New Estimate of Amount of Water on Surface of Mars

Mars_Science_Laboratory_Curiosity_rover

NASA’s rover Curiosity, which landed on the surface of Mars on 6 August 2012, has led to more detailed estimates of the amount of water on the Martian surface. The Finnish Meteorological Institute is part of the NASA research team. Read More →

Mapping Clouds on Exoplanet Kepler-7b

NASA's depiction of an exoplanet discovered last year. (Credit: NASA)

NASA’s depiction of an exoplanet discovered last year. (Credit: NASA)

An international team, with participation from the University of Bern, has produced the first map of clouds on an exoplanet using the Kepler Space Telescope. Studying the atmospheres of exoplanets is the path towards ultimately identifying life elsewhere in the Universe. Understanding the role of clouds in exoplanet atmospheres is a necessary ingredient in the cosmic hunt for life. Read More →

Prawn Nebula and New Stars in High Resolution

The glowing jumble of gas clouds visible in new image make up a huge stellar nursery nicknamed the Prawn Nebula. Taken using the VLT Survey Telescope at ESO’s Paranal Observatory in Chile, this may well be the sharpest picture ever taken of this object. It shows clumps of hot new-born stars nestled in among the clouds that make up the nebula. This image also contains information from images of this object taken by Martin Pugh.

The glowing jumble of gas clouds visible in new image make up a huge stellar nursery nicknamed the Prawn Nebula. Taken using the VLT Survey Telescope at ESO’s Paranal Observatory in Chile, this may well be the sharpest picture ever taken of this object. It shows clumps of hot new-born stars nestled in among the clouds that make up the nebula. This image also contains information from images of this object taken by Martin Pugh.

A glowing jumble of clouds nicknamed the Prawn Nebula containing clumps of hot new-born stars is visible in a new, sharp image taken with the European Southern Observatory’s (ESO) VLT Survey Telescope in Chile as part of a public survey led by University of Hertfordshire astronomers. Read More →

Could Life Have Survived a Fall to Earth?

Asteroid impacting Earth's oceans. Credit: NASA/Don Davis

Asteroid impacting Earth’s oceans. Credit: NASA/Don Davis

It sounds like science fiction, but the theory of panspermia, in which life can naturally transfer between planets, is considered a serious hypothesis by planetary scientists. The suggestion that life did not originate on Earth but came from elsewhere in the universe (for instance, Mars), is one possible variant of panspermia. Planets and moons were heavily bombarded by meteorites when the Solar System was young, throwing lots of material back into space. Meteorites made of Mars rock are occasionally found on Earth to this day, so it is quite plausible that simple life forms like yeasts or bacteria could have been carried on them. Read More →

A Universe of New Worlds to Discover & Explore

Exoplanets

In 1992, scientists made one of the most significant discoveries in the history of astronomy; the first confirmed detection of an extrasolar planet. For many decades, it had been widely believed that planets existed around stars other than our own, but it was not until the discovery of two planets orbiting a distant star some 1000 light years away (1 light year = about 6 trillion miles) that their existence was proven beyond doubt. As detection methods advance, particularly thanks to the highly successful Kepler Space Telescope launched in 2009, new alien worlds are being discovered almost every week. Read More →

Astronomers Image Lowest-mass Exoplanet Around a Sun-like Star

Using infrared data from the Subaru Telescope in Hawaii, an international team of astronomers has imaged a giant planet around the bright star GJ 504. Several times the mass of Jupiter and similar in size, the new world, dubbed GJ 504b, is the lowest-mass planet ever detected around a star like the sun using direct imaging techniques.

Glowing a dark magenta, the newly discovered exoplanet GJ 504b weighs in with about four times Jupiter's mass, making it the lowest-mass planet ever directly imaged around a star like the sun. Image Credit: NASA's Goddard Space Flight Center/S. Wiessinger

Glowing a dark magenta, the newly discovered exoplanet GJ 504b weighs in with about four times Jupiter’s mass, making it the lowest-mass planet ever directly imaged around a star like the sun.
Image Credit: NASA’s Goddard Space Flight Center/S. Wiessinger

“If we could travel to this giant planet, we would see a world still glowing from the heat of its formation with a color reminiscent of a dark cherry blossom, a dull magenta,” said Michael McElwain, a member of the discovery team at NASA’s Goddard Space Flight Center in Greenbelt, Md. “Our near-infrared camera reveals that its color is much more blue than other imaged planets, which may indicate that its atmosphere has fewer clouds.”

GJ 504b orbits its star at nearly nine times the distance Jupiter orbits the sun, which poses a challenge to theoretical ideas of how giant planets form.

This composite combines Subaru images of GJ 504 using two near-infrared wavelengths (orange, 1.6 micrometers, taken in May 2011; blue, 1.2 micrometers, April 2012). Once processed to remove scattered starlight, the images reveal the orbiting planet, GJ 504b. Image Credit: NASA’s Goddard Space Flight Center/NOAJ

This composite combines Subaru images of GJ 504 using two near-infrared wavelengths (orange, 1.6 micrometers, taken in May 2011; blue, 1.2 micrometers, April 2012). Once processed to remove scattered starlight, the images reveal the orbiting planet, GJ 504b.
Image Credit: NASA’s Goddard Space Flight Center/NOAJ

According to the most widely accepted picture, called the core-accretion model, Jupiter-like planets get their start in the gas-rich debris disk that surrounds a young star. A core produced by collisions among asteroids and comets provides a seed, and when this core reaches sufficient mass, its gravitational pull rapidly attracts gas from the disk to form the planet.

While this model works fine for planets out to where Neptune orbits, about 30 times Earth’s average distance from the sun (30 astronomical units, or AU), it’s more problematic for worlds located farther from their stars. GJ 504b lies at a projected distance of 43.5 AU from its star; the actual distance depends on how the system tips to our line of sight, which is not precisely known.

“This is among the hardest planets to explain in a traditional planet-formation framework,” explained team member Markus Janson, a Hubble postdoctoral fellow at Princeton University in New Jersey. “Its discovery implies that we need to seriously consider alternative formation theories, or perhaps to reassess some of the basic assumptions in the core-accretion theory.”

The research is part of the Strategic Explorations of Exoplanets and Disks with Subaru (SEEDS), a project to directly image extrasolar planets and protoplanetary disks around several hundred nearby stars using the Subaru Telescope on Mauna Kea, Hawaii. The five-year project began in 2009 and is led by Motohide Tamura at the National Astronomical Observatory of Japan (NAOJ).

This chart locates the fifth-magnitude star GJ 504, also known as 59 Virginis, which is visible to the unaided eye from suburban skies. Image Credit: NASA’s Goddard Space Flight Center

This chart locates the fifth-magnitude star GJ 504, also known as 59 Virginis, which is visible to the unaided eye from suburban skies.
Image Credit: NASA’s Goddard Space Flight Center

While direct imaging is arguably the most important technique for observing planets around other stars, it is also the most challenging.

“Imaging provides information about the planet’s luminosity, temperature, atmosphere and orbit, but because planets are so faint and so close to their host stars, it’s like trying to take a picture of a firefly near a searchlight,” explained Masayuki Kuzuhara at the Tokyo Institute of Technology, who led the discovery team.

The SEEDS project images at near-infrared wavelengths with the help of the telescope’s novel adaptive optics system, which compensates for the smearing effects of Earth’s atmosphere, and two instruments: the High Contrast Instrument for the Subaru Next Generation Adaptive Optics and the InfraRed Camera and Spectrograph. The combination allows the team to push the boundary of direct imaging toward fainter planets.

A paper describing the results has been accepted for publication in The Astrophysical Journal and will appear in a future issue.

The researchers find that GJ 504b is about four times more massive than Jupiter and has an effective temperature of about 460 degrees Fahrenheit (237 Celsius).

It orbits the G0-type star GJ 504, which is slightly hotter than the sun and is faintly visible to the unaided eye in the constellation Virgo. The star lies 57 light-years away and the team estimates the systems is about 160 million years, based on methods that link the star’s color and rotation period to it age.

Young star systems are the most attractive targets for direct exoplanet imaging because their planets have not existed long enough to lose much of the heat from their formation, which enhances their infrared brightness.

“Our sun is about halfway through its energy-producing life, but GJ504 is only one-thirtieth its age,” added McElwain. “Studying these systems is a little like seeing our own planetary system in its youth.”

Source: NASA/Goddard Space Flight Center

NASA Hubble Finds New Neptune Moon

This composite Hubble Space Telescope picture shows the location of a newly discovered moon, designated S/2004 N 1, orbiting Neptune. The black and white image was taken in 2009 with Hubble’s Wide Field Camera 3 in visible light. Hubble took the color inset of Neptune on August 2009. Image Credit: NASA, ESA, M. Showalter/SETI Institute

This composite Hubble Space Telescope picture shows the location of a newly discovered moon, designated S/2004 N 1, orbiting Neptune. The black and white image was taken in 2009 with Hubble’s Wide Field Camera 3 in visible light. Hubble took the color inset of Neptune on August 2009.
Image Credit: NASA, ESA, M. Showalter/SETI Institute

NASA’s Hubble Space Telescope has discovered a new moon orbiting the distant blue-green planet Neptune, the 14th known to be circling the giant planet.

The moon, designated S/2004 N 1, is estimated to be no more than 12 miles across, making it the smallest known moon in the Neptunian system. It is so small and dim that it is roughly 100 million times fainter than the faintest star that can be seen with the naked eye. It even escaped detection by NASA’s Voyager 2 spacecraft, which flew past Neptune in 1989 and surveyed the planet’s system of moons and rings.

Mark Showalter of the SETI Institute in Mountain View, Calif., found the moon July 1, while studying the faint arcs, or segments of rings, around Neptune. “The moons and arcs orbit very quickly, so we had to devise a way to follow their motion in order to bring out the details of the system,” he said. “It’s the same reason a sports photographer tracks a running athlete — the athlete stays in focus, but the background blurs.”

The method involved tracking the movement of a white dot that appears over and over again in more than 150 archival Neptune photographs taken by Hubble from 2004 to 2009.

On a whim, Showalter looked far beyond the ring segments and noticed the white dot about 65,400 miles from Neptune, located between the orbits of the Neptunian moons Larissa and Proteus. The dot is S/2004 N 1. Showalter plotted a circular orbit for the moon, which completes one revolution around Neptune every 23 hours.

The Hubble Space Telescope is a cooperative project between NASA and the European Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Md., conducts Hubble science operations. STScI is operated by the Association of Universities for Research in Astronomy Inc., in Washington.

Source: NASA/Goddard Space Flight Center

New Knowledge About Early Galaxies

Galaxy Formation

The early galaxies of the universe were very different from today’s galaxies. Using new detailed studies carried out with the ESO Very Large Telescope and the Hubble Space Telescope, researchers, including members from the Niels Bohr Institute, have studied an early galaxy in unprecedented detail and determined a number of important properties such as size, mass, content of elements and have determined how quickly the galaxy forms new stars. The results are published in the scientific journal, Monthly Notices of the Royal Astronomical Society (cited below).

Graphic: Chano Birkelind, Niels Bohr Institute

Quasars are among the brightest objects in the universe and can be used as lighthouses to study the universe between the quasars and Earth. Here researchers have discovered a galaxy that lies in front of a quasar and by studying the absorption lines in the light from the quasar, they have measured the elemental composition in the galaxy in great detail, despite the fact that we are looking approx. 11 billion years back in time.
Graphic: Chano Birkelind, Niels Bohr Institute

“Galaxies are deeply fascinating objects. The seeds of galaxies are quantum fluctuations in the very early universe and thus, understanding of galaxies links the largest scales in the universe with the smallest. It is only within galaxies that gas can become cold and dense enough to form stars and galaxies are therefore the cradles of starsbirths”, explains Johan Fynbo, professor at the Dark Cosmology Centre at the Niels Bohr Institute at the University of Copenhagen.

Early in the universe, galaxies were formed from large clouds of gas and dark matter. Gas is the universe’s raw material for the formation of stars. Inside galaxies the gas can cool down from the many thousands of degrees it has outside galaxies. When gas is cooled it becomes very dense. Finally, the gas is so compact that it collapses into a ball of gas where the gravitational compresion heats up the matter, creating a glowing ball of gas – a star is born.

Cycle of stars

In the red-hot interior of massive stars, hydrogen and helium melt together and form the first heavier elements like carbon, nitrogen, oxygen, which go on to form magnesium, silicon and iron. When the entire core has been converted into iron, no more energy can be extracted and the star dies as a supernova explosion. Every time a massive star burns out and dies, it hence flings clouds of gas and newly formed elements out into space, where they form gas clouds that get denser and denser and eventually collapse to form new stars. The early stars contained only a thousandth of the elements found in the Sun today. In this way, each generation of stars becomes richer and richer in heavy elements.

In today’s galaxies, we have a lot of stars and less gas. In the early galaxies, there was a lot of gas and fewer stars.

“We want to understand this cosmic evolutionary history better by studying very early galaxies. We want to measure how large they are, what they weigh and how quickly stars and heavy elements are formed,” explains Johan Fynbo, who has lead the research together with Jens-Kristian Krogager, PhD student at the Dark Cosmology Centre at the Niels Bohr Institute.

Early potential for planet formation

The research team has studied a galaxy located approx. 11 billion years back in time in great detail. Behind the galaxy is a quasar, which is an active black hole that is brighter than a galaxy. Using the light from the quasar, they found the galaxy using the giant telescopes, VLT in Chile. The large amount of gas in the young galaxy simply absorbed a massive amount of the light from the quasar lying behind it. Here they could ‘see’ (i.e. via absorption) the outer parts of the galaxy. Furthermore, active star formation causes some of the gas to light up, so it could be observed directly.

Using the Hubble Space Telescope, researchers have been able to pinpoint the galaxy causing the absorption in the quasar lying behind it. In the image to the left the quasar is seen as the bright source in the center, while the absorbing galaxy, which lies in front of the quasar, is seen to the left and slightly above the quasar. In the image to the right, most of the light from the quasar is removed so the galaxy is seen more clearly. The distance between the center of the galaxy and point were the light from the quasar passes is approx. 20,000 light years, which is slightly less than the distance between the Sun and the center of the Milky Way. Credit: Hubble Telescope

Using the Hubble Space Telescope, researchers have been able to pinpoint the galaxy causing the absorption in the quasar lying behind it. In the image to the left the quasar is seen as the bright source in the center, while the absorbing galaxy, which lies in front of the quasar, is seen to the left and slightly above the quasar. In the image to the right, most of the light from the quasar is removed so the galaxy is seen more clearly. The distance between the center of the galaxy and point were the light from the quasar passes is approx. 20,000 light years, which is slightly less than the distance between the Sun and the center of the Milky Way.
Credit: Hubble Telescope

With the Hubble Space Telescope they could also see the recently formed stars in the galaxy and they could calculate how many stars there were in relation to the total mass, which is comprised of both stars and gas. They could now see that the relative proportion of heavier elements is the same in the centre of the galaxy as in the outer parts and it shows that the stars that are formed earlier in the centre of the galaxy enrich the stars in the outer parts with heavier elements.

“By combining the observations from both methods – absorption and emission – we have discovered that the stars have an oxygen content equivalent to approx. 1/3 of the Sun’s oxygen content. This means that earlier generations of stars in the galaxy had already built up elements that made it possible to form planets like Earth 11 billion years ago,” conclude Johan Fynbo and Jens-Kristian Krogager.

Source: University of Copenhagen – Niels Bohr Institute

Reference:

Jens-Kristian Krogager, Johan P. U. Fynbo, Cédric Ledoux2, Lise Christensen, Anna Gallazzi, Peter Laursen, Palle Møller, Pasquier Noterdaeme, Céline Péroux, Max Pettini, & Marianne Vestergaard (2013). Comprehensive study of a z = 2.35 DLA Galaxy: mass, metallicity, age, morphology and SFR from HST and VLT Monthly Notices of the Royal Astronomical Society, 433 (1) : 10.1093/mnras/stt955

Riding Hexapod Walkers on Dusty Alien Worlds

Hexapod Walker

Speculative fiction is the home of countless machines that fly in space, yet resemble humanoid lifeforms. Scientists are now working on the next generation of robots that will blaze a trail in space by going where humans simply can’t maneuver on their own. Like so many things in the field of space exploration, the descendents of those working on these projects will be the ones to really reap the benefits of this research.

That being said, some scientists and engineers are beginning to consider the possibility of new types of craft that use human pilots while incorporating robotic structures to facilitate planetary exploration. Numerous remotely tele-operated vehicles like the Lunakhod and the Sojourner have already been used with great success to explore extraterrestrial surfaces. The use of human pilots in these past missions would of course been foolish, however, as  technology advances it’s somewhat easier to believe that such endeavors in the future may be realistic. Robotics will undoubtedly become increasingly important as space travel becomes commonplace in the years ahead. Automatic piloting aren’t the only thing that these units will be useful for, however. Semiautonomous navigation devices are old news. Treads won’t be able to explore extremely treacherous terrain on rocky worlds. We need to figure out ways to get humans involved in planetary surface exploration.

One viable option to accomplish this may involve hexapod walkers similar to the one shown above. These units would be far more stable over irregular terrain than treads or wheels. Astronauts landing on other planets wouldn’t be able to work with equipment that’s as straightforward as the buggy used on the Apollo 15, 16 and 17 missions. By using six symmetrical legs, new robotic vehicles could descend vast gorges without tumbling the way conventional vehicles do.

Robotic algorithms can do more than merely pilot units as well. As brain interfaces become safer, astronauts may be able to directly interface with their vehicles. Hexapod legs could actually become extensions of their physical bodies. Some people have proposed constructing piloted robotic vehicles that look like some form of giant humans in order to speed up the learning process. Nevertheless, the human body isn’t exactly a great thing to model a machine after. While the human body might be balanced in its organic form, it wouldn’t really work as a machine. Humans require liquid in the inner ear canal to remain balanced. Hexapod units derive balance from their structure.

Interestingly, not all of a six-legged robot’s legs are necessary to remain upright. If a few of the legs were damaged, it might be able to still move. That makes this design particularly useful for astronauts who would be operating away from technical crews in extremely hazardous environments. Training problems might still be pretty serious, which is why some people have proposed chicken walkers and numerous other sophisticated designs as alternatives.

Conclusion

Industrial robotics have been used in spacecraft rendezvous and docking simulation conditions so these may be the best approach in the future once we figure out how to get humans to planetary bodies. It’s not hard to believe their use will continue to grow as we continue to push the boundaries of space exploration in the future. As we continue moving forward with our space exploration efforts, the involvement of humans should be considered as increases in our technological capabilities are realized.  Brain interfaces and walker units may be integral components in these future planetary exploration efforts.

Reference:

Toralf Boge, & Ou Ma (2011). Using Advanced Industrial Robotics for Spacecraft Rendezvous and Docking simulation Robotics and Automation (ICRA), 1-4 DOI: 10.1109/ICRA.2011.5980583

Wilcox, B. (1992). Robotic vehicles for planetary exploration Applied Intelligence, 2 (2), 181-193 DOI: 10.1007/BF00058762

Meteorites May Reveal Mars’ Secrets of Life

Life

In an effort to determine if conditions were ever right on Mars to sustain life, a team of scientists, including a Michigan State University professor, has examined a meteorite that formed on the red planet more than a billion years ago.

And although this team’s work is not specifically solving the mystery, it is laying the groundwork for future researchers to answer this age-old question.

The problem, said MSU geological sciences professor Michael Velbel, is that most meteorites that originated on Mars arrived on Earth so long ago that now they have characteristics that tell of their life on Earth, obscuring any clues it might offer about their time on Mars.

“These meteorites contain water-related mineral and chemical signatures that can signify habitable conditions,” he said. “The trouble is by the time most of these meteorites have been lying around on Earth they pick up signatures that look just like habitable environments, because they are. Earth, obviously, is habitable.

“If we could somehow prove the signature on the meteorite was from before it came to Earth, that would be telling us about Mars.”

Specifically, the team found mineral and chemical signatures on the rocks that indicated terrestrial weathering – changes that took place on Earth. The identification of these types of changes will provide valuable clues as scientists continue to examine the meteorites.

“Our contribution is to provide additional depth and a little broader view than some work has done before in sorting out those two kinds of water-related alterations – the ones that happened on Earth and the ones that happened on Mars,” Velbel said.

Image Credit: Michigan State University

Image Credit: Michigan State University

The meteorite that Velbel and his colleagues examined – known as a nakhlite meteorite – was recovered in 2003 in the Miller Range of Antarctica. About the size of a tennis ball and weighing in at one-and-a-half pounds, the meteorite was one of hundreds recovered from that area.

Velbel said past examinations of meteorites that originated on Mars, as well as satellite and Rover data, prove water once existed on Mars, which is the fourth planet from the sun and Earth’s nearest Solar System neighbor.

“However,” he said, “until a Mars mission successfully returns samples from Mars, mineralogical studies of geochemical processes on Mars will continue to depend heavily on data from meteorites.”

Velbel is currently serving as a senior fellow at the Smithsonian Institution’s National Museum of Natural History in Washington D.C.

The research is published in Geochimica et Cosmochimica Acta (citation below), a bi-weekly journal co-sponsored by two professional societies, the Geochemical Society and the Meteoritical Society.

Source: Michigan State University

Reference:

Stopar, J., Taylor, G., Velbel, M., Norman, M., Vicenzi, E., & Hallis, L. (2013). Element abundances, patterns, and mobility in Nakhlite Miller Range 03346 and implications for aqueous alteration Geochimica et Cosmochimica Acta, 112, 208-225 DOI: 10.1016/j.gca.2013.02.024