THE SOLAR WIND CONTINUES TO BLOW: For the third day in a row, Earth is inside a stream of solar wind flowing from a canyon-like hole in the sun's atmosphere. So far the stream has under-performed; compared to predictions of possible G2-class magnetic storms, it has produced only lessor G1-class storms. However, that's good enough for beautiful auroras around the Arctic Circle. NOAA forecasters estimate a 45% chance of more G1-class storms on Oct. 26th. Free: Aurora Alerts.
AN UNUSUAL COMET DIVES TOWARD THE SUN: Deep inside the orbit of Mercury, unusual comet 96P/Machholz is diving toward the sun today. At closest approach on Oct. 27th, it will swoop through the sun's gravity well just 0.12 AU from the star. Coronagraphs onboard the orbiting Solar and Heliospheric Observatory (SOHO) are monitoring the flyby:
Comet 96P does this every 5.24 years. It is a short period comet that experiences frequent blasts of solar heat. During a similar flyby in 2002, SOHO observed two tiny fragments ahead of the main nucleus. This means the comet may be actively evolving, and it could shed more pieces during this week's dive.
This is no ordinary comet. Its orbit connects it with a bewildering menagerie of other things in the solar system: Comet 96P is linked to as many as three meteor showers (the Daytime Arietids, Southern Delta Aquarids, and Quadrantids), two families of sungrazing comets, and an asteroid (2003 EH1). Millennia ago, the whole ensemble was probably part of the same parent object that exploded or fell apart.
Does this comet even belong to our own solar system? A scientific study published in 2008 found that 96P/Machholz has "extremely anomalous molecular abundances." Chemically speaking, it's not like other comets that have been studied in the same way. Perhaps it comes from another star system, flung into space and later captured by our own sun's gravity.
96P/Machholz will remain visible in SOHO coronagraphs from now until Oct. 30th. Check back often for updated images.
Realtime Space Weather Photo Gallery
OPALITE CRYSTAL SPACE PENDANT: On Oct. 15, 2017, the students Earth to Sky Calculus launched a space weather balloon from the Sierra Nevada mountains of central California. Its mission: to measure cosmic rays at the top of Earth's atmosphere. The payload carried an array of X-ray/gamma-ray detectors, GPS trackers, temperature/pressure sensors and, for fundraising, opalite crystals:
With a soothing blue glow that matches the otherworldly color of Earth's upper atmosphere, these crystals ascended to an altitude of 32 km (105,000 feet) where the balloon exploded. The payload parachuted back to Earth, landing in the Eureka Valley on the outskirts of Death Valley National Park.
You can have one for $119.95. Each necklace comes with a unique gift card showing the pendant floating at the top of Earth's atmosphere. The interior of the card tells the story of the flight and confirms that this gift has been to the edge of space and back again.
Far Out Gifts: Earth to Sky Store
All proceeds support hands-on STEM education
FIRST CONTACT WITH THE SOLAR WIND: A stream of solar wind wrapped itself around Earth on Oct. 24th. First contact turned the Arctic night green. Alan Dyer witnessed the display from the sea surface outside Tromsø, Norway:
"The arrival of enhanced solar wind from a coronal hole gave us superb auroras," Dyer says. "I took the picture from the ferry ship Nordlys (well-named for chasing the Northern Lights) operated by the Hurtigruten ship line."
In Lofoten, Norway, citizen scientist Rob Stammes of the Polarlightcenter experienced first contact in a different way. Electricity began to flow through the ground and Stammes' magnetic sensors went haywire:
"Last evening the expected solar wind arrived as a kind of shockwave on my instruments just before local midnight." says Stammes. In his plot, the green curve shows ground currents induced by the sudden storminess of the local magnetic field. "From that moment of high activity, I waited with eagerness for darkness to fall so I could see the auroras."
WANTED: TALES OF SPOOKY SPACE WEATHER: Have you ever been spooked by something you saw in the night sky? Maybe it was a ghoulish form in the aurora borealis, or the haunting glow of a rocket fuel dump--or something you couldn't figure out at all! In the spirit of Halloween, Spaceweather.com is reaching out to you, our readers, to share a spooky story about the night sky. Fill out this short survey, and your tale could end up on the front page of our web site as Halloween approaches. (Note: Image and audio files are accepted by the survey form.