SOLAR MINIMUM CONDITIONS ARE IN EFFECT: The sun is blank again today--the 191st day of 2018 that the sun has been without spots. To find a similar stretch of blank suns, you have to go back to 2009 when the sun was experiencing the deepest solar minimum in a century. Solar minimum has returned, bringing extra cosmic rays, long-lasting holes in the sun's atmosphere, and strangely pink auroras. Free: Aurora Alerts
A RAINBOW AT NIGHT: We've all seen rainbows--bands of color arcing across the sky after summer rainstorms. But how many of us have seen a rainbow at night? "I have," says Chad Blakley of Lights Over Lapland. "We saw one just last night in Abisko, Sweden."
Blakley has been running an aurora tour guide service in Abisko National Park for 10 years, and he has seen almost everything the Arctic sky has to offer.
"But last night was truly amazing," he says. "The evening started in the usual way – the Sun went down and Northern Lights began to dance across the sky in reaction to a stream of solar wind. We were all enjoying the scene when suddenly a bit of rain started to fall in the distance. Normally this would be a disappointment, but not this time. Moisture in the air combined perfectly with bright Moonlight to form a lunar rainbow that shared the sky with an impressive aurora display."
Lunar rainbows--a.k.a. "moonbows"--form in the same way as regular rainbows. Beams of light bounce in and out of falling raindrops, splitting the light into fundamental colors. The only difference is, at night the Moon provides illumination instead of the sun. Says Blakley, "as you might imagine, this was a magical thing to watch!"
A COMET WITH TWO TAILS: Newly-discovered Comet Machholz-Fujikawa-Iwamoto (C/2018 V1) has sprouted a tail. Actually, two tails. Michael Jaeger of Jauerling, Austria, photographed them both on Nov. 18th as the comet was gliding through the star fields of Virgo:
Why does Comet Machholz-Fujikawa-Iwamoto have two tails? Almost all comets do. The sun-warmed nucleus of a comet spews a mixture of dust and gas into space. Quickly, the mixture separates into two distinct tails: The gaseous "ion tail" is pushed straight away from the sun by solar wind. The weightier dust tail resists solar wind pressure and aligns itself more or less with the comet's orbit. In Jaeger's short video, the long ion tail points up and left; the stubby dust tail points up and right.
Comet Machholz-Fujikawa-Iwamoto appears to be a first-time visitor to the inner solar system. It is plunging toward the sun on nearly-parabolic orbit that will take it just inside the orbit of Mercury. Closest approach to the sun (0.38 AU) is on Dec. 3-4; closest approach to Earth (0.67 AU) is Nov. 27th. Amateur astronomers can find it--and its two tails--shining like a star of 8th magnitude in the constellation Virgo in the pre-dawn sky.
Resources: 3D Orbit; Ephemeris; Orbital Elements;
A GIFT FROM THE EDGE OF SPACE: Don't just see the Northern Lights, wear them! To support their cosmic ray balloon program, the students of Earth to Sky Calculus have flown a payload of Northern Light Pendants to the edge of space. This one reached an altitude 109,908 feet above Earth's surface:
You can have it for $79.95. The students are selling these pendants to pay their helium bill. Each one comes with a greeting card showing the item in flight and telling the story of its journey to the edge of space. All sales support the Earth to Sky Calculus cosmic ray ballooning program and hands-on STEM research.
Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education