A Workable Interstellar Spaceship?

Artist's conception of a nuclear-powered spaceship.  Credit:  NASA

A former colleague of Edward Teller -- father of the hydrogen bomb -- has published a new paper proposing a design for what could the the first practical fusion-powered spacecraft.

As described here at Centauri Dreams, the design has certain similarities to MagOrion, a 1990s-era proposal for nuclear-powered spaceship with a magnetic sail and propelled by small-yield fission devices.

The proposal's author also has links to the British Interplanetary Society's Project Daedalus, a 1970s proposal for an unmanned fusion-powered interstellar probe designed to reach 12% of the speed of light on its way to Barnard's Star. 

All of which, of course, begs the question:  if we can do it, why wouldn't others?

Mars Rover "Spirit" Has Behavior Problems

Artist's concept of Mars Exploration Rover. Image credit: NASA/JPL-Caltech/Cornell University.

What's next, running away from home?

NASA is reporting some troubling behavior by one of its aging children on Mars --Spirit -- one of NASA's twin Martian Rovers:

The team operating NASA's Mars Exploration Rover Spirit plans diagnostic tests this week after Spirit did not report some of its weekend activities, including a request to determine its orientation after an incomplete drive.

On Sunday, during the 1,800th Martian day, or sol, of what was initially planned as a 90-sol mission on Mars, information radioed from Spirit indicated the rover had received its driving commands for the day but had not moved. That can happen for many reasons, including the rover properly sensing that it is not ready to drive. However, other behavior on Sol 1800 was even more unusual: Spirit apparently did not record the day's main activities into the non-volatile memory, the part of its memory that persists even when power is off.

NASA scientists aren't afraid to consider therapeutic intervention:

"We don't have a good explanation yet for the way Spirit has been acting for the past few days," said JPL's Sharon Laubach, chief of the team that writes and checks commands for the rovers. "Our next steps will be diagnostic activities."

Among other possible causes, the team is considering a hypothesis of transitory effects from cosmic rays hitting electronics. On Tuesday, Spirit apparently used its non-volatile memory properly.

Despite the rover's unexplained behavior, Mars Exploration Rovers' Project Manager John Callas of JPL said Wednesday, “Right now, Spirit is under normal sequence control, reporting good health and responsive to commands from the ground."

I wonder if they have thought to search Spirit's room for contraband.

Not to worry.  The latest reports are that Spirit is doing well while the diagnostics continue.

Baked Planet

The planet HD80606b glows orange from its own heat in this computer-generated image. A massive storm has formed in response to the pulse of heat delivered during the planet's close swing past its star. The blue crescent is reflected light from the star. Image by D. Kasen, J. Langton, and G. Laughlin (UCSC). 

Source:  University of California-Santa Cruz

Astronomers have observed the intense heating of a distant planet as it swung close to its parent star, providing important clues to the atmospheric properties of the planet. The observations enabled astronomers at the University of California, Santa Cruz, to generate realistic images of the planet by feeding the data into computer simulations of the planet's atmosphere.

"We can't get a direct image of the planet, but we can deduce what it would look like if you were there. The ability to go beyond an artist's interpretation and do realistic simulations of what you would actually see is very exciting," said Gregory Laughlin, professor of astronomy and astrophysics at UCSC. 

The researchers used NASA's Spitzer Space Telescope to obtain infrared measurements of the heat emanating from the planet as it whipped behind and close to its star. In just six hours, the planet's temperature rose from 800 to 1,500 Kelvin (980 to 2,240 degrees Fahrenheit).

Known as HD 80606b, the planet circles a star 200 light years from Earth, is four times the mass of Jupiter, and has the most eccentric orbit of any known planet. It spends most of its 111.4-day orbit at distances that would place it between Venus and Earth in our own solar system, while the closest part of its orbit brings it within 0.03 astronomical units of its star (one astronomical unit is the distance between Earth and the Sun). The planet zips through this dramatic close encounter with its star in less than a day.

At the closest point, the sunlight beating down on the planet is 825 times stronger than the irradiation it receives at its farthest point from the star. "If you could float above the clouds of this planet, you'd see its sun growing larger and larger at faster and faster rates, increasing in brightness by almost a factor of 1,000," Laughlin said.

Spitzer observed the planet for 30 hours before, during, and just after its closest approach to the star. The planet passed behind the star (an event called a secondary eclipse) just before the moment of its closest approach. This was a lucky break for Laughlin and his colleagues, who had not known that would happen when they planned the observation. The secondary eclipse allowed them to get accurate measurements from just the star and thereby determine exact temperatures for the planet.

Read more here, and view a movie of the thermal storms evolving on the planet here.

The Invisible Man Nears Reality

I've posted three times before -- in May, July and August -- about various scientific teams around the world racing to perfect the first workable technology to render objects and people invisible.

This is not science fiction, but does remind you of Arthur C. Clarke's oft-quoted maxim that any sufficiently advanced technology will appear to us to be magic.

Now comes word from Duke University of yet another advance:

A device that can bestow invisibility to an object by “cloaking” it from visual light is closer to reality. After being the first to demonstrate the feasibility of such a device by constructing a prototype in 2006, a team of Duke University engineers has produced a new type of cloaking device, which is significantly more sophisticated at cloaking in  a broad range of frequencies.

The latest advance was made possible by the development of a new series of complex mathematical commands, known as algorithms, to guide the design and fabrication of exotic composite materials known as metamaterials. These materials can be engineered to have properties not easily found in natural materials, and can be used to form a variety of “cloaking” structures. These structures can guide electromagnetic waves around an object, only to have them emerge on the other side as if they had passed through an empty volume of space.

Here's news coverage from Science Daily and CBS News.

CoRoT: Two Years, Five Planets

Credit:  ESA/Ill. C.Carreau.

Source:  CNES (French Space Agency)

Thanks to CNES’s CoRoT space telescope, which recently completed its second year of observations, five exoplanets have already been identified and scientists are learning more every day about the inner structure of stars.

Next up: the discovery of an Earth-like planet might not be far away.

Unlike its illustrious cousin Hubble, CNES’s space telescope doesn’t acquire images of stars.  CoRoT’s mission is to record any variations in brightness of the celestial objects it is pointed at. These may be stars, but also and above all exoplanets outside our solar system.

CoRoT can observe 12,000 stars at the same time and measure variations in their brightness precisely.

CoRoT’s list of discoveries already includes five confirmed Jupiter-like exoplanets.

Among these are CoRoT-Exo-3b and CoRoT-Exo-4b, two very exotic objects.  The first is a particularly massive object somewhere between a star and a planet, while the second orbits its star in around nine days, a relatively long orbital period for an exoplanet.

But what many astronomers are now awaiting is the discovery of the first Earth-like exoplanet.

CoRoT is currently detecting large Jupiter-like planets, but it was designed above all to observe objects much smaller than Uranus, even with a radius only two or three times larger than Earth’s.

Space telescopes offer the capability to observe the same star for months at a time and record a wealth of data about its behavior.  This can only be achieved from space, because Earth’s rotation makes it impossible to point a ground telescope at a star for a long period.

Moreover, space telescopes are free from Earth’s thick obscuring atmosphere.

As CoRoT starts its third year of observations, the venerable Hubble Space Telescope is being prepared for one last Space Shuttle mission to upgrade it in May.

Our Neighbor Next Door?

Views of Alpha Centauri    Credit:  ESO    Explanation

Back in March I posted about a team of researchers at the University of California-Santa Cruz who have proposed a computer model that predicts Alpha Centauri -- the star closest to our own Sun -- may harbor at least one Earth-like terrestrial planet orbiting within the habitable zone of one of the system's component stars.  Astronomers hope they may be able to detect such planets, if they exist, in the relatively near future using the well-established radial velocity method that measures the wobble caused by planets as they orbit their host stars. 

The hunt for that Earth-like planet around Alpha Centauri B is now underway in Chile.

According to the NASA/JPL website Planet Quest:

At a little over four light years from Earth, the sunlike star Alpha Centauri B -- actually a member of a three-star system -- is our sun's closest neighbor and practically a stone's throw away in celestial terms.

[The] planet-hunting team is using a telescope in Chile to keep an eye on the star for the next three years, in order to collect enough data to determine whether or not the next Earthlike planet lies next door.

Such a planet would be too small to see, but its gravity will pull on its host star, making it rock back and forth in a way that the telescope can detect. With NASA funding, they're also working on simulations that may be able to predict how a solar system could have formed around our cosmic neighbor.

I wish them success.  Other searches for a planet around the nearest star, Proxima Centauri,  have so far yielded nothing -- but the quest continues.

You can read the full Planet Quest article here.

Extrasolar Super-Neptune

Credit: David A. Aguilar (CfA) 

Astronomers at the Harvard-Smithsonian Center for Astrophysics in Cambridge, MA have discovered a planet somewhat larger and more massive than Neptune orbiting a star 120 light-years from Earth. While Neptune has a diameter 3.8 times that of Earth and a mass 17 times Earth's, the new world (named HAT-P-11b) is 4.7 times the size of Earth and has 25 Earth masses.

HAT-P-11b was discovered because it passes directly in front of (transits) its parent star, thereby blocking about 0.4 percent of the star's light. This periodic dimming was detected by a network of small, automated telescopes known as "HATNet," which is operated by the Center in Arizona and Hawaii. HAT-P-11b is the 11th extrasolar planet found by HATNet, and the smallest yet discovered by any of the several transit search projects underway around the world.

The newfound world orbits very close to its star, revolving once every 4.88 days. As a result, it is baked to a temperature of around 1100 degrees F. The star itself is about three-fourths the size of our Sun and somewhat cooler.

HAT-P-11 is in the constellation Cygnus, which puts in it the field of view of NASA's upcoming Kepler spacecraft. Kepler will search for extrasolar planets using the same transit technique pioneered by ground-based telescopes. This mission potentially could detect the first Earth-like world orbiting a distant star. 

Source:  Harvard-Smithsonian Center for Astrophysics (CfA)

A New Dawn For Science

As New Scientist reports today, President Barack Obama injected a new respect for science into his inaugural address and his administration:

"We will restore science to its rightful place, and wield technology's wonders to raise health care's quality and lower its cost. . . . We will harness the Sun and the winds and soil to fuel our cars and run our factories . . . . we will work tirelessly to lessen the nuclear threat, and roll back the spectre of a warming planet."

You can read the full New Scientist article here.

First Earth-Size Exoplanet Already Found?

Illustration:  ESO

New Scientist is reporting the extrasolar planet MOA-2007-BLG-192Lb -- whose discovery was announced just last summer -- may actually be the first truly Earth-sized exoplanet to be identified.

According to New Scientist, a new analysis suggests the planet weighs less than half the original estimate of 3.3 Earth masses.  The new estimate -- which scientists hope to confirm with more observations in the near future -- peg the planet's size at 1.4 Earth masses.

The new estimate is the result of recent observations suggesting the planet's host star is more massive than originally thought, meaning the planet must be smaller than scientists originally estimated.  Astronomers first thought the host star was a tiny brown dwarf , but now realize it is actually a red dwarf.

The planet orbits a small red dwarf star some 3,000 light-years distant and orbits its host star at a distance of 0.62 astronomical units (an astronomical unit is the distance from the Earth to the Sun, or about 93 million miles) -- about the same distance as Venus from our Sun.

One significance of the planet's discovery is that it points to the probable ubiquity of smaller terrestrial planets in somewhat Earth-like orbits -- at least when it comes to red dwarf stars, the oldest and most numerous stars in the galaxy.

Scientists don't think MOA-2007-BLG-192Lb is likely to harbor life but concede it may be habitable due to a probably thick atmosphere and possible oceans.

Astronomers first discovered the planet using a technique called gravitational microlensing, a technique that may be sensitive enough to detect planets with masses one-tenth that of Earth.

You can view a video report from the discoverers here.

Life On Mars?! Can It Be?

Well, don't hold your breath, but the British tabloid The Sun thinks there is -- and that NASA will announce it to the world Thursday.

According to a NASA media alert, a team of Mars scientists will brief the press at 2:00 PM EST on Thursday, January 15th, regarding "analysis of the Martian atmosphere that raises the possibility of life or geologic activity."

The Sun, of course, is trumpeting this rather tentative announcement as proof that NASA scientists believe "alien microbes living just below the Martian soil are responsible for a haze of methane around the Red Planet."

The more mundane truth, probably, is that NASA will announce firm evidence of the presence of methane in the Martian atmosphere and discuss its possible origins as indicated in the NASA media alert:  life, or geologic activity.

(Coincidentally, Wired.com today published its list of the top 5 bets for alien life in our solar system -- the list includes Mars along with Saturn's moons Enceladus and Titan and Jupiter's moons Europa and Io.)

We've been through this drill before, of course -- remember the hullabaloo in August (partially stirred up by yours truly) over a supposed White House briefing on an impending announcement related to the potential for life on Mars?  Turned out there was a discovery -- of perchlorate in Martian soil -- but NASA denounced media reports of the White House briefing as bogus.

According to the NASA media alert, those presenting the briefing -- to be carried live on NASA TV -- will be:

- Michael Meyer, Mars program lead scientist, NASA Headquarters in Washington 
- Michael Mumma, senior planetary scientist and director, Goddard Center for Astrobiology, NASA's Goddard Space Flight Center in Greenbelt, Md. 
- Geronimo Villanueva, planetary scientist and astrobiologist, Goddard Space Flight Center 
- Sushil Atreya, professor of atmospheric and space science, University of Michigan, Ann Arbor 
- Lisa Pratt, professor of geological sciences, Indiana University in Bloomington. 

Tune in if you can, but don't expect an announcement of cosmic proportions.

But, as always, I could be wrong.

Planet Hunters Chalk Up Another

Artist's impression of an exoplanet.  Credit:  NASA

A joint Chinese/Japanese team has announced the latest extrasolar planet discovery.  

According to a press release from the Chinese Academy of Sciences:

 A joint team of National Astronomical Observatories, CAS (NAOC) and Okayama Astrophysical Observatory, Japan, recently discovered an extrasolar planet by using 2.16m astronomical telescope and 1.88m astronomic telescope respectively. The discovery was published by Research in Astronomy and Astrophysics, January 2009.

The planet is a companion to the giant star DH 173416. Scientists from Xinglong station, NAOC and Okayama Astrophysical Observatory, Japan had been observing star DH 173416 since 2004. By adopting the radial velocity method they detected the planet and further confirmed it was a new one. The planetary companion has a minimum mass of 2.7 MJ, an eccentricity of 0.21, a semimajor axis of 1.16 AU and an orbital period of 324 days. It is the first exoplanet ever discovered by the Chinese astronomers using 2.16m astronomical telescope.

The discovery is the 335th exoplanet to be discovered, and the 284th extrasolar planetary system.

Just Damn Cool

Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA

Saturn, as imaged by the Cassini probe, courtesy of NASA's Astronomy Picture of the Day:

Explanation: In the shadow of Saturn, unexpected wonders appear. The robotic Cassini spacecraft now orbiting Saturn recently drifted in giant planet's shadow for about 12 hours and looked back toward the eclipsed Sun. Cassini saw a view unlike any other. First, the night side of Saturn is seen to be partly lit by light reflected from its own majestic ring system. Next, the rings themselves appear dark whensilhouetted against Saturn, but quite bright when viewed away from Saturn, slightly scattering sunlight, in this exaggerated color image. Saturn's rings light up so much that new rings were discovered, although they are hard to see in the image. Seen in spectacular detail, however, is Saturn's E ring, the ring created by the newly discovered ice-fountains of the moon Enceladus and the outermost ring visible above. Far in the distance, at the left, just above the bright main rings, is the almost ignorable pale blue dot of Earth.

2009: An Astronomer's Delight

Artist's Conception of ALMA Array in Chile.  Credit:  ESO

As I told you last week, 2009 is the International Year of Astronomy.  The International Astronomical Union and UNESCO proclaimed it so in honor of the 400th anniversary of Galileo's telescope.

And appropriately so.  As laid out in this McClatchy Newspapers article, astronomers are looking forward to numerous major new optical and radio telescopes coming on line in 2009:

-- A major upgrade of the 19-year-old Hubble Space Telescope, including two advanced detectors that will vastly improve its vision for another five years.

-- A bigger European rival to Hubble called the Herschel Space Observatory.

-- ALMA, an array of 50-plus telescopes on a lofty desert in Chile that will be the most powerful ground-based observation system to date.

-- Kepler, an orbiting telescope designed specifically to look for inhabitable planets around distant stars.

-- Pan-STARRS, a set of four inter-connected telescopes to detect fast-moving hazardous objects, such as satellites or space rocks.

-- IceCube, an upside-down space particle observatory buried under the ice at the South Pole.

-- The Allen Telescope Array, a set of 42 of radio telescopes listening for extra-terrestrial messages from possible civilizations around another stars.

Get the full scoop here.

Obama Briefed On Renegade Space Plan

Credit: The DIRECT Team, www.directlauncher.com

Potential Jupiter Direct Configurations

As I mentioned back in August, a group of moonlighting engineers and space buffs has been pushing an alternative to the Ares rocket, NASA's planned launcher to replace the space shuttle.  The alternative, now called Jupiter Direct, has caught the attention of President-Elect Obama's transition team.

 

According to engineers working on the Jupiter Direct project, the Obama team received their proposal cordially but with no promises made.  

For now, at least, it looks like NASA is sticking with the Ares project.

Countdown To Kepler

Credit:  NASA, Carter Roberts

NASA's planet-hunting Kepler mission is set to launch late on the evening of March 6th.  A few days ago the space telescope arrived in Florida for final launch preparations.

According to the NASA/JPL Planet Quest website:

NASA's Kepler spacecraft, scheduled to launch in March on a journey to search for other Earths, has arrived in Cape Canaveral, Fla.

Kepler will hunt for planets using a specialized one-meter diameter telescope called a photometer to measure the small changes in brightness caused by the transits.

Over a four-year period, Kepler will continuously view an amount of sky about equal to the size of a human hand held at arm's length or about equal in area to two "scoops" of the sky made with the Big Dipper constellation.

A map of the area Kepler will search is shown above superimposed on a photograph of the constellation Cygnus, The Swan.  More information on the Kepler Field of View can be found here.

NASA has posted a countdown clock for Kepler, as well as animations of the spacecraft mission and the science objectives.

Sunset On Mars

Credit: Mars Exploration Rover Mission, Texas A&M, Cornell, JPL, NASA

This falls into the category of "just damn cool."

Courtesy of NASA's Astronomy Picture of the Day:

This month, the Mars Exploration Rovers are celebrating their 5th anniversary of operations on the surface of the Red Planet. The serene sunset view, part of their extensive legacy of images from the martian surface, was recorded by the Spirit rover on May 19, 2005. Colors in the image have been slightly exaggerated but would likely be apparent to a human explorer's eye. Of course, fine martian dust particles suspended in the thin atmosphere lend the sky a reddish color, but the dust also scatters blue light in the forward direction, creating a bluish sky glow near the setting Sun. The Sun is setting behind the Gusev crater rim wall some 80 kilometers (50 miles) in the distance. Because Mars is farther away, the Sun is less bright and only about two thirds the size seen from planet Earth.

Age Of The Cyborg

New Scientist has a lengthy article about an issue I've posted about several before:  the dawning of the age of the truly bionic prosthetic, and what it may mean for our future.

From the article:

Emerging prosthetic technologies promise not only greater power and flexibility but also pressure-sensitive artificial skin, and even limbs that are bonded to the body and controlled by the mind - and much of this within five years. Rebuilding amputees to be faster and stronger than before is rapidly becoming a realistic possibility. With experimental prosthetics increasingly able to integrate with flesh, bone and the nervous system, the very idea of "losing a limb" may one day become obsolete.

Read the entire article here.

South Korea Goes SETI

The 7.2-meter radio telescope at the Gwacheon National Science Museum will be used specifically to search for signs of extraterrestrial intelligence.  Credit:  The Korea Times

I've posted before about SETI as a primarily American scientific venture, although some other nations have been jumping into the fray recently.   Now there is another:  South Korea.

From The Korea Times:

The Gwacheon National Science Museum said its brand new 7.2-meter telescope, to be activated this month, will be used to search for signs of extraterrestrial intelligence.

Local astronomers are analyzing radio signals detected by the telescope, which is now under a test run, according to Lee Kang-hwan, who will head the museum’s SETI (search for extra-terrestrial intelligence) program.

The telescope’s targets will include the Milky Way and about 250 planetary systems, Lee said.

``Our radio telescope is one of the first instruments of its kind specializing in finding indications of alien life,’’ Lee said.

``There’ve been consistent efforts in several countries to search for radio signals produced by extra-terrestrial life, but no substantial results have been reported. Science needs more research in this area, and we are glad to be part of the process,’’ he said.

Read the complete article here.

New Study: Earth-Like Planets Are Common

Image: NASA/JPL-Caltech   

New research announced yesterday at the American Astronomical Society's meeting in Long Beach, California, provides new support for the idea that Earth-like habitable planets are common in our galaxy.

According to a press release from the Jet Propulsion Laboratory:

Observations made with NASA's Spitzer Space Telescope reveal six dead "white dwarf" stars littered with the remains of shredded asteroids. This might sound pretty bleak, but it turns out the chewed-up asteroids are teaching astronomers about the building materials of planets around other stars.

So far, the results suggest that the same materials that make up Earth and our solar system's other rocky bodies could be common in the universe. If the materials are common, then rocky planets could be, too.

"If you ground up our asteroids and rocky planets, you would get the same type of dust we are seeing in these star systems," said Michael Jura of the University of California, Los Angeles, who presented the results today at the American Astronomical Society meeting in Long Beach, Calif. "This tells us that the stars have asteroids like ours -- and therefore could also have rocky planets." 

Get more info here from Wired.com or New Scientist.

Extrasolar Carbon Dioxide

Giant planet HD 189733b is about to disappear behind its star. Credit: ESA, NASA, M. Kornmesser (ESA/Hubble), and STScI

For the first time, scientists have discovered carbon dioxide in the atmosphere of an extrasolar planet, the increasingly well-known HD 189733b.  

The planet has become well-known for extrasolar "firsts."  In February, scientists announced the first-ever extrasolar discovery of methane in the planet's atmosphere -- the first time an organic molecule had been found in the atmosphere of an extrasolar planet -- and in July 2007 scientists made the first-ever extrasolar discovery of water in the same planet's atmosphere.  

According to Planet Quest.com:

NASA's Hubble Space Telescope has discovered carbon dioxide in the atmosphere of a planet orbiting another star. This breakthrough is an important step toward finding chemical biotracers of extraterrestrial life. 

The Jupiter-sized planet, called HD 189733b, is too hot for life. But the Hubble observations are a proof-of-concept demonstration that the basic chemistry for life can be measured on planets orbiting other stars. Organic compounds also can be a by-product of life processes, and their detection on an Earthlike planet someday may provide the first evidence of life beyond our planet. 

More information available at NASA and Astrobiology Magazine.

International Year of Astronomy

The International Astronomical Union and UNESCO  (remember them?)  have proclaimed 2009 the International Year of Astronomy.  

Courtesy of NASA's Astronomy Picture of the Day:

Explanation: Astronomers all over planet Earth invite you to experience the night sky as part of the International Year of Astronomy 2009. This year was picked by the International Astronomical Union and the United Nations Educational, Scientific, and Cultural Organization because it occurs 400 years after Galileo turned one of the first telescopes toward the heavens. Peering through that small window, Galileodiscovered that the Moon has craters, Venus has phases, Jupiter has moons, and Saturn has rings. This year you can discover these and many modern wonders of the amazing overhead tapestry that is shared by all of humanity. If, like many others, you find the night sky wondrous and educational, be sure to attend an IYA2009 event in your area, and tell any schools and children that might be interested. Also, please feel free to explore the extensive IYA2009 web pages to find international media events that include blogs, webcasts and much much more.