Humans on Mars by 2023?

Artist concept of the Mars One lander, a variant on the SpaceX Dragon. Credit: Mars One

Reality TV goes to Mars! Dutch entrepreneur Bas Lansdorp is leading a group visionaries and businesspeople who want to send four humans to Mars by 2023, and they say they can achieve their goal at an estimated cost of $6 billion USD. How can they do it? By building it into a global media spectacle. And oh, by the way, this will be a one-way trip.

“Who would be able to look away from an adventure such as this one?” asks Lansdorp in his bio on the Mars One website. “Who wouldn’t be compelled to watch, talk about, get involved in the biggest undertaking mankind has ever made? The entire world will be able to follow this giant leap from the start; from the very first astronaut selections to the established, independent village years later. The media focus that comes with the public’s attention opens pathways to sponsors and investors.”

As far as the one-way mission (a concept that Universe Today has written about extensively) the Mars One website notes, “this is no way excludes the possibility of a return flight at some point in the future.”

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The difference between this mission and the one proposed by Jim McLane back in 2008 is that McLane wanted to send just one person to Mars.

However, the Mars One group says that once the first trip is successful and Mars becomes developed, it will be “much easier to build the returning rocket there.”

In a Q&A on reddit, Lansdorp said the biggest challenge will be financing.

“We have estimated, and discussed with our suppliers that it will cost about 6 billion US$ to get the first crew of four people to Mars. We plan to organize the biggest media event ever around our mission. When we launch people to Mars and when they land, the whole world will watch. After that a lot of people will be very interested to see how ‘our people on Mars’ are doing.”

But the big challenge is that the biggest expenditures will be building the equipment before they send people to Mars. “This is why we are building a very strong technical case now. If we can convince sponsors and investors that this will really happen, then we believe that we can convince them to help us finance it,” Lansdorp said.

As far as technologies, Mars One expects to use a SpaceX Falcon 9 Heavy as a launch vehicle, a transit vehicle/space habitat built by Thales Alenia Space, a variant on the SpaceX Dragon as the lander, an inflatable habitat built by ILC Dover, a rover vehicle by MDA Space Missions, and Mars spacesuits made by Paragon.

The project website says “no new technologies” will be needed, but does any space agency or company really have a good handle on providing providing ample air, oxygen, energy, food and water for extended (lifetimes?) periods of time? Instead, the website provides more details on FAQ’s like, What will the astronauts do on Mars? Why should we go to Mars? Is it safe to live on Mars? How does the Mars base communicate with Earth? And the Mars One team emphasizes that this can be done with current technology. However, no one really knows how to land large payloads on Mars yet, so at least some development will be required there.

Who will go? Later this year they will begin to take applications and eventually 40 people will take part in a rigid, decade-long training program (which sounds very expensive) where the ‘contestants” will essentially be voted off the island to get to the final four astronauts. The selection and training process will be broadcast via television and online to public, with viewers voting on the final selected four.

It’s an intriguing proposition, but one filled with technological hurdles. I’ve just finished reading Ben Bova’s “Mars,” so I’m also thinking the Mars One folks will need to be on the lookout for micrometeorite swarms.

Mars One website.

Science Fiction Author Ray Bradbury Dies

Ray Bradbury.

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Author Ray Bradbury — who sent generations of readers on travels to fantastic future worlds — has died this morning in Los Angeles, at the age of 91.
Author of more than 27 novels and story collections, such as his famous “The Martian Chronicles,” the enduring “Fahrenheit 451,” “Dandelion Wine” and “Something Wicked This Way Comes,”and more than 600 short stories, the influential Bradbury has been credited with bringing a bit of class to science fiction, helping to move the sometimes maligned genre into the real literature.

In a podcast on the 365 Days of Astronomy, Bradbury said that he wanted to be buried on Mars.

“I don’t want to be the first live person to arrive there,” he said. “It’ll be too late. But I want to be the first dead person that gets there. I want to arrive in a Campbell’s soup can. Bury me on Mars in thing called the Bradbury Abyss. They gotta name a place on Mars for me, and I will welcome that.”

Bradbury definitely needs to have a place on Mars named after him.

Bradbury wrote this advice in “Fahrenheit 451”: “Stuff your eyes with wonder, live as if you’d drop dead in 10 seconds. See the world. It’s more fantastic than any dream.”

Ray Douglas Bradbury was born Aug. 22, 1920, in Waukegan, Illinois and used the ambiance of small time life to enhance his fiction.

“When I was born in 1920,” he told the New York Times Magazine in 2000, “the auto was only 20 years old. Radio didn’t exist. TV didn’t exist. I was born at just the right time to write about all of these things.”

Bradbury will be missed.

The sad news came via i09.

Amazing Transit of Venus Images From Around the World

Perfect shot of what appears to be a Boeing 727 passing in front of the sun while Venus is transiting. Credit: Jim Nista on Flickr.

Wow! Amateur astronomers around the world looked to the sky last night and early this morning to observe Venus as it passed across the face of the Sun for the last time this century. The images are coming in fast and furious from what was an awesome event! Our lead image is from Jim Nista in Huntington Beach, California who said on Flickr, “Saw the contrails approaching the Sun’s disk and starting snapping as fast as the Canon 7D could go!”

See more below from all around the world, and also check out some of the first images and videos from last night. You can also watch a replay of our live webcast here. For many of the images from Flickr, click on the images for a higher resolution view.

A close-up of the Sun with Venus transiting, along with the silhouettes of buildings in Israel. Credit: Gadi Eidelheit

Our friend Gadi Eidelheit from Israel hosted a transit event, taking this sci-fi- looking image, and many more. He has a full write-up on his Venus Transit blog.

Transit of Venus - Observed from Puerto Rico. Credit: Efrain Morales.

This composite of a sequence of images are from Efrain Morales in Puerto Rico. “Clouds moved out and but the Sahara dust still lingered,” Efrain told Universe Today. “Started my sequence on 22:07ut thru 22:36ut. It was a Spectacular sight.” Equipment: SolarMax40 Refractor, PowerMate 2.5x barlows, P/B LX200ACF 12 in. OTA, CGE mount, PGR Flea3 Ccd, Astronomik Ir filter.

Purdue Astronomy Club showing rtheir setup of viewing the transit. Credit: Kaizad Viraf Raimalwala

Kaizad Viraf Raimalwala from the Purdue University Astronomy Club in Indiana sent in this image: “In this picture, we were using an 8″ Meade LX-200 and piggybacked my friend’s Nikon D7000 on it. Took this picture myself with my Nikon D90,” he told us. “Had a lot of cloud cover at start so we missed the ‘teardrop’ effect and since we were in West Lafayette, Indiana, the sun set long before Contact 3 and 4.”

The lovely but surreal looking image of the Venus transit caught the exit just in time on Mount Dandenong, Australia, just as the clouds moved in. Credit: andrewm2008 on Flickr.
A digital filtergram of the transit of Venus, as seen from Australia. Credit: Monty Leventhal.

Renowned amateur astrophotographer Monthy Leventhal from Australia sent us this ‘digital filtergram’ of the Venus. He said seeing conditions were poor, as it was very cloudy, with showers, but he still managed a great shot. Camera: Canon 600D, Filter: H-alpha 6Å, Telescope: Solaris.

Venus visible transiting the Sun through the clouds, as seen from Navarre Beach, Florida, USA. Credit: M.M. Meeks.
Beautiful view of the Transit of Venus from Italy. Credit: Niki Giada
Venus Transit as seen from Malta. Credit: Leonard E. Mercer

Leonard E. Mercer from Malta wrote us, “Here is one of my images taken today at 6.01.57 local time (UT.04.01.57). The conditions were very favourable. I didn’t expect such sharpness considering the sun was so low. From our region we could only view the end of the transit. But still I am very happy with the resulting image.”

Venus against the setting Sun, as seen from Arizona, USA. Credit: Rob Sparks (hale_bopp37 on Flickr)
View of the Venus Transit from Alberta, Canada. Some sun spots are also visible. The darker parts on the lower right are caused by passing clouds. Credit: Dave Griffith.

This one from Dave Griffith in Canada, who said, “Made at 6:05 PM with a Pentax K-r, a Takumar-A 2x tele-converter, a Sigma 100-300mm 1:4.5-6.7 DL lens, and a solar filter made from a sheet of Seymour Solar Optical Thin Film. The image was made on the side of Highway 63 between Fort McMurray and Edmonton. This was taken at ISO 100 with an aperture of f/11 and an equivalent focal length of 900mm. A brief tale about how I lucked out in even seeing the sun today is posted here.

Venus Transit as seen from Pakistan. Credit: Ramiz Qureshi

Ramiz Qureshi from Pakistan wrote to tell Universe Today, “We were badly clouded out here in Karachi, Pakistan for the past 2 days. In an awesome coincidence, the clouds stayed still on the morning of transit, doubling as an atmospheric filter. This allowed us to observe the Sun plainly with our naked eyes as it rose with the transit already in progress.” Qureshi added that the two silhouettes actually is a composite/overlap of two shots taken an hour apart.

Venus Transit as seen from Tehran, Iran. Credit: Saeed Amiri

Saeed Amiri from Tehran, Iran took this image at 8:12 AM local time using a Canon PowerShot SX210 with Focal length: 70 mm, Exposure time: 1/640 sec, ISO: 100
F-stop: f/5.9, Filter: Mylar.

An artistic look at the Venus Transit, from Vihtavuori, Laukaa, Central Finland. Credit: Jukka Seppälä

Jukka Seppälä from Finland wrote to show us his artistic views of the Venus transit. “I have tried to get some kind of artistic impression by manipulating photos with extreme exposure, contrast, brightness levels etc.”

Patrick Cullis provided this video of an airliner joining in on the transit action:
https://vimeo.com/43523342

Taken with a cheap digital camera through a piece of Welder's Glass. Credit: Bill Schlosser.
'I took this picture with my Omni XLT 120 refractor and Sony A33 camera. Sun was so low on the horizon that I was able to safely take out the solar filter without frying my camera's sensor,' said photographer Gustavo Sanchez.
Venus Transit in H-alpha Composite of two images taken June 5, 2012. Taken with Coronado PST & Nikon D7000. Ottawa, Ontario, Canada. Credit: Andrew Symes (failedprotostar on Flickr)
The Transit of Venus - Black Drop Effect. And a few sunspots, as seen from North Carolina, USA. Credit: Tavi Greiner

Another phenomenon observed during the transit included the ‘black drop’ effect – the small black teardrop shape that appears to connect Venus to the limb of the Sun just after it has fully entered the solar disc and again later, when it begins to leave the disc. Tavi Greiner captured it!

Transit of Venus from Brixton, London. 3rd. contact through the clouds. EOS 7D with a Celestron ST80 80mm aperture F5 telescope and mylar Solar filter. Credit: Own Llewellyn on Flickr.
A view of a view of the Venus Transit, as seen from Tallinn, Estonia. via @karthikvj on Twitter.

Thanks to everyone who sent in images or posted them to our Flickr page. As always, you can see more great images at our pool page on Flickr.

Stunning Timelapse: Spacecraft Capture the Transit of Venus

SDO's Ultra-high Definition View of 2012 Venus Transit -- Path Sequence. Credit: NASA/SDO

Here’s the entire 7-hour transit of Venus across the face of the Sun – shown in several views — in just 39 seconds, as seen by the Solar Dynamics Observatory on June 5, 2012. This view is in the 171 Angstrom wavelength, so note also the the bright active region in the northern solar hemisphere as Venus passes over, with beautiful coronal loops visible. The transit produced a silhouette of Venus on the Sun that no one alive today will likely see again. With its specialized instruments SDO’s high-definition view from space provides a solar spectacular!

Scott Wiessinger from NASA Goddard’s Scientific Visualization Studio wrote this morning to tell us, “If you have the space and the bandwidth, I really recommend downloading this large file on the SVS to view. YouTube compression is hard on solar footage, so it looks even better when you watch it at true full quality.”

Below is a composite image from SDO of Venus’ path across the Sun, as well as another great timelapse view from ESA’s PROBA-2 microsatellite:

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This movie shows the transit of Venus as seen from SWAP, a Belgian solar imager onboard ESA’s PROBA2 microsatellite. SWAP, watching the Sun in EUV light, observes Venus as a small, black circle, obscuring the EUV light emitted from the solar outer atmosphere – the corona – from 19:45UT onwards (seen on the running timer on the video). At 22:16UT – Venus started its transit of the solar disk.

Venus appears to wobble thanks to the slight up-down motion of Proba-2 and the large distance between the satellite and the Sun.

The bright dots all over the image, looking almost like a snow storm, are energetic particles hitting the SWAP detector when PROBA2 crosses the South Atlantic Anomaly, a region where the protection of the Earth magnetic field against space radiation is known to be weaker.

And as if the Sun is just showing off, a Coronal Mass Ejection is visible as well towards the end of the video, seen as a big, dim inverted-U-shape moving away from the Sun towards the bottom-right corner. This is a coronal mass ejection bursting out from the Sun.

Repaired Space Shuttle Enterprise to set Sail on Final Voyage

NASA’s Space Shuttle Enterprise suffered minor damage to a wingtip on June 3, during the initial stages of her seagoing journey to her new home at the Intrepid Sea, Air and Space Museum. Inset shows location of the damage, which has since been repaired. Credit: Ken Kremer

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Enterprise, post boo-boo and postponed a day by rainy weather, should arrive at the Intrepid today !

The final leg of the final voyage of Space Shuttle Enterprise is due to conclude on Wednesday, June 6 with a journey by barge up the Hudson River on Manhattan’s West Side to her permanent new home at the Intrepid Sea, Air and Space Museum.

And it can’t come soon enough. As might be expected, Barge rides for Space Shuttles can be both visually stunning and downright perilous.

And for the initial seagoing leg of Enterprise’s journey on Sunday, June 3, it was a mixture of both – mostly thrilling (as I can attest) plus a few bad moments

During Sunday’s transit of Enterprise across the New York skyline, the shuttle suffered some minor damage to the wing tip (see photo above) soon after she set sail.

According to collectSpace.com, Enterprise grazed a New York railroad bridge when wind gusts caused the shuttle loaded aboard the Weeks Marine barge to veer off course.

“Mother nature did not smile on us. Just as the barge entered the railroad bridge, the wind caught it and pushed the right wing into the bridge abutment. Fortunately, the damage seems to be cosmetic, limited to the foam that covered the wingtip. No structure or mechanisms appear to have been damaged,” wrote Dennis Jenkins who was aboard the barge with Enterprise.

Winds gusts caused Space Shuttle Enterprise to grazed a bridge and suffer minor damage to a wingtip on June 3, during the initial stages of her seagoing journey on a Weeks marine barge to her new home at the Intrepid Sea, Air and Space Museum. Credit: Ken Kremer

The remainder of the voyage went off without a hitch and was enjoyed by throngs of onlookers including myself.

I caught some shots of the damage late in the day as the crew from Weeks Marine was towing Enterprise into port for the night.
Workers have already repaired Enterprise, the Intrepid said in a statement.

On Wednesday morning, Enterprise is due to set sail atop a barge from Bayonne, New Jersey from where she docked on Sunday, June 3 on the initial leg of her seagoing journey to her permanent new home.

Enterprise is scheduled to depart from Bayonne at 10:15 am and then make her way North passing the Statue of Liberty at approximately 10:52 am and Ground Zero at about 11:30 am says the Intrepid. She will reach the Museum at around 12:30 pm and be hoisted onto the flight deck later in the day – all of which is weather permitting.

On July 19, Enterprise will be opened to public viewing

Ken Kremer

Earth Threatened By Glowing Green Asteroid?

Killer asteroid coming for the Earth?
Killer asteroid coming for the Earth?

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The Daily Mail is reporting that a youtube user has found a strange object while poking around in Google Sky. It looks suspiciously like a glowing green asteroid and he claims it’s heading right for us. But before we call in the experts, let’s do a little bit of critical analysis on our own.

First off, the image raises alarm bells because of the apparent size of the object. Without knowing how far away it may be, it’s hard to say how large it would actually be, but we can put some limits on it. I looked up the region on Aladin and the angular distance between the two stars just to the upper right of the object is 1 arc minute. The object seems to be about that size, so we can use that as a baseline.

Assuming that the object was somewhere in the vicinity of Pluto (roughly 6 billion km), doing a bit of quick geometry means the object would be somewhere around 580,000 km. To put that in context, that’s about 40% the diameter of the Sun. If that were the case, this wouldn’t be an asteroid, it would be a small star. The funny thing about stars is that they tend to be somewhat bright and a lot more round. So that rules out that extreme.

But what if it were very close? At the distance of the moon, that would mean the object would be about 300 km in diameter which would make this thing slightly smaller than the largest asteroid, Ceres. However, this raises another issue: With that much mass, the object should still be pretty round. Additionally, with such a size and distance, it would be very bright. And it’s not.

2011 MD on Monday, June 27, 2011 at 09:30 UTC with RGB filter. Credit: Ernesto Guido, Nick Howes and Giovanni Sostero at the Faulkes Telescope South.
Even closer we run into additional issues. Astronomical images aren’t taken as a single color image. Images like this are taken in 3 filters (RGB) and then combined to make a color image. If the object is nearby, it moves from image to image, showing up in the final image in 3 places, each as a different color. For example, here’s an image of 2011 MD illustrating the effect. Given the object in question doesn’t have this tri-color separation going on, it can’t be nearby.

So this has pretty much ruled out anything anywhere in our solar system. If it’s close, it should have color issues and be bright. If it’s far, it’s too massive to have been missed. Outside of our solar system and it wouldn’t have any apparent motion and should be visible in other images. And it’s not.

In fact, searching the various databases from which Google Sky draws its data (SDSS, DSS, HST, IRAS, and WMAP), the killer asteroid doesn’t appear at all. Thus, it would seem that this object is nothing more than a technical glitch introduced by Google’s stitching together of images. Sorry conspiracy theorists. No Planet X or Nibiru out there this time!

Venus Transit As Seen from the International Space Station

The transit of Venus on June 5, 2012 as seen from the International Space Station. Credit: NASA/Don Pettit

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The guy known as Mr. Fixit in space was also Mr. Prepared. This image is from NASA Astronaut Don Pettit on board the International Space Station, who had the foresight to bring a solar filter for his camera. “I’ve been planning this for a while,” said Pettit. “I knew the Transit of Venus would occur during my rotation, so I brought a solar filter with me when my expedition left for the ISS in December 2011.”

This is his first image, and we’ll add more as they become available. Pettit is trying to download his images almost real-time. He is photographing the historic transit of Venus through the Space Station’s Cupola, removing the scratch panes on the Cupola’s windows to get crisp, clear images.

Pettit is using a high-end Nikon D2Xs camera and an 800mm lens with a full-aperture white light solar filter.

Transit of Venus: First Images

Stack of 15 images taken at about 5:22:00 pm CDT as Venus fully enters the Sun's disc. Credit: Jason Melquist

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The transit of Venus across the face of the Sun — the last one for another 105 years — has begun! Here are some first images from various astrophotographers, telescopes, space missions. This first one comes from amateur astronomer Jason Melquist from Minneapolis, Minnesota USA taken just as Venus began its ingress into the Sun’s interior face.

See more below, and we’ll be adding images as they come in! And if you aren’t watching our live webcast, see it here.

This image from the Solar Dynamics Observatory has a definite ‘WOW!’ factor, with huge coronal loops just under Venus transiting the Sun:

Solar Dynamics Observatory image of the Venus transit with stunning coronal loops. Credit: NASA/SDO
An awesome shot of a plane transiting the Sun along with Venus. This is a cross view stereo pair and can be viewed in 3-D by the free fusion method. Credit: BillDavis6959 on Flickr
From the Solar Dynamics Observatory: Planet Venus transiting the Sun in the 304 Anstrom wavelength at approx. 90,000 degrees Fahrenheit. Credit: NASA/SDO

This one comes via Camilla SDO, the fearless mascot of the Solar Dynamics Observatory, who says of this image taken in 304 Angstrom wavelength, “This channel is especially good at showing areas where cooler dense plumes of plasma (filaments and prominences) are located above the visible surface of the Sun. Many of these features either can’t be seen or appear as dark lines in the other channels. The bright areas show places where the plasma has a high density.”

Below is a quick first movie from SDO of Venus’ ingress in 171 Angstrom!

And here’s SDO’s first “official” image of the transit, in 171 Anstrom wavelength:

Venus transit from the Solar Dynamics Observatory, the first view. Credit: NASA/SDO
View from Mike Phillips, who participated in Universe Today's live webcast feed. Credit: Mike Phillips.
Venus Transit and a few Sunspots, through passing clouds. Taken with Canon XTi/400D and hand-held Baader filter. Credit: Tavi Greiner.
Screenshot from the NASA Sun/Earth Day webcast feed, with telescopes using a red filter, via Beth Beck on Google+
Transit through the clouds. Credit: JCC_Starguy on Flickr.
Safe transit viewing setup by Jeremy Smith in Atlanta, Georgia, USA.

Jeremy Smith from Atlanta Georgia sent us views of his setup for ‘safe’ viewing of the transit. “My safe viewing rig is composed of a cheap tripod, a faulty rifle scope, three FedEx boxes and a FedEx mailer,” he said. “I got to see it with my daughter at home but we lost it behind the trees. We hightailed it to the local park but by the time we got there, it was a wash. We lost it behind clouds. The pictures of the transit didn’t turn out very well though. But I saw it!”

His view, below:

The 'safe' view of the Venus transit. Credit: Jeremy Smith
Venus continuing its transit of the Sun. Taken with a Megrez II 80mm, Thousand Oaks Optical Type 2+ White Light Glass Solar Filter and a Nikon 1 V1 camera with the 10-30 mm lens. Credit: Fernando Corrada
Transit of Venus photos taken from Matamata New Zealand as clouds allowed. Taken with filer on 400mm filter on Canon 60D. Credit: Alison Thomas

Want to get your Venus Transit image featured on Universe Today? Join our Flickr group, or send us your images by email (this means you’re giving us permission to post them). Please explain when you took it, the equipment you used, etc.

Newest X-Ray Observatory Will Hunt for Black Holes and More

An artist's concept of NuSTAR in space. Image credit: NASA/JPL-Caltech/Orbital Sciences

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The next launch of a NASA space mission is the Nuclear Spectroscopic Telescope Array, or NuSTAR. It study wide range of objects in space, from massive black holes to our own Sun, and will be the first space telescope to create focused images of cosmic X-rays with the highest energies.

“We will see the hottest, densest and most energetic objects with a fundamentally new, high-energy X-ray telescope that can obtain much deeper and crisper images than before,” said Fiona Harrison, the NuSTAR principal investigator, who has been working on this project for 20 years.

Meanwhile, NASA has cancelled another X-ray telescope, the Gravity and Extreme Magnetism Small Explorer (GEMS) X-ray telescope, an astrophysics mission that was going to launch in 2014 to observe the space near neutron stars and black holes. GEMS failed meet a the qualifications of a confirmation review and was heading to go over budget.

“The decision was made to non-confirm GEMS,” said Paul Hertz, director of NASA’s Astrophysic Division, at a meeting of the National Research Council’s Committee on Astronomy and Astrophysics. “The rationale was that the pre-confirmation cost and schedule growth was too large.” The project was going well over the initial cost of $105 million and was facing a delay in launch.

But NuSTAR is scheduled to launch on June 13 from the Kwajalein Atoll in the Pacific Ocean near the equator. The X-ray space telescope will initially take off on a L-1011 “Stargazer” aircraft, and then launch in midair into orbit on a Pegasus XL rocket from Orbital Sciences.

The mission has been awaiting launch since March, when NASA delayed its liftoff pending a review of the rocket.

NuSTAR will work with other telescopes in space now, including NASA’s Chandra X-ray Observatory, which observes lower-energy X-rays. Together, they will provide a more complete picture of the most energetic and exotic objects in space, such as black holes, dead stars and jets traveling near the speed of light.

This new observatory looks with X-rays similar to the X-rays used in hospitals and airports, but the telescope will have more than 10 times the resolution and more than 100 times the sensitivity of previous telescopes.

“NuSTAR uses several innovations for its unprecedented imaging capability and was made possible by many partners,” said Yunjin Kim, the project manager for the mission at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “We’re all really excited to see the fruition of our work begin its mission in space.”

NuSTAR has an innovative design using a nested shell of mirrors to provide better focus. It also has state-of-the-art detectors and a large 33-foot (10-meter) mast, which connects the detectors to the nested mirrors, providing the long distance required to focus the X-rays. This mast is folded up into a canister small enough to fit atop the Pegasus launch vehicle. It will unfurl about seven days after launch. About 23 days later, science operations will begin.
The mission will focus on studying the formation of black holes and investigate how exploding stars forge the elements that make up planets and people, along with study the Sun’s atmosphere.

Sources: JPL Space News (GEMS)

First SETI Search of Gliese 581 Finds No Signs of ET

An artist’s impression of Gliese 581d, an exoplanet about 20.3 light-years away from Earth, in the constellation Libra. Credit: NASA

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The first targeted SETI search of a system with a potentially habitable world has come up empty, but perhaps finding signals wasn’t the main objective in this search. Back in 2007 a group of astronomers used the Australian Long Baseline Array to listen for radio signals from Gliese 581, a red dwarf star that is now known to host at least six planets, with one in the star’s habitable zone. This was a SETI-type search for extraterrestrial-made signals, and it initially found 222 candidate signals. However, the team was able to reject all of them using automated analysis techniques, determining they were caused by Earth orbiting satellites. So why is this potentially good news?

This search was actually a proof of concept for using the Very Long Baseline Interferometry (VLBI) for targeted SETI searches, and that it worked well is great news for future searches that look specifically at a particular star system. Until recently most SETI searches were wide sky surveys, scanning wide, random areas of space looking for radio signals. But now, with the success of the exoplanet hunting Kepler mission, we now know of some potentially habitable systems and planets, and astronomers can do targeted searches, looking at specific spots in the sky.

It wasn’t known if the VLBI technique would be successful for such a “directed” targeted search, but this search by Hayden Rampadarath and team from the International Centre for Radio Astronomy Research at Curtin University in Australia proves it does.

The Australian Long Baseline Array is a combination of three radio antennae: the 22-meter Mopra Telescope, Parkes Observatory and the Australia Telescope Compact Array (ATCA) which are each a few hundred kilometers apart from each other. The data from the three locations are combined, making them act as one huge radio telescope, with an extraordinary angular resolution in the milli-arcsecond regime, the highest resolution in astronomy. And it turns out that VLBI techniques are great for SETI searches because they automatically exclude many Earth-based sources of interference that might otherwise look like SETI signals. That’s because the same signals have to show up at all the telescopes several hundred kilometers apart.

The team pointed the telescopes at Gliese 581 (Gl581), located 20 light-years distant in the constellation Libra for about 8 hours, tuning into frequencies close to 1500 megahertz.

The team said that the array would have been able to pick up a broadcast with a power output of at least 7 megaWatts per hertz, which means that if Gliese inhabitants had been broadcasting directly to Earth using an 300-meter Arecibo-style dish, the signals would have easily been picked up. However, ordinary radio transmissions, such as the ones Earthlings regularly transmit into space, would have been too weak to be detected.

But this bodes well for using other more powerful VLBI arrays such as the European VLBI Network, current most-sensitive VLBI array in the world or the upcoming Square Kilometre Array, which will have the sensitivity to pick up broadcasts of a few kilowatts per Hertz from 20 light years away.

So while this doesn’t mean that there is no life in the Gliese 581 system, this does mean we now have an expanded arsenal of tools for looking.

Read the team’s paper.

Source: Technology Review Blog