Did Oscar-winning actor Russell Crowe really capture photos of a UFO outside his office in Australia, passing over Sydney's Royal Botanic Gardens? Or was it just a sailboat passing by?

In a series of Twitter updates, Crowe — who won the best-actor Oscar for his role in "Gladiator" and recently starred in another Oscar-nominated film, "Les Miserables" — insists that the pictures are real and that they don't show reflections or lens flare. What the YouTube video does show is a series of three timed-exposure photos, with a flat red light moving across the frame.

Crowe said the pictures were taken by a camera (a Canon 5D with no flash, to be precise) that was set up on the balcony of his office in the Sydney suburb of Woolloomooloo to capture pictures of fruit bats rising from the gardens. "This was a big surprise," Crowe wrote.

Some commenters quickly speculated that the UFO was nothing more than reflections from a light, perhaps from a beacon on a sailboat that was passing through nearby Woolloomooloo Bay. But Crowe defended the sighting: "The camera is on a balcony, not behind glass," he told one questioner. "Can't be a lens flare because it moves, camera is fixed," he said in another tweet.

Unless Crowe 'fesses up to a publicity stunt, or accepts one of the alternate explanations offered by skeptics, this sighting is likely to go into a big thick folder of unsolved celebrity UFO files. The conversation also rates a place among Crowe's most entertaining tweets. For what it's worth, here's another one from the Twitter files: "Due to a hangover of massive proportions ... anything I say on Leno tonight needs to be taken with a pinch of salt ... and a slice of lime."

I'll drink to that.

Update for 8 p.m. ET March 6: Facebook friend Tom Jorgenson came up with what seems to be the best explanation for the red light: It's reflected sunlight from a plane passing across the scene near sunset. You can make out what appears to be the outline of the plane's fuselage and tail. The exposure setting may have made the time-lapse pictures look more dramatic. To confirm that hypothesis, you'd have to check the time for the photo-taking session (at sunset) and the orientation of the camera (pointing to reflect the sun's rays into the camera lens). But I think we have a winner. What do you think?

Update for 12:13 a.m. ET March 7: OK, here's a much better explanation. ParaBreakdown's Phil Poling shows why Russell Crowe's UFO is most likely to be a series of long-exposure photos of an Unidentified Floating Object ... which now appears to have been identified. The YouTube video below breaks it down:

More from Cosmic Log's UFO files:

• Exploding UFO looks like weather balloon
• Middle East UFO linked to Russian missile test
• Cosmic Log archive on UFOs

Tip o' the Log to Huffington Post UK for the ParaBreakdown video.

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.

This story was originally published on Wed Mar 6, 2013 5:52 PM EST

Koby Barhad / RCA

Koby Barhad's concept for an installation called "All That I Am" suggests creating genetically engineered mice that reflect some of the traits associated with Elvis Presley. It's important to note, however, that no mice have yet been Elvisized.

A British artist’s plan to create a mouse with Elvis Presley’s DNA has set websites buzzing over the past week, but right now it’s nothing more than an art-school concept. And it's not clear whether the concept will ever go any further, due to ethical and legal concerns about blending human and animal DNA.

"The purpose of the work was to raise those almost frightening issues," artist Koby Barhad told me. Mission accomplished, Koby.

Actually, celebrity DNA is quite the commodity. A few years ago, a venture called MyDNAFragrance marketed several perfumes that supposedly reflected the DNA coding of Elvis as well as Michael Jackson and other dead celebs. (Sorry, those celebrity-themed fragrances, including "Blue Suede," are no longer available.) The DNA for that project came from University Archives' collection of historical hair. The Elvis hair that Barhad used came from another source: an eBay vendor who was selling strands for $22. (He says he also bought strands of hair attributed to Princess Diana and President John F. Kennedy.)

Barhad, a 35-year-old MFA student at London's Royal College of Art, said he didn't actually submit the Elvis strands for DNA sequencing. Instead, he conducted a practice run with the aid of a couple of researchers from Imperial College. The scientists analyzed DNA extracted from their own strands of hair, as well as from cheek swabs, to confirm that it would be possible to get some sort of genetic reading from the hair alone.

Barhad was particularly interested in seeing whether the DNA tests could identify a variant of the human ACTN3 gene that has been associated with athletic performance. "We proved that those particular scientists didn't have that gene," he told me. Theoretically, then, the DNA tests might be able to identify the genetic signatures of particular traits in Presley's DNA — although realistically, there's some question about how much the DNA might have degraded over the decades.

The next step in the concept would be to breed mice that reflected that genetic signature. Theoretically, you could insert a string of code from the Elvis genome into the desired mouse gene, through a procedure similar to that used to create lab animals with specific mutations. Barhad said another option would be to identify a genetic twist in the mouse genome that parallels the twist in the Elvis genome. For example, if Presley had a particular mutation of the ACTN3 gene, mice could be bred with a similar mutation.

Koby Barhad / RCA

Koby Barhad's concept envisions a stacked series of mouse cages that reflect different aspects of Elvis Presley's life.

The final step in Barhad's art project, titled "All That I Am," would put the Elvis-themed mice in a variety of postmodernistic cages that reflect phases of the rock star's life: One cage might have a funhouse mirror to enlarge the mouse's image, just as Presley's ego was enlarged by fame's mirror. Another would put the mouse on a treadmill, calling to mind how "Elvis worked himself to death" in his final years.

It's worth emphasizing that the Elvis mice do not exist, despite what some websites initially reported.

"I guess the project created a space to imagine a scenario we are all afraid of and want to experience at the same time," Farhad said in an email, "and that was the reason all the news [sites] published it as if I produced this specific mouse, instead of just suggesting it. The funny, or actually scary, thing is that a place in the U.S. ... already contacted me to buy the specific mice. So I think it kind of proves that it is much more real than I even imagined it would be. I'm still writing emails to everyone saying I didn't actually go as far as producing the clones."

In today's follow-up Skype voice call, Barhad said he had no intention of creating an Elvis mouse. "The thing I'm thinking of doing is having my own mouse" that would reflect his own genetic code, he said.

However, Barhad said he'd have to do some more research before going forward with that part of the art.

"Humanized" versions of genes, such as the FOXP2 gene that's associated with speech, have been inserted in mice for research purposes for years. But it's one thing to do that sort of thing under the stringent guidelines that govern genetic studies, and quite another to do it for an art exhibit — even if it's an exhibit designed to call attention to the controversy over transgenic DNA.

"I'm actually going over the law on that," Barhad told me.

Would it be wise for him do it? Or would Elvis observe that when it comes to splicing celebrity DNA, "only fools rush in"?

More about Elvis ... and DNA:

• Auction house all shook up over Elvis hair
• Arthur C. Clarke's DNA odyssey
• Looking for alien DNA
• Cows make humanized milk — but is it safe?

Tip o' the Log to Wired UK's Ian Steadman.

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 dwarf planet and the search for new worlds.

Noel Vasquez / Getty Images

Ashton Kutcher, seen here at a Los Angeles Lakers basketball game in February, is the 500th customer to sign up for a Virgin Galactic suborbital spaceflight.

Virgin Galactic says uber-celebrity Ashton Kutcher is the company's 500th customer to sign up for a suborbital trip into outer space.

"I gave Ashton a quick call to congratulate and welcome him," Virgin Galactic's billionaire founder, Richard Branson, said today in a blog post announcing that Kutcher was coming on board. "He is as thrilled as we are at the prospect of being among the first to cross the final frontier (and back!) with us and to experience the magic of space for himself."

Kutcher, who got his start in television on "That '70s Show" and is now one of the stars of the highly rated sitcom "Two and a Half Men," is said to have a net worth of around $140 million. So the $200,000 fare for a ride on Virgin Galactic's SpaceShipTwo rocket plane, also known as the VSS Enterprise, shouldn't break the bank. He's as well-known for his online presence (with 9.8 million Twitter followers) and his gossip-column appeal (due to last year's breakup with Demi Moore) as he is for his filmography.

All this makes him arguably the highest-profile prospective spaceflier confirmed to be on Virgin Galactic's list — although Tom Hanks, Katy Perry, Brad Pitt and Angelina Jolie are reportedly on the list as well. Beyonce and Jay-Z are among other celebs considering a flight. The stars are reportedly all paying their own way, except for physicist Stephen Hawking, who is receiving a free ride courtesy of Branson.

For Stephen Attenborough, Virgin Galactic's commercial director, getting to the 500-passenger point is as big a milestone as getting Ashton Kutcher to sign on. "It's great to get to No. 500," he told me.

It's way too early to put Kutcher's flight on the calendar. SpaceShipTwo is still in the midst of free-glide flight tests, with rocket-powered test flights expected to begin this year. Last year, Branson said he was holding out hope that he and members of his family will be able to take a ride into space as this year's Christmas present. That suggests 2013 could mark the start of commercial service, although Virgin Galactic and its partners at California-based Scaled Composites say the schedule is totally dependent on the outcome of tests at the Mojave Air and Space Port.

The current plan calls for commercial flight operations to be based at Spaceport America in New Mexico. SpaceShipTwo, which is capable of carrying six passengers and two pilots, would be linked up to its wide-winged WhiteKnightTwo carrier airplane and brought up to an altitude of 50,000 feet. At that height, SpaceShipTwo would drop from its mothership and turn on its hybrid rocket engine. The blast would take the craft beyond 62 miles (100 kilometers), the internationally accepted boundary of outer space — a commanding height from which Kutcher and his fellow passengers could see the arc of planet Earth and the dark sky of space above.

There'd be a few minutes of weightlessness, and then the passengers would return to their seats for the descent. After weathering up to 6 G's of acceleration, the fliers would glide down to the landing — and get their astronaut wings back at Spaceport America.

Attenborough said Virgin Galactic is already giving a lot of thought to determining who would fly when. One of the factors in the formula would give priority to customers "roughly in the order that they signed up," he said, but the schedulers also would consider customer preferences and the possibility of achieving firsts in spaceflight (for example, ahem, first prime-time TV star in space). "We're expecting to be able to keep everyone happy," Attenborough told me. 

How long do you think it'll be before Kutcher is clicking his camera on the final frontier? And do you suppose there'll be a deal to document everything for reality TV? Feel free to weigh in with your comments below.

More about celebrity spaceflight:

• Fly Justin Bieber into space, scientist says
• Bunnies in jetpacks? It's Playboy Club in space!
• Director James Cameron targets spaceflight
• Celebrities in space?

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.

Danny Martindale / Getty Images

Reality-TV impresario Simon Cowell poses for photos with fans as "Britain's Got Talent" kicks off its annual talent search Friday with an event at the Lyric Theatre in Manchester.

More than a decade after the first effort to blend reality TV with real-world spaceflight, talent-show impresario Simon Cowell says the winner of "Britain's Got Talent" could go into outer space on Virgin Galactic's SpaceShipTwo rocket plane.

"I love the idea that if they are up for it they have the option of performing in space," Cowell told Britain's Daily Star. The comment comes as Cowell is ramping up for a new season of the show that inspired "America's Got Talent."

Cowell has already signed up for his own flight on SpaceShipTwo, which could start flying passengers beyond the 100-kilometer (62-mile) boundary of outer space on $200,000 suborbital rides as early as next year. The longtime record producer, who left an enduring mark on reality-TV history as the black-garbed, brutally frank judge on "American Idol," hinted that he's worked out a deal with British billionaire Richard Branson, founder of Virgin Galactic.

"It's tens of millions of pounds, but Richard genuinely is up for doing it," Cowell told the Star. "I am being serious, I swear to God and on my mum’s life. Don’t worry about the details, we’ll make it happen."

If Cowell is to make it happen anytime soon, the winner would most probably have to travel to New Mexico to follow through on the flight plan. And it seems unlikely that going into space would be a requirement placed on the winner, whoever he or she turns out to be.

Producers have tried for years to put together a reality-TV show focusing on spaceflight. The highest-profile effort was "Survivor" executive producer Mark Burnett's plans in 2000 for a show that would follow contestants through the training routine for spaceflight. The winner would have been sent to Russia's Mir space station — but that concept fizzled out even before Mir was deorbited in 2001.

Other proposed entertainment projects have revolved around pop singer Lance Bass and film director James Cameron. Just last week, Beyonce and Jay-Z were said to be interested in doing a music video aboard SpaceShipTwo.

No Hollywood space effort has yet gotten off the ground, but if anyone has the required combination of guts, glitz and gold, I suppose that'd be Branson. Like Cowell, Branson is a veteran of reality TV, having starred in "The Rebel Billionaire," a series that aired on Fox in 2004-2005.

Who knows? In the next year or two, there may be more than one way for reality-TV contestants to get into outer space. Andrew Nelson, chief operating officer for XCOR Aerospace, says his company is moving ahead with its own Lynx rocket plane — and he's not shy about courting Cowell's attention.

"If Simon wants to take a more exciting ride at half the price, I'd take his call," Nelson told me today.

More about commercial space:

• Next steps in a new space race
• Virgin Galactic picks Air Force pilot for spaceship
• Slideshow: The making of SpaceShipTwo
• Gallery: Ten players in the commercial space game

Alan Boyle is msnbc.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. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds. 

Dave Hogan / Getty Images file

Talulah Riley and Elon Musk strike a celebrity pose after their arrival at the Orange British Academy Film Awards ceremony held at London's Royal Opera House last February.

Elon Musk, the founder of the SpaceX rocket venture and head of Tesla Motors, heralded the end of his high-profile marriage to British actress Talulah Riley last night with a tragic tweet.

"It was an amazing four years," Musk said in a Twitter update addressed to Riley. "I will love you forever. You will make someone very happy one day."

Musk, 40, and Riley, 26, capped their relationship in 2010 with a storybook wedding in the same Scottish castle where the singer Madonna was married to actor Guy Ritchie. (That marriage also ended in divorce, which could impact Skibo Castle's reputation as a wedding chapel.) Musk was just coming out of a messy divorce from sci-fi novelist Justine Musk, his first wife and the mother of his five children. Riley, meanwhile, was riding high after taking on notable roles in "Pride and Prejudice" and "St. Trinian's."

Just a few months ago, Britain's Tatler magazine published an interview with the couple that gave little hint of the breakup. Today, Musk told Forbes magazine's Hannah Elliott that he would "always be friends" with Riley but that it was "far too difficult to stay married."

"We took some time apart for several months to see if absence makes the heart grow fonder, and unfortunately it did not," Elliott quoted Musk as saying. "I still love her, but I’m not in love with her. And I can’t really give her what she wants."

There's been no public reaction from Riley, either in the press or on Twitter.

Beyond the tabloids
Now that we're done with the tabloid angle, I'll just note that Musk has more on his mind than his marital troubles: First, the timing for the demonstration flight of SpaceX's Dragon capsule to the International Space Station is currently in limbo. It had been scheduled for Feb. 7, but this week SpaceX said the launch would be delayed to address "a few areas that will benefit from additional work."

For now, SpaceX isn't specifying exactly which areas of the project could use some additional work, but the launch isn't expected to be delayed more than a couple of months. "We will launch when the vehicle is ready," company spokeswoman Kirstin Brost Grantham said in an emailed statement. 

The Dragon's launch on a Falcon 9 rocket would herald a major milestone in the commercialization of orbital spaceflight. The current plan, which has to be cleared not only by NASA but also by the Russians and other space station partners, calls for the unmanned capsule to approach within 1.5 miles (2.5 kilometers) of the orbital outpost, and then go into a holding pattern. If everything checks out, the Dragon would make another approach, stopping just a few yards (meters) from a docking port. Then the station crew would use the robotic arm to pull the capsule in for a docking. After running through tests, the Dragon would undock and head back to an ocean splashdown.

A fully successful test would open the way for commercial cargo flights to the space station, and give a boost to NASA's plans for commercial crew operations sometime in the latter part of this decade.

Even as SpaceX continues with preparations for the launch, Musk has another "launch" coming up: the unveiling of Tesla Motors' all-electric Model X crossover vehicle, scheduled for Feb. 9. The Model X, a minivan-SUV-type automobile, is due to join the Roadster and the Model S sedan as a Tesla offering in late 2013.

More about Musk and his ventures:

• Next steps in a new space race
• SpaceX gets go-ahead for space station trip
• Elon Musk sets his sights on Mars
• Battery cars face an uphill climb

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.

Frazer Harrison / Getty Images file

Jay-Z and Beyonce strut their stuff during a performance at the 2006 BET Awards. The couple, who just had a baby girl last week, are reportedly talking about doing a music video together in space.

Record executives are reportedly talking about sending Jay-Z and Beyonce into space to make a music video — and although Virgin Galactic's executives aren't yet in on the discussions, they say the pop-music power couple are welcome to take a ride. They can even bring their celebrity daughter along.

The idea came to light on Thursday in The Sun, a British tabloid that specializes in the exploits of the rich and famous.

"The label people have been talking about making a music vldeo in space," The Sun's Harry Haydon quoted a source as saying. "Beyonce and Jay-Z seemed the obvious option. Everything is being done to make it happen."

Executives are reportedly inquiring behind the scenes about making the video on Virgin Galactic's SpaceShipTwo rocket plane. Scenes for the video would be shot during the few minutes of weightlessness that come at the peak of the suborbital space ride, more than 62 miles (100 kilometers) above Earth's surface.

SpaceShipTwo isn't due to start commercial service until the end of this year at the earliest, which is probably a good thing, because I'm guessing that Jay-Z and Beyonce have their hands full right now with Blue Ivy Carter, their newborn daughter. Blue Ivy has already hit the Billboard music charts, and eventually she might hit the heights of outer space as well.

"We're having no talks with Beyonce and/or Jay-Z (or indeed Blue Ivy!) but would be more than happy to take mum and dad or the whole family to space at some point!" Stephen Attenborough, Virgin Galactic's commercial director, told me in an email today.

Celebrities lining up
Beyonce is already known to have a soft spot for space: She recorded a special audio message for the crew of Atlantis during last summer's final space mission. "You inspire us all of us to dare to live our dreams, to know that we're smart enough and strong enough to achieve them," she told the astronauts.

If the project comes together, Jay-Z and Beyonce could make the first professional music video performed in outer space. But they wouldn't be the only celebrities in space. The glitterati rumored to be on the list of prospective Virgin Galactic passengers include Katy Perry and Russell Brand (who recently broke up), Brad Pitt and Angelina Jolie, Paris Hilton, Tom Hanks and Victoria Principal.

Then there's Stephen Hawking, the superstar quadriplegic physicist who just turned 70. Hawking took a zero-gravity airplane flight five years ago and is still up for a Virgin Galactic spaceflight. Attenborough said that Virgin Galactic's founder, British billionaire Richard Branson, "was delighted to attend his 70th birthday celebrations last weekend and reiterated Virgin Galactic's commitment to do everything possible make it happen."

No freebies for the stars
SpaceShipTwo is designed to carry just six passengers and two pilots — which means celebrities can bring a small entourage along with them. Hawking would reportedly ride for free, but other celebs shouldn't expect freebies: The cost of a space travel package is $200,000 per seat, and Branson said last year that he wouldn't be offering any special deals.

"I'm in the airline business, and a lot of people ask for upgrades, and we're not going to get the same thing happening with our space program," he told The Canadian Press.

So when might the tourist treks to space begin? Attenborough didn't mention an exact date in his email, but he said "2012 is going to be the most exciting year yet."

"We are poised on the edge of the final stretch of flight testing, with the commencement of SpaceShipTwo powered tests expected in the not-too-distant near future and ramping up, if all goes well, to space flight within the 12-month period," he said. "Clearly we will also require the FAA licences before we embark on passenger flights, but are continuing to see a major gear-up in the Spaceport America-based operation in preparation for that."

Virgin Galactic has more than 450 would-be spacefliers signed up, and Attenborough said "we are continuing to see near-record growth in the numbers of future astronauts."

"I expect in the early part of this year we will have more paid-up customers than have been to space to date — which will be an exciting milestone," he said.

More about Beyonce and Jay-Z:

• 'Bootylicious' fly named after Beyonce
• Slideshow: Beyonce, a star at last
• Beyonce baby complaints at hospital dismissed
• Jay-Z raps about baby, mentions miscarriage

More about Virgin Galactic:

• Planning the next steps in a new space race
• New Mexico's desert spaceport makes a splash
• Slideshow: The making of SpaceShipTwo
• Gallery: Ten players in the commercial space race
• Cosmic Log archive on the new space race

Alan Boyle is msnbc.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. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.