Giant Lake Confirmed on Saturn's Moon Titan

By Jeanna Bryner,Senior Writer

A giant, glassy lake larger than North America's Lake Ontario graces the south pole of Saturn's largest moon Titan, new research confirms.

"This is the first observation that really pins down that Titan has a surface lake filled with liquid," said lead researcher Robert Brown of the University of Arizona's Lunar and Planetary Laboratory in Tucson.

Called Ontario Lacus, the lake extends 150 miles (235 kilometers) and covers an area of about 7,800 square miles (20,000 square kilometers). The lake structure is filled mostly with methane and ethane, hydrocarbons that are gases on Earth but liquid on the bone-chilling surface of Titan.

Wet ideas

The finding, detailed in the July 31 issue of the journal Nature, is just another gold star for Titan, which has become one of the most fascinating bodies in the solar system for exploring environments that may give rise to life. Boasting a size that's one-and-a-half times that of Earth's moon and bigger than Mercury, Titan is the only solar system moon known to support a planet-like atmosphere.

The idea of liquid features on Titan is not new. Before the Cassini mission to Saturn, astronomers thought Titan was covered in a global ocean, though the spacecraft's flybys of the moon sucked the life out of that wet notion. Even still, evidence for features similar to Earth's lakes and seas, along with telltale signs of erosion from flowing water, have since come to light.

Possible evidence for lake-like features came from radar images, but this method can't distinguish between liquid and very fine gravel or other tiny solids, Brown explained.

"Detection of liquid ethane in Ontario Lacus confirms a long-held idea that lakes and seas filled with methane and ethane exist on Titan," said researcher Larry Soderblom of the U.S. Geological Survey in Flagstaff, Ariz.

Titan lake

Soderblom, Brown and their colleagues used the infrared abilities of Cassini's visual and infrared mapping spectrometer, or VIMS, to peer through Titan's cotton-ball-like veil of hydrocarbons that extends more than 620 miles (1,000 km) above the moon's surface.

The measurements showed three features of the lake structure: the shoreline, or the outer edge of the lake; the so-called beach just inside the shoreline, which could be a sort of "bathtub ring" of material left behind as the ethane mixture evaporated; and the lake's interior, which appears dark, the researchers say.

"It seems to have partially evaporated, and that makes sense because the south pole has just gone through summer," Brown told SPACE.com. "The maximum evaporation will have already occurred or is in the process of occurring."

He added, "There's still a lot of liquid left in that lake, and we don't think it's going to evaporate much further."

Plus, the lake feature could be replenished by Titan's dreary drizzle of methane, which when hit by sunlight breaks down into ethane.

As for how the liquid lake feature would feel if one were to step in, "Liquid ethane-methane mix would be less viscous than water," Brown said. "If riffling your fingers through it you wouldn't feel as much resistance."

The Cassini mission is an international cooperative effort of NASA, the European Space Agency (ESA), Italian Space Agency (ASI) and several separate European academic and industrial contributors.

Plants Talk, Even Eavesdrop

By Robert Roy Britt, LiveScience Managing Editor

Close-up of a dodder
seedling attaching to a
tomato plant.
Credit: Justin Runyon/
De Moraes and Mescher
Labs

It's bad enough when a parasite latches on to your body to suck you dry. But when it starts eavesdropping on your communications, enough already.

That's what the parasitic dodder vine does. It consumes water and nutrients from a host plant and, scientists have just discovered, it taps into the host's communication system.

Plants use RNA molecules to send messages to different parts, say from roots to leaves. In the new study, RNA molecules from a host tomato plant were found in the parasitic dodder vine, up to a foot away (30 cm) from where the dodder grafted itself to the host.

Picking up these RNA messengers could help the parasite synchronize its lifecycle with that of the host plant, explained Neelima Sinha at the University of California, Davis. "It might be important for the parasite to know when the host is flowering, so it can flower at the same time," before the host dies, she said.

The research, funded by the Rockefeller Foundation and detailed online in the journal New Phytology, could lead to new ways to combat parasites that attack crop plants.

The discovery is yet one more surprising method of communication involving planets.

In a 2006 study, baby dodder plants were found to sniff the air for signs of plant victims, then attack.

Similarly, a western U.S. shrub called sagebrush has a remarkable ability to chat. When one is damaged by insects, it broadcasts the predator's presence by releasing odors into the air. Other sagebrush pick up on the smells from their wounded brethren and get their defenses going.

Earlier this year, a research team found that insects below and above the ground use the mustard plant like a chemical telephone. A bug munching on the roots, for example, could send chemical signals up to the leaves to essentially put out a "no vacancy" sign.

NASA says Mars craft "touched and tasted" water

By Jill Serjeant

LOS ANGELES (Reuters) - NASA scientists said on Thursday they had definitive proof that water exists on Mars after further tests on ice found on the planet in June by the Phoenix Mars Lander.

"We have water," said William Boynton, lead scientist for the Thermal and Evolved-Gas Analyzer instrument on Phoenix.

"We've seen evidence for this water ice before in observations by the Mars Odyssey orbiter and in disappearing chunks observed by Phoenix last month, but this is the first time Martian water has been touched and tasted," he said, referring to the craft's instruments.

NASA on Thursday also extended the mission of the Phoenix Mars Lander by five weeks, saying its work was moving beyond the search for water to exploring whether the red planet was ever capable of sustaining life.

"We are extending the mission through September 30," Michael Meyer, chief scientist for NASA's Mars exploration program, told a televised news conference.

The extension will add about $2 million to the $420 million cost of landing Phoenix on May 25 for what was a scheduled three-month mission, Meyer said.

Phoenix is the latest NASA bid to discover whether water -- a crucial ingredient for life -- ever flowed on Mars and whether life, even in the form of mere microbes, exists or ever existed there.

Phoenix touched down in May on an ice sheet and samples of the ice were seen melting away in photographs taken by the lander's instruments in June.

Boynton said that water was positively identified after the lander's robotic arm delivered a soil sample on Wednesday to an instrument that identifies vapors produced by heating.

Mission scientists said the extension would give time for more analysis of Martian samples. They plan to dig two additional trenches -- dubbed "cupboard" and "neverland" -- using the robotic arm on the Phoenix craft.

"We hope to be able to answer the question of whether this was a habitable zone on Mars. It will be for future missions to find if anyone is home on this environment," Phoenix principal investigator Peter Smith told the news conference.

Mission scientists said in June that Martian soil was more alkaline than expected and had traces of magnesium, sodium, potassium and other elements. They described the findings as a "huge step forward."

Meyer said the scientific proof of the existence of water meant that Phoenix could "move from looking for water to seeing whether there were habitats for life.

"We are moving towards understanding whether there were or could be places on Mars that are habitable," Meyer said.

(Reporting by Jill Serjeant; Editing by Eric Walsh)

Super-Earths

Astronomers find batch of "super-Earths



WASHINGTON (Reuters) - European researchers said on Monday they discovered a batch of three "super-Earths" orbiting a nearby star, and two other solar systems with small planets as well.
They said their findings, presented at a conference in France, suggest that Earth-like planets may be very common.
"Does every single star harbor planets and, if yes, how many?" asked Michel Mayor of Switzerland's Geneva Observatory. "We may not yet know the answer but we are making huge progress towards it," Mayor said in a statement.
The trio of planets orbit a star slightly less massive than our Sun, 42 light-years away towards the southern Doradus and Pictor constellations. A light-year is the distance light can travel in one year at a speed of 186,000 miles a second, or about 6 trillion miles.
The planets are bigger than Earth -- one is 4.2 times the mass, one is 6.7 times and the third is 9.4 times.
They orbit their star at extremely rapid speeds -- one whizzing around in just four days, compared with Earth's 365 days, one taking 10 days and the slowest taking 20 days.
Mayor and colleagues used the High Accuracy Radial velocity Planet Searcher or HARPS, a telescope at La Silla observatory in Chile, to find the planets.
More than 270 so-called exoplanets have been found. Most are giants, resembling Jupiter or Saturn. Smaller planets closer to the size of Earth are far more difficult to spot.
None can be imaged directly at such distances but can be spotted indirectly using radio waves or, in the case of HARPS, spectrographic measurements. As a planet orbits, it makes the star wobble very slightly and this can be measured.
"With the advent of much more precise instruments such as the HARPS spectrograph ... we can now discover smaller planets, with masses between 2 and 10 times the Earth's mass," said Stephane Udry, who also worked on the study.
The team also said they found a planet 7.5 times the mass of Earth orbiting the star HD 181433 in 9.5 days. This star also has a Jupiter-like planet that orbits every three years.
Another solar system has a planet 22 times the mass of Earth, orbiting every four days, and a Saturn-like planet with a 3-year period.
"Clearly these planets are only the tip of the iceberg," said Mayor.
"The analysis of all the stars studied with HARPS shows that about one third of all solar-like stars have either super-Earth or Neptune-like planets with orbital periods shorter than 50 days."
(Reporting by Maggie Fox; Editing by John O'Callaghan)

Ancient cave linked to early Christians in Jordan

Ancient cave linked to early Christians
By DALE GAVLAK, Associated Press Writer Wed Jun 11, 9:21 PM ET




For more pictures on the cave Click Here

AMMAN, Jordan - Archaeologists in Jordan have discovered a cave underneath one of the world's oldest churches and say it may have been an even more ancient site of Christian worship. But outside experts expressed caution about the claim.
Archaeologist Abdel-Qader al-Housan, head of the Rihab Center for Archaeological Studies, said this week that the cave was unearthed in the northern Jordanian city of Rihab after three months of excavation and shows evidence of early Christian rituals.
The cave is under St. George's Church, which some believe was built in the year 230, though the date is widely disputed. That would make it one of the oldest churches in the world, along with one unearthed in the Jordanian southern port of Aqaba in 1998 and another in Israel discovered in 2005.
Al-Housan said there was evidence that the underground cave was used as a church by 70 disciples of Jesus in the first century after Christ's death, which would make it the oldest Christian site of worship in the world.
He described a circular worship area with stone seats separated from a living area that had a long tunnel leading to a source of water. He said the early Christians hid there from persecution.
A mosaic inscription on the floor of the later church of St. George above refers to "the 70 beloved by God and the divine" who founded the worship there.
S. Thomas Parker, a historian at North Carolina State University who led the team that discovered the church in Aqaba, said that while he hadn't seen the Rihab site, any such claim should be taken with a degree of caution.
"An extraordinary claim like this requires extraordinary evidence," he said. "We need to see the artifacts and dating evidence to suggest such an occupation in the 1st century A.D."
Parker asked how archeologists could be certain whether the "cave was actually a center of Christian worship."
The archaeologist also noted that mosaics are difficult to date unless there is a precise date in the text of the mosaic inscriptions themselves and typical mosaic inscriptions with Christian themes are from the 5th to 6th century.
"It's quite possible that there was a cave with earlier occupation which was later converted to Christian use. But to make the jump that this was actually used by Christians fleeing Jerusalem in the 1st century A.D. seems like a stretch to me," Parker said.
Australian archaeologist Kate da Costa of the University of Sydney, who works in northern Jordan where the cave was found, also said the evidence needs to be confirmed by other archaeologists.
"And even if the cave can be proved to have been in use in the first (century) A.D., there needs to be additional evidence that it was used by Christians," she told the AP.
She also said that St. George's church is not universally accepted as the oldest church in the world. Da Costa said a date of 230 for a constructed church "is over 200 years earlier than any other known church."
Archimandrite Nektarious, bishop deputy of the Greek Orthodox Archdiocese in Amman, hailed the discovery, calling it an "important milestone for Christians all around the world and right here at home."
"It confirms that Christians in this region are not strangers," he said. "They are real citizens who have always had roots in this region from those days until the present."

Single-horned 'Unicorn' deer found in Italy

Single-horned 'Unicorn' deer

By MARTA FALCONI, Associated Press Writer Wed Jun 11, 3:06 PM ET
ROME - A deer with a single horn in the center of its head — much like the fabled, mythical unicorn — has been spotted in a nature preserve in Italy, park officials said Wednesday.
"This is fantasy becoming reality," Gilberto Tozzi, director of the Center of Natural Sciences in Prato, told The Associated Press. "The unicorn has always been a mythological animal."
The 1-year-old Roe Deer — nicknamed "Unicorn" — was born in captivity in the research center's park in the Tuscan town of Prato, near Florence, Tozzi said.
He is believed to have been born with a genetic flaw; his twin has two horns.
Calling it the first time he has seen such a case, Tozzi said such anomalies among deer may have inspired the myth of the unicorn.
The unicorn, a horse-like creature with magical healing powers, has appeared in legends and stories throughout history, from ancient and medieval texts to the adventures of Harry Potter.
"This shows that even in past times, there could have been animals with this anomaly," he said by telephone. "It's not like they dreamed it up."
Single-horned deer are rare but not unheard of — but even more unusual is the central positioning of the horn, experts said.
"Generally, the horn is on one side (of the head) rather than being at the center. This looks like a complex case," said Fulvio Fraticelli, scientific director of Rome's zoo. He said the position of the horn could also be the result of a trauma early in the animal's life.
Other mammals are believed to contribute to the myth of the unicorn, including the narwhal, a whale with a long, spiraling tusk.

Egyptian Pharoah's 'Missing' Pyramid Found

Egyptian Pharoah's 'Missing' Pyramid Found
Katarina Kratovac, Associated Press


Egyptian archaeologists have uncovered the "missing pyramid" of a pharaoh and a ceremonial procession road where high priests carried mummified remains of sacred bulls, Egypt's antiquities chief said Thursday.
Zahi Hawass said the pyramid -- of which only the base remains -- is believed to be that of King Menkauhor, an obscure pharaoh who ruled for only eight years more than 4,000 years ago.
In 1842, German archaeologist Karl Richard Lepsius mentioned Menkauhor's pyramid among his finds at Saqqara, calling it the "Headless Pyramid" because its top was missing, Hawass said.
But the desert sands covered Lepsius' discovery, and no archaeologist since was able to find it.
"We have filled the gap of the missing pyramid," Hawass told reporters on a tour of the discoveries at Saqqara, the necropolis and burial site of the rulers of ancient Memphis, the capital of Egypt's Old Kingdom, south of Cairo.
Only the pyramid's base -- or the superstructure as archaeologists call it -- was found after a 25-foot-high mound of sand was removed over the past year and a half by Hawass' team.
The base was in a 15 foot-deep pit dug out by workers, with heaps of huge rocks marking its entrance and walls. A burial chamber also was discovered.
Hawass said the style of the pyramid and of a gray granite sarcophagus lid found in the burial chamber indicates the pyramid was from the Fifth Dynasty, a period that began in 2,465 B.C. and ended in 2,325 B.C.
The period spanned approximately 140 years of the Old Kingdom. That would put it about two centuries after the completion of the Great Pyramid of Giza, believed to have been finished in 2,500 B.C.
Archaeologists have not found a cartouche -- a pharoah's name in hieroglyphs -- of the pyramid's owner. But Hawass said that, based on the estimated dating of the pyramid, he was convinced it belonged to Menkauhor.
The second discovery Hawass announced Thursday was a part of a ceremonial procession road, dating back to the Ptolemaic period, which ran for about 300 years before 30 B.C.
It runs alongside Menkauhor's pyramid, leading from a mummification chamber toward the Saqqara Serapium, a network of underground tombs where sacred bulls were interred, discovered by French archaeologist August Mariette in 1850.
A high priest would carry the mummified bulls' remains down the road -- the only human allegedly allowed to walk on it -- to the chambers where the bulls would be placed in sarcophagi in the Serapium, about a third of a mile away, he said.
Ancient Egyptians considered Apis Bulls to be earthy incarnations of the city god of Memphis and connected with fertility and the sun-cult.
A bull would be chosen for its deep black coloring and would be required to have a single white mark between the horns. Selected by priests and honored until death, it was mummified and buried in the Serapium's underground galleries.
The sprawling archaeological site at Saqqara is most famous for the Step Pyramid of King Djoser -- the oldest of Egypt's over 100 pyramids, built in the 27th century B.C.