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Space News Update — June 19, 2015 —

Contents

In the News

Story 1:

Study suggests active volcanism on Venus

Story 2:

All Systems Go for NASA's Mission to Jupiter Moon Europa

Story 3:

For comet scientists, elation and redemption at Philae’s wakeup

Departments

The Night Sky

ISS Sighting Opportunities

NASA-TV Highlights

Space Calendar

Food for Thought

Space Image of the Week

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1. Study suggests active volcanism on Venus

An international team of scientists has found

some of the best evidence yet that Venus,

Earth's nearest neighbor, is volcanically active.

In combing through data from the European

Space Agency's Venus Express mission, the

scientists found transient spikes in

temperature at several spots on the planet's

surface. The hotspots, which were found to

flash and fade over the course of just a few

days, appear to be generated by active flows

of lava on the surface.

"We were able to show strong evidence that Venus is volcanically, and thus internally, active today," said

James W. Head, a geologist at Brown University and co-author of a paper describing the new research. "This is

a major finding that helps us understand the evolution of planets like our own."

The research is published online in Geophysical Research Letters.

The hotspots turned up in thermal imaging taken by the Venus Express spacecraft's Venus Monitoring Camera.

The data showed spikes in temperature of several hundred degrees Fahrenheit in spots ranging in size from 1

square kilometer to over 200 kilometers.

The spots were clustered in a large rift zone called Ganiki Chasma. Rift zones are formed by stretching of the

crust by internal forces and hot magma that rises toward the surface. Head and Russian colleague Mikhail

Ivanov had previously mapped the region as part of a global geologic map of Venus generated from the Soviet

Venera missions in the 1980s and U.S. Magellan mission in the 1990s. The mapping work had shown that

Ganiki Chasma was quite young, geologically speaking, but just how young wasn't clear until now.

"We knew that Ganiki Chasma was the result of volcanism that had occurred fairly recently in geological terms,

but we didn't know if it formed yesterday or was a billion years old," Head said. "The active anomalies

detected by Venus Express fall exactly where we had mapped these relatively young deposits and suggest

ongoing activity."

The latest finding is consistent with other data from Venus Express that have hinted at very recent volcanic

activity. In 2010, infrared imaging from several volcanoes seemed to indicate lava flows from thousands to a

few million years old. A few years later, scientists reported transient spikes in sulfur dioxide in Venus' upper

atmosphere, another potential signal of active volcanism.

The observation of hotspots by Venus Express, combined with the geologic mapping from Venera and

Magellan, make a strong case for a volcanically active Venus, Head says.

"This discovery fits nicely with the emerging picture of very recent activity in Venus' geologic history," he said.

"These remarkable findings were the result of collaborations spanning many years and many political borders.

They underscore the importance of international collaboration in exploring our solar system and understanding

how it evolves."

Source: Eureka Alert Return to Contents

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2. All Systems Go for NASA's Mission to Jupiter Moon Europa

Beyond Earth, Jupiter's moon Europa is considered one of the most promising places in the solar system to

search for signs of present-day life, and a new NASA mission to explore this potential is moving forward from

concept review to development.

NASA's mission concept -- to conduct a detailed survey of Europa and investigate its habitability -- has

successfully completed its first major review by the agency and now is entering the development phase known

as formulation.

"Today we're taking an exciting step from concept to mission, in our quest to find signs of life beyond Earth,"

said John Grunsfeld, associate administrator for NASA's Science Mission Directorate in Washington.

"Observations of Europa have provided us with tantalizing clues over the last two decades, and the time has

come to seek answers to one of humanity's most profound questions."

NASA's Galileo mission to Jupiter in the late 1990s produced strong evidence that Europa, about the size of

Earth's moon, has an ocean beneath its frozen crust. If proven to exist, this global ocean could hold more than

twice as much water as Earth. With abundant salt water, a rocky sea floor, and the energy and chemistry

provided by tidal heating, Europa may have the ingredients needed to support simple organisms.

The mission plan calls for a spacecraft to be launched to Jupiter in the 2020s, arriving in the distant planet's

orbit after a journey of several years. The spacecraft would orbit the giant planet about every two weeks,

providing many opportunities for close flybys of Europa. The mission plan includes 45 flybys, during which the

spacecraft would image the moon's icy surface at high resolution and investigate its composition and the

structure of its interior and icy shell.

NASA's Jet Propulsion Laboratory in Pasadena, California, has been assigned the responsibility of managing the

project. JPL has been studying the multiple-flyby mission concept, in collaboration with the Johns Hopkins

University Applied Physics Laboratory (APL) in Laurel, Maryland, since 2011.

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Instruments selected for the Europa mission's scientific payload were announced by NASA on May 26.

Institutions supplying instruments include APL; JPL; Arizona State University, Tempe; the University of Texas

at Austin; Southwest Research Institute, San Antonio; and the University of Colorado, Boulder.

"It's a great day for science," said Joan Salute, Europa program executive at NASA Headquarters in

Washington. "We are thrilled to pass the first major milestone in the lifecycle of a mission that will ultimately

inform us on the habitability of Europa."

For more information about NASA's mission to Europa, visit: http://www.nasa.gov/europa

Source: JPL Return to Contents

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3. For comet scientists, elation and redemption at Philae’s wakeup

Research teams across Europe spent the last half-year

meticulously going through a wish list of experiments for the

Philae comet lander without knowing whether they would ever

get a chance to execute the tasks.

With Philae now awake after a seven-month slumber, scientists

are eager to turn on the lander’s instruments, take fresh images

and eventually attempt to sample a block of organic dust and

ice perched just out of the probe’s grasp.

Jean-Pierre Bibring, Philae’s chief scientist, said the dishwasher-

sized lander can rotate to put the cometary material within

reach of its drill. But such movement is risky, and mission

planners only want to command the rotation when they are

sure Philae is able to charge its battery.

“In the last seven months, we were not just praying for the lander being back,” said Barbara Cozzoni, an

engineer at Philae’s control center in Cologne, Germany. “We worked a lot so we have could some operations

ready. We will start with what we call low-cost, low-risk (activities).”

Engineers will first have to wrestle control of the lander. Philae’s Rosetta mothership — the centerpiece of

Europe’s comet mission — is moving to a new orbit to improve the communications link with the probe on the

surface.

Rosetta dropped Philae to the nucleus of comet 67P/Churyumov-Gerasimenko in November, but the landing

craft bounced off the comet and settled a half-mile from its intended touchdown zone. Philae ended up lodged

against a cliff eclipsing sunlight, and the solar-powered spacecraft ran out of juice 60 hours after landing.

Scientists were optimistic the hibernating probe would wake up as comet 67P streaked closer to the sun, and

Philae finally radioed Earth through Rosetta on June 13, three months after controllers started listening for

new signals from the lander.

The comet is heading for perihelion — the point in its orbit closest to the sun — on Aug. 13. Rosetta and

Philae are conducting the most extensive survey ever made of a comet.

“This (comet) is 4 kilometers (2.5 miles) across,” said Mark McCaughrean, a senior science adviser at the

European Space Agency, which oversees the Rosetta mission. “It looks like it’s made of rock, but we now

know that it has density less than that of water — half the density of water. It’ a mixture of ice and dust and

complex molecules — carbon-bearing molecules — and a completely bizarre landscape in which we see

boulders sitting on the surface at apparently bizarre angles. We see plains of dust and rivulets of material.”

Pits and fissures on the comet’s nucleus — dormant when the body was far away from the sun in the cold

outer solar system — are firing up as the tiny world encounters warmer conditions.

Philae’s science team is hopeful the lander will make measurements from the comet’s surface when it is most

active in August and September.

“This extraordinary journey is by no means over,” McCaughrean said. “We are not at a dead object. We are at

a living, breathing dragon of a comet, which is coming to life as we come close to the sun.”

Once engineers establish a stable communications link with Philae, the science team will ease the lander back

into action.

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“We have to improve the connection between Rosetta and the lander,” Bibring said in a press briefing

Wednesday at the Paris Air Show. “We are marginal in the duration of the link now. We are in the few tens of

seconds to minutes. We want to go to tens of minutes.”

First up for scientists will be to activate the lander’s low-power instruments. At the top of that list are Philae’s

magnetometer and sensors to deduce the physical properties — temperature, texture, density and electrical

conductivity — of rock and dust at the landing site, according to Philippe Gaudon, the lander’s project manager

at CNES, the French space agency.

If ground teams are satisfied — and if Philae’s power status continues to improve — the next step will be to

switch on probe’s cameras, potentially beaming back fresh views of the the lander’s treacherous surroundings.

Philae’s descent camera and panoramic imaging system returned photos of the craft’s landing sequence and

final resting place before the lander went into hibernation in November.

Gas analyzers mounted on Philae could then be powered up to sniff the dust around the spacecraft in search

of organic molecules, and potentially amino acids, the building blocks of life-supporting proteins.

Engineers will also resume a ranging experiment using radio signals sent between Rosetta and Philae. The

transmissions serve two purposes: studying the comet’s internal structure and helping scientists pinpoint the

lander’s exact location, which remains unconfirmed.

Using signals from Philae’s November landing and high-resolution imagery from Rosetta’s camera, officials say

they have narrowed the craft’s location to an ellipse about the size of a football field.

The final instruments to be turned on will be Philae’s X-ray spectrometer — called APXS — positioned on a

boom extended to the comet’s surface, along with the lander’s sampling drill — named SD2.

“The last activity should be the most risky,” Gaudon said. “That means to do a second deployment of APXS

after rotation of the lander to optimize the distance between the platform and the soil. We should be able,

with APXS, to touch the soil, and we should be able, with SD2, to retrieve a sample.”

The tentative plan calls for the sample to be imaged by Philae’s cameras, then dumped into ovens inside the

main body of the spacecraft for heating and chemical analysis.

“It’s something we can do maybe not in the next weeks, but certainly in the next months,” Gaudon said.

The sun is shining on Philae’s body-mounted power-generating solar panels more than twice as long each day

than in November, and the comet — which rotates every 12.4 hours — is closer to the sun, further boosting

the energy output from the solar cells.

“Because the comet has come closer to the sun, we have gained at least a factor of four in terms of energy on

the solar panels,” Gaudon said.

Philae transmitted useful science data from eight of its 10 instruments during the initial phase of the mission in

November. The lander ran out of power before it could complete experimental runs with the X-ray

spectrometer and drill.

Scientists now have a second chance, a prospect that Bibring and other members of the Philae team said they

expected. Nevertheless, scientists could not be sure the lander would ever wake up.

Assuming the lander still has all its functions, researchers have a bounty of discoveries looming just an arm’s

length from Philae.

“We know exactly by which angle we should rotate for the drill now to access the surface and even the

subsurface,” Bibring said. “That’s part of the game here — that if we wakeup and if we have the capability to

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go up to where we want to go, which is to have access to this material, we know how do do it … These are

the carbon-rich materials. They’re everywhere, and they’re at hand.”

Source: Spaceflight Now Return to Contents

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The Night Sky

Source: Sky and Telescope Return to Contents

Friday, June 19

The pair-up of Venus and Jupiter is becoming ever

more eye-catching in the west at dusk, as they near

their June 30th closest approach. This evening as

twilight fades, look below them for the thin waxing

crescent Moon, as shown here.

Saturday, June 20

The Moon, Jupiter, and Venus form a striking triangle

in the west during and after dusk. Regulus and the

Sickle of Leo watch over them from the upper left.

Think photo opportunity!

Sunday, June 21

Now the Moon shines left of Regulus in the evening.

Jupiter and Venus are farther lower right, as shown

here.

Today is the longest day of the year in the Northern

Hemisphere; the shortest in the Southern

Hemisphere. The solstice is at 12:38 p.m. EDT (16:38

UT), marking the official start of northern summer

(southern winter). Because the solstice time falls

right between the nights before and after in the

Eastern time zone, you can have two Midsummer's

Night parties!

Monday, June 22

Saturn is the brightest point glowing in the south

these evenings. The stars of upper Scorpius glitter

below and lower left of it.

Tuesday, June 23

As night falls, look for the Big Dipper hanging straight

down in the northwest. Its bottom two stars, the

Pointers, point to the right toward modest Polaris,

the handle-end of the Little Dipper. Most of the Little

Dipper is very dim. This is the time of year when it

floats straight upward from Polaris when nightfall is

complete — like a helium balloon escaped from some

June evening party.

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ISS Sighting Opportunities

Date Visible Max Height Appears Disappears

Fri Jun 19, 10:21 PM 2 min 12° 10 above WSW 12 above SW

Sat Jun 20, 9:27 PM 4 min 24° 15 above W 11 above S

Mon Jun 22, 9:18 PM 1 min 10° 10 above WSW 10 above SW

Sighting information for other cities can be found at NASA’s Satellite Sighting Information

NASA-TV Highlights (all times Eastern Time Zone)

11 a.m., Tuesday, June 23 - Space Station Live (NTV-2 (Education), NTV-3 (Media)) 11 a.m., Tuesday, June 23 - NASA Astronaut Reid Wiseman Discusses Living and Working Aboard the ISS (NTV-1 (Public)) 11:30 a.m., Tuesday, June 23 - Weekly Update on the New Horizons/Pluto Pre-Flyby Mission (NTV-2 (Education)) 12:30 p.m., Tuesday, June 23 - ISS Expedition In-Flight Event with CBS Evening News with Expedition 44 Flight Engineer Scott Kelly -- Event Begins 12:45 p.m. ET (all channels)

Watch NASA TV online by going to the NASA website. Return to Contents

Space Calendar

Jun 19 - Asteroid 2015 KS57 Near-Earth Flyby (0.046 AU) Jun 19 - Asteroid 24761 Ahau Closest Approach To Earth (0.754 AU) Jun 19 - Asteroid 25137 Seansolomon Closest Approach To Earth (0.836 AU) Jun 19 - Asteroid 37655 Illapa Closest Approach To Earth (1.626 AU)

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Jun 19 - Asteroid 8353 Megryan Closest Approach To Earth (1.755 AU) Jun 19 - Asteroid 365756 ISON Closest Approach To Earth (6.502 AU) Jun 19 - Kuiper Belt Object 50000 Quaoar At Opposition (41.979 AU) Jun 20 - Cassini, Orbital Trim Maneuver #413 (OTM-413)

Jun 20 - [Jun 17] Asteroid 2015 LR21 Near-Earth Flyby (0.006 AU) Jun 20 - Asteroid 2015 KC57 Near-Earth Flyby (0.068 AU) Jun 20 - Asteroid 10563 Izhdubar Closest Approach To Earth (0.594 AU) Jun 20 - Asteroid 1685 Toro Closest Approach To Earth (0.723 AU) Jun 20 - Asteroid 4660 Nereus Closest Approach To Earth (0.949 AU) Jun 20 - Asteroid 3352 McAuliffe Closest Approach To Earth (1.391 AU) Jun 20 - 345th Anniversary (1670), Discovery Of Nova 1670 Vulpecula

Jun 21 - [Jun 15] Summer Solstice, 16:38 UT Jun 21 - Mars Spacecraft Solar Conjuction Ends Jun 21 - Comet 238P/Read Closest Approach To Earth (2.297 AU)

Jun 21 - [Jun 16] Asteroid 2015 LP21 Near-Earth Flyby (0.090 AU) Jun 21 - Asteroid 2010 LN14 Near-Earth Flyby (0.048 AU) Jun 21 - Asteroid 827 Wolfiana Closest Approach To Earth (1.302 AU) Jun 21 - Asteroid 2866 Hardy Closest Approach To Earth (1.691 AU) Jun 21 - Asteroid 54522 Menaechmus Closest Approach To Earth (1.772 AU) Jun 21 - Asteroid 249521 Truth Closest Approach To Earth (2.028 AU) Jun 21 - Asteroid 8990 Compassion Closest Approach To Earth (2.045 AU) Jun 21 - Asteroid 24101 Cassini Closest Approach To Earth (2.453 AU)

Jun 22 - [Jun 18] Sentinel 2A Vega Launch Jun 22 - Comet P/2011 W2 (Rinner) At Opposition (4.297 AU) Jun 22 - Asteroid 2709 Sagan Closest Approach To Earth (1.153 AU) Jun 22 - Asteroid 6758 Jesseowens Closest Approach To Earth (1.378 AU) Jun 22 - Asteroid 10221 Kubrick Closest Approach To Earth (1.492 AU) Jun 22 - Centaur Object 10199 Chariklo At Opposition (14.105 AU) Jun 22 - Centaur Object 10370 Hylonome At Opposition (22.041 AU) Jun 22 - Royal Greenwich Observatory's 340th Birthday (1675) Jun 23 - Comet 208P/McMillan Closest Approach To Earth (2.413 AU) Jun 23 - Comet 298P/Christensen Closest Approach To Earth (2.982 AU) Jun 23 - Asteroid 2015 KK57 Near-Earth Flyby (0.021 AU)

Jun 23 - [Jun 17] Asteroid 2015 LM24 Near-Earth Flyby (0.056 AU) Jun 23 - Asteroid 4330 Vivaldi Closest Approach To Earth (1.290 AU) Jun 23 - Centaur Object 55576 Amycus At Opposition (18.223 AU) Jun 23 - Jaume Nomen's 55th Birthday (1960) Jun 23 - Donn Eisele's 85th Birthday (1930)

Source: JPL Space Calendar Return to Contents

Food for Thought

Titan's atmosphere even more Earth-like than previously thought

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Scientists at UCL have observed how a widespread polar wind is driving gas from the atmosphere of Saturn's

moon Titan. The team analysed data gathered over seven years by the international Cassini probe, and found

that the interactions between Titan's atmosphere, and the solar magnetic field and radiation, create a wind of

hydrocarbons and nitriles being blown away from its polar regions into space. This is very similar to the wind

observed coming from the Earth's polar regions.

Titan is a remarkable object in the Solar System. Like Earth and Venus, and unlike any other moon, it has a

rocky surface and a thick atmosphere. It is the only object in the Solar System aside from the Earth to have

rivers, rainfall and seas. It is bigger than the planet Mercury.

Thanks to these unique features, Titan has been studied more than any moon other than Earth's, including

numerous fly-bys by the Cassini probe, as well as the Huygens lander which touched down in 2004. On board

Cassini is an instrument partly designed at UCL, the Cassini Plasma Spectrometer (CAPS), which was used in

this study.

"Titan's atmosphere is made up mainly of nitrogen and methane, with 50% higher pressure at its surface than

on Earth," said Andrew Coates (UCL Mullard Space Science Laboratory), who led the study. "Data from CAPS

proved a few years ago that the top of Titan's atmosphere is losing about seven tonnes of hydrocarbons and

nitriles every day, but didn't explain why this was happening. Our new study provides evidence for why this is

happening."

Hydrocarbons are a category of molecules that includes methane, as well as other familiar substances

including petrol, natural gas and bitumen. Nitriles are molecules with nitrogen and carbon tightly bound

together.

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The new research, published today in the journal Geophysical Research Letters, explains that this atmospheric

loss is driven by a polar wind powered by an interaction between sunlight, the solar magnetic field and the

molecules present in the upper atmosphere.

"Although Titan is ten times further from the Sun than Earth is, its upper atmosphere is still bathed in light,"

says Coates. "When the light hits molecules in Titan's ionosphere, it ejects negatively charged electrons out of

the hydrocarbon and nitrile molecules, leaving a positively charged particle behind. These electrons, known as

photoelectrons, have a very specific energy of 24.1 electronvolts, which means they can be traced by the

CAPS instrument, and easily distinguished from other electrons, as they propagate through the surrounding

magnetic field."

Unike Earth, Titan has no magnetic field of its own, but is surrounded by Saturn's rapidly rotating magnetic

field, which drapes forming a comet-like tail around the moon. In 23 fly-bys which passed through Titan's

ionosphere or its magnetic tail, CAPS detected measurable quantities of these photoelectrons up to 6.8 Titan

radii away from the moon, because they can easily travel along the magnetic field lines.

The team found that these negatively-charged photoelectrons, spread throughout Titan's ionosphere and the

tail, set up an electrical field. The electrical field, in turn, is strong enough to pull the positively charged

hydrocarbon and nitrile particles from the atmosphere throughout the sunlit portion of the atmosphere, setting

up the widespread 'polar wind' that scientists have observed there.

This phenomenon has only been observed on Earth before, in the polar regions where Earth's magnetic field is

open. As Titan lacks its own magnetic field the same thing can occur over wider regions, not just near the

poles. A similarly widespread 'polar wind' is strongly suspected to exist both on Mars and Venus - the two

planets in the Solar System which are most Earth-like. It gives further evidence of how Titan, despite its

location in orbit around a gas giant in the outer Solar System, is one of the most Earth-like objects ever

studied.

Source: Eureka Alert Return to Contents

Space Image of the Week

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Dione's Craggy Surface Image credit: NASA/JPL-Caltech/Space Science Institute

NASA's Cassini imaging scientists processed this view of Saturn's moon Dione, taken during a close flyby on June 16, 2015. This was Cassini's fourth targeted flyby of Dione and the spacecraft had a close approach altitude of 321 miles (516 kilometers) from Dione's surface.

The bright rings of Saturn can be seen at left, in the background of the image.

North on Dione is up and rotated 44 degrees to the left. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on June 16, 2015.

The view was acquired at a distance of approximately 48,000 miles (77,000 kilometers) from Dione and at a sun-Dione-spacecraft, or phase, angle of 128 degrees. Image scale is 1,519 feet (463 meters) per pixel.

Source: JPL Return to Contents