NASA to send submarine to Saturn’s moon Titan

 

By: PTI | Washington | February 17, 2015 7:08 pm

US Space agency NASA's single-tonne concept robot submarine is equipped with a seafloor camera and sampling system. (Reuters)

 

NASA is planning to send a nuclear-powered submarine to explore one of the methane seas located on Saturn’s moon Titan.

The single-tonne concept robot submarine is equipped with a seafloor camera and sampling system.

The submarine could fit into a space plane such as Boeing’s X-37, which was recently used for a classified Air Force mission.

The plane could land on Kraken Mare, the largest known body of liquid on Titan that consists mostly of liquid methane, or possibly drop the submarine using a parachute, ‘ibtimes.com’ reported.

“The vehicle would use conventional propulsors to yaw around, using a sun sensor to determine the initial azimuth to Earth and begin communication using a terrestrial radio as a more precise reference,” NASA said.

NASA hopes to use the submarine to explore the chemistry of Titan’s seafloor and sea composition, as well as study its tides, weather, shoreline, islands and search for any type of life.

The submarine concept was showcased by NASA Glenn’s COMPASS Team and researchers from Applied Research Lab at the NASA Innovative Advanced Concepts (NIAC) Symposium in Florida.

The concept of the submarine is still in its very early stages, but the team expects that it may be up and running by 2047.

“Measurement of the trace organic components of the sea, which perhaps may exhibit prebiotic chemical evolution, will be an important objective, and a benthic sampler (a robotic grabber to sample sediment) would acquire and analyse sediment from the seabed,” the US space agency explained.

These measurements, and seafloor morphology via sidescan sonar, may shed light on the historical cycles of filling and drying of Titan’s seas.

Models suggest Titan’s active hydrological cycle may cause the north part of Kraken to be ‘fresher’ (more methane-rich) than the south, and the submarine’s long traverse will explore these composition variations.

http://www.financialexpress.com/article/lifestyle/science/nasa-to-send-submarine-to-saturns-moon-titan/44138/

Mysterious giant clouds spotted on Mars

 

Feb 17, 2015, 04.59 PM IST

On two separate occasions in March and April 2012, amateur astronomers reported definite plume-like features developing on the planet.

LONDON: Mysterious cloud-like plumes seen reaching high above the surface of Mars have puzzled scientists studying the atmosphere of the Red Planet.

On two separate occasions in March and April 2012, amateur astronomers reported definite plume-like features developing on the planet.

The plumes were seen rising to altitudes of over 250km above the same region of Mars on both occasions. By comparison, similar features seen in the past have not exceeded 100km.

"At about 250km, the division between the atmosphere and outer space is very thin, so the reported plumes are extremely unexpected," said Agustin Sanchez-Lavega of the Universidad del Pais Vasco in Spain, lead author of the paper published in the journal Nature.

The features developed in less than 10 hours, covering an area of up to 1000 x 500 km, and remained visible for around 10 days, changing their structure from day to day.
None of the spacecraft orbiting Mars saw the features because of their viewing geometries and illumination conditions at the time, researchers said.

However, checking archived Hubble Space Telescope images taken between 1995 and 1999 and of databases of amateur images spanning 2001 to 2014 revealed occasional clouds at the limb of Mars, albeit usually only up to 100km in altitude.

But one set of Hubble images from May 17, 1997 revealed an abnormally high plume, similar to that spotted by the amateur astronomers in 2012.

Scientists are now working on determining the nature and cause of the plumes by using the Hubble data in combination with the images taken by amateurs.

"One idea we've discussed is that the features are caused by a reflective cloud of water-ice, carbon dioxide-ice or dust particles, but this would require exceptional deviations from standard atmospheric circulation models to explain cloud formations at such high altitudes," said Agustin.

"Another idea is that they are related to an auroral emission, and indeed auroras have been previously observed at these locations, linked to a known region on the surface where there is a large anomaly in the crustal magnetic field," added Antonio Garcia Munoz, a research fellow at ESA's ESTEC and co-author of the study.

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READ ALSO: Kerala girl a step away from ticket to Mars
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http://timesofindia.indiatimes.com/Home/Science/Mysterious-giant-clouds-spotted-on-Mars/articleshow/46274950.cms

Life on Earth May Have Begun 1 Billion Years Earlier Than Thought, Scientists Say

 

Feb 17, 2015, 10:02 AM ET

By ALYSSA NEWCOMB

The earliest life forms may have blossomed on Earth 1 billion years earlier than previously thought.

Working together, scientists at the University of Washington and the University of Johannesburg in South Africa found evidence that life may have thrived on Earth 3.2 billion years ago, upending the belief that Earth's atmosphere at the time was uninhabitable.

The study is based on an analysis of 52 rock samples collected in South Africa and northwestern Australia and range in age from 2.75 to 3.2 billion years old.

Roger Buick, a University of Washington professor and co-author of the article that was published Monday in the journal Nature, said the rock samples his team analyzed showed that there was plentiful nitrogen 3.2 billion years ago to sustain the most basic life forms, including bacteria, viruses and other organisms.

While life can exist without oxygen, nitrogen is an essential building block for genes.

"People always had the idea that the really ancient biosphere was just tenuously clinging on to this inhospitable planet, and it wasn't until the emergence of nitrogen fixation that suddenly the biosphere become large and robust and diverse," Buick told UW Today.

Rosetta Space Probe Takes Sharp, Close-up Images of Comet

Titan: How NASA Got the Clearest Photo Ever of Saturn's Moon

Astronomers Discover Ancient Solar System With 5 Earth-Like Planets

 

http://abcnews.go.com/Technology/life-earth-begun-billion-years-earlier-thought-scientists/story?id=29017106

Einstein's Theory of General Relativity

by Nola Taylor Redd, SPACE.com Contributor   |   September 18, 2012 06:52pm ET

Einstein's theory of general relativity predicted that the space-time around Earth would be not only warped but also twisted by the planet's rotation. Gravity Probe B showed this to be correct.

In 1905, Albert Einstein determined that the laws of physics are the same for all non-accelerating observers, and that the speed of light in a vacuum was independent of the motion of all observers. This was the theory of special relativity. It introduced a new framework for all of physics and proposed new concepts of space and time.

Einstein then spent ten years trying to include acceleration in the theory and published his theory of general relativity in 1915. In it, he determined that massive objects cause a distortion in space-time, which is felt as gravity.

The tug of gravity

Two objects exert a force of attraction on one another known as "gravity." Even as the center of the Earth is pulling you toward it (keeping you firmly lodged on the ground), your center of mass is pulling back at the Earth, albeit with much less force. Sir Isaac Newton quantified the gravity between two objects when he formulated his three laws of motion. Yet Newton's laws assume that gravity is an innate force of an object that can act over a distance.

Albert Einstein, in his theory of special relativity, determined that the laws of physics are the same for all non-accelerating observers, and he showed that the speed of light within a vacuum is the same no matter the speed at which an observer travels. As a result, he found that space and time were interwoven into a single continuum known as space-time. Events that occur at the same time for one observer could occur at different times for another.

As he worked out the equations for his general theory of relativity, Einstein realized that massive objects caused a distortion in space-time. Imagine setting a large body in the center of a trampoline. The body would press down into the fabric, causing it to dimple. A marble rolled around the edge would spiral inward toward the body, pulled in much the same way that the gravity of a planet pulls at rocks in space.

Experimental evidence

Although instruments can neither see nor measure space-time, several of the phenomena predicted by its warping have been confirmed.

 Einstein's Cross is an example of gravitational lensing.
Credit: NASA and European Space Agency (ESA)

Gravitational lensing: Light around a massive object, such as a black hole, is bent, causing it to act as a lens for the things that lay behind it. Astronomers routinely use this method to study stars and galaxies behind massive objects.

Einstein's Cross, a quasar in the Pegasus constellation, is an excellent example of gravitational lensing. The quasar is about 8 billion light-years from Earth, and sits behind a galaxy that is 400 million light-years away. Four images of the quasar appear around the galaxy because the intense gravity of the galaxy bends the light coming from the quasar.

Changes in the orbit of Mercury: The orbit of Mercury is shifting very gradually over time, due to the curvature of space-time around the massive sun. In a few billion years, it could even collide with the Earth.

Frame-dragging of space-time around rotating bodies: The spin of a heavy object, such as Earth, should twist and distort the space-time around it. In 2004, NASA launched the Gravity Probe B. The precisely calibrated satellite caused the axes of gyroscopes inside to drift very slightly over time, a result that coincided with Einstein's theory.

Gravitational redshift: The electromagnetic radiation of an object is stretched out slightly inside a gravitational field. Think of the sound waves that emanate from a siren on an emergency vehicle; as the vehicle moves toward an observer, sound waves are compressed, but as it moves away, they are stretched out, or redshifted. Known as the Doppler Effect, the same phenomena occurs with waves of light at all frequencies. In 1959, two physicists, Robert Pound and Glen Rebka, shot gamma rays of radioactive iron up the side of a tower at Harvard University and found them to be minutely less than their natural frequency due to distortions caused by gravity.

Gravitational waves: Violent events, such as the collision of two black holes, are thought to be able to create ripples in space-time known as gravitational waves. The Laser Interferometer Gravitational Wave Observatory is presently searching for the first signs of these tell-tale indicators.

— Nola Taylor Redd, SPACE.com Contributor

Related:

• Video: Flying Space-time's Warps and Twists
• Top 10 Strangest Things in Space
• Twisted Physics: 7 Mind-Blowing Findings

http://www.space.com/17661-theory-general-relativity.html?cmpid=514630_20150207_40021356&adbid=10152625773696466&adbpl=fb&adbpr=17610706465

Seven new galaxies discovered

20 Nov, 2014 at 12:41:PM IST

In a surprising development which could provide a deeper insight into the universe, seven new galaxies have been galaxies have been discovered by the astronomers.

The Subaru Telescope in Japan was used by a team of astronomers, led by graduate student Akira Konno and Dr Masami Ouchi, to identify to search a particular type called Lyman-alpha Emitters (LAEs) which are low mass galaxies.

According to astronomers, the most massive objects in the universe are galaxy clusters as they contain hundreds to thousands of galaxies. The gravitational force keeps the galaxies together.

It is notable that Big Bang led to the creation of the universe about 13.8 billion years ago. It was the time when stars and galaxies were formed initially and later their ultraviolet light ionised which is a process called 'cosmic reionisation'.

The astronomers have searched for early LAE galaxies at a distance of 13.1 billion light years, in a bid to investigate the phenomenon of cosmic reionisation.

"At first we were very disappointed at this small number. But we realised that this indicates LAEs appeared suddenly about 13 billion years ago. This is an exciting discovery. We can see that the luminosities suddenly brightened during the 700 to 800 million years after the Big Bang. What would cause this?" Konno said.

The findings of the study are published in the Astrophysical Journal.

http://www.delhidailynews.com/news/Seven-new-galaxies-discovered-1416467462/

Two New Subatomic Particles Found Using Large Hadron Collider, Scientists Say

Discovery Helps Understanding of How Things Operate on Very Small Scale

Technicians worked on part of the Large Hadron Collider at CERN in July.

Gautam Naik

Updated Nov. 19, 2014 10:14 a.m. ET

Scientists using the atom-smashing machine known as the Large Hadron Collider said Wednesday they had observed two new particles never seen before, a discovery that refines physicists’ understanding of how elementary particles interact and the forces between them.

Theoretical models had predicted the existence of the particles. Scientists used the collider to smash particles together and then sifted through the result to pinpoint the existence of the new particles and identify their mass.

“Now we know exactly what the mass is,” said Patrick Koppenburg from the Netherlands’ Nikhef Institute. Dr. Koppenburg is currently based at the European Organization for Nuclear Research, or CERN, which operates the world’s largest and most powerful particle accelerator, the Large Hadron Collider.

The new particles are six times as large as the proton, the positively-charged subatomic particle that is found in the nucleus of every atom.

The new particles are members of the baryon family, which also includes protons and neutrons. Baryons are made from three quarks, which are the building blocks of matter.

The observation of the baryons isn't of the same consequence as the CERN‘s 2012 discovery of the Higgs boson, which is a fundamental particle that helps explain how particles get their mass. But because it is extremely hard to model how baryons behave, the new discovery is a significant contribution to our understanding of how things operate on the scale of the very small.

“There are maybe three-to-five such particles discovered each year,” said Dr. Koppenburg. “Here we have two in one go, which is quite extraordinary.”

The measurements that pinpointed the baryons were based on data collected at the Large Hadron Collider during 2001 and 2012. It is currently shut down and is scheduled to restart by the spring and to operate at higher energies and using more intense beams than before.

http://online.wsj.com/articles/two-new-subatomic-particles-found-using-large-hadron-collider-scientists-say-1416409980

Facts about Titan

• Titan's atmosphere
• Titan's surface
• Life on Titan?

Titan, Saturn's largest moon

Titan is the largest moon of Saturn, the second largest in the Solar System (after Ganymede of Jupiter). It was discovered by Christiaan Huygens in 1655.

Titan's rotation period of about 16 days is synchronous to Saturn (meaning the same side always faces Saturn). It is the only moon in the Solar System known to have clouds and a thick, planet-like atmosphere.

Distance from Saturn
1 221 870 km

Distance from Sun
1 427 000 000 km (9.54 AU)

Diameter (atmosphere)
5550 km

Diameter (surface)
5150 km

Mass
1/45 that of Earth

Average density
1.881 times liquid water

Surface temperature
94K (-180 degrees C)

Atmospheric pressure at surface
1500 mbar (1.5 times Earth's)

Atmospheric composition
Nitrogen, methane, traces of ammonia, argon, ethane

Orbital period (Titanic day)
15.95 Earth days

Titan’s atmosphere

NASA's Voyager 1 provided the first detailed images of Titan in 1980. They showed only an opaque, orange atmosphere, apparently homogeneous.

It was so thick that you could not see the surface. However, other data revealed exciting things. Similarly to Earth, Titan's atmosphere is mostly nitrogen but there is also methane and many other organic compounds.

Before the arrival of the ESA Huygens probe, planned for January 2005, astronomers will observe Titan using the most powerful ground-based telescopes.

 

Titan's murky atmosphere with the Huygens probe descending on the left

Images from the WM Keck Observatory reveal methane-containing clouds near Titan's south pole. This could mean that Titan has the equivalent of a weather cycle similar to ours on Earth.

This is a major discovery which means that the atmosphere is much more dynamic than previously thought.

The NASA Cassini orbiter will clearly see these clouds, carrying out precise observations before, during and after releasing the Huygens probe.

First view of Titan from Cassini-Huygens

Titan’s surface

Over the years, scientists have dramatically changed their minds about Titan's surface. In the 1990s, the NASA/ESA Hubble Space Telescope spied an area on Titan that was brighter than the rest.

More recent observations show the same feature better. What are these bright and dark patches? Some scientists believe the bright area could be a continent and the rest oceans, but no one knows for sure, yet.

The recently discovered large continent-sized feature (red) is called Xanadu. It is unclear whether Xanadu is a mountain range, a giant basin, a smooth plain or a combination of all three. It may be dotted with hydrocarbon lakes but that is also unknown.

All that is presently known is that in Earth-based images, it is the brightest region on Titan. There is no doubt, though, that the surface appears very diverse, not uniform. There are a lot of surprises waiting for us there.

Where will Huygens land? ESA scientists predict the probe will land close to the bright patch, but not on it. This could be a landing in an ocean - which would be the first splashdown landing in an ocean off the Earth!

To land on an ocean would probably mean better data from Huygens. Even if the probe lasted only a few minutes before sinking, it would at least stay in an upright position. Being the right way up is essential for sending the data back to the Cassini orbiter and to the scientists on Earth.

Moreover, some of Huygens's instruments are better prepared to analyse liquids. If Huygens lands on a solid surface instead, there is a higher risk of falling in the wrong direction and not being able to easily communicate with Cassini.

Life on Titan

Will Huygens land or splashdown on Titan?

Titan, Saturn's largest moon, is a mysterious place. Its thick atmosphere is rich in organic compounds. Some of them would be signs of life if they were on our planet.

How do they form on Titan? Will they help us to discover how life began on Earth?

Titan's atmosphere is mostly nitrogen but there are also methane and many other organic compounds. Organic compounds form when sunlight destroys methane. If sunlight is continuously destroying methane, how is methane getting into the atmosphere?

On Earth today, it is life itself that refreshes the methane supply. Methane is a by-product of the metabolism of many organisms. On Earth, the simplest biological sources, such as those associated with peat bogs, rice fields and ruminant animals, continuously supply fresh gas to replace that destroyed by oxidation. Could this mean there is life on Titan?

Titan is not a pleasant place for life. It is far too cold for liquid water to exist, and all known forms of life need liquid water. Titan's surface is -180°C. According to one exotic theory, long ago, the impact of a meteorite, for example, might have provided enough heat to liquify water for perhaps a few hundred or thousand years.

However, it is unlikely that Titan is a site for life today. But scientists are still currently puzzled by the amount of methane that persists in Titan's atmosphere. Could there be oceans of methane on or under the surface?

http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens/Facts_about_Titan

Titan: Overview

 

Saturn's moon Tethys with its prominent Odysseus Crater silently slips behind Saturn's largest moon Titan.

Titan is Saturn's largest moon. It is surrounded by a thick, golden haze, and only certain kinds of telescopes and cameras can see through the haze to the surface. Titan is of great interest to scientists because it has flowing liquids on its surface and a dense, complex atmosphere.

10 Need-To-Know Things About Titan

1. If the sun were as tall as a typical front door, Earth would be the size of a nickel and Titan would be the size of a pea.
2. Titan is a moon that orbits the planet Saturn. Saturn is the sixth planet from the sun at a distance of about 1.4 billion km (886 million miles) or 9.5 AU.
3. One day on Titan (the time it takes for Titan to rotate or spin once) takes about 16 Earth days. The length of Titan's day is the same as the amount of time it takes Titan to orbit Saturn. Saturn makes a complete orbit around the sun (one Saturn year) in about 29 Earth years (10,759 Earth days).
4. Like many other moons (including Earth's moon), Titan is locked by gravity to its planet so that the same side always faces toward Saturn.
5. Titan has been called the most earthlike world in the solar system because it has lakes, seas and flowing rivers on its surface, although the liquid is methane (CH₄) and ethane (C₂H₆) instead of water.
6. Like Earth, Titan's atmosphere is mostly nitrogen (N₂). It also contains small amounts of methane and other complex hydrocarbons. Titan's atmosphere is slightly denser than Earth's.
7. Titan does not have rings. Its gravity helps to shape ringlets, gaps and other structures in Saturn's rings.
8. Titan has been visited by two spacecraft and one surface lander. Voyager 2 made the first flyby of Titan in 1980. The Cassini spacecraft has made scores of flybys of Titan since 2004. The Huygens probe, carried to Saturn by Cassini, parachuted to the surface in 2005.
9. Scientists who study living things do not think life as we know it is likely on Titan's surface. Some scientists think Titan's subsurface ocean might contain a habitable environment.
10. Seas on Titan are named for mythical sea monsters, while its mountains are named for mountains found in the works of author J.R.R. Tolkien.

Saturn's moon Tethys with its prominent Odysseus Crater silently slips behind Saturn's largest moon Titan.

Titan is the biggest of 53 confirmed moons orbiting Saturn (another 9 moons are being confirmed). Titan is a frigid world enveloped by a thick, hazy atmosphere that obscures its surface. Titan has been studied in great detail only in the past few years, with the arrival of the Cassini-Huygens mission at Saturn in 2004.

Titan is the second largest moon in our solar system, with an equatorial radius of 2,575 km (1,600 miles). It is bigger than Earth's moon, and even larger than the planet Mercury.

Only Jupiter's moon Ganymede is larger than Titan, with a diameter barely 112 km (62 miles) greater.

The temperature at Titan's surface is about -178 degrees Celsius (-289 degrees Fahrenheit). At this frigid temperature, water ice is as hard as rock - in fact, most of the rock on Titan's surface is water ice.

Titan orbits Saturn at a distance of about 1.2 million km (745,000 miles), taking almost 16 days to complete a full orbit.

Titan is of great interest to scientists because it is the only other place in the solar system known to have an earthlike cycle of liquids flowing across its surface. That Titan has seas of liquid methane was suspected before the first spacecraft flyby, but its opaque atmosphere prevented close inspection even then. In 1980, NASA's Voyager 1 spacecraft tried to take close up images of the natural features of Titan's landscape, but was unable to penetrate the thick clouds. Instead, the images showed only slight color and brightness variations in the atmosphere. Titan's atmospheric pressure is about 60 percent greater than Earth's -- roughly the same pressure found at the bottom of a swimming pool.

In 1994, NASA's Hubble Space Telescope recorded pictures of Titan, which suggested that a huge bright continent exists on the hemisphere that faces forward in orbit. These Hubble results didn't prove that liquid seas existed, however; only that Titan has large bright and dark regions on its surface.

NASA's Cassini spacecraft (currently orbiting Saturn) has finally revealed the mysterious moon's true nature. Cassini was specially designed to peer through Titan's haze with radar and in certain colors of light, called spectral windows, that allow a glimpse of what lies below. During dozens of flybys, the Cassini orbiter has mapped a large fraction of Titan's surface and made detailed studies of its atmosphere. Cassini also carried the European-built Huygens probe, which parachuted through Titan's atmosphere in 2005 to make the first landing on a body in the outer solar system.

From Cassini-Huygens, we now know that Titan has lakes and seas of liquid methane (natural gas) and ethane near its poles. These bodies of standing liquids appear to grow and shrink in a seasonal cycle as storms bring rain to one hemisphere, then the other. The mission has revealed drainage channels on the surface that were carved by flowing liquid.

Cassini's radar instrument revealed that large swaths of the surface near the equator are blanketed by dune fields, similar to the Namibian desert on Earth. The mission has also found that Titan has an internal ocean of liquid water.

Because of the extremely cold temperatures at Titan's distance from the sun, chemical processes take longer to unfold, leaving the chemistry of the moon's atmosphere in a state of deep freeze. This carbon-rich chemistry is of great interest to scientists because it could be similar to the atmosphere of early Earth, before life emerged on our planet.

Discovery:
Titan was discovered on 25 March 1655 by the Dutch astronomer Christiaan Huygens.

How Titan Got its Name:
The name Titan comes from a generic term for the children of Ouranos (Uranus) and Gaia in ancient Greek mythology. In the stories, the Titans were the ancestors of the human race. The Titans were known to have devoured the limbs of Dionysus, the son of Zeus. Enraged, Zeus struck the Titans with lightning. (Zeus had intended this child to have dominion over the world.) The lightning burned the Titans to ashes, and from the ashes, mankind was formed.

http://solarsystem.nasa.gov/planets/profile.cfm?Object=Sat_Titan