NASA followed one of the classic rules for Internet videos during its first space-to-Earth Google Hangout on Friday: If you want to bring in the viewers, don't forget the cats.

Astronaut Tom Marshburn's demonstration of how an astronaut in the International Space Station's zero-gravity environment can imitate a falling kitty was one of the highlights of the hourlong video chat, which addressed more than 30 questions sent in via YouTube, Twitter, Facebook, Google+ and real-time hookups with kids across the country.

One of the questions, phrased in the form of a video, came from the host of the "Smarter Every Day" webcast series, a rocket engineer known as Destin. (He keeps mum about his last name to protect his kids, who appear in the webcasts.) Destin ran his own mini-video showing how a falling cat rights itself in the air to land on its feet, and asked if the astronauts could match that feat in zero-G.

"We don't have any cats onboard," said space station commander Kevin Ford, "but we have a medical doctor who maybe can try to demonstrate the next best thing to a cat."

Marshburn, who's a physician as well as an astronaut, then proceeded to float in front of the camera and twist his body to change position — not quite as adroitly as the cats, but not bad for a human.

"I hope you believe that what you saw happened with the cat isn't a mystery, and that it can happen in space, too," Ford concluded. You can watch the demonstration around the 33-minute mark in the Hangout video.

Other astronauts participating in the chat included Canada's Chris Hadfield aboard the station, and NASA's Ron Garan and Nicole Stott on the ground. They took questions passed along from social media by NASA moderator John Yembrick; from live-video hookups with classrooms at University High School in Orlando, Fla., and Mescalero Apache School in New Mexico; and from a youngster named Fred whose video link was facilitated by the Make-a-Wish Foundation.

Google

Astronauts Tom Marshburn, Kevin Ford and Chris Hadfield join the Google+ Hangout.

Here are a few more nuggets from the video:

• Hadfield said that this week's communications outage on the space station was "not that big a deal," and that the crew members were well-trained to operate the station even when they were out of contact with ground controllers. "It wasn't any sort of panic or anything, it was just us dealing with a problem on the ground, and our crew dealing with the problem on board," he said. 
• Getting into the right sleep cycle is a big challenge on the space station, where there are 16 sunsets and sunrises every day. Garan said that when it gets close to bedtime, some astronauts avoid looking out the window at Earth's bright side. Stott said NASA is experimenting with a scheme that makes the lighting inside the space station more bluish for the "morning" of the astronauts' workday, and more orangish during the "evening."
• The station's crew members showed off the medical kits they kept on board for health problems, but if there's a life-threatening emergency on board, astronauts would get into one of the Russian Soyuz capsules attached to the station and fly the stricken crew member back to Earth. "Our Soyuz is our ambulance," Marshburn said. 
• When the astronauts were asked which scientist from the past they wish they could bring to the space station, Marshburn instantly said Isaac Newton, who drew up physics' three laws of motion in the 17th century. "We see what he could only imagine," Marshburn said. 
• Taking pictures from space is a challenging task that requires advance training, due to the sharp contrast between the blackness of outer space and the brilliance of the planet below, Hadfield said. But there's one big plus: Because of the zero-G environment, it's a lot easier to handle huge telephoto lenses. "Every photographer in the world would love to have that much glass in front of their eyes ... and not have to balance it," Hadfield said.
• When the astronauts were asked about their growing social-media stardom, Hadfield said, "I don't think anybody tries to push the edge of human experience more than we do." Being able to see the whole world below is "too good an experience not to share," and avenues such as Twitter, Facebook and Google+ help facilitate that, he said. He noted that a lot of the astronauts' popularity had to do with their unique perspective. "We know just how lucky we are to be here," Hadfield said.

For more outer-space video goodness, tune in the Weekly Space Hangout at 3 p.m. ET Friday. Yours truly will be on the screen along with other scribes to review the week's space news, including the meteor blast that hit Russia a week ago.

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

NASA

NASA astronaut Tom Marshburn (left), Canadian astronaut Chris Hadfield (center) and space station commander Kevin Ford strike a zero-G pose in the International Space Station's Harmony node. All three will participate in Friday's Google+ Hangout.

Friday's live Google+ Hangout represents one small step for NASA, one giant leap for the Web-based videoconferencing tool.

Space-to-Earth hookups are nothing new for the International Space Station: NASA TV regularly broadcasts video from the orbital outpost as it circles the globe at an altitude of 240 miles (385 kilometers). Astronauts have been sending Twitter updates and Flickr photos from space for years. Heck, even NASA's robots have Facebook pages. But Friday's hourlong event, scheduled to run from 10:30 to 11:30 a.m. ET, marks the first time that NASA has done a Hangout.

"We're looking forward to it," said Jason Townsend, a spokesman at NASA Headquarters in Washington.

He said NASA has selected 20 video questions from the scads that were sent in by the agency's social-media followers, and at least some of those questions will be aired for the space station astronauts to answer during a 20-minute downlink opportunity starting at 11 a.m. ET. "We're angling to fill every minute," Townsend told NBC News.

Three of the space station's six astronauts — station commander Kevin Ford, NASA colleague Tom Marshburn and Canada's Chris Hadfield — will participate in the space-plus-Earth Hangout. (The three others, all Russians, will presumably be minding the store.)

Townsend said that for the balance of the hour, questions will be handled by two NASA astronauts on the ground: Ron Garan, a social-media star who's in nearly 3 million Google+ circles; and Nicole Stott, who participated in the space station's first live NASA Tweetup in 2009.

Questions can be submitted during the Hangout via Google+, via Twitter (by including the hashtag #askAstro) and via NASA's Facebook page.

The outer-space Hangout is just the latest leap for NASA's social-media strategy: The Tweetups of the late space shuttle era have given way to a string of NASA Social gatherings. One took place just this week at NASA Headquarters. NASA regularly sets aside seats for social-media mavens at big events, including next month's SpaceX Dragon launch.

Last year, NASA's social-media teams presented 16 events that brought more than 1,000 followers to NASA facilities and other spacey locales. Mars Curiosity rover has been the star of the show, thanks in part to her (yes, her) 1.3 million Twitter followers. During the rover's landing last August, NASA served up a record 36 million webcast streams, and the six-wheeled robot has been known to check in to Foursquare from Mars.

How can the Three Amigos on the space station possibly compete with Curiosity (and her cantankerous, non-NASA-sponsored alter ego, Sarcastic Rover)? Tune in on Friday and find out.

More marvels from the space station:

• Astronaut's artistry hits warp speed
• Space-plus-Earth duet makes debut
• Online contest to boost space station power

After NASA's Hangout, keep an eye out for the Weekly Space Hangout, which brings space scribes together for an hour starting at 3 p.m. ET. Universe Today's Fraser Cain and Astrosphere's Scott Lewis (the Bald Astronomer) are among the ringleaders.

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Slideshow: Take a virtual dive

Catlin Seaview Survey

See dozens of wonders from coral reefs and other exotic seascapes, courtesy of the Catlin Seaview Survey.

Launch slideshow

Thousands of images from Australia's Great Barrier Reef and other coral locales are being stitched together into an eye-popping array of 360-degree panoramas for Google Maps' Street View feature — but this million-dollar-plus project isn't just about pretty pictures. It's about sharing the wonders and the woes of the world's coral reefs with people around the globe.

"This will allow the 99.9 percent of the population who have never been diving to go on a virtual dive for the first time," said Richard Vevers, project director for the Catlin Seaview Survey.

In partnership with Google, the Seaview Survey has been mounting a series of expeditions to capture high-resolution imagery of the Great Barrier Reef and other coral reef locales. It's sponsored by Catlin Group Ltd., a global insurance group. The project went through a preview phase back in February, and since then, it has continued to ramp up. Even before the official unveiling, the Seaview Survey has gained more than 1.4 million fans on Google+.

"Now we are actually in full expedition mode," Vevers said. To celebrate Wednesday's official kickoff, the survey is staging its first public real-time dive at the Great Barrier Reef via a Google+ Hangout at 1:30 p.m. ET. It'll be the middle of the night in Australia, but it'll be getting toward midday at the Blue Ocean Film Festival in Monterey, Calif., where Vever and other Seaview Survey organizers are hanging out this week.

Here are some of the 360-degree, Street View-style goodies that are already available via Google Maps:

• Australia's Heron Island Resort, where you swim with sea turtles.
• Lady Elliot Island Underwater, where a manta ray is silhouetted in the sunlight.
• Wilson Island, Great Barrier Reef, where you pop your head up to watch a sunset.
• The Philippines' Apo Island, where you come face to face with coral.
• Maui's Molokini Crater in Hawaii, where divers drift nearby.
• Oahu's Hanauma Bay, where you watch snorkelers pass overhead.

Vevers and his colleagues aim to take 50,000 shallow-reef pictures, using a specially designed SVII camera. When all those images are stitched together into a continuous skein, the 360-degree panoramas will let users navigate their own way through one long virtual Google Maps dive. There'll also be a deep-reef survey, conducted using picture-snapping robots.

Scientists plan to analyze the photos using image-recognition software to get a quick read on coral reef health. That's a crucial issue for the decades ahead. Half of the ocean's coral communities have been lost over the past 40 years, said the survey's chief scientist, Ove Hoegh-Guldburg of the University of Queensland's Global Change Institute. The decline is due to a variety of causes, ranging from coastal water quality to overfishing to ocean warming and acidification, he said.

"The evidence of these changes is there, but people outside the scientific community don't understand the significance of those changes," Hoegh-Guldburg told me. "If we're going to tackle these global issues, we need everyone on the planet to understand what we are in danger of losing, and what we can do to stop the decline."

He said the Seaview Survey's biggest benefit will be to give people a greater appreciation of the world's coral reefs, whether they're Australian business executives or Russian grandmothers.

Sharing the seas' wonders
The Seaview Survey aims to conduct regular expeditions that can be shared via Hangouts and other live events. All the scientific data will be made public via an online Global Reef Record database, Hoegh-Guldburg said. He's also looking into ways to enlist volunteers to analyze coral reef pictures, an idea that's taken from the citizen-science playbooks for Zooniverse and the Cornell Lab of Ornithology.

The survey is due to focus on the Great Barrier Reef and the Coral Sea is due to run until the end of December, and then it'll move on to other locations around the globe, including Hawaii, the Philippines and Bermuda. Hoegh-Guldburg said the survey's tools and techniques are designed to be adapted easily for a wide range of coral reef settings — including countries that haven't been able to assess their own coral reefs.

"Many of these countries know that their reefs are in trouble, but they don't know how much they're losing, or where they're losing the most," Hoegh-Guldburg said. "This can help them prioritize. If you don't prioritize, it's very hard to get traction."

The way he sees it, the Catlin Seaview Survey is coming just in time.

"Everybody is waking up to the realization that this is a critical decade," Hoegh-Guldburg said. "We're making decisions that could haunt us for hundreds of years if we don't get them right. It's now or never." 

More Google Street View goodies:

• Google maps ancient Mexican ruins
• Google tours NASA's Kennedy Space Center
• Take a Death Valley drive with the click of a mouse
• Google view of Amazon (the real Amazon) now live

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Google / DigitalGlobe / GeoEye

An intriguing site near an Egyptian town called Dimai consists of a large, square formation and smaller features.

Remember that researcher who thought she spotted previously undiscovered Egyptian pyramids in Google Earth imagery? It turns out that there really are some ruins in the picture, but they’re not pyramids.

That's the verdict of an Italian archaeologist who has been surveying the area around the present-day town of Dimai in Egypt's Fayoum Desert.

"The features in Google images are well-known since 1925, when they were surveyed by G. Caton-Thompson and E.W. Gardner," Paola Davoli, an Egyptologist at Italy's University of Salento and co-director of the Soknopaiou Nesos Project, told me in an email. "They are natural mounds surmounted by a building (the biggest one) and by dug wells (in the other cases). For sure they are not pyramids, but their date and use are still not known."

The Dimai formations have been a subject of interest for many years. "We [have] still not dug them, but they will be the objects of future study by the Soknopaiou Nesos Project," Davoli said.

For more than a decade, the project has been doing a territorial survey of the area around Dimai, which was known as Soknopaiou Nesos during the Greco-Roman period in Egypt. The city is thought to have been founded by Ptolemy II in the third century B.C., on a site that shows evidence of habitation going back to the Neolithic period. During its heyday, it was situated on the shore of a large freshwater lake, but the lake has shrunk and gone salty since ancient times.

Davoli said the prevailing view is that the structures might have been watchtowers, designed to look over "an agricultural area or a paleo-lake just in front of them to the east," or perhaps tombs.

Dan Billin, a former newspaper reporter in New Hampshire who turned us on to the Soknopaiou Nesos Project, cites multiple reports about the Dimai site. "Micol was correct to think that at least one of the anomalies she saw on Google Earth was a man-made feature," Billin wrote in an email. "What she didn't manage to discover, however, was that archaeologists already knew about it, and that it's surrounded by numerous other archaeological sites."

Bob Brier, an Egyptologist based at Long Island University's C.W. Post Campus, said in an email that Billin's evaluation of the site "sounds like a reasonable scenario."

Google Earth via Angela Micol

Several eroded features can be seen in this image of terrain about 12 miles from Abu Sidhum, a city on the Nile.

"Note, there is no mention of pyramids," Brier wrote.

The North Carolina researcher who started the fuss over the "Google Earth pyramids," Angela Micol, had pointed to another intriguing area of the Egyptian desert with four mounds and a large, triangular-shaped plateau, alongside the Nile in Upper Egypt, 12 miles (19 kilometers) from Abu Sidhum. The prevailing view is that those formations are not mounds or pyramids built by human hands, but are buttes carved by natural erosion.

Such formations are commonly seen in that part of the desert, James Harrell, professor emeritus of archaeological geology at the University of Toledo, told Life's Little Mysteries.

More mysteries from Egypt:

• Severed right hands unearthed in ancient Egyptian palace
• Ancient Egyptian calendar notes flickering 'Demon Star'
• Mystery of pyramid hieroglyphs: It all adds up
• Lost pyramids spotted by space scientists

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

INAH

Children watch as a rider drives a camera-equipped tricycle around a temple at the Chichen Itza archaeological site in the Mexico's Yucatan state. Imagery from the tricycle trip has been incorporated into Google Street View.

Google is expanding its Street View offerings to include dozens of 360-degree photo tours of ancient Mexican monuments such as Teotihuacan, Chichen Itza and Palenque.

The additions are aimed at helping Mexico "open a window to the world, to encourage physical visits to the pre-Hispanic sites and thus in turn benefit cultural tourism," Miguel Angel Alva, director of marketing for Google Mexico, said this week in an announcement from Mexico's National Institute of Anthropology and History, or INAH.

Google collected the all-around views by having riders pedal camera-equipped tricycles around the Mexican sites, with INAH's cooperation. INAH said the photo project started two years ago. Thirty sites have been added to Google Street View so far, with the aim of having more than 80 sites online by the end of the year. Eventually, all 189 of the archaeological sites under INAH's custody will be cataloged, the institute said.

The virtual tours highlight some of Mexico's best-known monuments:

• Chichen Itza's El Castillo, also known as the Temple of Kukulkan, a Maya pyramid built more than a millennium ago. Some researchers say the temple's staircase was designed to create a "feathered serpent" shadow during the spring and autumn equinoxes, and can also produce quetzal-bird echoes when you clap your hands at just the right spot.
• Teotihuacan, the monumental city that was founded by a mysterious pre-Aztec culture and reached its height somewhere between 100 B.C. and the year 750.
• Tulum, a Maya walled city on the Yucatan Peninsula's Caribbean coast that dates back to the 13th century and was still occupied when the Spanish arrived in the early 16th century. Today the well-preserved ruins are the middle of a modern-day resort area.
• Palenque, an important Maya site in the Mexican state of Chiapas that reached its peak in the 7th century. Last year, the remote-controlled exploration of a 1,500-year-old tomb at the Palenque site made headlines. 
• Uxmal, a city that flourished during the Classic Maya period and is now a popular tourist attraction. Among its best-known ruins are the Pyramid of the Magician and the Governor's Palace.

Update for 4:45 p.m. ET Aug. 18: Keir Clarke has put together this longer list of links to Google Street View panoramas of Mexican archaeological sites over at Google Maps Mania. If you've found more, please pass them along in your comments on Keir's blog (and right here as well, OK?).

More from Google Street View:

• Google tours NASA's Kennedy Space Center
• Take a Death Valley drive with the click of a mouse
• Google Street View goes undersea
• Google view of Amazon (the real Amazon) now live

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

Google

Winners of the Google Science Fair's top prizes include, from left, Lauren Hodge in the 13-14 age category; Shree Bose in the 17-18 age category and Grand Prize competition; and Naomi Shah in the 15-16 age category.

Shree Bose, an aspiring young scientist from Fort Worth, Texas, won the top prize in the Google Science Fair for her project on ovarian cancer's resistance to cisplatin, a common chemotherapy drug.

Bose's stash of geeky goodies includes $50,000 in scholarship money, a ticket for a 10-day trip to the Galapagos Islands, a chance to visit one of four big science institutions ... and a custom-made set of blocks from Lego, one of the sponsors of the contest.

Shree Bose with Vint Cerf, Google's vice president and Chief Internet Evangelist.

Lauren Hodge and Naomi Shah were also winners in the judges' eyes. Hodge won in the 13- to 14-year-old category for her project on the effects of marinades on carcinogens in grilled chicken. Shah looked into the effect of air pollution on asthma — research that won her the top prize in the 15- to 16-year-old category. Shree Bose was the winner in the 17- to 18-year-old category as well as the winner of the Google Grand Prize. 

All three winners were given trophies made of Lego blocks. 

Google announced the science-fair competition in January and was flooded with 7,500 project entries from more than 10,000 participants in 90 countries. Judges whittled this list down to 15 finalists in the three age groups. 

The winners were selected by a cast of research bigwigs, including the director general of CERN, the editor-in-chief of Scientific American, National Geographic explorers, science filmmakers, and Google's own director of research, Peter Norvig. 

The teens who made the list of finalists investigated problems we already have, and some even built solutions. Who wouldn't want a safer sailboat or a safer herbicide? 

The finalists in the 13- to 14-year-old age group are: 

• Michelle Guo - Alzheimer's disease
• Anand Srinivasan - prosthetics technology
• Lauren Hodge - carcinogens in marinades 
• Daniel Arnold - railroad switch designs to prevent derailments 
• Luke Taylor - "Programming in Pure English" 

The 15- to 16-year-olds stepped it up a notch:

• Dora Chen - facial recognition for dementia patients 
• Naomi Shah - air pollution and asthma
• Harine Ravichandran - power lines and efficient electricity transmission 
• Gavin Ovsak - submersible water turbines
• Skanda Koppula - mapping the ocean floor

The 17- to 18-year-olds that made the finals were: 

• Shree Bose - ovarian cancer and drug resistance
• Christopher Neilson - a better GPS using stereoscopic cameras
• Vighnesh Leonard Shiv - music algorithms 
• Shaun Lim Hsein Yang - UV light as a natural herbicide
• Matthew Morris - improved keel design for safer sailboats 

After a weekend of visiting and touring the Google HQ in Mountain View, Calif., the 15 finalists presented their projects to the judging panel before the awards ceremony.

The prize winners were announced at a gala event at Google's headquarters, presided over by Mariette DiChristina, the editor-in-chief of Scientific American. There were other speakers, too: Google CEO Eric Schmidt, who joked that he wanted to hire all 15 finalists; and inventor Dean Kamen, whose advice to the young scientists included the Google motto: "Don't be evil." 

More on science contests:

• The science fair goes online
• 'Trek' tricorders could win $10 million 
• Google funds $30 million moon prize  

Nidhi Subbaraman writes about science and technology at msnbc.com. Find her on Twitter, and join our conversation on the Cosmic Log Facebook page.

By now, you've found your house, your favorite golf course, the Grand Canyon, Disney World, maybe even the world's largest beaver dam using Google Earth. Now, the application will let you explore the oceans in greater detail than ever before.

This week the search giant released new high-resolution maps of the seafloor, based on more than 20 years of data collected by 12 research institutions during nearly 500 ocean cruises. All those readings have been scientifically curated by the Lamont-Doherty Earth Observatory at Columbia University.

The new maps, available as a layer in Google Earth, provide views of volcanic ridges, seafloor volcanoes with summit craters and calderas, submarine canyons that drain debris from rivers into the abyss of the ocean, and areas where earthquakes lift up the seafloor and trigger tsunamis.

All told, the new imagery covers an area larger than North America. That sounds big, but it actually accounts for only about 5 percent of the world's seafloor area. As oceanographers like to point out, we know more about the surfaces of the moon and Mars than we do about the ocean floor. 

Users of the software have been able to view some portions of the ocean floor since 2009. Today's update sharpens the resolution in covered areas from 1-kilometer grids to just 100 meters (330 feet).

The sharper imagery allows scientists to see, for example, the details of earthquake fault zones and underwater landslides. Shifts in the seafloor along fault lines can trigger tsunamis, as witnessed off the coast of Japan this year and in the Indian Ocean in 2004. Such shifts are known to pose a risk for the northwest coast of North America as well.

The imagery is based on data collected by scientific research vessels that have traveled about 3 million miles across the oceans over the past two decades. A plug-in for Google Earth, the Columbia Terrain Synthesis, shows the tracks of the cruises that have produced the higher-resolution imagery.

To learn more about the application, read this news release from the Lamont-Doherty Earth Observatory.

More about ocean exploration:

• Billionaire's next feat: Plumb the ocean depths
• Google Earth lets users explore oceans and Mars
• Robots explore the ocean's depths
• 10 deep-sea secrets revealed

John Roach is a contributing writer for msnbc.com. Connect with the Cosmic Log community by hitting the "like" button on the Cosmic Log Facebook page or following msnbc.com's science editor, Alan Boyle, on Twitter (@b0yle).