Take a break from doomsday to enjoy the Geminid meteor shower

The Geminids will appear to radiate from near Castor and Pollux, the two brightest stars in Gemini the Twins. The shower peaks Weds. night – Thurs. morning. Maps made with Stellarium

Doomsday, smoomsday – let’s interrupt this broadcast to talk about the best meteor shower of the year. The Geminids will liven up skies this Thursday night – Friday morning Dec. 13-14 with up to 50 meteors per hour. We’ve all been burned a little by showers that dribble out meteors once every half hour. Not the Geminids. They’re a strong, reliable shower right on par with the August Perseids.

Although occurring at a cold time of year, the shower offers compensation in putting on a decent show during evening hours. You can start watching for meteors around 9  p.m. when Gemini, home to the Geminids, is up in the east. Rates will improve after midnight when the radiant – the point in the sky from which the shower members appear to radiate or travel – climbs high in the southern sky. Hard-core meteor watchers will be out from 2 a.m. until dawn Friday, but casual observers can start around 9 or 10 p.m.

Beautiful Geminid fireball from a few years back. Credit and copyright: Wally Pacholka

With the moon at new phase, expect ideal conditions for viewing. To improve your counts, consider a drive to the country to put the hurt on city light pollution. Real darkness can make a big difference, since there are far more faint meteors than bright.

Most meteor showers originate from debris lost by comets as they orbit the sun. When Earth plows into the stuff, it burns up through friction with our atmosphere, flaring as a meteor or shooting star.

Photos of the Geminid parent asteroid 3200 Phaethon taken over a span of 45 minutes with a 15-inch telescope on Dec. 25, 2010. Dust and rock association with this asteroid is responsible for the Geminids. Credit: Marco Langbroek

The Geminids are different. Instead of comet bits, we’re showered by bits of rock from the asteroid 3200 Phaethon. What likely happened was that sometime in the distant past, the asteroid collided with another, spreading rocky debris along its orbital path. Every year in mid-December, Earth gets peppered by Phaethon dust as we pass through the stream. Geminids are typically travel at modest speeds compared to some showers and appear white to yellow.

If your weather looks cloudy tomorrow night, you’ll still see some Geminids a couple days before and after the Thursday night peak. For best viewing, dress warmly, pack a thermos of your favorite beverage, face east or south and kick back in a chair. I’ve heard hot tubs also make good meteorite viewing stations.

As long as we’re touching on asteroids, last night the sky cleared just enough in my neighborhood to watch asteroid 2012 XE54 creep across the stars of Taurus and Orion during its close pass of Earth. The approximately 120-foot-wide space rock moved in real time like a very slow satellite at 142x through my 15-inch telescope. While the asteroid was exactly on track, it arrived about 3 minutes early of position.

As for 2012 XE54′s predicted eclipse by Earth – yes, it did happen! Others who followed 2012 XE54 measured a steep drop in its brightness to about 17.5 magnitude during the predicted time, much too dim to see in nearly all amateur scopes. It would have been cool to watch it fade from view for an hour, but the sky here in Duluth, Minn. was cloudy then. To see how the asteroid’s light changed during the eclipse, check out the light curve at amateur astronomer Pete Birdwhistle’s site.


Most recent Goldstone radar image of asteroid 4179 Toutatis taken on Dec. 10, 2012. Click picture to see more. Credit: NASA

Toutatis, another Earth-approaching asteroid we looked at a couple days ago, will be making its closest approach tonight around 10 p.m. (CST) at a relatively distant 4.3 million miles.

Radio astronomers will be closely watching the space rock to further refine its orbit, shape and surface features. Amateurs with small telescopes from 4.5 inches on up can spot it traveling slowly among the stars of Cetus the Sea Monster shining at about magnitude 10.8. If you miss tonight, don’t worry. Toutatis will be brighter than 12th magnitude (visible in a 6-inch telescope) all month.

To find Toutatis in your scope, head over to JPL’s Horizons site, select your location and time period, then click the Generate Ephemeris button. That will give you a list of positions for the asteroid you can hand-plot on a detailed star atlas. I’ll try to post a chart for you later today if I can find time.

I’m hoping the Chinese will share closeup photos during the planned flyby of the asteroid tomorrow with their Chang’ e 2 spacecraft. Stay tuned.

UPDATE: Potential second NEW meteor shower is expected Thursday night. Click HERE for more info.

Asteroid 2012 XE54 may be eclipsed during close flyby tonight

The path of 2012 XE54 (in blue) during tonight’s close flyby.  At minimum distance, it will be about 139,500 miles away. Credit: NASA/JPL

Newly-discovered asteroid 2012 XE54 will fly by Earth tonight only 139,500 miles away or slightly more than half the distance to the moon. The rocky body, estimated at between 50-165 feet across (15-50 meters), was discovered only yesterday and will reach minimum distance tomorrow morning around 4:10 a.m. (CST) as it zips through northern Puppis southwest of Sirius. For a few hours before and after that, the asteroid should be visible in 8-inch and larger telescopes at around 13th magnitude. As with all these small bodies, 2012 XE54 will look like a starlight point of light on the move.

When brightest this evening at around 12.9-13.0 magnitude, the asteroid will be cruising through Orion and Monoceros. Positions are shown each hour starting at 9 p.m. CST. Created with Chris Marriott’s SkyMap software

According to Pasquale Tricarico, research scientist at the Planetary Science Institute, there’s a good chance the asteroid will be partially eclipsed by Earth’s shadow between 7:22 – 8 p.m. (CST), an unusual if obscure event. Amateurs and professionals watching at that time might see a drop in the 2012 XE54′s brightness.

It’s not often we get to see an asteroid eclipse. The first known case happened in 2008 when 2008 TC3 passed into Earth’s shadow for an hour before entering the atmosphere, where it shattered and dropped about 10 lbs. of meteorites over Sudanese desert.

Just so we’re clear, we’ve nothing to fear from tonight’s flyby. The asteroid will pass safely by Earth like so many others have in recent years. The map above gives you a general idea of 2012 XE54′s path across the sky. To create your own detailed map to find it in a telescope, click over to the JPL HORIZONS site. There you can set your location and time interval and then plot the asteroid’s positions on a detailed star map. Or you can input its orbital elements into your star-charting program. To see a very cool animation of the possible eclipse, check out Pasquale Tricarico’s website.

Squiggly-tailed comet C/2012 V4 eyed by solar probe

Highly processed photo of Comet C/2012 V4 taken with the HI2B camera on STEREO-B shows a small, bright head and long, skinny tail. Click image to see the comet in time-lapse motion. Credit: NASA

Looks to me like a tadpole wriggling in that big, dark pond we call outer space. C/2012 V4, the likely return of Comet Pons-Gambart, last seen in 1827, has been spotted in pictures taken by one of the SECCHI (Sun Earth Connection Coronal and Heliospheric Investigation) cameras on board the STEREO-B solar probe. The instrument watches the space between Earth and the sun, monitoring the progress of solar storms before they impact our planet.

The twin STEREO probes orbit well ahead and behind Earth, so they can photograph both the front and back sides of the sun. C/2012 V4 and its tadpole tail show up so well because from STEREO-B’s location, it’s considerably closer than it is from here on Earth.

C/2012 V4 hangs out low in the southwestern sky above the Handle of the Teapot (constellation Sagittarius) outlined here. It’s also not far from Mars. Comet positions are shown every 5 days at 5:20 p.m. (CST) about an hour after sunset. Stars plotted to mag. 8.5. Right-click to save and then print. Created with Chris Marriott’s SkyMap software

You may have heard that the comet, which appears to be headed in Earth’s direction, could actually strike our dear planet. Don’t worry, won’t happen. C/2012 V4 lies some 144 million miles away or more than 1.5 times the Earth-sun distance and moves farther away every day. On Dec. 18, it will swing wide around the sun at a distance of 75 million miles and then recede into the depths. Amateur astronomers with 8-inch or larger telescopes and a clear view down to the southwestern horizon can use the map to try and spot this long-lost visitor. It’s currently about magnitude 8.5, about as bright as it will get.

The brightest, easiest comet to see from mid-northern latitudes this month is C/2012 K5, now gliding beneath the handle of the Big Dipper and high overhead before dawn. Austrian amateur Michael Jaeger caught it this morning Dec. 9, 2012 at ~ 9.5 magnitude near the bright star Alkaid at the end of the Big Dipper’s handle. 

Be sure to click on the photo at top to watch a short video of the comet’s movement over several days time. Alan Watson of Australia did a great job combining SECCHI photos to show how the tail of the C/2012 V4 wriggles as high-speed particles from the sun called the solar wind sweep past. They make the comet come alive!

Why the world won’t end on Dec. 21, 2012

Will the world end on Dec. 21? Better not. I’m planning to celebrate the solstice and call my mom.  Photo: Bob King

I know it sounds like a “how does he know it won’t?” headline, but my crystal ball shows nothing unusual happening on that date outside of the winter solstice at 5:12 a.m. (CST).

I like the solstice; it’s cause for optimism for lovers of daylight. My wife surely sees it that way. From Dec. 21 forward, darkness is cast away a minute at a time as the sun ambles back north.

But what about all these dark thoughts people are having about world’s end? By now we’ve all heard it originates with the ancient Mayan calender rumored to come to an end – and bring the world along with it – on Dec. 21. While a “Great Cycle” of the calendar does conclude on that date, a new cycle begins, much like the transition on our Western calendar from Dec. 31, 1999 to Jan. 1, 2000. Granted, a lot of people got freaked out and made crazy predictions during that transition, but did the world change overnight? No.

Mayan mask from 250-600 A.D. on display in the National Museum of Anthropology in Mexico City. Credit: Wolfgang Sauber

Each Great Cycle of the Mayan calendar lasts 7,885 years, at the conclusion of which the Mayans believed the universe would be destroyed and recreated. While I like to clean house like anybody else, the last time I checked, the universe was still around in 6000 B.C., the approximate date of the conclusion of the previous cycle. This belief was undoubtedly important to Mayan spiritual life, but it’s not connected to the real world as we know it. No matter what calendar you consult, ancient or new, they’re all man-made devices with no sway whatsoever over the powers of nature.

No planets will be in any particular alignment on Dec. 21, 2012. This view shows the solar system seen from above the north pole of the Earth. Illustration: Bob King

Then there’s all the chatter of a planetary alignment and how the combined gravity of the planets will rock the Earth or split the Earth or send a beam of supercharged particles at Earth or … fill in the blank.

First, there are no planetary alignments on or around Dec. 21, 2012. Matter of fact, the first week of December has been filled with great alignments of Venus, Mercury, Saturn and the moon, and we’re none the worse for it.

All’s quiet on Dec. 21. The quarter moon will be in Pisces the Fish and Jupiter shining brightly in Taurus in the evening sky (left). Venus and Saturn are visible in the south before and at dawn. Created with Stellarium

Even if all the planets queued up in a perfectly straight line with the Earth and sun, the amount of additional tug on Earth would be negligible. Certainly not enough to raise tides like the much closer moon and much weightier sun do.

Next we bump into the made-up planet Nibiru that’s supposed to be on a collision course with Earth. Nobody, not NASA, not a single professional observatory anywhere, no spacecraft and no amateur astronomer has ever detected or photographed any sign of this fictional world. If it were headed toward our planet and big enough to crush us like so many bugs, it would be so close by now we’d see it with the naked eye.

You may have also heard how the sun will line up directly over the black hole at the center of the Milky Way galaxy, triggering beams of radiation that will turn the Earth into over-grilled hamburger. Fact-checking shows that the sun will not line up with the central black hole because its path across the sky lies well to the north of this location. Even if it did, the the two are separated by 27,000 light years, a distance so vast they’re completely unrelated to one another. Lineups do little to enhance gravity’s attraction despite the human mind’s obvious attraction to linearity.

The sun will shine from the constellation Sagittarius the Archer well to the northeast of the galactic center, site of our galaxy’s supermassive black hole. Illustration: Bob King

Gravity is the weakest of the four forces that include electromagnetism and the weak and strong nuclear forces. While it acts over great distances, lining things up in a row only affects another planet when the objects you’re lining up are relatively large and very close – like the moon – or extremely massive and relatively close, like the sun. The strength of gravity or any other interaction between the sun and the black hole in the center of the galaxy is virtually nil. Likewise for small objects like nearby comets and asteroids.

Powerful solar flare on May 9, 2012 photographed by the Solar Dynamics Observatory. Credit: NASA

Speaking of the sun, some are predicting a massive solar flare on the first day of winter. That’s always possible, but no one, not even top solar scientists, can forecast the date of a solar storm, only a probability. Since we’re approaching the high or active end of the current sunspot cycle when storms are more common, a flare is more likely now than when the solar activity bottoms out at minimum.

The sun’s up and down cycle has been happening for hundreds of years; a normal to below normal amount of activity is expected when the current cycle peaks in May 2013.

We can’t end without addressing the pole switch-over, which isn’t about Earth’s axis flipping about – that’s nicely stabilized by the moon – but the north and south magnetic poles changing places. Some are predicting a flip-flop on Dec. 21. While this really does happen, it occurs rarely; about once every 200,000 to 300,000 years (or longer). The one occurred about 800,000 years ago. Since then the magnetic poles have wandered this way and that, but compasses needles still point north and will continue to do so for thousands more years.

Schematic illustration of Earth’s magnetic field. Our iron-nickel core and spinning rotation create a magnetic field around the planet that causes our compass needles to point north. Credit and copyright: Peter Reid

Even when switch-overs happen, they’re gradual and take up to a few thousand years to complete. Since Earth and its bevy of life, including humans during the most recent flip, have survived, we’ll undoubtedly make it through the next one.

I’ve heard of some really nutty stuff like the particle accelerator at CERN sending protons into the Earth, creating a chain-reaction that blows giant holes in the ground, releasing firestorms of methane gas. The minute amounts of matter involved in these experiments are self-contained not to mention it’s difficult to imagine exactly how a chain-reaction could be started. Earth rock isn’t made of highly processed nuclear materials just waiting for a fuse.

I think I do understand why we’re obsessed with end-of-world scenarios. It was built-in by evolution as a way for us to anticipate the worst and act to ensure our survival. Fair enough. But when it’s co-opted by people who either don’t understand the fundamentals of nature and science or who do, but prey on the fears and ignorance of others to enhance their status or make money, it’s wrong. That’s why the more observant you are of the world, the less heed you’ll pay to those who distort the truth.

That includes accepting the fact that volcanoes, earthquakes, floods, droughts and meteor hits are part of the price we pay for living on an active, evolving planet. No magical alignments or minuscule comets are necessary to explain these behaviors. While there are many things we still don’t know, based on what we do know, there’s no reason to fear Dec. 21, 2012.

Whenever you hear someone say the world will end on this or that date, remember that thousands of people before them predicted the same and yet we’re all still here paying the bills and shopping for Christmas. Even if the worst were to happen, say a 5-mile-diameter asteroid crashing into Earth, life would sustain some serious damage, but the remaining plants, animals and humans would go on to populate the future. We live in one tough neighborhood, but have what it takes to survive.

And if I’m wrong on Dec. 21 and the world does end, I’ll be very embarrassed. Promise.

More moon and morning planet alignments in store this weekend

Mercury, Venus, Saturn and Spica alignment Thursday morning Dec. 6 from East Dayton, Ohio. Details: 17mm lens at f/8, 6-second exposure at ISO 400. Credit: John Chumack

Couldn’t get to Egypt to see the planets hovering over the Pyramids of Giza at dawn earlier this week? Cloudy skies or a work schedule that wouldn’t allow a dawn sashay?

Good news. You still have plenty of time to see some great planetary lineups. Unlike eclipses and some meteor showers, planet pairings can linger for days. While Mercury, Venus and Saturn may not be equally spaced as they were on Dec. 3, they still form a delightful connect-the-dots alignment along with the star Spica an hour before sunrise. With a visitation by the thinning crescent moon beginning tomorrow, you have all the ingredients for a series of special events worth a smidge of sleep loss.

The moon, planets and Spica tomorrow morning Dec. 8, 2012 facing southeast about an hour before sunrise. For many locations that’s around 6:30-7 a.m. The five worlds will span some 45 degrees of sky. Views created with Stellarium

Tomorrow’s garland-like arrangement of planets, star and moon is arguably more striking than Monday’s highly publicized alignment of Saturn, Venus and Mercury. Look at how nicely these celestial orbs are strung out across the dawn sky. To see them all, make sure you’re somewhere with a wide open view to the south-southeast.

There’s something for everybody in the dawn sky now through early next week as the moon “visits” each planet in turn while slimming to a slender crescent.

Then on the 9th, the moon passes little more than a degree (two moon diameters) south of Virgo’s brightest star Spica (SPY-kuh). Saturn will be 4 degrees north of the moon the following morning, and on Dec. 11, a pleasing thin crescent glides just a degree and a half south of Venus.

Enjoy these sights while you can. I hear the end of the world’s coming on Dec. 21. We’ll look at why that’s not likely to happen in a blog I’m hoping to write tomorrow. If there is a tomorrow …

Chinese probe to make daring flyby of asteroid Toutatis

Illustration of the Chang’e 2 probe flyby of Toutatis next week. Chang’e 2 originally was used to map the moon and then repurposed for the asteroid flyby. Chang’e is named after an ancient Chinese moon goddess. Credit: Andrzej Mirecki

If all goes according to plan, one week from today on Dec. 13, the Chinese Chang’e 2 probe will snap closeup photos of near-Earth asteroid 4179 Toutatis (too-TAT-us) from only 200 miles away. Toutatis will be making its own close approach the day before, zooming by Earth at a distance of 4.3 million miles.

Traveling at about 7 miles a second, the ship will have only the briefest of opportunities to shoot photos as it rapidly approaches and then departs the asteroid. High-resolution cameras should resolve features tens of meters (~65 to 150 feet) across, giving us our most detailed optical views ever of this 3-mile-long space rock shaped like a bowling pin.

Click to watch Toutatis’ topsy-turvy rotation. Images from NASA radar

Our best “photos” to date are a series of remarkable images made by beaming radio waves at the asteroid during previous close approaches and analyzing the reflected echoes. Those images reveal an irregular body with two pronounced lobes that may once have been two separate asteroids. Possibly an older asteroid was broken apart during an earlier collision, pieces later reassembling to form present-day Toutatis.

Unlike the planets, which spin on one axis in one direction, Toutatis spins about two axes, wobbling about like a poorly-thrown football pass. If you stood on the asteroid’s surface, the sun would rise at random times along random points on the horizon. Makes me dizzy just thinking about it.

Toutatis is a rocky asteroid about 3 miles long. These 1992 radar images from NASA’s Goldstone radar dish reveal an undulating surface, craters and two large lobes that may have once been separate asteroids. Courtesy Steve Ostro, JPL

Toutatis orbits the sun every 4 years in nearly the same plane as Earth’s orbit and is a frequent visitor to the inner planets. When closest to the sun, it’s located just inside Earth’s orbit; when farthest it travels among its fellow asteroids in the outer fringes of main asteroid belt between Mars and Jupiter.

Every four years Toutatis passes through our neighborhood, which is why it’s designated as a PHA or potentially hazardous asteroid. PHAs are asteroids that come within 5 million miles of Earth and are large enough to survive atmospheric entry and cause major destruction.

Radar picture of Toutatis taken by the Goldstone antenna on Dec. 3, 2012 as part of the 2012 campaign (see below). Credit: NASA/JPL

Toutatis is the largest asteroid we know of that approaches Earth most closely. That doesn’t mean it’s going to hit us, only that a collision is remotely possible. Calculations based on many observations since its discovery in 1989 have ruled out any chance of a hit for at least the next six centuries. Rest easy.

Toutatis came as close as 967,000 miles or just shy of 4 lunar distances on September 29, 2004. This time around, it will draw to within 4.3 million miles, more than four times farther away but still be bright enough at 10.5 magnitude to be seen in a small telescope. I’ll provide directions on how to find it early next week.The next time the asteroid makes a close close approach to Earth will be in November 2069 (7.7 lunar distances).

Toutatis is shown on Dec. 12 when nearest Earth. Its orbit (in blue) takes the asteroid to just within Earth’s orbit to well beyond Mars. Credit: JPL

The 230-foot radar dish at Goldstone has already swung in Toutatis’ direction and made early images of the flyby in a special 2012 campaign to better model its rotation, shape and surface features. Combined with the pictures from Chang’e 2, we’ll soon have a clearer portrait of this unique object.

No kidding, let’s talk Sirius


The sky’s brightest star Sirius is also the Alpha star in the constellation Canis Major the Large Dog. Back in ancient Egypt, its rising at dawn signaled the start of the flooding of the Nile River. The name Sirius comes from the Latinized version of the Greek “seirios” meaning scorching and referring to its brilliance. Photo: Bob King

Sirius is a star to be taken seriously. As the brightest in the night sky, it has no equal. We’re not talking intrinsic brightness – that award could easily go to many naked eye stars rendered faint only by distance – but Sirius wins by proximity. At just 8.7 light years from Earth, it’s the 5th closest star system beyond the sun. It also doesn’t hurt that Sirius is 1.75 times the size of the sun and 26 times as luminous.

Sirius has an Earth-sized white dwarf companion named Sirius B. White dwarfs are hot, incredibly dense stars that represent the end point of evolution for stars like the sun and Sirius. The right panel shows Sirius compared to the sun – it’s hotter, brighter and nearly twice as big. Credit: NASA/ESA (left) and Wikipedia

Last night it came up bright, white and twinkling in the southeast around 10:30 p.m. Because of its brilliance, no star crackles more intensely especially when viewed low in the sky, which is where Sirius spends a fair amount of its time as seen from mid-northern latitudes.

Our atmosphere’s to blame for Sirius’ flashy personality. Starlight passes through air pockets of different density and humidity on its way to our eyes. Each pocket act like an individual lens that focuses its own image of the star. As the air churns and the winds blow, the number and positions of all those individual images are constantly changing.

The color and brightness of Sirius can change rapidly as it twinkles. I shot these slightly out of focus to spread the color out and show it more clearly. Not only are the hues striking but brightness changes are obvious, too. Photo: Bob King

We perceive these nonstop, tiny shifts as sputtering light or twinkling. The scientific description of the cause is atmospheric refraction. Refraction by moving air causes star images to constantly jump about and change brightness. Although it was calm on the ground, air currents high above made Sirius spark and sputter spectacularly last night. If you didn’t know what you were looking at, you might think it was a UFO on its way to the next abduction. Sirius has been confused with such by inexperienced observers.

Look southeast after 10 p.m. for the three stars in Orion’s Belt. Draw a line through them toward the horizon and you’ll arrive at Sirius. Photo: Bob King

The colors come from the air, too. Just as white light is composed of a rainbow or spectrum of individual colors from indigo to green to red, so is starlight. When a star is near the horizon, refraction is strong enough to create images of it in every color of the rainbow and cast them about in different directions. To our eye, the star looks like a continuous sparkle of varying colored light as split-second variations in moving air pockets make it dance about.

Because Sirius is close to Earth, its motion through space causes it to slowly move across the sky. Not much mind you, but enough to make it one of the few stars to have moved noticeably in recorded history.

In the days of ancient Egypt, the star was further northeast of where it is today. A keen-eyed skywatcher transported from that time to ours would easily see the change.

Like all the stars, Sirius moves through space around the center of the Milky Way galaxy. It’s one of the few that moved noticeably over recorded history. Diagram created with Chris Marriott’s SkyMap software.

You can find Sirius anytime by facing southeast after 10 o’clock and shooting a line through Orion’s Belt down and to the left. Enjoy the sparkles!

Curiosity soil sample results in; see the moon by night or day

Self-portrait of Curiosity at the Rocknest site, where it scooped up soil samples from a wind drift of sandy material. Click for larger annotated picture. Credit: NASA/JPL-Caltech

Mars Curiosity delivered this week on the eagerly anticipated soil sample analysis, sniffing out water, sulfur and chlorine-containing substances, among other ingredients. The rover examined the sample with the Sample Analysis at Mars (SAM) suite and Chemistry and Mineralogy (CheMin) instrument. SAM used three methods to analyze gases given off from the dusty sand when it was heated in a tiny oven. By the way, the water seen by SAM was not wet but bound as molecules to grains of sand or dust. Interestingly, the amount measured was higher than anticipated.

Although SAM can detect organic compounds, none were found with the exception of chlorinated methane. NASA cautions that while the chlorine part was definitely Martian, the carbon in this one-carbon organic molecule may have been brought to Mars by the rover.

“We have no definitive detection of Martian organics at this point, but we will keep looking in the diverse environments of Gale Crater,” said SAM Principal Investigator Paul Mahaffy of NASA’s Goddard Space Flight Center in Greenbelt, Md.

CheMin’s examination of Rocknest samples found the sandy soil composed of about half common volcanic minerals mixed with other rocky materials including a substantial amount of small bits of glass.

Collage showing the variety of soils found at landing sites on Mars. The investigations found similar soil at all landing sites.The Mars Exploration Rover Spirit’s landing region in Gusev Crater is seen in both pictures at top; Viking’s landing site is shown at lower left; and a close-up of Curiosity’s Gale Crater soil is at lower right. In Gusev Crater, white subsurface deposits (upper left) excavated with Spirit’s wheels proved to be minerals that formed in wet environments. Credit: NASA/JPL-Caltech

Carbon from Earth may not have been all Curiosity brought from home. About 250,000 bacterial spores – a tiny but not negligible number -  throughout the rover are assumed to have survived the landing, NASA officials say, according to a September article in the LA Times. Nearly all of them are believed to have perished within minutes of exposure to bitter cold, intense ultraviolet radiation and an atmosphere of mostly carbon dioxide. Still, some bacteria have survived worse.

SAM also found the oxygen-chlorine compound perchlorate, a salt of perchloric acid that’s used here on Earth in the making of fireworks, rocket fuel and some medicines. Perchlorate was also found in the Martian Arctic by NASA’s Phoenix lander in 2010.

For more details, check out the press release I used as my source. In related news, Curiosity has made the list of candidates for TIME magazine’s Person of the Year 2012. If the rover and her team rate high on your list of high achievers, click HERE to cast your vote. Voting closes on 11:59 PM on December 12th. Real-time rankings are HERE – as of this afternoon, the robot is in 8th place, ahead of Barack Obama, Mitt Romney and The Higgs Boson Particle. Go Curiosity!

The moon rises south of Regulus tonight around 10:15 p.m. and clears the treetops a half hour or more later. Watch for it again in the opposite part of the sky during the morning hours tomorrow. Created with Stellarium

Last night our sky finally cleared again. Great to see the Milky Way followed by the rising of the waning gibbous moon. This morning, I caught the moon again around 9 a.m. in a blue sky off to the west. Tonight the moon rises about an hour later and will come up alongside Leo’s brightest star Regulus. If you’re out around 11 o’clock you’ll see it in a dark sky; look again Wednesday morning between sunrise and 10 a.m. and you’ll see it in full daylight, too.

The moon can appear both at night and day when it rises late at night and occupies the same part of the sky the sun does in the summer months. Like the summer sun, the moon stays up a long time before it sets, allowing us to spot in daylight.

Jupiter biggest, brightest, closest for the year

Jupiter is the very bright “star” in the eastern sky at nightfall in the constellation Taurus. Look for the Pleiades star cluster to its upper right. Photo: Bob King

If you haven’t noticed Jupiter the past few weeks, your skies are even cloudier than mine. The solar system’s biggest planet is now at opposition and closest to the Earth for the year. Closest also means biggest and brightest. Look up the next clear night and let your eyes be drawn to a vivid light in the east. Yes, that’s the bad boy we’re talking about.

Opposition – when an outer planet lines up on the same side of the sun as our own – happens when Earth laps the planet. For Jupiter, this happens very 13 months. Mars takes about two years to reach opposition, because it orbits much closer to the sun and move so quickly, Earth needs extra time to catch up.

Overnight Dec. 2-3 Jupiter reached opposition, lining up with the Earth on the same side of the sun. Jupiter is now at its brightest and closest in 2012. Illustration: Bob King

Jupiter’s orbit isn’t a perfect circle but slightly oblong, so the distance between it and Earth at each opposition varies over a period of about 12 years. Earth and Jupiter were closest in 2010 and have been gradually separating since. We’ll have to wait until 2021 until we’re this close again, making 2012-13 the best time to observe the planet for the next 9 years.

Since planets at opposition are opposite the sun in the sky, Jupiter rises at sunset in the constellation Taurus the Bull and remains visible all night long. Only when the sun rises again, does the planet slip below the western horizon for some shuteye.

The photo, taken Nov. 21, 2012, shows Jupiter’s current appearance through a telescope. Easiest to see are the equatorial belts, followed by the North Temperate Belt. The planet is capped by dusky gray-brown polar regions. The directions are flipped with south up and north down, the way most telescopes show the sky.  Photo by Damian Peach

That’s plenty of time to use binoculars to spot up to four of its brightest moons snugged up on either side of the planet. Highlights for those with telescopes include the two rusty-red stripes on either side of Jupiter’s midsection. Called the North and South Equatorial Belts or NEB and SEB, they remind me muddy tire tracks. Careful study will reveal the narrower North and South Temperate Belts parallel to their equatorial cousins. And if the air is steady enough to allow magnifications of 100x or higher, you might even catch a glimpse of the Great Red Spot (GRS), a pale red-orange “eye” located in a hollow just south of the SEB.

Jupiter and its four brightest moons Io, Europa, Ganymede and Callisto on Nov. 28. The photo gives a good idea of their appearance in a very small telescope. Credit: John Chumack

Jupiter is the color planet. On good nights, I can see dirty reds in the equatorial belts, shades of gray and brown in the temperate belts, hints of orange sherbet in the GRS and occasional yellow shades in the lighter zones that separate the belts.

All these shades are due to the presence of chemical compounds containing elements like sulfur and phosphorus in clouds composed of ammonia ice crystals.

Wind speed measurements on Jupiter have been added to
this image of the planet. The vertical black line equals zero wind speed. The fastest winds exceed 325 mph. Notice how wind direction alternates from belt to zone. Credit: NASA

Multiple jet streams with winds blasting up to 325 mph alternate eastward to westward with latitude and streamline the clouds into the stripes or belts that give Jupiter its distinctive bumble bee look.

Jupiter’s rapid rotation rate of just 9.8 hours helps drive the fierce winds and also flattens the planet out like a chef spinning a ball of pizza dough. With no solid surface, it spins fast enough to stretch out into an oval more than 6,000 miles wider at its equator than pole to pole. Look closely and you can’t miss Jupiter’s squashed appearance through the telescope.

No matter how you take your cup of Jupiter, whether by naked eye or sweetened with binoculars or telescope, the view is always rewarding.

Long-lost comet Pons-Gambart finally returns home

Comet Pons-Gambart, also known as C/2012 V4,  photographed on Nov. 30 by Andres Chapman from his Observatorio Cruz del Sur (Southern Cross Observatory) in Argentina. The comet’s bright, condensed center is clothed in a fuzzy coma of vaporizing ice and dust. Click for more photos. Credit: Andres Chapman

A comet long considered lost has been found again!

Comet Pons-Gambart was discovered on June 21, 1827 by Jean Louis Pons, observing from Florence, Italy and Adolphe Gambart in Marseilles, France. It brightened to the naked-eye limit (between 5th and 6th magnitude) and then quickly faded. Pons last observed the comet on July 21, 1827 calling it “very faint”.

With only a month of observations, no one bothered to determine an orbit for the comet until a year later. Based on those calculations, it appeared that Pons-Gambart was like many comets, one-hit wonders destined to never return.

Fast forward to 1917 when a second look at the data by astronomer Dr. S. Ogura led him to calculate an elliptical orbit. A comet in an elliptical orbit regularly cycles around the sun making repeat visits. The length of time between visits is called its period. Ogura predicted a period of just under 64 years for Pons-Gambart with an uncertainty of +/- 10 years. Further investigation of its orbit in 1978 gave a period of 58 years plus or minus 10.

We knew it was a repeat or periodic comet, but with no observations since 1827, it appeared hopelessly lost. Hence its official name as D/1827 Pons-Gambart, the “D” meaning lost or deceased.

Color image of C/2012 V4 – the likely return of D/1827 Pons-Gambart taken on Dec. 2, 2012. Credit: Rob Kaufman

Then came a happy turn of events. In November, space scientist and amateur astronomer Rob Matson of Newport Coast, Calif. spotted and tracked a comet in pictures taken by the SWAN camera aboard the Solar Heliospheric Observatory (SOHO). Matson put out a call via e-mail for confirmation photos from the ground. Battling trees and moonlight, Australian amateur Terry Lovejoy photographed and confirmed the comet just two days later on Nov. 29.

Preliminary calculation of its orbit shows an excellent fit to Pons-Gambart’s.  Despite being missed on two previous flybys, this welcome stranger has returned home.

Reincarnated now as comet C/2012 V4, it reaches perihelion, the point in its orbit closest to the sun, on Dec. 18 at a distance of about 75 million miles. Astronomer Rob McNaught described its appearance as a “spring onion” with bright fuzzy core and short spike of a tail to the northeast.

Based on the present return date, we can figure Pons-Gambart’s period at about 62 years. After discovery in 1827, its appearances in 1889 and 1951 were missed, but thanks to space-based cameras and Matson’s keen eye, this time the comet didn’t get away.

Amateur astronomers will find the comet near the well-know Dipper-like asterism in Sagittarius called the “Milk Dipper” shown here an hour after sunset from the northern U.S.  Comet positions are shown for 5:30 p.m. (CST) every five nights. Stars plotted to mag. 8.5. Click for detailed timetable and orbital elements. Created with Chris Marriott’s SkyMap software

Next question – can you see it? No problem if you live in the far southern U.S. and points further south. Skywatchers in South America and Australia have the best view. It’s currently about magnitude 9.5 and visible in 4.5-inch and larger telescopes in the constellation Sagittarius. From mid-northern latitudes, it might be visible with a bigger scope (8 inches and up) very, very low in the southwestern sky at dusk in the coming week.

You can use the map above to help you find it – just right-click, save and print out a copy. One big help in locating the comet is its proximity to the planet Mars (not for real, just line of sight). On the 7th, the two will be in conjunction less than 1 degree apart!

Over the next few weeks, C/2012 V4  will stay fairly close to the sun; not until mid-January will northerners have a better shot at seeing it, when the comet tracks through the constellations Scutum and Aquila in the pre-dawn sky. Pons-Gambart shines brightest now through mid-December and then slowly fades. I hope at least some of you will be able to put out the welcome mat for this lost soul. There’s a thrill in finding a comet that no one’s seen hide nor hair of in 185 years.