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Space News Update — December 3, 2013 —

Contents

In the News

Story 1:

Spectacular Liftoff Thrusts China’s First Rover ‘Yutu’ to the Moon

Story 2:

India’s First Mars Probe ‘MOM’ Blasts Free of Earth Joining MAVEN in Race to

Red Planet

Story 3:

Mach 1000 Shock Wave Lights Supernova Remnant

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. Spectacular Liftoff Thrusts China’s First Rover ‘Yutu’ to the Moon

China successfully launched its first ever lunar rover bound for the Moon‟s surface aboard a Long March rocket at 1:30 a.m. Beijing local time, Dec. 2, 2013 (12:30 p.m. EST, Dec. 1) from the Xichang Satellite Launch Center in southwest China.

The spectacular night time blastoff of the Long March-3B carrier rocket with the „Yutu‟ rover was carried live on China‟s state run CCTV enabling viewers worldwide to watch the dramatic proceedings as they occurred in real time – including fantastic imagery of booster jettison, spacecraft separation, thruster firings and exquisite views of Earth from cameras aboard the booster.

The entire flight sequence proceeded flawlessly and placed the combined Chang‟e 3 lunar landing vehicle and „Yutu‟ rover on the desired earth-moon transfer orbit following spacecraft separation and unfurling of the life giving solar panels and landing legs, announced Zhang Zhenzhong, director of the Xichang center.

“The Chang‟e probe is on its way to the moon, of course, is a symbol of China‟s national prowess,” said Zhang Zhenzhong through a translator during the live CCTV broadcast. “Of course, it‟s a symbol of China‟s national power and prowess.”

The three stage 55 meter (185 foot) tall Long March-3B carrier rocket was uniquely equipped with a quartet of strap on liquid fueled boosters to provide the additional liftoff thrust required for the four day journey to Earth‟s Moon.

The name for the „Yutu‟ rover – which translates as „Jack Rabbit‟ – was chosen after a special naming contest involving a worldwide poll and voting to select the best name. „Yutu‟ stems from a Chinese fairy tale, in which

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the goddess Chang‟e flew off to the moon taking her little pet Jade rabbit with her. „Yutu‟ is sitting atop the 4 legged landing probe during the launch and voyage to the Moon. Jack Rabbit measures 150 centimeters high and weighs approximately 120 kilograms.

The Chang‟e 3 lander will fire thrusters to enter lunar orbit on Dec. 6. It is due to make a powered descent to the lunar surface on Dec. 14, firing thrusters at an altitude of 15 km (9 mi) for touchdown in a preselected area called the Bay of Rainbows or Sinus Iridum region.

If successful, the Chang‟e 3 mission will mark the first soft landing on the Moon since the Soviet Union‟s unmanned Luna 24 sample return vehicle landed nearly four decades ago back in 1976.

A complex maneuver will be used to deploy the six-wheeled „Jack Rabbit‟ rover. It will be lowered in stages to the moon‟s surface and then drive off a pair of landing ramps to explore the moon‟s terrain.

The rover and lander are equipped with multiple cameras, spectrometers, an optical telescope, radar and other sensors to investigate the lunar surface and composition. One highly anticipated highlight will be when the lander and deployed Jack Rabbit rover image each other on the surface.

The rover is expected to continue operating for at least three months.

The Chang‟e 3 landing mission marks the beginning of the second phase of China‟s lunar robotic exploration program. It follows a pair of highly successful lunar orbiters named Chang‟e 1 and 2 which launched in 2007 and 2010.

The next step will be an unmanned lunar sample return mission, perhaps around 2020.

Source: Universe Today Return to Contents

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2. India’s First Mars Probe ‘MOM’ Blasts Free of Earth Joining MAVEN in Race to Red Planet

India‟s first ever Mars probe „MOM‟ successfully fired its main engine, blasting the craft free of the Earth‟s sphere of influence forever to begin her nearly yearlong momentous voyage to the Red Planet.

Indian space engineers initiated the 440 Newton liquid fueled engine firing precisely as planned at 00:49 hrs (IST) on Sunday, Dec. 1, 2013 during a critical nail-biting burn lasting some 22 minutes.

The Trans Mars Insertion (TMI) firing propelled India‟s Mars Orbiter Mission (MOM) away from Earth forever and placed the spacecraft on course for a rendezvous with the Red Planet on September 24, 2014 – where it will study the atmosphere and sniff for signals of methane.

Sunday‟s Mars insertion burn imparted the vehicle with an incremental velocity of 647.96 meters per second (m/sec) consuming 198 kg of fuel.

The maneuver dubbed „The mother of all slingshots‟ enabled MOM to finally achieve escape velocity and catapulted the 1,350 kilogram (2,980 pound) spacecraft on an historic flight streaking towards Mars.

“The Earth orbiting phase of the spacecraft ended,” with this maneuver said ISRO. MOM is healthy and all systems are functioning normally. While MOM was cycling Earth, ISRO scientists and engineers activated and tested the probes systems and science payloads.

MOM is nicknamed „Mangalyaan‟ – which in Hindi means „Mars craft.‟ MOM‟s journey began with a picture perfect Nov. 5 liftoff atop India‟s highly reliable four stage Polar Satellite Launch Vehicle (PSLV) C25 from ISRO‟s Satish Dhawan Space Centre SHAR, Sriharikota. The PSLV booster precisely injected MOM into an initial elliptical Earth parking orbit of 247 x 23,556 kilometers with an inclination of 19.2 degrees.

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PSLV does not have sufficient thrust to send MOM streaking directly to the Red Planet. Therefore since the flawless launch, the engine has been fired 6 times on November 7, 8, 9, 11, and 16 plus one supplementary maneuver to gradually raise the spacecrafts apogee from 23556 km to 192,874 km.

The most recent orbit raising maneuver occurred on Nov 16, 2013 with a burn time of 243.5 seconds and increased the apogee from 118,642 km to 192,874 km.

Today‟s burn was the final one around Earth and absolutely crucial for setting her on course for Mars. MOM was the first of two missions dispatched to Mars by Earthlings this November.

Half a world away, NASA‟s MAVEN orbiter blasted off on Nov. 18 from Cape Canaveral Air Force Station, Florida atop an Atlas V booster on a direct path to the Red Planet.

The MOM spacecraft is now on traveling on a heliocentric elliptical trajectory to begin a 300 day long interplanetary voyage of more than 700 Million kilometers (400 Million miles) to the Red Planet. Along the path to Mars, ISRO plans to conduct a series of Trajectory Correction Maneuvers (TCMs) using MOM‟s Attitude and Orbit Control System (AOCS) thrusters to precisely navigate the probe to the point required to achieve orbit around the Red Planet

Following the ten month cruise through space the orbital insertion engine will fire for a do or die burn on September 24, 2014 placing MOM into an 377 km x 80,000 km elliptical orbit around Mars.

MOM will reach Mars vicinity just two days after MAVEN‟s arrival on September 22, 2014.

Although they were developed independently and have different suites of scientific instruments, the MAVEN and MOM science teams will “work together” to unlock the secrets of Mars atmosphere and climate history

Source: Universe Today

MAVEN Status Update: December 2, 2013

MAVEN operations are going smoothly with all spacecraft systems healthy and all communication events have been

nominal. The mission is now in its early cruise mission phase and, as of December 2nd, the spacecraft was approximately

2.7 million miles (4.36 million kilometers) from Earth. MAVEN‟s current sun-centered speed is 73,497 mph (7,812 mph

relative to earth). The next big milestone for the team is a planned trajectory correction maneuver on Dec. 3 followed by

the power up of the eight science instruments between Dec. 4 and Dec. 10.

When the MAVEN spacecraft received its final boost out of Earth orbit and on its trajectory towards Mars, the Centaur

upper stage responsible for that boost also entered heliocentric orbit. This orbit was designed to have the upper stage

miss Mars, limiting any possibility that it could contaminate the Red Planet with Earth-borne microbes. Because MAVEN

was placed into the same trajectory as the Centaur, the operations team will conduct a series of trajectory correction

maneuvers (TCMs) designed to put the spacecraft back on a course to intercept Mars in September 2014.

The first TCM, planned for December 3rd will also serve as a test run for Mars Orbit Insertion (MOI) procedures, and will

use the same engines and scripts for the TCM-1 that will be used for MOI.

Source: NASA Return to Contents

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3. Mach 1000 Shock Wave Lights Supernova Remnant

When a star explodes as a supernova, it shines brightly for a few weeks or months before fading away. Yet the material blasted outward from the explosion still glows hundreds or thousands of years later, forming a picturesque supernova remnant. What powers such long-lived brilliance?

In the case of Tycho's supernova remnant, astronomers have discovered that a reverse shock wave racing inward at Mach 1000 (1000 times the speed of sound) is heating the remnant and causing it to emit X-ray light.

"We wouldn't be able to study ancient supernova remnants without a reverse shock to light them up," says Hiroya Yamaguchi, who conducted this research at the Harvard-Smithsonian Center for Astrophysics (CfA).

This is a photograph of the Tycho supernova remnant taken by the Chandra X-ray Observatory. Low-energy X-rays (red) in the image show expanding debris from the supernova explosion and high energy X-rays (blue) show the blast wave, a shell of extremely energetic electrons.

Credit: X-ray: NASA/CXC/Rutgers/K. Eriksen et al.; Optical (starry background): DSS

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Tycho's supernova was witnessed by astronomer Tycho Brahe in 1572. The appearance of this "new star" stunned those who thought the heavens were constant and unchanging. At its brightest, the supernova rivaled Venus before fading from sight a year later.

Modern astronomers know that the event Tycho and others observed was a Type Ia supernova, caused by the explosion of a white dwarf star. The explosion spewed elements like silicon and iron into space at speeds of more than 11 million miles per hour (5,000 km/s).

When that ejecta rammed into surrounding interstellar gas, it created a shock wave - the equivalent of a cosmic "sonic boom." That shock wave continues to move outward today at about Mach 300. The interaction also created a violent "backwash" - a reverse shock wave that speeds inward at Mach 1000.

"It's like the wave of brake lights that marches up a line of traffic after a fender-bender on a busy highway," explains CfA co-author Randall Smith.

The reverse shock wave heats gases inside the supernova remnant and causes them to fluoresce. The process is similar to what lights household fluorescent bulbs, except that the supernova remnant glows in X-rays rather than visible light. The reverse shock wave is what allows us to see supernova remnants and study them, hundreds of years after the supernova occurred.

"Thanks to the reverse shock, Tycho's supernova keeps on giving," says Smith.

The team studied the X-ray spectrum of Tycho's supernova remnant with the Suzaku spacecraft. They found that electrons crossing the reverse shock wave are rapidly heated by a still-uncertain process. Their observations represent the first clear evidence for such efficient, "collisionless" electron heating at the reverse shock of Tycho's supernova remnant.

The team plans to look for evidence of similar reverse shock waves in other young supernova remnants.

Source: Eurekalert Return to Contents

A montage of images of Comet ISON taken from September 24 to November 15, 2013. Credit and copyright: Damian Peach.

Read more: http://www.universetoday.com/#ixzz2mN4Wlbo5

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The Night Sky

Source: Sky and Telescope Return to Contents

Tuesday, December 3

Yes, the Summer Triangle is still high after dusk in December. Spot Vega, its brightest star, in the west-northwest. The brightest above Vega is Deneb. Look farther to Vega's right for Altair.

Wednesday, December 4

Look for the waxing crescent Moon far lower right of Venus in twilight, as shown here.

Watch Jupiter's moon Io gradually disappear into eclipse by Jupiter's shadow, just off the planet's western limb, around 10:58 p.m. EST. A small telescope is all you need.

Thursday, December 5

The crescent Moon poses about 7° to Venus's upper right in twilight, as shown here. As the sky darkens, look with binoculars for Alpha and Beta Capricorni to the Moon's upper left. Both are double stars for binoculars: Alpha is very easy to resolve, Beta is harder.

Friday, December 6

The waxing crescent Moon hangs high over Venus at dusk, with Alpha and Beta Capricorni now to its lower right.

Saturday, December 7

Earliest sunset of the year (near 40° north latitude). The longest night won't come until December 21st at the solstice, and the latest sunrise doesn't happen until January 4th.

The reason? Local Apparent Solar Time is shifting with respect to Local Mean Time during this part of the year, an effect caused by the tilt of Earth's axis and the ellipticity of Earth's orbit. Be glad that we use standardized time, so you don't have to keep adjusting your clocks to the inconstant motions of the Sun like in olden days. Standard time made things a lot simpler for society but complicated things for careful skywatchers.

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ISS Sighting Opportunities

For Denver:

ISS is not visible at Denver until Saturday, December 7th.

Sighting information for other cities can be found at NASA’s Satellite Sighting Information NASA-TV Highlights (all times Eastern Time Zone)

December 3, Tuesday

11:20 a.m. - ISS Expedition 38 In-Flight Interviews with CBS Radio Network/Newspath

Syndication and KOMU-TV, Columbia, Mo. - JSC (All Channels)

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

MAVEN Launch November 18, 2013 NASA

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Space Calendar

Dec 03 - MAVEN, Trajectory Correction Maneuver #1 (TCM-1) Dec 03 - Comet 9P/Tempel At Opposition (3.754 AU)

Dec 03 - [Dec 01] Asteroid 2013 WV43 Near-Earth Flyby (0.024 AU) Dec 03 - Asteroid 7986 Romania Closest Approach To Earth (1.378 AU) Dec 03 - Asteroid 12574 LONEOS Closest Approach To Earth (1.501 AU) Dec 03 - Asteroid 14094 Garneau Closest Approach To Earth (1.904 AU) Dec 03 - 40th Anniversary (1973), Pioneer 10, Jupiter Flyby

Dec 04 - Cassini, Orbital Trim Maneuver #365 (OTM-365) Dec 04 - Comet 184P/Lovas At Opposition (0.970 AU) Dec 04 - Comet 269P/Jedicke Closest Approach To Earth (3.529 AU) Dec 04 - Asteroid 230975 Rogerfederer Closest Approach To Earth (1.758 AU)

Dec 04 - 35th Anniversary (1978), Pioneer Venus 1, Venus Orbit Insertion Dec 05 - NROL-39 Atlas 5 Launch

Dec 05 - [Nov 29] Topaz 3/ ALICE/ SMDC-ONE 2.3 & 2.4/ SNap/TacSat 6/FIREBIRD A & B/ AeroCube 5A & 5B/ IPEX/ CUNYSAT 1/ M-Cubed/COVE 2 Atlas 5 Launch

Dec 05 - Asteroid 2010 TK7 (Earth Trojan) Closest Approach To Earth (0.197 AU) Dec 05 - Kuiper Belt Object 84922 (2003 VS2) At Opposition (35.572 AU)

Dec 06 - [Dec 02] Chang'e 3 Lunar Orbit Insertion (China)

Dec 06 - Asteroid 21088 Chelyabinsk Closest Approach To Earth (0.958 AU) Dec 06 - Asteroid 1831 Nicholson Closest Approach To Earth (1.541 AU) Dec 06 - Asteroid 2531 Cambridge Closest Approach To Earth (1.956 AU) Dec 07 - Comet 84P/Giclas Closest Approach To Earth (1.246 AU) Dec 07 - Asteroid 18024 Dobson Closest Approach To Earth (2.406 AU)

Dec 08 - Inmarsat 5 F1 Proton M-Briz M Launch

Source: JPL Space Calendar Return to Contents

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Food for Thought

Figures of Eight and Peanut Shells: How Stars Move at the Center of the Galaxy

'An artist‟s impression showing how the Milky Way galaxy would look seen from almost edge on and from a very

different perspective than we get from the Earth. The central bulge shows up as a peanut shaped glowing ball of

stars and the spiral arms and their associated dust clouds form a narrow band. Credit: ESO/NASA/JPL-Caltech/M.

Kornmesser/R. Hurt'

Two months ago astronomers created a new 3D map of stars at the centre of our Galaxy (the Milky Way), showing more clearly than ever the bulge at its core. Previous explanations suggested that the stars that form the bulge are in banana-like orbits, but a paper published this week in Monthly Notices of the Royal Astronomical Society suggests that the stars probably move in peanut-shell or figure of eight-shaped orbits instead.

The difference is important; astronomers develop theories of star motions to not only understand how the stars in our galaxy are moving today but also how our galaxy formed and evolves. The Milky Way is shaped like a spiral, with a region of stars at the centre known as the "bar," because of its shape. In the middle of this region, there is a "bulge" that expands out vertically.

In the new paper Alice Quillen, professor of astronomy at the University of Rochester, and her collaborators created a mathematical model of what might be happening at the centre of the Milky Way. Unlike the Solar System where most of the gravitational pull comes from the Sun and is simple to model, it is much harder to describe the gravitational field near the centre of the Galaxy, where millions of stars, vast clouds of dust, and even dark matter swirl about. In this case, Quillen and her colleagues considered the forces acting on the stars in or near the bulge.

As the stars go round in their orbits, they also move above or below the plane of the bar. When stars cross the plane they get a little push, like a child on a swing. At the resonance point, which is a point a certain distance from the center of the bar, the timing of the pushes on the stars is such that this effect is strong enough to make the stars at this point move up higher above the plane. It is like when the child on the swing has been

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pushed a little everytime he comes round and eventually he is swinging higher. These stars that are pushed out form the edge of the bulge.

The resonance at this point means that stars undergo two vertical oscillations for every orbital period. But what is the most likely shape of the orbits in between? The researchers showed through computer simulations that peanut-shell shaped orbits are consistent with the effect of this resonance and could give rise to the observed shape of the bulge, which is also like a peanut-shell.

Next month the European Space Agency will launch the Gaia spacecraft, which is designed to create a 3D map of the stars in the Milky Way and their motions. This 3D map will help astronomers better understand the composition, formation and evolution of our Galaxy.

"It is hard to look back into the past of our galaxy and know what was there, but simulations can give us clues," explained Quillen. "Using my model I saw that, over time, the resonance with the bar, which is what leads to these peculiarly shaped orbits, moves outwards. This may be what happened in our galaxy."

"Gaia will generate huge amounts of data – on billions of stars," said Quillen. This data will allow Quillen and her colleagues to finesse their model further. "This can lead to a better understanding of how the Milky Way might have evolved into the shape it has today."

Quillen explained that there are different models as to how the galactic bulge was formed. Astronomers are interested in finding out how much the bar has slowed down over time and whether the bulge "puffed up all at once or slowly." Understanding the distributions of speeds and directions of motion (velocities) of the stars in the bar and the bulge might help determine this evolution.

"One of the predictions of my model is that there is a sharp difference in the velocity distributions inside and outside the resonance," Quillen said. "Inside – closer to the galactic centre – the disk should be puffed up and the stars there would have higher vertical velocities. Gaia will measure the motions of the stars and allow us to look for variations in velocity distributions such as these."

To be able to generate a model for the orbits of stars in the bulge, Quillen needed to factor in different variables. She first needed to understand what happens at the region of the resonance, which depends on the speed of the rotating bar and the mass density of the bar.

"Before I could model the orbits, I needed the answer to what I thought was a simple question: what is the distribution of material in the inner galaxy?" Quillen said. "But this wasn't something I could just look up. Luckily my collaborator Sanjib Sharma was able to help out."

Sharma worked out how the speed of circular orbits changed with distance from the galactic centre (called the rotation curve). Using this information, Quillen could compute a mass density at the location of the resonance, which she needed for her model.

Quillen was also able to combine the new orbit models with the speed of the bar (which is rotating) to get a more refined estimate of the mass density 3000 light years from the Galaxy centre (about one eighth of the distance from the centre of the Galaxy to Earth), which is where the edge of the bulge is.

And there is not long now to wait now for Gaia to start collecting data. Gaia's launch time is set for December 19, and will be streamed live on the ESA Portal.

Source: Eurekalert Return to Contents

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Space Image of the Week

A Laser Strike at the Galactic Center Image Credit: Yuri Beletsky (ESO)

Explanation: Why are these people shooting a powerful laser into the center of our Galaxy? Fortunately, this is not meant to be the first step in a Galactic war. Rather, astronomers at the Very Large Telescope (VLT) site in Chile are trying to measure the distortions of Earth's ever changing atmosphere. Constant imaging of high-altitude atoms excited by the laser -- which appear like an artificial star -- allow astronomers to instantly measure atmospheric blurring. This information is fed back to a VLT telescope mirror which is then slightly deformed to minimize this blurring. In this case, a VLT was observing our Galaxy's center, and so Earth's atmospheric blurring in that direction was needed. As for inter-galaxy warfare, when viewed from our Galaxy's center, no casualties are expected. In fact, the light from this powerful laser would combine with light from our Sun to together appear only as bright as a faint and distant star.

If Time Continues: Free APOD 2014 Calendar in PDF format Tomorrow's picture: the comet that lived

Source: APOD NASA Return to Contents