching from beyond the orbit of Mars on Aug. 30th. Click to view a 3D visualization of Comet Borisov's orbit from NASA's Jet Propulsion Lab:

3D visual

Based on observations gathered since Borisov discovered the distant fuzzball, the comet seems to be following a hyperbolic orbit with an eccentricity greater than 3.5. This means the comet is unbound to the sun. Indeed, it is moving some 30.7 km/s (68,700 mph) too fast for the sun's gravity to hang onto it. Comet Borisov is a first time visitor to the inner solar system, and after this flyby it will return to deep space.

Comet Borisov will make its closest approach to the sun (2 AU) around Dec. 7th. Three weeks later, near the end of December, it will make its closest approach to Earth (also 2 AU). At the moment the comet is very dim, around magnitude +18. How bright it may become by December is anyone's guess.


Above: Dim and distant, Comet Borisov was photographed in the constellation Cancer on Sept. 12th by Graziano Ventre using an 11-inch telescope.

The first known interstellar object to visit our solar system, 'Oumuamua, caused a sensation when it was discovered racing away from the sun in late 2017. Speculation about its nature ranged from an alien spacecraft to a fossil exocomet. Astronomers still aren't sure what it was. Comet Borisov, on the other hand, appears to have a fuzzy atmosphere (a "coma") and perhaps a stubby tail--signs that it really is a comet.

Because Comet Borisov is still just entering the solar system, astronomers will have plenty of time to study it in the months ahead. Is it truly interstellar? What are comets from other solar systems made of? Answers to these and many other questions are forthcoming.

Don't you have to wonder now Why? Why suddenly are we getting interstellar visitors? Are we starting to merge with another galaxy? Just a thought.

[Agent0013]

Don't you have to wonder now Why? Why suddenly are we getting interstellar visitors? Are we starting to merge with another galaxy? Just a thought.

I think you may be correct in your speculation here. Supposedly, certain astronomers have determined that the Milky Way is currently devouring a smaller galaxy. We on Earth cannot see it because it is on the other side of the galactic center. Infrared and radio telescopes seem to have detected this ongoing collision, which has been occurring for several thousand years already. The smaller galaxy seems to have already been mostly absorbed by the Milky Way.


What astronomers used to believe to be a very rare astronomical event actually turned out to be the normal way things work in this Universe. Indeed we are headed for a collision with the Great Galaxy in Andromeda. A few tens of millions of years from now, the largest two galaxies in our local group will begin to merge. The view for whomever is alive at that time will be spectacular, to say the least. 

[sidherose]

I recall the Thunderbirds saying something about a small galaxy in Sagittarius. I wonder if that's the one. That *would* be behind Galactic Center.

[Agent0013]

I recall the Thunderbirds saying something about a small galaxy in Sagittarius. I wonder if that's the one. That *would* be behind Galactic Center.

That would be the right position, I would think.


Large galaxies like the Milky Way grow larger by eating the smaller ones. From what I gathered, the galaxy being absorbed into our galaxy is a dwarf galaxy no larger than the Small Magellanic Cloud.

[sidherose]

This comet is apparently coming from somewhere between Cassiopeia and Perseus.