Peculiar ‘Cauliflower Rocks’ May Hold Clues To Ancient Mars Life

"Cauliflower" shaped silica-rich rocks photographed by the Spirit Rover near the Home Plate rock formation in Gusev Crater in 2008. Could microbes have built their nodular shapes? Credit: NASA/JPL-Caltech
“Cauliflower” shaped silica-rich rocks photographed by the Spirit Rover near the Home Plate rock formation in Gusev Crater in 2008. Credit: NASA/JPL-Caltech

Evidence of water and a warmer, wetter climate abound on Mars, but did life ever put its stamp on the Red Planet? Rocks may hold the secret. Knobby protuberances of rock discovered by the Spirit Rover in 2008 near the rock outcrop Home Plate in Gusev Crater caught the attention of scientists back on Earth. They look like cauliflower or coral, but were these strange Martian rocks sculpted by microbes, wind or some other process?

Close-up of the lobed silica rocks on Mars photographed by the Spirit Rover on Sol 1157. Credit: NASA/ JPL-Caltech
Close-up of the lobed silica rocks on Mars photographed by the Spirit Rover’s microscopic imager on Sol 1157. It’s not known where wind (or other non-biological process) or micro-life had a hand in creating these shapes. Credit: NASA/ JPL-Caltech

When analyzed by Spirit’s mini-TES (Mini-Thermal Emission Spectrometer), they proved to be made of nearly pure silica (SiO2), a mineral that forms in hot, volcanic environments. Rainwater and snow seep into cracks in the ground and come in contact with rocks heated by magma from below. Heated to hundreds of degrees, the water becomes buoyant and rises back toward the surface, dissolving silica and other minerals along the way before depositing them around a vent or fumarole. Here on Earth, silica precipitated from water leaves a pale border around many Yellowstone National Park’hot springs.

The Grand Prismatic Spring at Yellowstone National Park. Could it be an analog to similar springs, hydrothermal vents and geysers that may once have existed in Gusev Crater on Mars? Credit: Jim Peaco, National Park Service
The Grand Prismatic Spring at Yellowstone National Park. Could it be an analog to similar springs, hydrothermal vents and geysers that may once have existed in Gusev Crater on Mars? Credit: Jim Peaco, National Park Service

Both at Yellowstone, the Taupo Volcanic Zone in New Zealand and in Iceland, heat-loving bacteria are intimately involved in creating curious bulbous and branching shapes in silica formations that strongly resemble the Martian cauliflower rocks. New research presented at the American Geophysical Union meeting last month by planetary geologist Steven Ruff and geology professor Jack Farmer, both of Arizona State University, explores the possibility that microbes might have been involved in fashioning the Martian rocks, too.


A sizzling visit to El Tatio’s geysers

The researchers ventured to the remote geyser fields of El Tatio in the Chilean Atacama Desert to study an environment that may have mimicked Gusev Crater billions of years ago when it bubbled with hydrothermal activity. One of the driest places on Earth, the Atacama’s average elevation is 13,000 feet (4 km), exposing it to considerably more UV light from the sun and extreme temperatures ranging from -13°F to 113°F (-10° to 45°C). Outside of parts of Antarctica, it’s about as close to Mars as you’ll find on Earth.

Ruff and Farmer studied silica deposits around hot springs and geysers in El Tatio and discovered forms they call “micro-digitate silica structures” similar in appearance and composition to those on Mars (Here’s a photo). The infrared spectra of the two were also a good match. They’re still analyzing the samples to determine if heat-loving microbes may have played a role in their formation, but hypothesize that the features are “micro-stromatolites” much like those found at Yellowstone and Taupo.

A stromatolite from Wyoming made of many layers of bacteria-cemented mineral grains. Credit: Bob King
A stromatolite from Wyoming made of many layers of bacteria-cemented mineral grains. Credit: Bob King

Stromatolites form when a sticky film of bacteria traps and cements mineral grains to create a thin layer. Other layers form atop that one until a laminar mound or column results. The most ancient stromatolites on Earth may be about 3.5 billion years old. If Ruff finds evidence of biology in the El Tatio formations in the punishing Atacama Desert environment, it puts us one step closer to considering the possibility that ancient bacteria may have been at work on Mars.

Scientists have found evidence that Home Plate at Gusev crater on Mars is composed of debris deposited from a hydrovolcanic explosion. The finding suggests that water may have been involved in driving an eruption that formed the deposits found on Home Plate. Spirit found the silica-rich rocks at lower right near
Scientists have found evidence that Home Plate at Gusev crater on Mars is composed of debris deposited from a hydrovolcanic explosion. The finding suggests that water may have been involved in driving an eruption that formed the deposits found on Home Plate. Spirit found the silica-rich rocks at lower right near Tyrone in 2008. Credit: NASA/JPL-Caltech

Silica forms may originate with biology or from non-biological processes like wind, water and other environmental factors. Short of going there and collecting samples, there’s no way to be certain if the cauliflower rocks are imprinted with the signature of past Martian life. But at least we know of a promising place to look during a future sample return mission to the Red Planet. Indeed, according to Ruff, the Columbia Hills inside Gusev Crater he short list of potential sites for the 2020 Mars rover.

More resources:

Viewing Guide to the 2015 Geminid Meteor Shower

A brilliant Geminid flashes below Sirius and Orion over Mount Balang in China. Credit: NASA/Alvin Wu

2015 looks like a fantastic year for the Geminids. With the Moon just 3 days past new and setting at the end of evening twilight, conditions couldn’t be more ideal. Provided the weather cooperates! But even there we get a break. With a maximum of 120 meteors per hour, the shower is expected to peak around 18:00 UT (1 p.m. EST, 10 a.m. PST) December 14th, making for two nights of approximately equal activity: Sunday night Dec. 13-14 and Monday night Dec. 14-15.  Continue reading “Viewing Guide to the 2015 Geminid Meteor Shower”

Earth May Be “Hairy” with Dark Matter

I’m losing mine, but the Solar System may be way hairier than we ever thought, with thick crops of filamentary dark matter streaming through Earth’s core and back out again even as you read this. 

Estimated distribution of matter and energy in the universe. Credit: NASA
Estimated distribution of matter and energy in the universe. Credit: NASA

A new study publishing this week in the Astrophysical Journal by Gary Prézeau of NASA’s Jet Propulsion Laboratory proposes the existence of long filaments of dark matter, or “hairs.” Dark matter is a hypothetical form of matter that emits no light, thereby resisting our attempts to see and photograph it, but based on many observations of its gravitational pull on ordinary matter, astronomers have measured the amount of dark matter to an accuracy of 1%.

Massive amounts of it formed a tangled web of filaments after the Big Bang and ensuing epoch of cosmic inflation that served as sites for the “condensation” of  bright matter galaxies. We likely owe our existence to this stuff, whatever it is, which has yet to be directly detected. Along with dark energy, it remains one of the greatest mysteries of our age.

This NASA Hubble Space Telescope image shows the distribution of dark matter in the center of the giant galaxy cluster Abell 1689, containing about 1,000 galaxies and trillions of stars. Researchers used the observed positions of 135 lensed images of 42 background galaxies to calculate the location and amount of dark matter in the cluster. They superimposed a map of these inferred dark matter concentrations, tinted blue, on an image of the cluster taken by Hubble
This Hubble image shows the distribution of dark matter in the center of the giant galaxy cluster Abell 1689, containing about 1,000 galaxies and trillions of stars. Researchers used the observed positions of 135 lensed images of 42 background galaxies to calculate the location and amount of dark matter in the cluster. They superimposed a map of these inferred dark matter concentrations, tinted blue, on an image of the cluster. The greastest concentration of dark matter is in the cluster’s center. Credit: NASA, ESA, D. Coe, N. Benitez , T. Broadhurst

As if that weren’t enough, dark matter comprises 85% of all the known matter reserves in the universe and 27% of the entire matter-energy cosmic budget. Ordinary stuff like stars, baseball bats and sushi constitute just 4.9% of the the total. The leading theory is that dark matter is “cold,” meaning it moves slowly compared to the speed of light, and it’s “dark” because it doesn’t produce or interact with light. The axion, a hypothetical elementary particle, appears to be good candidate for dark matter as do WIMPs or weakly interacting massive particles, but again, these exist only on paper.

According to calculations done in the 1990s and simulations performed in the last decade, dark matter forms “fine-grained streams” of particles that move at the same velocity and orbit galaxies such as ours. Streams can be much larger than our Solar System and criss-cross the galaxy. Prézeau compares the formation of fine-grained streams of dark matter to mixing chocolate and vanilla ice cream. Swirl a scoop of each together a few times and you get a mixed pattern, but you can still see the individual colors.

“When gravity interacts with the cold dark matter gas during galaxy formation, all particles within a stream continue traveling at the same velocity,” Prézeau said.

This illustration zooms in to show what dark matter hairs would look like around Earth. The hairs in this illustration are not to scale. Simulations show that the roots of such hairs can be 600,000 miles (1 million kilometers) from Earth, while Earth's radius is only about 4,000 miles (6,400 kilometers). Credit: NASA /JPL-Caltech
This illustration zooms in to show what dark matter hairs would look like around Earth. The hairs in this illustration are not to scale. Simulations show that the roots of such hairs can be 600,000 miles (1 million km) from Earth. Credit: NASA /JPL-Caltech

But a different scenario unfolds when a stream passes by an obstacle like the Earth or a moon. Prézeau used computer simulations to discover that when dark matter stream passes through a planet — dark matter passes right through us unlike ordinary matter — it’s focused into an ultra-dense filament or hair. Not a solo strand but a luxuriant crop bushy as a brewer’s beard.

According to Prézeau, hairs emerging from planets have both “roots,” the densest concentration of dark matter particles in the hair, and “tips,” where the hair ends. When particles of a dark matter stream pass through Earth’s core, they focus at the “root” of a hair, where the density of the particles is about a billion times more than average. The root of such a hair should be around 600,000 miles (1 million km) away from the surface, or a little more than twice as far as the moon. The stream particles that graze Earth’s surface will form the tip of the hair, about twice as far from Earth as the hair’s root.

The root of a dark matter hair produced from particles going through Jupiter's core would be about 1 trillion times denser than average. Credit: NASA/JPL-Caltech
The root of a dark matter hair produced from particles going through Jupiter’s core would be about 1 trillion times denser than average. Credit: NASA/JPL-Caltech

A stream passing through more massive Jupiter would have roots a trillion times denser than the original stream. Naturally, these dense concentrations would make ideal places to send a probe to study dark matter right here in the neighborhood.

The computer simulations reveal that changes in Earth’s density from inner core to outer core to mantle and crust are reflected in the shape of the hairs, showing up as “kinks” that correspond to transitions from one zone to the next. If it were possible to get our hands on this kind of information, we could use it to map to better map Earth’s interior and even the depth of oceans inside Jupiter’s moon Europa and Saturn’s Enceladus.

Earth getting its roots done. What’ll they think of next?

Do Comets Explain Mystery Star’s Bizarre Behavior?

The story of KIC 8462852 appears far from over. You’ll recall NASA’s Kepler mission had monitored the star for four years, observing two unusual incidents, in 2011 and 2013, when its light dimmed in dramatic, never-before-seen ways. Models to explain its erratic behavior were so lacking that some considered the possibility that alien megastructures built to capture sunlight around the host star (think Dyson Spheres) might be the cause.

But a search using the SETI Institute’s Allen Telescope Array for two weeks in October detected no significant radio signals or other signs of intelligent life emanating from the star’s vicinity. Something had passed in front of the star and blocked its light, but what?

The Spitzer Space Telescope observatory trails behind Earth as it orbits the Sun. Credit: NASA/JPL-Caltech
The Spitzer Space Telescope observatory trails behind Earth as it orbits the Sun. Credit: NASA/JPL-Caltech

Shattered comets and asteroids were also suggested as possible explanations — dust and ground-up rock would be at the right temperature to glow in the infrared — but Kepler could only observe in visible light where any debris would be invisible or swamped by the light of the star. So researchers looked through older observations made in 2010 by the  Wide Field Infrared Survey Explorer (WISE) space telescope. Unfortunately, WISE observed the star before the strange variations were seen and therefore before any putative dust-busting collisions.

Not to be stymied, astronomers next checked out the data from NASA’s Spitzer Space Telescope, which like WISE, is optimized for infrared light.  Spitzer just happened to observe KIC 8462852 much more recently in 2015.

“Spitzer has observed all of the hundreds of thousands of stars where Kepler hunted for planets, in the hope of finding infrared emission from circumstellar dust,” said Michael Werner, the Spitzer project scientist and the lead investigator of that particular Spitzer/Kepler observing program.

Comet Siding Spring (C/2007 Q3) as imaged in the infrared by the WISE space telescope. The images was taken January 10, 2010 when the comet was 2.5AU from the Sun. Credit: NASA/JPL-Caltech/UCLA
Comet Siding Spring (C/2007 Q3)  imaged in the infrared by the WISE space telescope in January 2010. Credit: NASA/JPL-Caltech/UCLA

I’d love to report that Spitzer tracked down glowing dust but no, it also came up empty-handed. This makes the idea of an asteroidal smash-up very unlikely, but not one involving comets according to Massimo Marengo of Iowa State University (Ames) who led the new study. Marengo proposes that cold comets are responsible. Picture a family of comets traveling on a very long, eccentric orbit around the star with a very large comet at the head of the pack responsible for the big fading seen by Kepler in 2011. Later, in 2013, the rest of the comet family, a band of various-sized fragments lagging behind, would have passed in front of the star and again blocked its light. By 2015, the comets would have moved even farther away on their long orbital journey, leaving no detectable infrared excess.

“This is a very strange star,” said Marengo. “It reminds me of when we first discovered pulsars. They were emitting odd signals nobody had ever seen before, and the first one discovered was named LGM-1 after ‘Little Green Men.'”

Clearly, more long-term observations are needed. And frankly, I’m still puzzled why cold or less active comets might still not be detected by their glowing dust. But let’s assume for a moment the the comet idea is correct. If so, we should expect to see similar dips in KIC 8462852’s light as the comet swarm swings around again.

Comet Catalina Grows Two Tails, Soars at Dawn

Amateur astronomer Chris Schur of Arizona had only five minutes to observe and photograph Comet Catalina this morning before twilight got the better of the night. In that brief time, he secured two beautiful images and made a quick observation through his 80mm refractor. He writes:

“Very difficult observation on this one. (I observed) it visually with the 35mm Panoptic ocular. It was a round, slightly condensed object with no sign of the twin tails that show up in the images. After five minutes, we lost it visually as it was 2° degrees up in bright twilight. Images show it for a longer time and a beautiful emerald green head with two tails forming a Y shaped fan.” 

Comet Catalina was about 3 high over Lake Superior near Duluth, Minn. IU.S.) at 5:55 a.m. this morning. Stars are labeled with their magnitudes. Details: 200mm lens, f/2.8, ISO 1250, 3-seconds.
Comet Catalina stands some 3° high over Lake Superior near Duluth, Minn. (U.S.) at 5:55 a.m. this morning, Nov. 22. Stars are labeled with their magnitudes. Details: 200mm lens, f/2.8, ISO 1250, 3-seconds. Credit: Bob King

Schur estimated the comet’s brightness at around magnitude +6. What appears to be the dust tail extends to the lower right (southeast) with a narrower ion tail pointing north. With its twin tails, I’m reminded of a soaring eagle or perhaps a turkey vulture rocking back and forth on its wings. While they scavenge for food, Catalina soaks up sunlight.

I also headed out before dawn for a look. After a failed attempt to spot the new visitor on Saturday, I headed down to the Lake Superior shoreline at 5:30 a.m. today and waited until the comet rose above the murk. Using 7×50 binoculars in a similar narrow observing window, I could barely detect it as a small, fuzzy spot 2.5° south of 4th magnitude Lambda Virginis at 5:50 a.m. 10 minutes after the start of astronomical twilight. The camera did better!

Chris's first photo was taken when the comet rose. This one was photographed minutes later with twilight coming on. Credit: Chris Schur
Chris’s first photo was taken when the comet rose. This one was photographed minutes later with twilight coming on. Credit: Chris Schur

With the comet climbing about 1° per day, seeing conditions and viewing time will continue to improve. The key to seeing it is finding a location with an unobstructed view to the southeast — that’s why I chose the lake — and getting out while it’s still dark to allow time to identify the star field and be ready when the comet rises to greet your gaze.

Two views of Comet C/2013 US10 Catalina made around 6:23 a.m. EST (11:23 Universal Time) on Nov. 21st. The left photo is a 30-second exposure with dawn light approaching fast. Exposure at right was 10 seconds.
North is up and east to the left in these two photos of the comet made by Dr. D.T. Durig at 6:23 a.m. EST on Nov. 21st from Cordell-Lorenz Observatory in Sewanee, Tenn. He estimated the coma diameter at ~2 arc minutes with a tail at least 10 arc minutes long . “I get a nuclear magnitude of 10.3 and an total mag of around 7.8, but that is with only 5-10 reference stars,” wrote Durig. Credit: Dr. Douglas T. Durig

Alan Hale, discoverer of Comet Hale-Bopp, also tracked down Catalina this morning with an 8-inch (20-cm) reflector at 47x. He reported its magnitude at ~+6.1 with a 2-arc-minute, well-condensed coma and a faint wisp of tail to the southeast. In an e-mail this morning, Hale commented on the apparent odd angle of the dust tail:

“Since the comet is on the far side of the sun as seen from Earth, with the typical dust tail lagging behind, that would seem to create the somewhat strange direction. It  (the tail) almost seems to be directed toward the Sun, but it’s a perspective effect.”

Venus glares inside the cone of the zodiacal light this morning at the start of astronomical twilight over the shoreline of northern Wisconsin. Jupiter is seen at top and Mars two-thirds of the way from Jupiter to Venus. Credit: Bob King
Venus glares inside the cone of the zodiacal light this morning at the start of astronomical twilight. Jupiter is seen at top and Mars two-thirds of the way from Jupiter to Venus. Arcturus shines at far left. Credit: Bob King

There were side benefits to getting up early today. Three bright planets lit up Leo’s tail and Virgo’s “Cup” and a magnificent display of zodiacal light rose from the lake to encompass not only the comet but all the planets as well.

It’s Finally Here! Comet Catalina Greets Dawn Skywatchers

If you love watching comets and live north of the equator, you’ve been holding your breath a l-o-n-g time for C/2013 US10 Catalina to make its northern debut. I’m thrilled to report the wait is over. The comet just passed perihelion on Nov. 15th and has begun its climb into morning twilight. 

Comet C/2013 US10 Catalina leaps into the morning sky in eastern Virgo this weekend at around magnitude +7. Comet positions are marked by small crosses every 5 days around 6 a.m. CST (12:00 Universal Time). Planet positions are shown for Nov. 21st. Stars to mag. +7. Source: Chris Marriott's SkyMap
Map showing the sky facing southeast around the start of dawn. Comet C/2013 US10 Catalina leaps into the morning sky in eastern Virgo beginning this weekend at around magnitude +7. Comet positions are marked by small crosses every 5 days around 6 a.m. CST (12:00 Universal Time) for mid-northern latitudes (Minneapolis, specifically). Planet positions are shown for Nov. 21st. Stars to mag. +7. Source: Chris Marriott’s SkyMap

The first post-perihelion photo, taken on Nov. 19th by astrophotographer Ajay Talwar from Devasthal Observatory high in the Indian Himalayas, show it as a starry dot with a hint of a tail only 1° above the eastern horizon at mid-twilight. Additional photos made on the following mornings show the comet inching up from the eastern horizon into better view. Estimates of its current brightness range from magnitude +6.8-7.0.

Sometimes black and white is better. This is the same chart as above. Credit: Chris Marriott's SkyMap
Sometimes black and white is better. This is the same chart as above but in a handier version for use at the telescope. Source: Chris Marriott’s SkyMap

Talwar, who teaches astrophotography classes and is a regular contributor to The World at Night (TWAN), drove 9 hours from his home to the Himalaya mountains, then climbed up the observatory dome to get enough horizon to photograph the comet. The window of opportunity was very narrow; Talwar had only 10 minutes to bag his images before the comet was overwhelmed by zodiacal light and twilight glow. When asked if it was visible in binoculars, he thought it would be but had too little time to check despite bringing a pair along.

The very first post-perihelion photo of Comet Catalina taken Nov. 19th from Devasthal Observatory. Prior to perihelion, the comet was only visible from the southern hemisphere. Copyright: Ajay Talwar
Ajay Talwar recorded the very first post-perihelion photo of Comet Catalina on Nov. 19th from Devasthal Observatory. Prior to perihelion, the comet was only visible from the southern hemisphere. Copyright: Ajay Talwar

A difficult object at the moment, once it frees itself from the horizon haze in about a week, Catalina should be easily visible in ordinary binoculars. Watch for it to gradually brighten through the end of the year, peaking around magnitude +5.5 — just barely naked eye — in late December and early January, when it will be well-placed high in the northeastern sky near the star Arcturus (see map). Matter of fact, on the first morning of the new year, it creeps only 1/2° southwest of the star for a splendid conjunction.

Even before perihelion, Comet Catalina was a beauty. This photo was taken on October 1, 2015. Credti: Jose Chambo
Even before perihelion, Comet Catalina was a beautiful thing. This photo was taken on October 1, 2015. Credit: Jose Chambo

Halloween 2013 was an auspicious one. That’s when Comet C/2013 US10 was first picked up by the Catalina Sky Survey. The “US10” part comes from initial observations that suggested it was an asteroid. Additional photos and observations instead revealed a fuzzy comet on a steeply tilted orbit headed for the inner Solar System after a long sojourn in the Oort Cloud.

Comet C/2013 US10 Catalina will slice through the plane of the Solar System at an angle of 149 never to return. Credit: JPL Horizons
Comet C/2013 US10 Catalina will slice through the plane of the Solar System at an angle of 149° never to return. It comes closest to Earth on Jan. 12, 2016. After that time, the comet will recede and fade. Credit: JPL Horizons

Its sunward journey has been nothing short of legendary, requiring several million years of inbound travel from the frigid fringe to the relative warmth of the inner Solar System. Catalina will pass closest to Earth on Jan. 12th at 66.9 million miles (107.7 million km) before buzzing off into interstellar space. Yes, interstellar. Perturbations by the planets have converted its orbit into a one-way ticket outta here.

Wow - check this out! Look to the east at the start of dawn on Dec. 7th to see a remarkable pairing of comet, Venus and the waning lunar crescent with earthshine. Source: Stellarium
Check this out! Look to the east at the start of dawn on Dec. 7th to see a remarkable pairing of comet, Venus and the waning lunar crescent with earthshine. Source: Stellarium

When using the maps above, keep in mind they show the comet’s changing position, but the constellations and planets can only be shown for the one date, Nov. 21st. Like the comet, they’ll also be slowly sliding upward in the coming days and mornings due to Earth’s revolution around the Sun; stars that are near the horizon on Nov. 21 at 5:30 or 6 a.m. will be considerably higher up in a darker sky by the same time in December. Adding the shift of the stars to that of the comet, Catalina gains about 1° of altitude per day in the coming two weeks.

When you go out to find Catalina in binoculars, note its location on the map and then use the stars as steppingstones, starting with a bright obvious one like Spica and “stepping” from there to the next until you arrive at the one closest to the comet.

I’m so looking forward to finding Catalina. Nothing like a potentially naked eye comet to warm up those cold December mornings. Mark your calendar for the morning of Dec. 7th, when this rare visitor will join Venus and the crescent Moon in the east at the start of morning twilight. See you in spirit at dawn!

Sweet Sights for November Nights

Clear night ahead? Let’s see what’s up. We’ll start close to home with the Moon, zoom out to lonely Fomalhaut 25 light years away and then return to our own Solar System to track down the 7th planet. Even before the sky is dark, you can’t miss the 4-day-old crescent Moon reclining in the southwestern sky. Watch for it to wax to a half-moon by Thursday as it circles Earth at an average speed of 2,200 mph (3,600 km/hr). That fact that it orbits Earth means that the angle the Moon makes with the sun and our planet constantly varies, the reason for its ever-changing phase.

You'll see two and possibly three lunar "seas" tonight (Nov. 15). Only a portion of Mare Tranquilliitatis (Seas of Tranquility) is exposed. The large crater Janssen, 118 miles wide and 1.8 miles deep, is visible in binoculars. Credit: Virtual Moon Atlas / Legrande and Chevalley
You’ll see two and possibly three lunar “seas” tonight (Nov. 15). Only a portion of Mare Tranquilliitatis (Seas of Tranquility) is exposed. The large crater Janssen, 118 miles wide and 1.8 miles deep, is visible in binoculars. Credit: Virtual Moon Atlas / Legrande and Chevalley

With the naked eye you’ll be able to make two prominent dark patches within the crescent — Mare Crisium (Sea of Crises) and Mare Fecunditatis (Sea of Fecundity). Each is a vast, lava-flooded plain peppered with thousands of craters , most of which require a telescope to see. Not so Janssen. This large, 118-mile-wide (190-km) ring will be easy to pick out in a pair of seven to 10 power binoculars. Janssen is named for 19th century French astronomer Pierre Janssen, who was the first to see the bright yellow line of helium in the sun’s spectrum while observing August 1868 total solar eclipse.

Piscis Austrinus, the Southern Fish, has but one bright star, 1st magnitude Fomalhaut. It shines all by its lonesome in the south around 7 p.m. local time at mid-month. The star is located only 25 light years from Earth. Source: Stellarium
Piscis Austrinus, the Southern Fish, has but one bright star, 1st magnitude Fomalhaut. It shines all by its lonesome in the south around 7 p.m. local time at mid-month. The star is located only 25 light years from Earth. Source: Stellarium

English scientist Norman Lockyer also observed the line later in 1868 and concluded it represented a new solar element which he named “helium” after “helios”, the Greek word for sun. Helium on Earth wouldn’t be discovered for another 10 years, making this party-balloon gas the only element first discovered off-planet!

See the fish now? Greek mythology tells us that Piscis Austrinus is the "Great Fish", the parent of the two fish in the zodiacal constellation of Pisces the Fish. Source: Stellarium
See the fish now? Greek mythology tells us that Piscis Austrinus is the “Great Fish”, the parent of the two fish in the zodiacal constellation of Pisces the Fish. Source: Stellarium

Directing your gaze south around 7 o’clock, you’ll see a single bright star low in the southern sky. This is Fomalhaut in the dim constellation of Piscis Austrinus, the Southern Fish. The Arabic name means “mouth of the fish”. If live under a dark, light-pollution-free sky, you’ll be able to make out a loop of faint stars vaguely fish-like in form. Aside from being the only first magnitude star among the seasonal fall constellations, Fomalhaut stands out in another way — the star is ringed by a planet-forming disk of dust and rock much as our own Solar System was more than 4 billion years ago.

The planet Fomalhaut b orbits Fomalhaut inside a circumstellar disk of dust and rock, taking about 1,700 years to orbit. Brilliant Fomalhaut, represented by the small, white dot, has been masked from view, so astronomers could photograph the much fainter disk. Credit: NASA / ESA / Hubble Space Telescope
The planet Fomalhaut b orbits Fomalhaut inside a circumstellar disk of dust and rock, taking about 1,700 years to orbit. Brilliant Fomalhaut, represented by the small, white dot, has been masked from view, so astronomers could photograph the much fainter disk. Credit: NASA / ESA / Hubble Space Telescope

Within that disk is a new planet, Fomalhaut b, with less than twice Jupiter’s mass and enshrouded either by a cloud of dusty debris or a ring system like Saturn. Fomalhaut b has the distinction of being the first extrasolar planet ever photographed in visible light. The plodding planet takes an estimated 1,700 years to make one loop around Fomalhaut, with its distance from its parent star varying from about 50 times Earth’s distance from the sun at closest to 300 times that distance at farthest.

Shoot a diagonal across the Square of Pegasus to 4th magnitude Delta Piscium. Point your binoculars here and slide east to 4th magnitude Epsilon and 2° south to the planet Uranus shines at magnitude +5.7 and can be glimpsed with the naked eye from a dark sky site. Time shown is around 7 p.m. local time. See detailed map below. Source: Stellarium
Shoot a diagonal across the Square of Pegasus to 4th magnitude Delta Piscium. Point your binoculars here and slide east to 4th magnitude Epsilon and 2° south to the planet Uranus shines at magnitude +5.7 and can be glimpsed with the naked eye from a dark sky site. Time shown is around 7 p.m. local time. See detailed map below. Source: Stellarium

Next, we move on to one of the more remote planets in our own solar system, Uranus. The 7th planet from the sun, Uranus reached opposition — its closest to Earth and brightest appearance for the year — only a month ago. It’s well-placed for viewing in Pisces the Fish after nightfall high in the southeastern sky below the prominent sky asterism, the Great Square of Pegasus.

Wide-field binocular view of Uranus' travels now through next April. I've labeled two stars near the planet with their magnitudes - 5.5 and 6.0 - which are similar to Uranus in brightness, so you don't confuse them with the planet. The others are naked eye stars in Pisces. Source: Chris Mariott's SkyMap
Wide-field binocular view of Uranus’ travels now through next April. I’ve labeled several stars near the planet with their magnitudes, which are similar in brightness to Uranus, so you’ll know to tell them apart from the planet. The others are naked eye stars in Pisces. Source: Chris Mariott’s SkyMap

A telescope will tease out its tiny, greenish disk,  but almost any pair of binoculars will easily show the planet as a star-like point of light slowly marching westward against the starry backdrop in the coming weeks. Check in every few weeks to watch it move first west, in retrograde motion, and then turn back east around Christmas. For those with 8-inch and larger telescopes who love a challenge, use this Uranian Moon Finder to track the planet’s two brightest moons, Titania and Oberon, which glimmer weakly around 14th magnitude.

We’ve barely scratched the surface of the vacuum with these offerings; they’re just a few of the many highlights of mid-November nights that also include the annual Leonid meteor shower, which peaks Tuesday and Wednesday mornings (Nov. 17-18). So much to see!

Spectacular Breakup of WT1190F Seen by Airborne Astronomers

Clouds hampered observations from the ground in Sri Lanka during the re-entry of WT1190F overnight, but a team of astronomers captured spectacular images of the object from a high-flying plane over the Indian Ocean very close to the predicted time of arrival. 

Peter Jenniskens of the SETI Institute and NASA Ames Research Center will operate eleven staring cameras with a wider field of view, including two spectographic cameras, to catch the reentry if pointing efforts fail. Credit: IAC/UAE Space Agency/NASA/ESA
Peter Jenniskens of the SETI Institute and NASA Ames Research Center is shown here before the flight setting up the eleven staring cameras with a wider field of view, including two spectographic cameras, to catch the reentry.  Credit: IAC/UAE Space Agency/NASA/ESA

The International Astronomical Center (IAC) and the United Arab Emirates Space Agency hosted a rapid response team to study the re-entry of what was almost certainly a rocket stage from an earlier Apollo moon shot or the more recent Chinese Chang’e 3 mission. In an airplane window high above the clouds, the crew, which included Peter Jenniskens, Mike Koop and Jim Albers of the SETI Institute along with German, UK and United Arab Emirates astronomers, took still images, video and gathered high-resolution spectra of the breakup.


Video and still imagery of WT1190F’s Reentry November 13, 2015

The group of seven astronomers hoped to study WT1190F’s re-entry as a  test case for future asteroid entries as well as improve our understanding of space debris behavior. Photos and video show the object breaking up into multiple pieces in a swift but brief fireball. From the spectra, the team should be able to determine the object’s nature — whether natural or manmade.

Wide view of the colorful fireball created when WT1190F burned up in Earth's atmosphere. Credit:
Wide view of the colorful fireball and breakup when WT1190F struck Earth’s atmosphere. More than 20 cameras were used to record the event. Credit: IAC/UAE Space Agency/NASA/ESA
Animation made on Nov. 12 when WT1190F was still in one piece in orbit about Earth. Credit: Marco Langbroek
Animation from photos made on Nov. 12 when WT1190F was still in one piece in orbit about the Earth. Credit: Marco Langbroek
Gulfstream 450 business jet, sponsored by United Arab Emirates and coordinated by Mohammad Shawkat Odeh from the International Astronomical Center, Abu Dhabi. There are only five windows available to observe the object. The observation teams comprise:
Flying observatory. This Gulfstream 450 business jet, sponsored by United Arab Emirates and coordinated by Mohammad Shawkat Odeh from the International Astronomical Center, Abu Dhabi, was used by the team to observe and record the re-entry. Only five windows were available to make observations. Credit: IAC/UAE Space Agency/NASA/ESA
SETI Institute staring cameras used for wide field observations of the re-entry. Credit:
SETI Institute “staring cameras” used for wide field observations of the re-entry. Credit: IAC/UAE Space Agency/NASA/ESA

Asteroid? Rocket Stage? Whatever it is, WT1190F Plunges to Earth Tonight

No one’s 100% certain what WT1190F is — asteroid or rocket stage — but we are certain it will light up like a Roman candle when it re-enters Earth’s atmosphere around 6:20 Universal Time (12:20 a.m. CST) tomorrow morning Nov. 13. 


Animation by Jost Jahn of WT1190F’s final hours as it races across the sky coming down off the coast of Sri Lanka

As described in an earlier story at Universe Today, an object discovered by the Catalina Sky Survey on Oct 3rd and temporarily designated WT1190F is expected to burn up about 60 miles (100 km) off the southern coast of Sri Lanka overnight. The same team observed it twice in 2013. Based upon the evolution of its orbit, astronomers determined that the object is only about six feet (2-meters) across with a very low density,  making it a good fit for a defunct rocket booster, possibly one used to launch either one of the Apollo spacecraft or the Chinese Chang’e 3 lander to the Moon.

Below a plot of the last three orbits of WT1190F. The small red circle is the earth. The big green circle is the orbit of the moon, just to give some scale to the chart (click on it for a bigger version).
Below a plot of the last three orbits of WT1190F. The small red circle is the Earth. For scale, the large green circle is the orbit of the Moon. Notice that its final orbit takes straight into Earth. Credit: Bill Gray / Project Pluto

Additional observations of WT1190F have been made in the past few days confirming its re-entry later tonight. Checking the latest predictions on Bill Gray of Project Pluto’s page, the object will likely be visible from Europe about an hour before “touchdown”. To say it will be moving quickly across the sky is an understatement. Try about 3 arc minutes per second or 3° a minute! Very tricky to find and track something moving that fast.

Three 90-second exposures showing WT1190F zipping across the Rosette Nebula taken on Nov. 11, 2015 at the Konkoly Observatory in Hungary. Credit: Krisztián Sárneczky
Three 90-second exposures showing WT1190F zipping across the Rosette Nebula taken on Nov. 11, 2015 at the Konkoly Observatory in Hungary. Credit: Krisztián Sárneczky

58 minutes later, in the minute of time from 6:18 to 6:19 UT,  WT1190F will move one full hour of right ascension and plummet 34° in declination while brightening from magnitude +8 to +4.5. If you’d like to attempt to find and follow the object, head over to JPL’s Horizons site  for the latest ephemerides and orbital elements. At the site, make sure that WT1190F is in the Target Body line. If not, click Change and search for WT1190F in the Target Body field at the bottom of the window.

WT1190F Re-Entry Trajectory – Data courtesy of Bill Gray, Project Pluto
WT1190F re-Entry Trajectory. The object is expected to break up and fall harmlessly into the ocean. Credit: Bill Gray, Project Pluto

You’ll find updates at Bill Gray’s site. According to the most recent positions, the object will pass almost exactly in front of the Sun shortly before plunging into the ocean. Sri Lanka’s capital, Colombo, is expected to get the best views.

Because the mystery object’s arrival has been fairly well publicized, I hope to update you with a full report and photos first thing tomorrow morning. Like many of you, I wish I could see the show.

Artificial Object in Trans-lunar Orbit to Impact Earth on November 13

Get ready for a man-made fireball. A object discovered by the Catalina Sky Survey on Oct 3rd temporarily designated WT1190F is predicted to impact the Earth about 60 miles (100 km) off the southern coast of Sri Lanka around 6:20 Universal Time (12:20 a.m CST) on November 13.

The object orbits Earth with a period of about three weeks. Because it was also observed twice in 2013 by the same survey team, astronomers have the data they need to model its orbit and trajectory, and as far anyone can tell,  it’s likely man-made. 

S-IVB stage of Apollo 17. Credit: NASA
The first two stages of the Saturn V rockets used to send the seven Apollo missions to the Moon fell back to Earth, but the third stage (S-IVB), pictured here, propelled the spacecraft into a lunar trajectory. Could this be WT1190F? Credit: NASA

Solar radiation pressure, the physical “push” exerted by photons of sunlight, is proportional to a space object’s area-to-mass ratio. Small, lightweight objects get pushed around more easily than heavier, denser ones. Taking that factor into account in examining WT1190F’s motion over two years, the survey team has indirectly measured WT1190F’s density at about 10% that of water. This is too low to be a typical asteroid made of rock, but a good fit with a hollow shell, possibly the upper stage of a rocket.

Spectacular re-entry of the Jules Verne ATV-1 cargo ship over the Pacific Ocean on September 29, 2008. Still image definition TV camera operated by Jessie Carpenter and Bill Moede of NASA Ames Research Center
Spectacular re-entry of the Jules Verne ATV-1 cargo ship over the Pacific Ocean on September 29, 2008. Still image from a TV camera operated by Jessie Carpenter and Bill Moede of NASA Ames Research Center. A similar spectacle is expected on November 13 south of Sri Lanka.

It’s also quite small, at most only about six feet or a couple of meters in diameter. Most or all of it is likely to burn up upon re-entry, creating a spectacular show for anyone near the scene. During the next week and a half, the European Space Agency’s NEO (Near-Earth Object) Coordination Center is organizing observing campaigns to collect as much data as possible on the object, according to a posting on their website. The agency has two goals: to better understand satellite re-entries from high orbits and to use the opportunity to test our readiness for a possible future event involving a real asteroid. The latter happened once before when 2008 TC3 (a real asteroid) was spotted on October 6, 2008 and predicted to strike Earth the very next day. Incredibly, it did and peppered the Sudan with meteorites that were later recovered.

Assuming WT1190F is artificial, its trans-lunar orbit (orbit that carries it beyond the Moon) hints at several possibilities. Third stages from the Saturn-V rockets that launched the Apollo missions to the Moon are still out there. It could also be a stage from one of the old Russian or more recent Chinese lunar missions. Even rockets used to give interplanetary probes a final push are game.

J002E3 discovery images taken by Bill Yeung on September 3, 2002. J002E3 is in the circle. Images taken with Astroworks Centurion 18" f2.8 scope and Apogee AP9e CCD camera, 10 u second exposure. Auto detected with PinPoint Astrometry Engine by Bob Denny. North is up. Animation created by Bob Denny.
Near-Earth object J002E3 discovery images taken by Bill Yeung on September 3, 2002. The 16th magnitude object was tentatively identified as the Apollo 12 third stage rocket. Animation created by Bob Denny.

Case in point. What was thought initially to be a new asteroid discovered by amateur astronomer Bill Yeung on September 3, 2002 proved a much better fit with an Apollo 12 S-IVB (third) stage after University of Arizona astronomers found that spectra taken of the object strongly correlated with absorption features seen in a combination of man-made materials including white paint, black paint, and aluminum, all consistent with Saturn V rockets.

On April 14th 1970, the Apollo 13 Saturn IVB upper stage impacted the moon north of Mare Cognitum, at -2.55° latitude, -27.88° East longitude. The impact crater, which is roughly 30 meters in diameter, is clearly visible in LROC NAC image M109420042LE. Credit: NASA/Goddard/Arizona State University
On April 14th 1970, the Apollo 13 Saturn IVB upper stage impacted the moon north of Mare Cognitum. The impact crater, which is roughly 30 meters in diameter, is clearly visible in this photo taken by the Lunar Reconnaissance Orbiter. Credit: NASA/Goddard/Arizona State University

Apollo 13’s booster was the first deliberately crashed into the Moon, where it blew out it a crisp, 98-foot-wide (30-meter) crater. Why do such a crazy thing? What better way to test the seismometers left by the Apollo 12 crew? All subsequent boosters ended their lives similarly in the name of seismography. Third stages from earlier missions — Apollos 8, 10 and 11 —  entered orbit around the Sun, while Apollo 12, which is orbiting Earth, briefly masqueraded as asteroid J002E3.

The nominal impact point is located about 60 miles south of the island nation Sri Lanka. Credit: Bill Gray at Project Pluto
The nominal impact point is located about 60 miles south of the island nation Sri Lanka. Given the object’s small size and mass, it will likely be completely incinerated during re-entry. Credit: Bill Gray at Project Pluto

Bill Gray at Project Pluto has a page up about the November 13 impact of WT1190F with more information. Satellite and asteroid watchers are hoping to track the object before and right up until it burns up in the atmosphere. Currently, it’s extremely faint and moving eastward in Orion. You can click HERE for an ephemeris giving its position at the JPL Horizons site. How exciting if we could see whatever’s coming down before its demise on Friday the 13th!