Blocking Light Sheds New Light on Exoplanet Atmospheres

Kepler-16b is but one example of an uncanny world. It orbits two suns. Credit: Discovery

Exoplanets are uncanny. Some seem to have walked directly out of the best science-fiction movies. For example, we’ve discovered a planet consisting purely of water (GJ 1214b) and one with two suns (Kepler 16b). Some planets nearly scrape their host stars once every orbit, while others exist in darkness without a host star at all. The field of exoplanet research is moving beyond detecting exoplanets to characterizing them – understanding which molecules are present and if they might possibly harbor life.

A key research element in characterizing these alien worlds is observing their atmospheres. But how exactly do astronomers do this? We can’t simply tug the planet toward us to get a closer look.  It’s also incredibly difficult to directly image their atmospheres from afar.  Why? Stars are incredibly bright in comparison to their puny, barely reflective, and nearby exoplanets. So a direct image of an exoplanet’s atmosphere seemed out of the question – until recently.

It may be tricky to directly image an exoplanet’s atmosphere, but astronomers always have quite a few tricks up their sleeves. The first one is in mounting an instrument called a coronagraph on your telescope.  This instrument blocks out the star’s light, leaving an image of the exoplanet alone.  Another trick, known as adaptive optics, is to send a laser beam through the atmosphere.  The changes in the laser allow us to monitor changes in the atmosphere, providing corrections to clean and smooth the image.

HR 8799, a large star orbited by four known giant planets, is relatively nearby (remember that ‘nearby’ is an astronomers way of saying that it is still pretty far, or in this case 130 light years away). In 2008, three of the planets were directly imaged using the Gemini and Keck telescopes on Mauna Kea, Hawaii.  In 2010, the fourth planet, which was closest to the star and therefore the most difficult to see was directly imaged by the Keck telescope.

Direct image of the HR 8799 system.  The star has been blocked and all four planets can clearby be seen. Credit: Oppenheimer et al. 2013
Direct image of the HR 8799 system. The star has been blocked and all four planets can clearby be seen. Credit: Oppenheimer et al. 2013

A direct image of an exoplanet’s atmosphere may tell us what color the atmosphere appears to be, and how thick the atmosphere is, but it gives us little more information.  We need to know the atmospheric composition – the specific molecules and their abundances that are present within the atmosphere itself.  If we’re looking at the question of habitability we need to know if there is water in the atmosphere or maybe carbon dioxide.

The key is in mounting a spectrograph on the telescope.  Instead of collecting the overall light from the planet, that light is broken up into a spectrum of wavelengths.  Imagine seeing a rainbow after a thunderstorm.  That rainbow is simply the light from the sun broken up across all visible wavelengths due to ice crystals in our atmosphere.  Molecules emit light at specific wavelengths, leaving well-known fingerprints that may be identified in a lab on Earth, in a rainbow in the sky, or in the spectrum of an exoplanet located 130 light years away.

When astronomers mounted their instrumentation (i.e. a coronagraph, an adaptive optics system, and a spectrograph) known as Project 1640 onboard the Palomar 5m Hale Telescope, they were able to shed new light on the HR 7899 system.  Only last month one of its exoplanets revealed a mixture of water vapor and carbon monoxide in its atmosphere, but the story has changed. See a previous article in Universe Today.

Project 1640 observed not one – but four atmospheres at once.  Gautam Vasisht of JPL explains, “in just one hour, we were able to get precise composition information about four planets around one overwhelmingly bright star.”  These four exoplanets are believed to be coeval, in that they formed from a protoplanetary disk at roughly the same time.  They also have the same luminosity and temperature, leading to the assumption that they are roughly similar to each other.  But results show that they all have radically different spectra, and therefore different chemical compositions!

More specifically, HR 8799 b and d contain carbon dioxide, b and c contain ammonia, d and e contain methane, and b, d, and e contain acetylene.  Noticing a few trends? There really aren’t any! Not only are these planets different from each other, they are also different from any other known objects. Acetylene, for example, has never been convincingly identified in a sub-stellar object outside the solar system.  While the varying spectra pose many questions, one thing is clear: the diversity of planets must be greater than previously thought!

This is only the first exoplanet system for which we’ve obtained direct spectra of all exoplanet atmospheres. Project 1640 will conduct a 3-year survey of 200 nearby stars. The hope is to find hot Jupiters located far from their host star.  While this is what the current technique allows astronomers to detect, it will also teach astronomers how Earth-like planets form.

“The outer giant planets dictate the fate of rocky ones like Earth. Giant planets can migrate in toward a star, and in the process, tug the smaller, rocky planets around or even kick them out of the system. We’re looking at hot Jupiters before they migrate in, and hope to understand more about how and when they might influence the destiny of the rocky, inner planets,” explained Vasisht.

In an attempt to understand our own blue marble, astronomers point their telescopes at uncanny worlds light years away. Project 1640 will block the light of distant stars in order to shed light on distant worlds as well as our own.

Sources: Jet Propulsion Laboratory, and B. R. Oppenheimer et al. 2013 ApJ 768 24

 

Hadfield’s Return to Earth: ‘I’m Still Learning How To Walk Again’

Chris Hadfield, speaking from Houston May 16, 2013 in his first press conference after his five-month mission. Credit: Canadian Space Agency/Ustream

Astronaut Chris Hadfield described himself as a man who never looks back. Still, he spoke fondly of his five months in space during the first press conference with media today (May 16) after his return to Earth earlier this week.

“I don’t spend my life going gosh, I went to [space station] Mir in 1995 and now everything else is boring. That’s not how I ever felt,” the Canadian said in a wide-ranging conversation that talked about everything from his future, to the science he performed, his favorite tweets while up in space.

First, let’s get a big question off the plate. Hadfield says himself he doesn’t know what he wants to do next. “I’m still learning how to walk again!” he exclaimed to one journalist who asked if he wanted to be Canadian Space Agency president.

Rehabilitation is occupying a lot of his time, he added: “I’m trying to stand up straight, and I have to sit down in the shower so I don’t faint and fall down. It’s like asking an infant if they’re ready for their Ph.D. yet. I’ll get there, but it’s too early to say.”

 Hadfield getting checked out by doctors after his return. 'Wired head, chest, arms and feet, learning how the body works when it has been weightless for half a year,' Tweeted Hadfield.
Hadfield getting checked out by doctors after his return. ‘Wired head, chest, arms and feet, learning how the body works when it has been weightless for half a year,’ Tweeted Hadfield.

Hadfield brushed aside notions that he is famous for himself, saying it is a reflection of the hard work his crew put in on the station orbiting Earth. Expedition 35 was the most productive in terms of the science-to-maintenance ratio aboard the station, despite an ammonia leak gumming up the schedule very late in the mission.

He spoke most warmly of the science performed while aboard station. The Alpha Magnetic Spectrometer found possible hints of dark matter during his stay, for example. Hadfield and colleague Tom Marshburn also did aging research in space on behalf of the University of Waterloo, specifically looking at how blood pressure and blood flow changes among astronauts in orbit.

Canadian astronaut Chris Hadfield gives a thumbs up after landing safely in Kazahkstan. Via NASA TV.
Canadian astronaut Chris Hadfield gives a thumbs up after landing safely in Kazahkstan. Via NASA TV.

Education and outreach were also something Hadfield was proud of. “The purpose is to help people to understand what is possible on the space station, and the things we are doing,” he said of his prolific tweeting and video creation.

The results, in many cases, were incredible. More than 7,000 Canadian students took part in experiments linked to the International Space Station, he said. Thousands more took part in a nation-wide singalong starring Hadfield. (Watch it below.)

Once Hadfield gets his feet underneath him and the mission fades into the past, he said he’s hoping to resume his life normally.

Astronauts of yesteryear, he said, often had big missions thrust upon them early in their lives. At age 53, for example, Hadfield is roughly 15 years older than Neil Armstrong was during the first moon landing in 1969.

For Hadfield, with two decades under his belt as an astronaut — three missions, several backup crew assignments, and some management positions to boot — he treats his everyday life with the same enthusiasm as his high-flying job.

“I take just as much pride in the big dock that my neighbor Bob and I built at the cottage as I do in building Canadarm2 on the space station. Those were both very complex projects that required a lot of physical effort, planning, decision making, and the product is out there for everybody to see. I feel really good about them both.”

Canadian astronaut Chris Hadfield in the Cupola of the International Space Station. Credit: NASA/CSA
Canadian astronaut Chris Hadfield in the Cupola of the International Space Station. Credit: NASA/CSA

He acknowledged that in a budget-conscious environment, the Canadian Space Agency is facing uncertainty, but he added that to treat today’s uncertainty as something unique is the wrong thing. Every mission carries a real risk of death. Every budget vote can kill or revive a space program — the station itself was only funded by a vote in one crucial Congress session in its history, he added.

“To say that things are uncertain is to talk about the space business. We are always hostage to our next launch. There has never been a period of certainty in the space business, ever,” he said.

His advice to those wanting to follow in his footsteps?

“The key thing is within yourself. If you want to become something, you have to start turning yourself into that thing, step by step, as a demonstration of personal will. That’s what I did when I was nine. I started turning myself into an astronaut.”

Watch the entire video of his press conference here.

Live Online Event: The Exploding Universe: the Realm of Supernovae

Animation of SN 2011fe in M101. Credit: Virtual Telescope Project

Supernovae are some of the fascinating objects in the Universe. The Virtual Telescope Project will be hosting a live webcast today UPDATE: the webcast will also be on May 17, 2013 as clouds arrived shortly into the webcast on on the 16th) at 21:00 UTC (5 pm EDT, 2 pm PDT) to explore in real-time — from the comfort of your home or office –the exciting world of supernovae, those incredible, violent exploding stars. All this with the live commentary from a professional astrophysicist, Gianluca Masi.

You can watch at this link.

During “The Exploding Universe: the Realm of Supernovae”, you can join in and surf the Cosmos in space and time, observing dying stars placed millions of light years way and shining as billions of Sun, while living the very final stages of their lives, before becoming a neutron star or a black hole.

‘Star Trek into Darkness’ & NASA Station Crews Join Forces at Live NASA Webcast

NASA and Star Trek connect on NASA TV on May 16 for the premiere of “Star Trek Into Darkness” on May 17, 2013 to celebrate the wonders of Space Exploration. Still image of the fictional star ship ‘Enterprise’. Credit: Star Trek

Science Fact and Science Fiction join forces in space today for a one of a kind meeting turning science fiction into reality – and you can participate courtesy of NASA and Hollywood!

Fictional astronauts and crews from the newest Star Trek incarnation; “Star Trek into Darkness” and real life astronauts taking part from outer space and Earth get connected today (May 16) via a live ‘space bridge’ webcast hosted by NASA. The movies premieres today – May 16.

NASA Television broadcasts the face-to-face meeting as a Google+ Hangout from noon to 12:45 p.m. EDT, May 16. Watch live below!

The webcast includes “Captain Kirk” – played by actor Chris Pine, and NASA astronaut Chris Cassidy – fresh off from his real life ‘emergency spacewalk’ this past weekend that saved the critically important cooling system aboard the International Space Station (ISS). “Into Darkness” features dramatic life and death spacewalks.

Astronaut Chris Cassidy during the May 11, 2013 emergency spacewalk at the ISS. Credit: NASA
Astronaut Chris Cassidy during the May 11, 2013 emergency spacewalk at the ISS. Credit: NASA

Also participating in the live NASA webcast are ‘Star Trek’ director J.J. Abrams, screenwriter and producer Damon Lindelof; and actors Alice Eve (Dr. Carol Marcus) and John Cho (Sulu) and astronauts Michael Fincke and Kjell Lindgren at NASA’s Johnson Space Center in Houston.

Fincke flew on the Space Shuttle and the ISS and made a guest appearance on the finale of the TV series – “Star Trek: Enterprise”. See photo below.

‘Star Trek Into Darkness’ movie still image. Credit: Star Trek
‘Star Trek Into Darkness’ movie still image. Credit: Star Trek

The ISS is a sort of early forerunner for the fictional ‘Federation’ in the ‘Star Trek’ Universe – constructed in low Earth orbit by the combined genius and talents of 5 space agencies and 16 nations of Earth to forge a united path forward for the peaceful exploration of Outer Space.

Cassidy will provide insights about everyday life aboard the real space station – like eating, sleeping, exercising and fun ( think Chris Hadfield’s guitar strumming ‘Space Oddity’ -watch the YouTube video below) – as well as the myriad of over 300 biological, chemical and astronomical science experiments performed by himself and the six person station crews during their six-month stints in zero gravity.

Astronaut Terry Virts, left, Actor Scott Bakula and Astronaut Mike Fincke, right, beam on the set of Star Trek's final Enterprise voyage. Credit: NASA
Astronaut Terry Virts, left, Actor Scott Bakula and Astronaut Mike Fincke, right, beam on the set of Star Trek’s final Enterprise voyage. Credit: NASA

The participants will ask questions of each other and take questions from the Intrepid Sea, Air & Space Museum in New York City (home of the space shuttle Enterprise), the Smithsonian’s National Air and Space Museum in Washington, and social media followers, says NASA.

Social media followers were allowed to submit 30 sec video questions until early this morning.

And you can submit questions today and during the live broadcast using the hashtag #askNASA on YouTube, Google+, Twitter and Facebook.

Captain Kirk and Mr. Spock in ‘Star Trek Into Darkness’. Credit: Star Trek
Captain Kirk and Mr. Spock in ‘Star Trek Into Darkness’. Credit: Star Trek

Watch the hangout live on NASA’s Google+ page, the NASA Television YouTube channel, or NASA TV starting at Noon EDT, May 16.

As a long time Star Trek fan (since TOS) I can’t wait to see ‘Into Darkness’

Ken Kremer

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Learn more about NASA missions, Mars, Curiosity and more at Ken’s upcoming lecture presentation:

June 12: “Send your Name to Mars” and “LADEE Lunar & Antares ISS Rocket Launches from Virginia”; Franklin Institute and Rittenhouse Astronomical Society, Philadelphia, PA, 8 PM.

NASA’s real life Space Shuttle Enterprise transits the NYC Skyline at Dusk on a barge on June 3, 2012 during a two stage seagoing  journey to her permanent  new home at the Intrepid Sea, Air and Space Museum. Enterprise is bracketed by the Empire State Building, The Freedom Tower (still under construction) and the torch lit Statue of Liberty. Credit: Ken Kremer
NASA’s real life Space Shuttle Enterprise transits the NYC Skyline at Dusk on a barge on June 3, 2012 during a two stage seagoing journey to her permanent new home at the Intrepid Sea, Air and Space Museum. Enterprise is bracketed by the Empire State Building, The Freedom Tower (still under construction) and the torch lit Statue of Liberty. Credit: Ken Kremer

More Insight on How NASA Might Revive the Kepler Space Telescope

Artst concept of the Kepler telescope in orbit. Credit: NASA

The future of NASA’s Kepler space telescope mission is in doubt, NASA announced yesterday, as it suffered a failure of a second reaction wheel, losing its ability to precisely point to look for planets orbiting other stars. Reaction wheels enable the spacecraft to aim in different directions without firing thrusters, and the spacecraft needs at least three of the four wheels working to provide the ability to point precisely enough to continue the mission.

But, as we pointed out in our article yesterday, the Kepler team said there are still possibilities of keeping the spacecraft in working order, or perhaps even finding other opportunities for different science for Kepler, something that doesn’t require such precise pointing abilities.

“We’re not ready to call the mission down and out just yet,” said John Grunsfeld, NASA’s associate administrator for the Science Mission Directorate, “but by any measure it’s been a spectacular mission.”

Space expert Scott Hubbard has provided additional insight on the possible ways that NASA could bring the spacecraft back online, and what planet hunters will do next if that’s not possible. Hubbard is a consulting professor of aeronautics and astronautics at Stanford’s School of Engineering, and served as director of NASA Ames Research Center during much of the building phase of the Kepler space telescope. He also worked on the project alongside William Borucki, the Kepler science principal investigator at Ames and the driving force behind the effort, for the decades leading up to formal approval of the mission.

Standford University provided this conversation Hubbard:

Q: How big of a loss will it be if the Kepler space telescope can’t be repaired?

Hubbard: The science returns of the Kepler mission have been staggering and have changed our view of the universe, in that we now think there are planets just about everywhere.

It will be very sad if it can’t go on any longer, but the taxpayers did get their money’s worth. Kepler has, so far, detected more than 2,700 candidate exoplanets orbiting distant stars, including many Earth-size planets that are within their star’s habitable zone, where water could exist in liquid form.

Kepler has done what the program managers said it would do, and that is to give us an inventory of extrasolar planets. It completed its primary observation phase, and had entered its extended science phase. We’re already in the gravy train period – there’s still a year and a half’s worth of data in the pipeline that scientists will analyze to identify other candidate planets, and there will continue to be Kepler science discoveries for quite some time.

Kepler space telescope's field of view. Credit: NASA
Kepler space telescope’s field of view. Credit: NASA

Q: How might NASA engineers go about getting Kepler functional again?

Hubbard: There are two possible ways to salvage the spacecraft that I’m aware of. One is that they could try turning back on the reaction wheel that they shut off a year ago. It was putting metal on metal, and the friction was interfering with its operation, so you could see if the lubricant that is in there, having sat quietly, has redistributed itself, and maybe it will work.

The other scheme, and this has never been tried, involves using thrusters and the solar pressure exerted on the solar panels to try and act as a third reaction wheel and provide additional pointing stability. I haven’t investigated it, but my impression is that it would require sending a lot more operational commands to the spacecraft.

Q: If neither of these options works, Kepler is still an amazing space instrument. Could it conduct other types of experiments?

Hubbard: People have asked about using it to find near-Earth objects, or asteroids. Kepler carries a photometer, not a camera, that looks at the brightness of stars, and so its optics deliberately defocus light from stars to create a nice spread of light on the detector, which is not ideal for spotting asteroids.

Whether or not it could function as a detector for asteroids is something that would have to be studied, but since it wasn’t built as a camera, I would say that I’m skeptical. That said, certainly between Ames Research Center and the Jet Propulsion Laboratory, they’ve got the best people in the world working on it.

Visualization of Kepler's planet candidates shown in transit with their parent stars. Credit: Jason Rowe/Kepler Mission/NASA
Visualization of Kepler’s planet candidates shown in transit with their parent stars. Credit: Jason Rowe/Kepler Mission/NASA

Q: What’s next for exoplanet hunters?

Hubbard: As I said earlier, there is still a year and a half’s worth of data in the pipeline to analyze to identify candidate planets, so there are still discoveries to be made.

It’s important to make clear, though, that in the original queue of missions aimed at finding life elsewhere, a mission like Kepler was a survey mission to establish the statistical frequency of whether these planets are rare or common. It lived the length of its prime mission, and was extremely successful during that time at achieving this goal. It has paved the way for additional missions, such as TESS – Transiting Exoplanet Survey Satellite – and TPF – Terrestrial Planet Finder – which will continue the search for Earth-like exoplanets in the near future.

Our Spoiler-Free Review of Star Trek: Into Darkness

Spock (Zachary Quinto) and Kirk (Chris Pine) as portrayed in Star Trek: Into Darkness. Credit: StarTrekMovie.com

If you’re a fan of the rebooted 2009 Star Trek film, we think you’ll love the second edition. You’ll find similar whip-cracking dialog, inside jokes and action-filled storyline in the sequel, Star Trek: Into Darkness, which opens in theaters in the United States and several other countries today.

While the first movie introduced us to the characters, this movie is all about choices… moral choices, and when it is best to help somebody, as opposed to letting things be. That’s where things can get uncomfortable, though.

The film’s start portrays a moral dilemma in the first few minutes, with choices that bring upon punishment for the players involved. The consequences are quite logical — Spock would point that out — but when more dilemmas pile up at the end of the film, many decisions go unquestioned.

Yes, this is an action film and yes, the Star Trek franchise is one that never lets itself get slowed down by plot holes and inconsistencies. (The plot isn’t that groundbreaking, either.) Still, the movie could have benefitted from an extra five or 10 minutes to show the reasoning behind the final few choices. Thinking over what happened, there could be problems with what the crew decided to do.

Nyota Uhura as seen in Star Trek: Into Darkness. Credit: StarTrekMovie.com
Nyota Uhura as seen in Star Trek: Into Darkness. Credit: StarTrekMovie.com

Enough Tribble-like quibbling, though. Star Trek: Into Darkness pulls you in with an action sequence in the first few minutes, and the pace never lets up. Spock (Zachary Quinto)’s straightforward nature gets him into trouble — as usual — with James T. Kirk (Chris Pine), leading to quotable insults that generated audience guffaws in an advance screening Universe Today saw in Ottawa, Canada.

There’s enough time and, well, space for other characters to shine as well. While Nyota Uhura (Zoë Saldana) spends ample screen time mooning about her boyfriend, she proves to be an excellent and forceful translator. Scotty (Simon Pegg) also has a wonderful back-and-forth sequence late in the movie, breaking up some intense moments with his slapstick humor.

Also: Another character comes along and — with a presence that commands attention on the big screen — threatens to steal the show from our heroes. You don’t want to like them, but as you get to know them you realize they have reasons behind their actions.

What did you think of the film? Please share your thoughts in the comments

Kepler Planet-Hunting Mission in Jeopardy

A diagram of the Kepler space telescope. Credit: NASA

NASA’s Kepler telescope has lost its ability to precisely point toward stars, putting its exoplanet search in jeopardy. One of the reaction wheels –devices which enable the spacecraft to aim in different directions without firing thrusters – has failed. This is of grave concern because last year reaction wheel #2 failed, and now #4 has failed. Kepler scientists say the spacecraft needs at least three reaction wheels to be able to point precisely enough to hunt for planets orbiting distant stars.

“We need three wheels in service to give us the pointing precision to enable us to find planets,” said Bill Borucki, Kepler principal investigator, during a press briefing today. “Without three wheels it is unclear whether we could continue to do anything on that order.”

But the Kepler team said there are still possibilities of keeping the spacecraft in working order, or perhaps even finding other opportunities for different science for Kepler, something that doesn’t require such precise pointing abilities.

“We’re not ready to call the mission down and out just yet,” said John Grunsfeld, NASA’s associate administrator for the Science Mission Directorate, “but by any measure it’s been a spectacular mission.”

Last year, NASA had approved an extended mission for Kepler through 2016, and so a lot is riding on the health of the spacecraft’s reaction wheels.

Yesterday, (May 14, 2013) Kepler went into safe mode, a pre-programmed software mode that if the observatory has trouble with pointing, it puts the spacecraft in a state where the solar panels turn towards the Sun to maintain power to its systems, as well as sending an alert to ground controllers. When engineers looked at telemetry, they saw indication that reaction wheel #4 was not moving, even after they commanded it to speed up.

“Initially, they did see some movement on the wheel,”said Charles Sobeck, Kepler deputy project manager during today’s briefing, “but it quickly went back to zero speed, indicative of internal failure on the wheel. Our next step is to see what we can do to reduce the fuel consumption, as we would like to extend the fuel reserve as long as we can.”

Sobeck said they have a few things to try yet to perhaps get wheel #4 working again, such as “jiggling” it or trying the wheel in reverse.

“We can try jiggling it, like you’d do with any wheel here on Earth, commanding it to move back and forth,” said Sobeck, “so we can try to bring the wheel back in service. Or perhaps since wheel #2 hasn’t been turned on for eight months, it may come back if we turn it on. It will take us awhile to come up with a plan.”

Sobeck explained they are currently using thrusters to stabilize the spacecraft, and in its current mode, the onboard fuel will last for several months. But they hope to soon put the spacecraft into what is called a “Point Rest State,” which would extend the fuel to last a period of several years.

“The Point Rest State is a sort of oasis where we can park the vehicle while we decide what we can do next, or see if there’s another mode we can operate the spacecraft in,” Sobeck said “Once we know how we can operate, we can know what the spacecraft can do in the future.”

The Point Rest State is a loosely-pointed, thruster-controlled state that minimizes fuels usage while providing a continuous X-band communication downlink. Sobeck described it as using the solar pressure from the Sun in conjunction with minimum thruster use to allow for a periodic slow back and forth rocking motion of the vehicle which is very fuel efficient but still keeps the solar arrays pointing towards the Sun and communications antennas pointed towards Earth.

The software to execute that state was loaded to the spacecraft last week, and last night the team completed the upload of the parameters the software will use.

Sobeck also said there is the possibility of the wheel running in the opposite direction, but running the wheel backward would mean they would need to use more thruster fuel. “The reaction wheels try to balance the forces from the solar pressure, that’s what forces a wheel to run,” he told Universe Today. “If you’re running the wheel backward, you don’t balance the forces, but add to it, and spacecraft will start to tip, so you will have to offset that with additional thruster firings.”

Reaction wheels have been a problem with several different missions, and Sobeck said NASA does have a team looking at problems of reaction wheels and trying to find ways to maximize their longevity.

Earlier this year, elevated friction was detected in reaction wheel #4, and so as a precaution for wheel safety, and as a measure to mitigate the friction, the reaction wheels were spun down to zero-speed and the spacecraft was placed in a thruster-controlled safe mode for several days. After that, the wheel was able to be used again and it operated until this week.

But the team stressed that even if the Kepler spacecraft is unable to make more observations, there are still terabytes of data to pore over yet from the mission.

“We have two years of data that has yet to be searched through,” said Borucki, “I’m optimistic that the data we have we’ll be able to accomplish Kepler’s mission of finding another Earth. We believe that in the next couple of years we will have many more exciting discoveries with respect to finding planets.”

Boricki added that while he’s delighted that they have found so many planetary candidates, on the other hand “I would have been even happier if it had continued another four years. That would have been frosting on the cake,” he said, “but we have an excellent cake right now.”

Kepler has found over 2,700 planetary candidates, with 130 confirmed planets, from the size of Earth’s moon to larger than Jupiter.

“We’ll continue to analyze the data to get the science that Kepler was designed to do,” said Paul Hertz, NASA’s astrophysics director. “Even though Kepler is in trouble, it has collected all the data necessary to answer its scientific objectives. Kepler is not the last exoplanet mission, but the first. It has been a great start to our path of exoplanet exploration.”

There’s also the chance that something else could be done with the spacecraft if it no longer can do planet hunting, such as asteroid hunting or other astronomical observations…just something that doesn’t need as precise ability for pointing. If that’s the case, Hertz said they would open up a call for science mission proposals.

Additional info here from the Kepler Mission Manager Update

Mars Gets Bombarded by 200 Small Asteroids and Comets Every Year

A relatively new cluster of impact craters on Mars as seen by the HiRISE camera on the Mars Reconnaissance Orbiter. Credit: NASA/JPL-Caltech/MSSS/Univ. of Arizona

One of the benefits of having a spacecraft in orbit around another planet for several years is the ability to make long-term observations and interpretations. The Mars Reconnaissance Orbiter has been orbiting Mars for over seven years now, and by studying before-and-after images from the High Resolution Imaging Science Experiment (HiRISE) camera, scientists have been able to estimate that the Red Planet gets womped by more than 200 small asteroids or bits of comets per year, forming craters at least 3.9 meters (12.8 feet) across.

“It’s exciting to find these new craters right after they form,” said Ingrid Daubar of the University of Arizona, Tucson, lead author of the paper published online this month by the journal Icarus. “It reminds you Mars is an active planet, and we can study processes that are happening today.”

New impact site on Mars formed between November 2005 and October 2010. Credit: NASA/JPL-Caltech/MSSS/Univ. of Arizona
New impact site on Mars formed between November 2005 and October 2010. Credit: NASA/JPL-Caltech/MSSS/Univ. of Arizona

Over the last decade, researchers have identified 248 new impact sites on parts of the Martian surface in the past decade from spacecraft images, determining when the craters appeared. The 200-per-year planetwide estimate is a calculation based on the number found in a systematic survey of a portion of the planet.

The orbiters took pictures of the fresh craters at sites where before-and-after images by other cameras helped figure out when the impacts occurred. This combination provided a new way to make direct measurements of the impact rate on Mars. This will lead to better age estimates of recent features on Mars.

Daubar and co-authors calculated a rate for how frequently new craters at least 3.9 meters in diameter are excavated. The rate is equivalent to an average of one each year on each area of the Martian surface roughly the size of the U.S. state of Texas. Earlier estimates pegged the cratering rate at three to 10 times more craters per year. They were based on studies of craters on the moon and the ages of lunar rocks collected during NASA’s Apollo missions in the late 1960s and early 1970s.

“Mars now has the best-known current rate of cratering in the solar system,” said HiRISE Principal Investigator Alfred McEwen of the University of Arizona, a co-author on the paper.

Examples of craters listed in the paper 'The Current Martian Cratering Rate.' Credit: NASA/JPL/Univ. of Arizona.
Examples of craters listed in the paper ‘The Current Martian Cratering Rate.’ Credit: NASA/JPL/Univ. of Arizona.

These asteroids, or comet fragments, typically are no more than 3 to 6 feet (1 to 2 meters) in diameter. Space rocks too small to reach the ground on Earth cause craters on Mars because the Red Planet has a much thinner atmosphere.

For comparison, the meteor over Chelyabinsk, Russia, in February was about 10 times bigger than the objects that dug the fresh Martian craters.

HiRISE targeted places where dark spots had appeared during the time between images taken by the spacecraft’s Context Camera (CTX) or cameras on other orbiters. The new estimate of cratering rate is based on a portion of the 248 new craters detected. It comes from a systematic check of a dusty fraction of the planet with CTX since late 2006. The impacts disturb the dust, creating noticeable blast zones. In this part of the research, 44 fresh impact sites were identified.

Estimates of the rate at which new craters appear serve as scientists’ best yardstick for estimating the ages of exposed landscape surfaces on Mars and other worlds.

One of many fresh impact craters spotted by the UA-led HiRISE camera, orbiting the Red Planet on board NASA's Mars Reconnaissance Orbiter since 2006. (Photo: NASA/JPL-Caltech/MSSS/UA).
One of many fresh impact craters spotted by the UA-led HiRISE camera, orbiting the Red Planet on board NASA’s Mars Reconnaissance Orbiter since 2006. (Photo: NASA/JPL-Caltech/MSSS/UA).

See the abstract and other information here.
Source: JPL

Timelapse Shows the Blazing Beauty of a ‘Ring of Fire’ Eclipse

Images and videos are still coming in from last week’s spectacular annular eclipse of the Sun, seen across Australia and the southern Pacific region on May 10, 2013. This gorgeous timelapse by Colin Legg captures the eclipse from 3 locations in the Pilbara, Western Australia where the Sun was rising at the time of the event. “If you ever get to see an annular eclipse, I recommend going to the path limits (sunset or sunrise),” Legg said on Vimeo. “All sorts of weird things happen to the Sun, right on the horizon.”

Wow.

See more at our previous gallery of images and video from the eclipse.

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Astrophoto: Stonehenge, the Milky Way and an Eta Aquarids Meteor

A meteor from the Eta Aquarids flashes over the iconic Stonehenge. Credit and copyright: Peter Greig.

Astrophotographer Peter Greig (St1nkyPete on Flickr) had always wanted to go to Stonehenge in Wiltshire, England, and chose to go there this year for his birthday. It turns out the Universe gave him a little birthday present, with a fabulous clear evening to see the Milky Way shining overhead, along with a few Eta Aquarid meteors flashing in the sky. He captured this amazing shot on May 12. Happy birthday, Peter!

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