Aurora through moderate cloud cover tonight in Duluth, Minn. around 11 p.m. Photo: Bob King
Woo-hoo! The aurora’s nearly out-competing the clouds tonight. The Kp index, a good indicator of auroral activity, shot up to “6″ or moderate storm level this evening around 9-10 p.m. As of 11 o’clock (CST) the northern sky was thick with a bright, green haze and large, soft rays extending nearly to the zenith. If it’s clear by you, take a look outside and don’t forget to bring a camera.
The auroral oval – the area where auroras are visible – has expanded well into the northern U.S. tonight Nov. 13-14. The map is based on satellite measurements made at 11:03 p.m. CST. Credit: NOAA
The satellite plot shows the northern lights dipping down across the full northern tier of states and fairly deep into Minnesota, Wisconsin and Michigan.
Interestingly, the NOAA space weather forecast has been predicting only “quiet” conditions the past few days. Apparently our planet’s stuck in the tail end of a high-speed stream of solar particles from a coronal mass ejection.
My photo only hints at what someone with clear skies would see. To see what it really looked liked, check out the photo below. Closer to home, Sarah D’Angelo had clear skies in the Upper Peninsula of Michigan and took these pictures from Whitefish Point last night.
A spectacular display of lights crowns the city of Tromso, Norway last night. Even the city’s light pollution couldn’t dim the aurora’s glory. Credit and copyright: Ole Salomonsen
UPDATE 11/14: The aurora raged all night, but the storm now appears to be subsiding. If by chance Earth’s magnetosphere works itself into a lather again tonight, I’ll update with fresh information. Meanwhile, check out more pictures of both the aurora and yesterday’s total eclipse HERE.
During a total solar eclipse, the moon gets exactly between the Earth and sun and casts a narrow, dark shadow called the umbra across a 95-mile-wide swath of Earth. Anyone living in the path of the umbra – moon’s shadow – will see a total eclipse. Credit: Windows to the Universe
Heads up. This afternoon U.S. time, residents of northern Australia and countless tourists on land and sea will witness a total eclipse of the sun. You will too if you check out one of the live streaming sites listed below. Since most of the streams originate in or near Cairns, Queensland, here are the times (in Central Standard) to watch. The sun will only be a degree above the horizon at eclipse start and just 14 degrees (a fist and a half) high during totality:
* Start of partial eclipse – 1:45 p.m. CST today
* Start of total eclipse – 2:38 p.m.
* End of total eclipse – 2:40 p.m.
* End of partial eclipse – 3:40 p.m.
The 95-mile-wide path of totality stretches from tip of Australia’s Northern Territory through Queensland and then across the Pacific Ocean. Unfortunately the forecast for the best land-viewing sites calls for mostly cloudy skies with only occasional breaks. For more on the viewing the eclipse, check out Joe Cali’s Waiting for the Shadow or NASA’s Total Solar Eclipse of 2012 Nov 13 sites.
There are currently 7 potentially inhabitable planets known. HD 40307 is the latest to make the list. Its average temperature could possible be as high as 48 degrees F. with large seasonal shifts as it orbits its host star. Credit: PHL@ UPR Areceibo (phl.upr.edu)
A newly discovered planet with 7 times the mass of Earth orbits in the habitable or “Goldilocks” zone around a 7th magnitude star HD 40307 in the southern constellation Pictor the Easel. Habitable doesn’t necessarily imply life could take spring forth on this weightier version of Earth, but it does mean the planet orbits at just the right distance for liquid water to be stable on its surface. Goldilocks refers to conditions being neither too hot nor too cold but “just right”.
HD 40307 is an orange-colored star a little smaller, less massive and cooler than the sun located 42 light years from Earth. Unremarkable perhaps except for one little detail: this sun is orbited by six planets. Five of them are close in and hotter than Hades, but the sixth orbits at about the same distance Earth does from the sun. While you’d weigh considerably more there due its greater mass, floating in an ocean to relieve the inevitable back pain is theoretically possible.
Video with further description of the HD 40307 solar system
HD 40307 is one of three new super-Earths (rocky extrasolar planets at least several times more massive than Earth) discovered around the star but the only potentially hospitable one. An international team, including Carnegie Institution for Science co-author Paul Butler, was led by Mikko Tuomi of the University of Hertfordshire and Guillem Anglada-Escudé of the University of Göttingen. The researchers re-analyzed the spectra or fingerprints of the star’s light made with the European Southern Observatory’s HARPS spectrograph using new software. Hidden in the data were signatures of the three additional planets.
HD 40307g belongs to a small but growing list of Earth-like planets orbiting a comfortable distance from their host stars. Most of the confirmed 849 extrasolar planets currently known are nicknamed “hot Jupiters” for good reason. They’re massive and orbit close to their suns, exerting measurable gravitational wobbles in their host stars that our equipment can detect. Smaller worlds orbiting at more habitable distances tug but a little and are much more difficult to identify.
Gamma Cephei is an easy naked eye star in the constellation Cepheus the King, now high in the northern sky. Created with Stellarium
In 1988 Canadian astronomers Bruce Campbell, G. A. H. Walker, and Stephenson Yang reported gravitational wobbles of the star Gamma in the constellation Cepheus and cautiously attributed it to a planet. Their observations weren’t confirmed until 2003, making Gamma Cephei Ab the first extrasolar planet discovered. The first definitive discovery of a pair of planets found orbiting a dense, rapidly-spinning star called a pulsar on April 21, 1992.
We’ve come far quickly. I suspect we’ll find a planet with signatures of life’s best indicators – water, methane and oxygen – in our lifetimes. Will it be HD 40307g?
Example of a NASA space station alert. The diagram below explains the information provided. Credit: NASA
I’ve always joked with my community ed astronomy class students that one day I’d be replaced by a mobile phone app. The writing’s on the wall.
NASA recently introduced a new free service called Spot the Station that will alert you by e-mail or text message several hours before the International Space Station (ISS) is predicted to make a pass over your town.
With the information from the alert you can picture how and where the space station will appear in the sky. This diagram is based on the example alert. Credit: NASA
Just go to the website and sign up. Mission Control at NASA’s Johnson Space Center in Houston, TX, makes predictions for 4,600 locations worldwide. Don’t worry if your specific location isn’t on the list. Since the space station is visible from a large area, pick the closest town and your time will easily be within a few minutes of the correct one.
One other small caveat. NASA will only alert the “good” passes when the station reaches an altitude of 40 degrees or more. No problem there. Those are the ones most of us want to see anyway.
The ISS, big as a pro football field, is an orbiting laboratory currently occupied by six astronauts. Three of the crew is set to undock and return to Earth in a Russian Soyuz spacecraft on Nov. 18, 2012. Credit: NASA
In the diagram above, based on the alert, the station first becomes easily visible 10 degrees above the west-southwest horizon at 7:45 p.m. 10 degrees is equal to one fist held vertically with the bottom touching the horizon. Maximum altitude of 66 degrees is reached a couple minutes later. Since the horizon is 0 degrees and the top of the sky is 90 degrees, 66 degrees is two-thirds of the way up from the horizon or about 6.5 fists high. Finally, the ISS remains in view for 4 minutes before disappearing in the northeastern sky.
It’s pretty slick. I even signed up to check it out. For old time’s sake, I’ll still update the blog with pass times for the Duluth, Minn. region along with interesting particulars like when the ISS disappears into Earth’s shadow or glides by a bright planet or star. Don’t forget, you can also get pass times at Spaceweather’s Satellite Flybys site by keying in your zip code and great maps and times at Heavens Above.
For the Duluth, Minn. region the International Space Station (ISS) will pass directly in front of Venus tomorrow morning Nov. 12 at about 5:49 a.m. Credit: Heavens Above
A new round of passes begins tomorrow morning for North America. When you go out to watch, look for a brilliant, pale yellow star moving about as fast as a high-flying plane from west to east. The station typically takes about 5 minutes to travel from one end of the sky to the other.
TIMES FOR THE DULUTH REGION:
* Mon. Nov. 12 beginning at 5:46 a.m. low in south-southeast. Passes right over Venus about 5:49 a.m. Be sure to watch for the thin crescent moon and Saturn low in the southeast below Venus around 6 a.m. local time. More info HERE.
* Tues. Nov. 13 at 6:32 a.m. High, brilliant pass in the south during morning twilight
* Weds. Nov. 14 at 5:43 a.m. across the south-southeast
* Thurs. Nov. 15 at 4:55 a.m. in the southeastern sky above Venus. Second pass high in the northern sky at 6:29 a.m.
* Fri. Nov. 16 at 5:41 a.m. Brilliant pass across the top of the sky. Best of the week!
* Sat. Nov. 17 at 4:54 a.m. Brief appearance in the eastern sky. Second flyby at 6:27 a.m. across the northern sky
* Sun. Nov. 18 at 5:40 a.m. across the northern sky
Photo taken by the Mars Reconnaissance Orbiter on the first day of spring in Mars’ southern hemisphere. Dark material is deposited on top of the ice carried there by escaping gas flowing through the spidery channels carved in the surface. Credit: NASA/JPL/University of Arizona
No birds twitter during Martian spring, but ice disappears and the landscape comes alive with spiders. Mars has seasons because its axis it tilted much like Earth’s. During the 6-month-long Martian winter, a significant fraction of its carbon dioxide atmosphere condenses out as ice at the poles. When spring arrives, sunlight vaporizes the ice, turning it directly from solid to gas.
In the photo above, taken on the first day of spring (Sept. 30, 2012 by Earth’s calendar) in Mars’ south polar region, the landscape is covered in ice, but even the slanted rays of the returning sun are enough to tip the scales.
Oct. 21, 2012 image of the south pole of Mars where sunlight is now defrosting CO2 ice. Alternating layers of dust and ice are exposed along the edge of the polar cap. Credit: NASA/JPL/ASU
Solar-liberated carbon dioxide gas coming from the bottom surface of the ice builds up pressure and carves channels into the ground on its way up and out into the atmosphere. Dark soils go along for the gassy ride and are deposited on the surface as spidery forms. Spring has sprung!
Martian seasons are about twice as long as our own because the planet’s year – the time it takes to go around the sun – is 687 Earth days. Seasons on our planet are of similar length because Earth’s orbit is nearly circular, so it moves at a near constant speed around the Sun. For the record, when closest to the sun in northern winter, Earth travels a little faster than when farthest in July. The difference is small enough so that season length varies from 89 days in winter to 93 days in summer.
Orbits of Mars and Earth seen from above our north pole. Season length varies from 199 Earth days when Mars is farthest from the sun (aphelion) to 147 days when closest (perihelion). Distance varies by 26.5 million miles. Credit: Wikipedia
Mars orbit is much more eccentric or oval-shaped than Earth’s with the distance between closest and farthest points varying by 26.5 million miles. This huge difference in distance and orbital speed throws its seasons out of balance.
Aphelion or furthest distance from the sun coincides with the northern hemisphere summer solstice. Summers there are longer and more temperate. When winter comes round, the planet is at perihelion or closest to the sun, making northern winters shorter and less intense.
In contrast, southern summer coincides with Mars’ closest approach to the sun. Compared to the northern hemisphere, southern summers are scorching and brief and followed by long and bitter winters at aphelion. The relatively intense heat during the southern summer is one of the reasons why dust storms are more frequent there than in the north.
Mars’ extremes of climate make Earth appear all that more clement especially when November winds tear at my shingles and rattle the house like they are today.
This map shows the sky facing southeast about an hour before sunrise. The lunar crescent stops near Venus Sunday morning the 11th and newly-emerging Saturn on Monday. Maps created with Stellarium
The moon’s on a tight schedule. So many places, so little time. It glides past Venus Sunday morning and a day later appears along a new morning planet, Saturn. Then on Tuesday – Weds. the new moon passes squarely in front of the sun for residents of northern Australia and several small islands in the Pacific for a solar eclipse appointment.
Venus and the moon at 9 a.m. local time with the sun well up in the southeastern sky.
Viewing the lunar crescent and Venus will be easy since both are bright and conveniently placed for viewing in morning twilight. For fun, see how long you can keep Venus in view after sunrise using the moon as a guide. If your sky is haze-free, I’m going to bet you’ll see it easily many minutes or even hours later. Let us know how you do.
The Saturn-moon conjunction Monday morning will be trickier, but worth the effort. Not only will you see the return of the ringed planet to the dawn sky but also a super-thin crescent. You’ll need a wide-open horizon to the east-southeast, since the pair will only be about 5 degrees high (about three fingers held together at arm’s length) an hour before sunrise. Bring binoculars as a back-up.
Anyone within the blue band will see a total solar eclipse Tuesday. Red marks the centerline of the eclipse. Cairns will get 2 minutes of totality. Maximum of 4 minutes happens over the South Pacific. Credit: NASA
On Nov. 14 about 6:30 a.m. Australian Eastern Standard time (4:30 p.m. CST Nov. 13) the moon will totally eclipse the sun during the early morning hours for lucky sky watchers in northern Australia.
The moon’s shadow first touches ground at sunrise in the wilds of the Northern Territory and tracks east at over a 1000 mph reaching the city of Cairns in Queensland with a population of about 150,000 at 6:39 a.m. local time.
Total solar eclipse south of Japan on July 22, 2009. The photographer caught the “diamond ring effect”, when the last bit of sunlight shines between mountains along the limb of the moon just before totality. Credit: AP Photo/Kyodo News, Akiko Matsushita
From there, totality races across the Coral Sea and South Pacific before wrapping up at sunset west of the Chilean coast. A much larger region including all of Australia, New Zealand, Papua New Guinea and southern South America will see varying degrees of partial eclipse.
From the northern hemisphere’s perspective, the moon misses the sun, passing to its south. Sorry, no eclipse. We’ll have to wait until August 21, 2017 for the next total solar eclipse. Click HERE for more details and times to watch Wednesday’s event down under.
Can’t afford a trip to Australia at the moment? Watch it instead via webcam. Here are some cams to check out when the time is nigh:
This composite image of asteroid 2007 PA8 was obtained using data taken by NASA’s 230-foot-wide (70-meter) Deep Space Network antenna at Goldstone, Calif. on Oct. 28, 29 and 30, 2012. Credit: NASA/JPL-Caltech/Gemini
Most asteroids look like stars in nearly every telescope because they’re too small and too far away to register as anything more than dots. Radio waves work better. Given a close pass, NASA’s 230-foot-wide Deep Space Network radio telescope at Goldstone, Calif. can synthesize an image of an Earth-approaching asteroid by bouncing radio waves off it and recording the “echo” of the returning waves. The pictures it provides are surprisingly detailed given how small most of these objects are.
The mile-wide 2007 PA8 flew only 5.6 million miles from Earth on Oct. 30 and got its portrait taken on Oct. 28, 29 and 30. Pictures show a rough-looking, elongated “boulder” with ridges and possible craters. JPL scientists chose to image asteroid due to a favorable combination of size and relative proximity to Earth at the point of closest approach.
The date also indicate that 2007 PA8 is rotating rather slowly, spinning just once approximately every 3-4 days. Good thing NASA made the most of this opportunity – this flyby was the closest Earth approach by this asteroid for at least the next 200 years.
Earth-approaching asteroid discoveries are fairly common nowadays thanks to the many surveys underway at observatories around the world. In the next week alone, four recently-discovered tiny asteroids – 2012 VB5, 2012 UV136, 2012 VQ6 and 2012 UY68 - ranging in size from 56 to 144 feet will zip by Earth between 432,000 and 1.6 million miles away. None poses any danger to the planet.
Located 61 million light years away in the faint constellation Fornax the Furnace, 9.6 magnitude NGC 1365 is 200,000 light years across and one of the largest spiral galaxies known. Credit: ESO/IDA/Danish 1.5 m/ R. Gendler, J-E. Ovaldsen, C. Thöne, and C. Feron
Like watching stars blow up? A recently discovered supernova in the southern galaxy NGC 1365 is now bright enough for amateur astronomers to spot in small to medium-sized telescopes. The galaxy, nicknamed the Great Barred Spiral Galaxy, is one of the most beautiful in the sky with sharply-etched spiral arms winding about its bar-like center. Droves of youthful stars populate the blue-tinted arms, while older stars illuminate the bar a warm yellow.
SN2012 fr is almost due north of the core of NGC 1365. Exact position is 52″ north, 2″ west. The “new star” is a Type Ia supernova, the violent explosion of a white dwarf star. This photo was taken on Nov. 4, 2012. Credit: Joseph Brimacombe
I only wish this gorgeous galaxy were higher in the sky from the northern U.S. As it is, it never climbs more than 7 degrees (less than one fist held at arm’s length) high in the southern sky. Skywatchers across the central and southern part of the country will find it both higher and easier to see.
The new supernova, dubbed SN2012 fr, was discovered by the automated La Silla TAROT telescope in Chile on Oct. 27, 2012 at 15th magnitude (dim!). It’s since rocketed to about 12th magnitude which puts into the range of a 6-inch telescope, especially for southern observers. It’s still brightening at this time so may become an easier target yet.
Type Ia supernovas occur in close binary stars where one member is a white dwarf. The dwarf’s gravity pulls material from the companion until the dwarf hits a weight limit of 1.38 times the mass of the sun. When that moment occurs, its core burns destructively.
SN2012 fr is the end of the line for a planet-sized but superdense white dwarf star that put on too much weight from munching on a nearby companion star. The material collected on the dwarf’s surface, increasing the pressure on the star’s core and initiating runaway burning. Like an uncontrolled wildfire, the energy released as carbon and oxygen in the core were set aflame blew the star to bits. Astronomers call a white dwarf detonation a Type Ia supernova.
This map shows the sky facing south around midnight local time in mid-November in the northern U.S. Orion is high in the southeast. To his right is the long, gangly constellation Eridanus the River. Follow the river down to the stars g and h Eridani. The supernova and galaxy lie 2 degrees due west of these stars in neighboring Fornax. Maps created with Stellarium
For more information and pictures of supernova 2012fr please check out Dave Bishop’s Latest Supernovae site.
Use this closeup chart of NGC 1365 and neighborhood to track down the galaxy in your telescope.
The two maps show the sky facing east on Nov. 3, when daylight saving time was still in effect, and tonight. Losing an hour makes the stars appear to move an hour westward, raising Orion up in the east at the same time on the clock. Created with Stellarium
Since dropping Daylight Saving Time last weekend you’ve probably noticed how swiftly evening darkness descends. The photojournalist part of me craves daylight, especially if I need to shoot a feature photo for my newspaper’s local news section. It’s not easy to find or photograph people out and about during twilight.
But there are compensations. One of them is the swift kick the stars get once DST is done. You may have noticed last week around 9:30 p.m. local time that Jupiter and his constellation buddies Taurus and Orion grazed the treetops low in the eastern sky.
With our return to standard time, the stars of the eastern sky are up an hour earlier, while those in the west set an hour earlier. If you’re a fan of Orion and Jupiter – and who isn’t? – you don’t have to stay up so late to see them. Meanwhile, you’d better get out early if you want to catch the late summer-early fall stars. They’re all in the western sky and getting the boot an hour sooner.
The secret to this remarkable sleight of hand is simple – 9:30 p.m. daylight time is the same as 8:30 standard time. For our clocks to read 9:30 standard time we have to wait an additional hour, during which time Orion sneaks up from below the horizon and Jupiter vaults higher in the east.
Many of the meteors in this composite photo belong to the Taurid meteor shower, which remains active through the weekend. The bright object at lower right is the moon. Credit: John Chumack
Having Taurus the Bull nosing up earlier is a good thing because the Taurid meteor shower’s putting on a decent show. I wish I could chime in with my own observations, but the sky’s been overcast here. Not so for astrophotographer John Chumack of Dayton, Ohio. He grabbed some great video stills yesterday morning at the start of the shower’s peak activity.
“The meteors were nice and slow … burning up and often leaving small afterglows (trails),” writes Chumack. “Not bad for a minor shower.” The Taurids will continue to fling meteors our way through the weekend. Click HERE for more information on how to view them.
Dr. Moody James shows where Ann Hodges was struck in the hip by an 8.5 lb meteorite that crashed through her roof (right). The photos appeared in the Dec. 13, 1954 issue of Life magazine.
It’s been 58 years since the last witnessed meteorite fell from Alabama skies. That one made a big impression. It was the first confirmed extraterrestrial object to injure a human being. On November 30, 1954 at 2:46 p.m. an 8.5 lb rock crashed through the roof of a home not far from the town of Sylacauga (sil-la-CAW-ga).
The grapefruit-sized Sylacauga meteorite that struck Hodges
It hit a radio console, bounced off the floor and struck the hand and hip of 31-year-old Ann Hodges who was asleep on the couch at the time. She awoke in surprise and pain thinking that a space heater had blown up, but when she noticed the hole in the roof and rock on the floor, Hodges figured the neighborhood kids had been up to no good.
Fortunately her injuries weren’t serious. Ann became a sudden celebrity; her photo even appeared on the cover of Life magazine with a story titled “A Big Bruiser From The Sky”. In 1956 she donated the meteorite to the Alabama Museum of Natural History in Tuscaloosa, where you can still see it to this day. A second meteorite from the fall weighing 3.7 lbs. was picked up the following day by Julius K. McKinney in the middle of a dirt road. McKinney sold his fragment to the Smithsonian and used the money to purchase a small farm and a used car. These days a single gram – if you can find any – costs about ten grand.
Ann and her husband Hewlett Hodges with the roof hole (left). At the time, the Hodges lived across the way from the Comet Drive-In movie theater. Cosmic coincidence.
For more on the fall including how the meteorite turned out to be anything but good luck for Hodges, click HERE and HERE.
Fast forward to October 30, 2012. That evening at 5:30 p.m. (CDT) a boulder-sized meteor broke into pieces as it came booming over northern Alabama between Birmingham and Huntsville. The sonic boom created by the faster-than-sound meteorite even registered on several area seismographs. Doppler weather radar sweeps picked up a rain of cosmic fragments and meteorite hunters were soon on the ground including a six-member NASA team.
Front and back side of the first meteorite found from the Alabama fall found by the search team of Stephen Beck, Tommy Brown, Jerry Hinkle, and Robert Woolard. It’s provisionally named Addison. The stone is covered in black fusion crust, features a metal vein (upper right) and weighs about 60 grams or 2 ounces. Credit: Tommy Brown
Meanwhile another pair of hunters, Robert Woolard and his pal Jerry Hinkle of Little Rock, Ark., had just subscribed to Galactic Analytics, a service run by Marc Fries that retrieves and examines Doppler radar weather data to create maps of potential meteorite falls. With maps in hand, Hinkle jetted off to Alabama to meet up with Woolard’s other friends, Tommy Brown and Stephen Beck, and by the end of the day Saturday (Nov. 3), they’d found the first meteorite!
Weather radar data (in blue) indicates the trail of the meteorite that fell in northern California near Sutter’s Mill on April 22, 2012. Credit: Google Earth / Marc Fries
This is incredible for at least two reasons. First, it took only 4 days from fall to find, proving yet again that radar is quickly becoming the tool of choice for locating fresh-falling meteorites.
Doppler’s better than eyewitness accounts because meteors stop flaring around 30 miles up yet continue moving along their flight path. Called “dark flight”, this portion of a meteorite’s journey may be invisible to the eye but detectable by reflected radio waves. The closer we’re able to track potential meteorites before they strike the ground, the better our chances of finding them.
Meteorites are named after the closest city or landmark to where they’re found. Provisionally named “Addison”, this is the 11th witnessed meteorite fall of the year, the most seen in one year since the new century began. So if it seems I’ve been writing a lot about meteorite falls lately, there’s a good reason for it. We’re on a hot streak!
Doris Day sings Stars Fell on Alabama
Maybe you’re familiar with the 1930s tune Stars Fell on Alabama. It was inspired by yet another meteoric event – the spectacular 1833 Leonid meteor storm, when thousands of meteors an hour rained from the sky. Enjoy.
Both the asteroid Vesta (left) and dwarf planet / asteroid Ceres are easily visible in binoculars this month and next as they travel through the early winter constellations Taurus and Gemini. Ceres is 590 miles in diameter; Vesta 326 miles. Credit: NASA, ESA
Would you like to pretend you’re riding piggyback on NASA’s Dawn mission hopping from the asteroid Vesta to its next target Ceres? All you need is a pair of 7×35 binoculars, a reasonably dark sky and a bit of imagination. November may not be the most pleasant month for skywatching in the northern hemisphere, but Ceres and Vesta, two of the brightest, biggest asteroids, are making their closest approach to the Earth in 2012 at nearly the same time. Surely this fortunate coincidence will inspire you to bundle up and brave the chill.
Vesta comes to opposition (closest to Earth) on December 9 when it will shine just below the naked eye limit at magnitude 6.4; Ceres reaches opposition only nine days later at magnitude 6.7. While the two almost-planets will be brightest then, they’re already nearly as bright and an easy catch now that the moon has retired from the evening sky.
Ceres is close to Eta Geminorum the next few nights. Later it passes under the open cluster M35. Positions are shown for 11 p.m. (CST) every five days. Stars are plotted to magnitude 9. North is up and west to the right. Maps created with Chris Marriott’s SkyMap software
Ceres is especially easy to spot over the next few nights since it keeps close company with the naked eye star Eta Geminorum in the toes of Gemini the Twins. Watch for it to buzz just south of M35 – one of the prettiest star clusters in the sky for both telescopes and binoculars – around Thanksgiving time. Consider their juxtaposition another reason to be thankful.
Ceres begins November at magnitude 8.0 but brightens to 7.3 by month’s end. Vesta meanwhile sidles up the south side of Taurus the Bull, home to the V-shaped Hyades star cluster and brilliant Jupiter. At magnitude 7.2 this week, you’ll find it a tad brighter and easier to see than Ceres. On the map, notice that Vesta glides through the northern edge of the bright, loose star cluster Collinder 65. Another bonus.
Vesta spends the next week crossing through the edge of the open cluster Collinder 65 as it works it way in Jupiter’s direction in the constellation Taurus. Stars plotted to magnitude 8. West is up and north to the left.
Both asteroids are presently traveling west – opposite their normal orbital motion – in what astronomers call a retrograde loop. The outer planets perform the same crazy backwards move around the time of their oppositions, too. Ceres and Vesta aren’t defying orbital mechanics. They only appear to move backwards because the faster Earth is passing them by, much like a car in the right lane appears to move backward as you pass it on the left. Soon enough, they’ll resume their routine eastern motion through the constellations as the viewing geometries of Earth and asteroids change.
A wide view of the sky facing east around 11 p.m. (CST) will help you get oriented when you look for the asteroids. The boxes show the general area covered in the more detailed charts above. Created with Stellarium
Dawn spent about a year in orbit around Vesta and finally departed late this summer with its sights set on a February 2015 encounter with Ceres. We learned lots at Vesta including that it differentiated into core and crust much like planets do. Rocks in its crust studied from orbit are a match for a suite of meteorites found on Earth called eucrites, diogenites and Howardites. No need for a sample return mission – pieces of Vesta have been falling from the sky for centuries.
Ceres is the largest asteroid – a dwarf planet actually – and another place altogether. By examining sunlight reflected from its surface, Ceres appears more carbon and water-rich than Vesta and a closer match to carbonaceous chondrite meteorites.
You can share in these discoveries and the road ahead by stepping outside the next clear night with binoculars and chart in hand. There’s nothing like seeing the real thing.
Let me know how you like the maps. I reversed the stars, going with black-on-white for greater clarity. Hopefully, they’re easier to read. To use a map, right-click and save to your desktop and then print out a copy. I’ll update them later this month, so you can continue to “mission along”.