CERES GETS REAL; PLUTO LURKS

Although we are still along way from understanding this fascinating little body, Ceres is finally becoming a real planet with recognizable features! And that's kinda cool. The now-released images from February show features roughly 4 kilometers across, including numerous well-preserved impact craters. These are distinct and clearly show central peaks superficially similar to what we observe on Dione and Tethys. They appear to be about as deep as expected, but measurements of their depths will be done on higher resolution data. Some circular features look rather like flattened craters, but again as to origins (whether relaxed by deformation of ice or by erosion or infilling), caution is in order as we are often fooled at these low resolutions.

Global map of Ceres

Global map of Ceres at 4 km/pixel (this is my version of the map that was released on March 2, and is NOT an official map product).

So, Ceres has impact craters, some of which could be modified by geologic processes. It might also have some tectonic features, though it is still too early to be sure of their extent, age, or importance. It even has those enigmatic bright spots (sorry no speculations at this point!), which hint at the possibility of more water-ice related features at higher resolution. All in all, though, it is nice to finally have a sense of Ceres as a body, even if that view is rather fuzzy at the moment. This bodes very well for the approaching mapping campaign.

Although there are still suggestions of linear features in the new images, our experience with similar-sized icy worlds orbiting Saturn is that only the most dramatic canyons are readily apparent at the current resolution. Tectonic features like simple fault scarps or cracks won't be obvious at Ceres until April (we have spent most of March on the dark side of Ceres at some distance thrusting the ion engines in order to achieve our first mapping orbit on April 22). Indeed, many of Tethys' smaller-scale fractures require resolutions down to 100 meters, which we won't see at Ceres till this summer. It is likely that Ceres may not betray many of its most interesting ice-related features till we get down to our formal mapping altitudes where resolutions will be a kilometer or less.

The most intriguing linear features are arcuate grooves radiating from a large southern impact basin roughly 250 kilometers across. Although these could be tectonic, the arcuate shape is consistent with secondary impact features related to the formation of the basin. The key test will occur when we get 1-kilometer data or better and can examine the detailed morphology.

Here are some Cassini images of Tethys, shown similar to our views of Ceres in mid- and late-April. Smooth regions, many craters, and the largest fracture system, Ithaca Chasma are all very recognizable, but the small fractures and crater chains across the surface are not yet apparent. By the last week of April we should be acquiring images of Ceres at resolutions of 1.3 kilometers, although at different phase angles as this 2-week-long RC3 phase goes to completion.

Tethys' anti-Saturn side

This is the side of tethys that faces away from Saturn. It includes the huge Odysseus basin in the north, and the crater Melanthius with its strange central ridge in the south. The central-peak crater Dolius just barely peeks into sunlight north of Melanthius. Cassini took the two images for this mosaic on Tethys on July 21, 2007 at 7:44 and 7:58 UTC as "ridealong" observations for a thermal infrared map of the moon. Tethys is 1062 kilometers in diameter and was 231,000 kilometers away at the time; the image has a scale of 1.4 kilometers per pixel.

Tethys in enhanced color: south pole and southern Ithaca Chasma

This portrait of Tethys is made of three Cassini images taken through infrared, green, and ultraviolet filters on May 10, 2008. It includes Tethys' south pole and the southern end of Ithaca Chasma, which is on the side of Tethys that faces Saturn. On the right side of the visible disk is the huge Telemus basin, but its topography is so subtle that it is difficult to see in this view.

This is Dione at 1.3 km/pixel (similar to Ceres during RC3). This exquisite image shows many features, including the relaxed craters at lower left (with prominent central peaks), the large 350-km-wide impact basin at bottom, the multiple fracture sets at right, and the smooth plains at left.

Dione in true color

Cassini took three photos of Dione through red, green, and blue filters at 19:32 UT on April 26, 2007 for this portrait of the icy moon. We are looking at the south pole and Saturn-facing hemisphere of Dione. The Palatine chasmata slice into the disk from its right edge to the center, with the flat-floored valley of Aufidus catena diverging south from Palatine toward the huge Evander basin, only half of which is visible at the bottom edge of the disk. Other prominent craters include central-peak crater Dido, at upper center, and slightly smaler peak-ridge crater Erulus, at bottom left.

Pluto

There are times in any great adventure when the pulse quickens just a little and the stomach tightens up a notch. I think I have finally reached that point with Pluto. Two weeks ago we passed the 1-AU point. One AU is the Earth-Sun distance (and yes the tiny Earth does orbit the gigantic Sun), which isn't much more than an anthropomorphic milestone. But we are also now well past the halfway point between Neptune's orbit and our destination. After 9 years of travel (not to mention a decade or more of work to get New Horizons approved, built and launched), it gives one a sense that we are really on final approach. We have passed the second-to-last signpost on the long trek. The last significant signpost will be when we reach the distance where our high-resolution camera gets images roughly equivalent to the Hubble Space telescope, sometime in May. We cannot give a precise date for this as the HST and LORRI imaging systems have different optical characteristics and whatnot. The Project will let us know when we cross this threshold. Still it will be the real mark that we are into new territory.

For the geology types out there (myself included), we will not be getting resolvable data until a few weeks before arrival. That doesn't mean we won't be doing anything. New Horizons is in Approach Phase, during which the Pluto system is under routine monitoring. This will allow us to track all the known moons to get precise orbits and monitor brightness changes to determine rotation periods and such. We are also looking for new moons and even ring systems, if they exist. So we will be very busy during approach doing things that Earth-bound telescopes can't do as well. I will have more on Pluto later this Spring.

See: http://www.planetary.org/blogs/guest-blogs/2015/0327-ceres-gets-real-pluto-lurks.html

'TEAPOT' NOVA BEGINS TO WANE

Unlike a supernova where the explosion happens in the star’s core and destroys it, a nova event takes place when arriving matter ignites on the hot surface of the white dwarf. Credit: Gray Lensman QX!

A star, or nova, has appeared in the constellation of Sagittarius and, even though it is now waning, it is still bright enough to be visible in the sky over Perth through binoculars or a telescope.

It was visible to the naked eye over the weekend.

A nova is characterised as a dim star that has suddenly brightened after an explosive event.

Curtin University astrophysicist Dr John Morgan says that this nova has occurred in a binary star system containing a white dwarf star and a larger companion star.

A white dwarf is the dense core of a mid-sized star that has reached the end of its active life and has lost its outer atmosphere.

"If small amounts of matter are able to transfer from the other star to the white dwarf then that mass can actually fuse in an explosive way," Dr Morgan says.

Unlike a supernova where the explosion happens in the star's core and destroys it, a nova event takes place when arriving matter ignites on the hot surface of the white dwarf.

"There are many cases of what is called a recurrent nova where this donation of mass continues and it explodes again," Dr Morgan says.

"Some of these known recurrent novae blow up every hundred years or so, but some of them blow up much more regularly, maybe once a decade."

The current nova, which was discovered by Australian amateur astronomer John Seach on March 15, has not been recorded before so it is not known if it is recurrent.

A diagram of a nova. Credit: NASA

It appears yellowish but as the expanding shell of gas around the nova expands and cools it will gradually turn orange and then red.

Novae are not unusual events but those that become visible to the naked eye are rare and occur because the unpredictable explosion is particularly violent.

This event has been officially named Nova Sagittarii 2015 No.2 because there was another, much dimmer, nova in Sagittarius in February.

The nova is visible between the two corners of the lid of the "teapot", a grouping of stars in Sagittarius that suggests the outline of a teapot on its side.

Sagittarius is rising at around midnight, two hours behind Scorpius the scorpion, which is easy to spot at the moment because bright Saturn is right beside its three-star head.

See: 

http://phys.org/news/2015-03-teapot-nova-wane.html?utm_content=buffere2f4a&utm_medium=social&utm_source=plus.google.com&utm_campaign=buffer#jCp

NASA ON ALERT AS HUGE ASTEROID 2014-YB35 SET TO 'SKIM PAST EARTH' AT 23,000 MPH ON FRIDAY

A 1,000 metre wide asteroid will skim past earth

The 1,000-metre wide monster will hurtle terrifyingly close to the planet within days, sparking fears of an unprecedented disaster.

The object called ‘2014-YB35’ is almost the same size as Ben Nevis and will skim the Earth on FRIDAY travelling at more than 23,000 mph.

Small meteorites often pass close by however one of this size is a once in 5,000-year occurrence, according to concerned astronomers.

AMAZING IMAGES OF THE EARTH CAPTURED FROM SPACE HERE

A collision with Earth would unleash an explosive force equivalent to more than 15,000 million tonnes - 15,000 megatons - of TNT.

The path of the asteroid is shown below in an animated 'trajectory map' released by NASA. It can clearly be seen only narrowly missing the Earth.

Any impact would trigger devastating changes in the climate, earthquakes and tsunamis leading to the eradication of entire communities.

**CLICK HERE FOR PICTURES FROM NASA's 43rd INTERNATIONAL SPACE MISSION**

The graphic shows the path of the asteroid closing in on earth

It would eclipse the destruction caused by the 1908 Tunguska Event which saw a 50-metre lump of extraterrestrial rock crash into Siberia.

It flattened an estimated 80 million trees and sent a shock wave across Russia measuring five on the Richter scale.

Experts warn it is only a matter of time before an asteroid capable of “lifer altering” damage collides with our planet.

WHEN WILL ASTEROID 2014-YB35 PASS EARTH: TIME DAY AND EVERYTHING YOU NEED TO KNOW

Bill Napier, professor of astronomy at the University of Buckinghamshire, said there is a “very real risk” of a comet or damaging asteroid hitting Earth.

He said: “Smaller scale events like Tunguska are absolutely a real risk, largely they are undiscovered and so we are unprepared.

“With something like YB35, we are looking at a scale of global destruction, something that would pose a risk to the continuation of the planet.

“These events are however very rare, it is the smaller yet still very damaging impacts which are a very real threat.”

Experts warn if one of these monsters were to hit Earth plumes of debris thrown into the atmosphere, changing the climate and potentially making the planet inhabitable for all life.

Smaller impacts would be capable of destroying cities and knocking out transport and communication networks.

Professor Napier added: “The real risk is from comets which even if the Earth passes through the tail can generate a massive plume of smoke with hugely significant consequences.

“There is absolutely a real risk and if you look at history, certainly biblical records, there are reports of fires in the heavens.

“Red hot debris resulting from the impact of something a kilometre wide would be capable of incinerating the planet.”

The asteroid could come very close to crashing into the earth

According to NASA’s Near Earth Object Programme the enormous lump of rock will pass within 2.8 million miles - a tiny distance in astronomical terms - of Earth on Friday.

Images from NASA’s jet propulsion Laboratory show the asteroid 'on course' with the Earth's own trajectory.

Though its exact size is unknown it is estimated to be from between 500 metres and 1km wide with 990 metres the most likely.

The object was first spotted by the Catalina Sky Survey at the end of last year with astronomers expected to be closely watching its progress this week.

Astronomers have named June 30 as Asteroid Day to highlight the dangers of Potentially Dangerous Asteroids (PHAs) hurtling through space.

Initiative co-founder Grigorij Richters warned there are thousands which have not been identified which could ”destroy life”.

He said: “It just takes one asteroid to completely destroy life, not just humanity, but all species.

See: http://www.express.co.uk/news/nature/566159/NASA-alert-asteroid-2014-YB35-near-hit-Earth

SHOULD WE KEEP A LOW PROFILE IN SPACE?

For more than a half-century, a small group of astronomers has sought intelligent company among the stars. They’ve done so by turning large radio antennas skyward, hoping to eavesdrop on signals from an advanced society. It’s a program known as SETI, the Search for Extraterrestrial Intelligence.

But now some researchers propose that we should do more than simply don headphones and await E.T.’s call: We should make serious efforts to encourage a response from putative aliens by deliberately transmitting our own messages. It’s a simple idea, akin to tossing a bottle into the cosmic ocean. But recent arguments for what’s termed active SETI have loosed a storm of controversy, one that has even washed into the halls of academe.

Why is this? Why has the sending of dispatches to worlds many trillions of miles distant suddenly become a hot-button issue? The simple answer is that there’s now a perception that advertising our existence could be a mortal threat to the planet.

The reasoning is this: While no one has yet offered decisive proof for life beyond Earth, in the past two years astronomers have learned that tens of billions of habitable planets suffuse our galaxy. Consequently, to believe that only Earth has spawned intelligence is to insist that our world is the site of a miracle. That point of view rarely appeals to scientists.

The aliens could very well be out there. And that realization has spurred a call by some for broadcasts intended to elicit a communication from at least the nearest other star systems. But we know nothing of the aliens’ possible motives or behavior. Therefore, it’s conceivable that betraying our existence might prompt aggressive action from space.

Broadcasting is likened to “shouting in the jungle” — not a good idea when you don’t know what’s out there. The British physicist Stephen Hawking alluded to this danger by noting that on Earth, when less advanced societies drew the attention of those more advanced, the consequences for the former were seldom agreeable.

It’s a worry we never used to have. Victorian-era scientists toyed with plans to use lanterns and burning pools of oil to contact postulated Martians. In the 1970s, NASA bolted greeting cards onto spacecraft that will leave our solar system and wander the vast reaches between the stars. The Pioneer and Voyager probes carry plaques and records with information about what humans look like and where Earth is, as well as a small sampling of our culture.

Those messages move at the speed of rockets. But in 1974, a three-minute encoded pictogram was transmitted using the large radio antenna at Arecibo, Puerto Rico. It moves at the speed of light, 20,000 times faster. More recent radio transmissions include a Beatles song beamed by NASA to the North Star, a Doritos advertisement launched to a planetary system in the Big Dipper, and a series of broadcasts sent to nearby stars using an antenna in Crimea.

When most people believed that aliens were no more than easy black hats for Hollywood, the idiosyncratic nature of these messages could be easily dismissed. But if cosmic company is a legitimate possibility, shouldn’t we offer up something more edifying than pop music and snack food? A deliberate transmission should represent all of humanity — not short-circuit the important question of who will speak for Earth.

Continue reading the main story

Consequently, recent conferences on the merits of active SETI have sought the advice of social scientists. Among their worries is whether to be up front about humanity’s seamy side: Should we tell the extraterrestrials about war and injustice?

Personally, I think this concern is overwrought. Any society that can pick up our radio messages will be at a level of development at least centuries beyond our own. They would be no more incensed by our bad behavior than historians who learned that Babylonians attacked one another with spears. It seems naïve to imagine that, by shielding aliens from the less flattering aspects of humanity, we would somehow lessen any incentive to do us harm. If there’s a danger, mincing words is unlikely to eliminate it.

A better approach is to note that the nearest intelligent extraterrestrials are likely to be at least dozens of light-years away. Even assuming that active SETI provokes a reply, it won’t be breezy conversation. Simple back-and-forth exchanges would take decades. This suggests that we should abandon the “greeting card” format of previous signaling schemes, and offer the aliens Big Data.

For example, we could transmit the contents of the Internet. Such a large corpus — with its text, pictures, videos and sounds — would allow clever extraterrestrials to decipher much about our society, and even formulate questions that could be answered with the material in hand. Sending the web on its way would take months if a radio transmitter were used. A powerful laser, conveying bits much like an optical fiber, could launch these data in a few days.

Sending messages — even big ones — is technically feasible. However, there’s still the highly controversial matter of whether to broadcast at all. Who decides? One could simply let the public weigh in, but doing so wouldn’t address the security issue. Even if a majority is comfortable with a transmission, how does that mitigate the possible danger?

The inability to gauge this peril prompts some critics to argue that, given the possibly existential threat posed by active SETI, we should choose the side of caution. We should simply forbid powerful transmissions to the skies. Indeed, a small consortium of academics in California has drafted a petition urging this.

It’s a wary approach. It’s also poor insurance. Any extraterrestrials with technology advanced enough to threaten us will surely have antennas larger than our own, instruments that can pick up the television and radio signals broadcast willy-nilly since World War II. We are already shouting into the jungle, albeit with less volume than a deliberate signal. But the dangerous creatures may have good hearing.

Additionally, if we forbid high-powered transmitters aimed at the sky, we shut out such obvious future technologies as better radars for aviation and tracking dangerous asteroids. Do we really want to hamstring our descendants this way?

A decision to engage in active SETI has not been made. The benefit — learning our place in the cosmos — is only hypothetical, and so is the danger. But I, for one, would hesitate to let a paranoia based on nothing more than conjecture shackle the activities of our children and our children’s children. The universe beckons, and we can do better than to declare that future generations should endlessly tremble at the sight of the stars.

Seth Shostak is the director of the Center for SETI Research at the SETI Institute, and a host of the radio program “Big Picture Science.”

See: http://www.nytimes.com/2015/03/28/opinion/sunday/messaging-the-stars.html?_r=1&utm_content=bufferbe149&utm_medium=social&utm_source=plus.google.com&utm_campaign=buffer

THE PHOTOS FROM THE LAST ATLANTIS FLIGHT ARE OUT OF THIS WORLD

Atlantis prepares for its final voyage at Kennedy Space Center on May 31

Atlantis on the launchpad July 7

On the eve of the launch

Crew members head to the launch pad

T minus 10-9-8...

Liftoff!

Climbing...

An external fuel canister detaches from Atlantis after launch

Atlantis in space

Astronauts Chris Ferguson and Doug Hurley on the crew's second day in space

Atlantis pictured over the Bahamas, getting ready to dock at the International Space Station July 10

Atlantis docks perfectly

The American astronauts meet three Russian cosmonauts and a Japanese astronaut aboard the International Space Station

Astronaut Ron Garan captures the space station, the Earth, and the Sun during a space walk July 12

Ron Garan does chores as the shuttle floats over the Persian Gulf

Group picture!

Sandy Magnus checks out the Earth from the space station

Atlantis and the International Space Station whirr over the Earth on July 18

Atlantis after detaching from the International Space Station

Atlantis enters the Earth's atmosphere one last time

Home safe and sound

See: http://www.businessinsider.com/photos-from-the-last-atlantis-flight-2011-7?op=1

FIRST YEAR-LONG MISSION ABOARD THE INTERNATIONAL SPACE STATION

The first year-long mission aboard the International Space Station is set to begin on Friday.

NASA Astronaut Scott Kelly and Russian Cosmonaut Mikhail Kornienko will become the first humans to spend a year in space aboard the International Space Station when they liftoff from Kazakhstan’s Baikonur Cosmodrome on a Russian Soyuz spacecraft at 3:42 p.m. EDT on Friday, March 27.

Kelly and Kornienko will join Russian Cosmonaut Gennady Padalka as a part of Expedition 43 to the International Space Station. Unlike the others, Padalka’s stay aboard the orbiting space station will last only six months.

While this won’t be the longest human spaceflight in history — Russian Cosmonaut Valeri Polyakov holds the record for the longest continuous human spaceflight spending more than 437 days on Mir — this mission will break a number of human spaceflight records.

[President Obama Praises NASA Astronaut In State Of The Union Address]

NASA astronaut Scott Kelly receives a standing ovation at the State Of The Union address on Jan. 20, 2015. Image Credit: NASA

This mission will set the record for the longest stay aboard the International Space Station. It will also break the record for the most time in space by a U.S. astronaut, currently held by Mike Fincke with 382 days spent in space. Kelly will be spending 342 days aboard the space station, culminating in a total of 522 days in space.

Previous missions to the space station typically consisted of stays of about four to six months. This will be the first year-long stay aboard the International Space Station, providing insights into the physical and psychological effects of prolonged spaceflight. Understanding the effects of long-duration space missions is a crucial step in preparation for future human missions to Mars.

“By doubling the length of this mission, researchers hope to better understand how the human body reacts and adapts to long-duration spaceflight,” NASA said in a statement. “This knowledge is critical as NASA looks toward human journeys deeper into the solar system, including to and from Mars, which could last 500 days or longer.”

NASA will be providing live coverage of Expedition 43 to the International Space Station starting at 2:30 p.m. EDT on Friday, March 27. NASA’s live coverage continues at 8:45 p.m. EDT when Expedition 43 approaches the International Space Station. Docking is scheduled to occur at 9:36 p.m. EDT.

Watch NASA’s live stream here: 

http://www.penny4nasa.org/2015/03/27/first-year-long-space-mission-aboard-the-international-space-station/

SUZAKU, HERSCHEL LINK A BLACK-HOLE "WIND" TO A GALACTIC GUSH OF STAR-FORMING GAS

By combining observations from the Japan-led Suzaku X-ray satellite and the European Space Agency's infrared Herschel Space Observatory, scientists have connected a fierce "wind" produced near a galaxy's monster black hole to an outward torrent of cold gas a thousand light-years across. The finding validates a long-suspected feedback mechanism enabling a supermassive black hole to influence the evolution of its host galaxy.

"This is the first study directly connecting a galaxy's actively 'feeding' black hole to features found at much larger physical scales," said lead researcher Francesco Tombesi, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and the University of Maryland, College Park (UMCP). "We detect the wind arising from the luminous disk of gas very close to the black hole, and we show that it's responsible for blowing star-forming gas out of the galaxy's central regions."

This artist's rendering shows a galaxy being cleared of interstellar gas, the building blocks of new stars. New X-ray observations by Suzaku have identified a wind emanating from the black hole's accretion disk (inset) that ultimately drives such outflows.

Image Credit: 

ESA/ATG Medialab

Star formation takes place in cold, dense molecular clouds. By heating and dispersing gas that could one day make stars, the black-hole wind forever alters a large portion of its galaxy.

In a study published in the March 26 edition of Nature, Tombesi and his team report the connection in a galaxy known as IRAS F11119+3257, or F11119 for short. The galaxy is so distant, its light has been traveling to us for 2.3 billion years, or about half the present age of our solar system.

Like most galaxies, including our own Milky Way, F11119 hosts a supersized black hole, one estimated at 16 million times the sun's mass. The black hole's activity is fueled by a rotating collection of gas called an accretion disk, which is some hundreds of times the size of our planetary system. Closest to the black hole, the orbiting matter reaches temperatures of millions of degrees and is largely responsible for the galaxy's enormous energy output, which exceeds the sun's by more than a trillion times. The galaxy is heavily enshrouded by dust, so most of this emission reaches us in the form of infrared light.

A red-filter image of IRAS F11119+3257 (inset) from the University of Hawaii's 2.2-meter telescope shows faint features that may be tidal debris, a sign of a galaxy merger. Background: A wider view of the region from the Sloan Digital Sky Survey.

Image Credit: 

NASA's Goddard Space Flight Center/SDSS/S. Veilleux

Unlabeled image

See: http://www.nasa.gov/content/goddard/suzaku-herschel-link-a-black-hole-wind-to-a-galactic-gush-of-star-forming-gas/?linkId=13124238&utm_content=buffer1dd02&utm_medium=social&utm_source=plus.google.com&utm_campaign=buffer#.VRYGm_ysVsI