GEOMAGNETIC STORM WATCH (UPGRADED): A solar wind stream is approaching Earth, and it could spark a G2-class (previously G1) geomagnetic storm when it arrives on Oct. 1st. The gaseous material is flowing from a double equatorial hole in the sun's atmosphere. High-latitude sky watchers should be alert for auroras on those dates. Aurora alerts: SMS Text
JUNO IS ABOUT TO BUZZ EUROPA: NASA's Juno spacecraft is about to make the closest flyby of Jupiter's moon Europa in more than 20 years. On Thursday, Sept. 29th, at 5:36 a.m. EDT, Juno will come within 222 miles of Europa's icy surface, taking pictures with a resolution of only 0.6 miles per pixel. Juno won't be able to see fish in Europa's oceans, but it could help NASA decide where future missions should look.
Above: An example of chaos terrain on Europa, photographed by NASA's Galileo spacecraft in the late 1990s.
Europa is one of the most interesting places in the solar system. Since Voyager 2 flew past the moon in 1979, evidence has mounted that Europa's icy surface overlies an enormous saltwater ocean--twice the volume of Earth's oceans combined. In 1989, NASA dispatched the Galileo spacecraft to investigate. Galileo buzzed Europa repeatedly, seeing "chaos terrain" where rafts of ice had seemingly broken free and re-frozen. Researchers suspected that water from beneath the surface must be breaking through from time to time. Indeed, in 2012 the Hubble Space Telescope found evidence (later confirmed by Keck) that Europa may be venting plumes of water vapor into space. Such plumes could lead back to a habitat for life.
During tomorrow's flyby "Juno will image an area of chaos terrain called 'Annwn Regio,'" says Candice Hansen, lead scientist for JunoCam at the Planetary Science Institute. "We will be on the lookout for anything different [since Galileo visited in the 90s] because such a find would be very exciting!"
Juno's instruments can sense plumes of water vapor if the spacecraft is lucky enough to fly through one. "We would have to be at the right place at just the right time, but if we are so fortunate, it’s a home run for sure," says Scott Bolton, Juno's Principal Investigator at the Southwest Research Institute.
Depending on the availability of the Deep Space Network, first images from the flyby could be available before the weekend. Stay tuned!
Raw Images from JunoCam
See the flyby photos as they arrive!
ASTEROID DIMORPHOS NOW HAS A TAIL: Two days ago, NASA's DART spacecraft slammed into asteroid Dimorphos at 14,000 mph. The dramatic impact expelled a cloud of dust and turned the asteroid into a type of comet. "Dimorphos now has a tail," reports Ernesto Guido who photographed the structure during the early hours of Sept. 28th:
"This shows the asteroid about 29 hours after impact," says Guido, who used a remotely-controlled 0.61-m telescope in El Sauce, Chile. "It developed a beautiful narrow tail 80 arcseconds long."
NASA was surprised by the easy visibility of DART's impact from Earth. The tail gives observers one more thing to monitor as astronomers look for changes to the asteroid's orbit. Even a slight shift would prove that human tech can alter an asteroid's trajectory--a possible strategy for future Planetary Defense. Stay tuned!
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RARE MR. SPOCK ORNAMENT: It's the logical way to decorate your Christmas tree--with a rare Mr. Spock ornament. This one has been to the edge of space. On Sept. 22, 2022, the students of Earth to Sky Calculus launched Spock to the stratosphere on board a cosmic ray research balloon:
You can have it for $129.95. The students are selling Spock ornaments to pay the helium bill for their cosmic ray ballooning program. Made by Hallmark in the 1990s, the ornament comes with a greeting card showing the science officer in flight and telling the story of its trip to the stratosphere and back again.
Far Out Gifts: Earth to Sky Store
All sales support hands-on STEM education
AURORAS OVERHEAD: "Fortune favors the prepared mind." Or in this case, the prepared camera. Aurora tour guide Marianne Bergli had her camera pointed at the sky over Tromsø, Norway, on Sept. 27th when a completely unexpected G2-class geomagnetic storm erupted:
"Wow, what a night!" she says. "It was an absolutely amazing view."
Bergli captured a special type of aurora called a "corona." Auroras are caused by energetic particles raining down on Earth's atmosphere. Coronas appear when the rain falls from straight overhead. They are considered to be the most beautiful auroral form.
This geomagnetic storm caught forecasters by surprise The CME that caused it was supposed to miss Earth and, indeed, it almost did. Most of the storm cloud sailed wide of our planet, but its flank shoved a dense mass of solar wind plasma onto Earth's magnetic field. The sudden load triggered the storm. Aurora alerts: SMS Text
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