In 1963, an astronomy student named Gail Smith working at an observatory in the Netherlands discovered something odd – a massive cloud of gas orbiting the Milky Way galaxy.

Smith’s cloud contained enough gas to make two million stars the size of our sun, and it was moving through space at 700,000 miles per hour.

For the next 40-plus years the cloud remained a curiosity, one of a growing number of so-called high velocity clouds circling the Milky Way – interesting but not sensational.

Then something changed.

In the mid-2000s, radio astronomer Jay Lockman and colleagues took a closer look at Smith’s Cloud using the Green Bank radio telescope in West Virginia, and they were able to calculate the cloud’s orbit.

Smith’s Cloud, it turns out, is on a collision course with the Milky Way.

Thirty million years from now, give or take a few million years, it will crash into the Perseus Arm of our galaxy. The impact will compress clouds of gas in that spiral arm, causing a brilliant burst of star formation.

There’s no real danger to the Milky Way. Smith’s Cloud is minuscule compared to the gigantic spiral of stars that makes up the backbone of our galaxy. But the coming collision has sharply increased interest in Smith’s Cloud.

“We don't fully understand the Smith Cloud's origin,” said Andrew Fox of the Space Telescope Science Institute. “There are two leading theories. One is that it was blown out of the Milky Way, perhaps by a cluster of supernova explosions. The other is that the Smith Cloud is an extragalactic object that has been captured by the Milky Way.”

To investigate these theories, Fox and colleagues recently peered into the cloud using the Hubble Space Telescope’s Cosmic Origins Spectrograph.

One of the elements they found was sulfur, absorbing ultraviolet light from the bright cores of three galaxies far beyond the cloud.

By analyzing the amount of light Smith’s Cloud absorbs, the astronomers were able to measure the abundance of sulfur in the cloud.

“The abundance of sulfur in Smith’s Cloud is similar to the abundance of sulfur in the outer disk of our own Milky Way,” Fox said.

This means we have a family relationship.

“The cloud appears to have been ejected from within the Milky Way and is now falling back,” Fox said. “The cloud is fragmenting and evaporating as it plows through a halo of diffuse gas surrounding our galaxy. It's basically falling apart. This means that not all of the material in Smith’s Cloud will survive to form new stars. But if it does survive, or some part of it does, it should produce an impressive burst of star formation.”

While Fox’s work has cleared up some of the mystery of the Smith Cloud, many questions remain: What calamitous event could have catapulted it from the Milky Way's disk, and how did it remain intact?

These are questions for future research. Thirty million years to impact: the clock is ticking!

NASA's Opportunity Mars rover will drive down a gully carved long ago by a fluid that might have been water, according to the latest plans for the 12-year-old mission.

No Mars rover has done that before.

The longest-active rover on Mars also will, for the first time, visit the interior of the crater it has worked beside for the last five years.

These activities are part of a two-year extended mission that began Oct. 1, the newest in a series of extensions going back to the end of Opportunity's prime mission in April 2004.

Opportunity launched on July 7, 2003, and landed on Mars on Jan. 24, 2004 (PST), on a planned mission of 90 Martian days, which is equivalent to 92.4 Earth days.

"We have now exceeded the prime-mission duration by a factor of 50," said Opportunity Project Manager John Callas of NASA's Jet Propulsion Laboratory, Pasadena, California. "Milestones like this are reminders of the historic achievements made possible by the dedicated people entrusted to build and operate this national asset for exploring Mars."

Opportunity begins its latest extended mission in the "Bitterroot Valley" portion of the western rim of Endeavour Crater, a basin 14 miles in diameter that was excavated by a meteor impact billions of years ago.

Opportunity reached the edge of this crater in 2011 after more than seven years of investigating a series of smaller craters. In those craters, the rover found evidence of acidic ancient water that soaked underground layers and sometimes covered the surface.

The gully chosen as the next major destination slices west-to-east through the rim about half a mile (less than a kilometer) south of the rover's current location. It is about as long as two football fields.

"We are confident this is a fluid-carved gully, and that water was involved," said Opportunity Principal Investigator Steve Squyres of Cornell University, Ithaca, New York. "Fluid-carved gullies on Mars have been seen from orbit since the 1970s, but none had been examined up close on the surface before. One of the three main objectives of our new mission extension is to investigate this gully. We hope to learn whether the fluid was a debris flow, with lots of rubble lubricated by water, or a flow with mostly water and less other material."

The team intends to drive Opportunity down the full length of the gully, onto the crater floor. The second goal of the extended mission is to compare rocks inside Endeavour Crater to the dominant type of rock Opportunity examined on the plains it explored before reaching Endeavour.

"We may find that the sulfate-rich rocks we've seen outside the crater are not the same inside," Squyres said. "We believe these sulfate-rich rocks formed from a water-related process, and water flows downhill. The watery environment deep inside the crater may have been different from outside on the plain -- maybe different timing, maybe different chemistry."

The rover team will face challenges keeping Opportunity active for another two years. Most mechanisms onboard still function well, but motors and other components have far exceeded their life expectancy.

Opportunity's twin, Spirit, lost use of two of its six wheels before succumbing to the cold of its fourth Martian winter in 2010. Opportunity will face its eighth Martian winter in 2017.

Use of Opportunity's non-volatile "flash" memory for holding data overnight was discontinued last year, so results of each day's observations and measurements must be transmitted that day or lost.

In the two-year extended mission that ended last month, Opportunity explored the "Marathon Valley" area of Endeavour's western rim, documenting the geological context of water-related minerals that had been mapped there from orbital observations.

Last month, the rover drove through "Lewis and Clark Gap," a low point in the wall separating Marathon Valley from Bitterroot Valley. A recent color panorama from the rover features "Wharton Ridge," which extends eastward from the gap.

This week, Opportunity is investigating rock exposures next to "Spirit Mound," a prominent feature near the eastern end of Bitterroot Valley.

The third main science goal of the new extended mission is to find and examine rocks from a geological layer that was in place before the impact that excavated Endeavour Crater.

The science team has not yet determined whether the mound area will provide rocks that old.

Opportunity and NASA’s next-generation Mars rover, Curiosity, as well as three active NASA Mars orbiters, and surface missions to launch in 2018 and 2020 are steps in NASA's Journey to Mars, on track for sending humans there in the 2030s.

JPL, a division of Caltech in Pasadena, California, built Opportunity and manages the mission for NASA's Science Mission Directorate, Washington. For more information about Opportunity, visit http://www.nasa.gov/rovers and http://marsrovers.jpl.nasa.gov .

LAKE COUNTY, Calif. – Lake County Animal Care and Control's shelter is filled with all kinds of dogs this week needing homes.

Dogs available at Lake County Animal Care and Control this include mixes of border collie, boxer, Chihuahua, collie, German Shepherd, Great Dane, hound, husky, Labrador Retriever, Rottweiler and pit bull.

The two remaining Clayton fire dogs are listed at the top, followed by dogs not taken in from the fire area.

Dogs that are adopted from Lake County Animal Care and Control are either neutered or spayed, microchipped and, if old enough, given a rabies shot and county license before being released to their new owner. License fees do not apply to residents of the cities of Lakeport or Clearlake.

If you're looking for a new companion, visit the shelter. There are many great pets hoping you'll choose them.

The following dogs at the Lake County Animal Care and Control shelter have been cleared for adoption (additional dogs on the animal control Web site not listed are still “on hold”).

CLAYTON FIRE DOGS

Labrador Retriever mix

This female Labrador Retriever mix has a short black coat.

She was found in the Clearlake area on Aug. 15.

She's in kennel No. 19, ID No. 5862.

Pit bull terrier mix

This female pit bull terrier mix has a short black and white coat.

She was found in the Lower Lake area on Aug. 20.

She's in kennel No. 33, ID No. 5878.

NON-FIRE DOGS AVAILABLE

'Audi'

“Audi” is a female Labrador Retriever mix.

She has a short black coat and floppy ears.

She's in kennel No. 2, ID No. 6188.

Pit bull terrier mix

This male pit bull terrier mix has a short blue and white coat.

He's in kennel No. 3, ID No. 6224.

Female Chihuahua mix

This female Chihuahua mix has a short brown and white coat.

She's in kennel No. 4, ID No. 6226.

Border collie mix

This young male border collie mix has a medium-length black and white coat.

He's in kennel No. 6a, ID No. 6198.

Border collie mix

This young female border collie mix has a medium-length black and white coat.

She's in kennel No. 6b, ID No. 6199.

Border collie mix

This young female border collie mix has a medium-length black and white coat. She already has been spayed.

Shelter staff said she has a great disposition and needs an active owner.

She's in kennel No. 7, ID No. 5943.

Hound mix

This young female hound mix has a short brindle and white coat.

She's in kennel No. 8, ID No. 6133.

Labrador Retriever mix

This female Labrador Retriever mix has a short black coat.

She's in kennel No. 12, ID No. 6235.

Boxer-pit bull mix

This female boxer-pit bull mix has a short brindle and white coat.

She's already been altered, shelter staff reported.

She's in kennel No. 14, ID No. 6194.

German Shepherd

This male German Shepherd has a medium-length black and tan coat.

He's in kennel No. 23, ID No. 6233.

Rottweiler mix

This male Rottweiler mix has a short black and tan coat.

He's in kennel No. 24a, ID No. 3557.

Rottweiler mix

This female Rottweiler mix has a black coat with some brindle markings.

Shelter staff said she need some training and is manageable on a leash. They said she is a very nice dog and knows not to jump when excited. After proper introductions, she has gotten along with other dogs she has met, including off-leash play. She would do best in a home with no cats.

She's in kennel No. 25, ID No. 5947.

'Koa'

“Koa” is a female husky mix with a medium-length black and white coat and blue eyes. She already has been spayed.

She's in kennel No. 26, ID No. 6166.

'Kenai'

“Kenai” is a female husky mix. She has a medium-length black and white coat and blue eyes, and already has been spayed.

She's in kennel No. 27, ID No. 6165.

'Lucky'

“Lucky” is a male hound and Great Dane mix with a short black and white coat.

He's in kennel No. 30, ID No. 6026.

'Flor'

“Flor” is a female Labrador Retriever mix with a short black and white coat.

She already has been spayed, which should lower her adoption cost.

She is in kennel No. 30b, ID No. 6041.

Female collie mix

This female collie mix has a medium-length black coat and white markings.

She's in kennel No. 32, ID No. 6223.

To fill out an adoption application online visit http://www.co.lake.ca.us/Government/Directory/Animal_Care_And_Control/Adopt/Dog___Cat_Adoption_Application.htm .

Lake County Animal Care and Control is located at 4949 Helbush in Lakeport, next to the Hill Road Correctional Facility.

Office hours are Monday through Friday, 11 a.m. to 5 p.m., and 11 a.m. to 3 p.m., Saturday. The shelter is open from 11 a.m. to 4 p.m. Monday through Friday and on Saturday from 11 a.m. to 3 p.m.

Visit the shelter online at http://www.co.lake.ca.us/Government/Directory/Animal_Care_And_Control.htm .

For more information call Lake County Animal Care and Control at 707-263-0278.

Email Elizabeth Larson at This email address is being protected from spambots. You need JavaScript enabled to view it. . Follow her on Twitter, @ERLarson, or Lake County News, @LakeCoNews.

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NORTHERN CALIFORNIA – With Halloween coming, spider web motifs are everywhere.

Although in nature there are many different types of webs, the ones with which we’re all most familiar are those spiral bicycle-wheel shaped webs found in gardens, forests and grassland fields made by the orb-weaver spiders.
 
The oldest known orb-weaver was a species known as Mesozygiella dunlopi, a now extinct spider that lived during the Lower Cretaceous period (about 125 to 140 million years ago).

Today, there are actually more than 2,800 species of orb-weavers across the globe, and they vary greatly in size, shape and coloring.

The one thing most of them have in common is the way they build their webs ... And most of the webs you see are built by the females.
 
Among orb-weavers, females are usually several times larger than the males, and the males only build webs for themselves when they’re very young.

When sexually mature, the males will venture out onto the female’s web, albeit very carefully because female orb-weavers are cannibalistic and will readily eat the males if they loiter for more than about 5 or 10 seconds.
 
An incredible engineer, the female orb-weaver will start her web by securing a strand of silk from her spinneret (the spider’s silk-spinning organ, usually found at the back of the abdomen) to some permanent surface like a tree limb, plant or rock.

Then the spider jumps and lets the wind carry it to another adjacent site while it continues to spin a non-sticky line of silk.

It anchors the loose end of the line to a second permanent surface, walks out across its now taut line to the center, and floats downward with a new strand of silk to form a sort of silken “Y.”

Once the Y is finished, the spider will use that as the base for its web and will continue to add more “spokes” to its circle.

Generally speaking, each of the long spokes of the web is made of non-sticky silk. The sticky-silk is saved for the spiral that runs from the center of the spoke-web, around and around to the outer edges of the web.

Once the web is completed, the spider may sit in the center of it, or hide somewhere close to the web with one appendage touching the nearest thread to feel for any movement that might indicate the web has captured some prey.
 
When small insects fly or blunder into the web, the spider comes out and incapacitates it with a bite.

Orb-weavers do produce venom, but it is low grade and not toxic to humans. They are also typically non-aggressive spiders that won’t bite people unless they’re provoked.
 
If the spider doesn’t consume the prey right away, it will wrap its victim up in silk and save it for later.

If the prey turns out to be something that has a stinger of its own, like a bee or wasp, the spider will protect itself by wrapping the dangerous prey up before it bites and consumes it.
 
Some orb-weavers eat their webs after one day and then spin a new one in the same general location the next, while others keep using the same web as long as it’s functioning properly.
 
You may also see some orb-weaver webs “decorated” with lines of detritus – such as dead insects, plant materials and leftovers – or crisscrossing bands of silk called “stabilimentum.”

The trashline spider and the black-and-yellow garden spider are prime examples of species that do this.

Scientists still haven’t agreed on what purpose these decorations serve. Some believe they help to lure in prey, advertise to mates or stabilize the web structure itself.

Most recent studies suggest, however, that because the stabilimentum are so conspicuous and bright, they actually trick prey into trying to avoid the structures and thereby crash into the web itself.
 
So, now when you see all the webs in the Halloween decorations, you’ll be more appreciative of the work the spiders put into them.

Mary K. Hanson is a Certified California Naturalist and author of the “Cool Stuff Along the American River” series of nature guides available at www.lulu.com . Tuleyome is a501(c)(3) nonprofit conservation organization based in Woodland, Calif. For more information, see their website at: www.tuleyome.org .

MENDOCINO NATIONAL FOREST, Calif. – Mendocino National Forest fire managers announced that it is time to prepare for prescribed burning on the Grindstone Ranger District.

Prescribed fires are conducted to help reduce the potential for future severe wildfires, increase firefighter safety, remove hazardous fuels, and protect communities and watersheds.

Prescribed fires may be implemented through the fall and winter pending appropriate conditions.

The ignition of all projects is dependent on the availability of personnel and equipment, favorable weather, conditions that minimize smoke impacts as best as possible and California Air Resources Board approval. 

The local air quality district manages the number of acres available to burn during allotted burn days based on the amount of projects proposed.

Burns are conducted within a “prescription” that is determined by appropriate fuel moisture, temperature, humidity, wind, and ventilation. 

Fire crews implement, monitor, and patrol each project to ensure it meets the goals and objectives outlined in the prescribed burn plans.

Forest officials said they strive to keep the public informed of planned prescribed fires as smoke may be visible at different times across the forest.

Forest visitors should contact the appropriate ranger district for prescribed fire information before beginning their trip to the forest.

These are the prescribed burning projects on the Grindstone Ranger District that may occur this year:

· Grindstone Type Conversation – 2,710 acres, units in Glenn and Colusa counties.
· Alder Springs Underburn – 2,241 acres, approximately 16 miles from Elk Creek.
· Ivory Mill Underburn – 1,056 acres, ten miles west of Elk Creek.
· Oak Ridge Underburn – 868 acres, 15 miles west of Paskenta.
· Little Stony Underburn – 2,975 acres, 43 miles southwest of Willows, and eight miles southwest of the community of Ladoga.
· Pacific Ridge Underburn – 1,324 acres (1,203 on Forest Service land and 121 acres on private land), within the South Fork Stony Creek watershed and in the Upper Little Stony Creek watershed.
· Grindstone Pile Burns – 1,514 acres, across the district within Colusa County, Glenn County and Tehama counties.
 
As projects are implemented, updates will be posted on the forest Web site, http://www.fs.usda.gov/mendocino .