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Space News Update — September 3, 2019 —

Contents

In the News

Story 1:

NASA’s James Webb Space Telescope Has Been Assembled for the First Time

Story 2:

Wind Mystery Inside Gas Giant Saturn Begins to Unravel

Story 3:

Arecibo Observatory Gets $19 Million NASA Grant to Help Protect Earth from Asteroids

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. NASA’s James Webb Space Telescope Has Been Assembled for the

First Time

The fully assembled James Webb Space Telescope with its sunshield and unitized pallet structures (UPSs) that fold up

around the telescope for launch, are seen partially deployed to an open configuration to enable telescope installation.

Credits: NASA/Chris Gunn

Reaching a major milestone, engineers have successfully connected the two halves of NASA’s James Webb

Space Telescope for the first time at Northrop Grumman’s facilities in Redondo Beach, California. Once it

reaches space, NASA's most powerful and complex space telescope will explore the cosmos using infrared

light, from planets and moons within our solar system to the most ancient and distant galaxies.

To combine both halves of Webb, engineers carefully lifted the Webb telescope (which includes the mirrors

and science instruments) above the already-combined sunshield and spacecraft using a crane. Team members

slowly guided the telescope into place, ensuring that all primary points of contact were perfectly aligned and

seated properly. The observatory has been mechanically connected; next steps will be to electrically connect

the halves, and then test the electrical connections.

“The assembly of the telescope and its scientific instruments, sunshield and the spacecraft into one

observatory represents an incredible achievement by the entire Webb team,” said Bill Ochs, Webb project

manager for NASA Goddard Space Flight Center in Greenbelt, Maryland. “This milestone symbolizes the efforts

of thousands of dedicated individuals for over more than 20 years across NASA, the European Space Agency,

the Canadian Space Agency, Northrop Grumman, and the rest of our industrial and academic partners.”

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Integration teams carefully guide Webb’s suspended telescope section into place above its Spacecraft Element just prior

to integration. Credits: NASA/Chris Gunn

Next up for Webb testing, engineers will fully deploy the intricate five-layer sunshield, which is designed to

keep Webb's mirrors and scientific instruments cold by blocking infrared light from the Earth, Moon and Sun.

The ability of the sunshield to deploy to its correct shape is critical to mission success.

“This is an exciting time to now see all Webb’s parts finally joined together into a single observatory for the

very first time,” said Gregory Robinson, the Webb program director at NASA Headquarters in Washington, D.C.

“The engineering team has accomplished a huge step forward and soon we will be able to see incredible new

views of our amazing universe.”

Both of the telescope’s major components have been tested individually through all of the environments they

would encounter during a rocket ride and orbiting mission a million miles away from Earth. Now that Webb is a

fully assembled observatory, it will go through additional environmental and deployment testing to ensure

mission success. The spacecraft is scheduled to launch in 2021.

Webb will be the world's premier space science observatory. It will solve mysteries in our solar system, look

beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe

and our place in it. Webb is an international project led by NASA with its partners, ESA (European Space

Agency), and the Canadian Space Agency.

Source: NASA Return to Contents

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2. Wind Mystery Inside Gas Giant Saturn Begins to Unravel

With this view, Cassini captured one of its last looks at Saturn and its main rings from a distance. Image credit:

NASA/JPL-Caltech/Space Science Institute

A new study argues that Saturn's interior flows like honey due to its magnetic field, which may help solve the

mystery of why the planet's powerful winds stop 8,500km inside the giant gas planet.

Unlike Earth, Saturn has no solid surface; it is a gaseous planet, consisting mostly of hydrogen and helium that

move around fluidly.

Strong winds, known as jet streams, form the appearance of stripes on Saturn's exterior - similar but less stark

than those on Jupiter.

Study co-author, Dr. Navid Constantinou from The Australian National University (ANU), said the recent space

mission Cassini offered a glimpse of what goes on below Saturn's cloud tops.

"At the end of its mission, Cassini dived into Saturn and made detailed measurements of Saturn's gravitational

field," he said.

"The measurements revealed that these jet streams continue about 8,500 km inside Saturn, which is roughly

15 per cent of the distance towards the planet's center."

Dr. Constantinou said the study may help solve the mystery of why Saturn's jet streams stop at a certain

depth.

"Deep into Saturn, where the pressure is high, the gas becomes a liquid that conducts electricity and is more

strongly influenced by the planet's magnetic field," he said.

"An electrically conducting, flowing liquid will bend or distort a magnetic field. We showed that the distortion

of the magnetic field makes the fluid more viscous, like honey."

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The team's theoretical model indicates this viscous effect from the magnetic field could be the reason why the

jet streams terminate at depths beyond 8,500 km.

"The mysteries of what goes on inside Saturn and the other gas giants in our Solar System are now slowly

starting to be unveiled," Dr. Constantinou said.

"Our findings provide a promising way for interpreting the data from planetary missions and offer a better

understanding of the planets in our Solar System and beyond."

Dr. Constantinou from the ANU Research School of Earth Sciences and Dr Jeffrey Parker from Lawrence

Livermore National Laboratory in the United States conducted the study.

The results are published in the Physical Review Fluids journal.

Source: Phys.org/ Australian National University Return to Contents

The globe of Saturn, seen

here in natural color, is

reminiscent of a holiday

ornament in this wide-angle

view from NASA's Cassini

spacecraft. The characteristic

hexagonal shape of Saturn's

northern jet stream,

somewhat yellow here, is

visible. At the pole lies a

Saturnian version of a high-

speed hurricane, eye and all.

This view is centered on

terrain at 75 degrees north

latitude, 120 degrees west

longitude. Images taken using

red, green and blue spectral

filters were combined to

create this natural-color view.

The images were taken with

the Cassini spacecraft wide-

angle camera on July 22,

2013.

This view was acquired at a

distance of approximately

611,000 miles (984,000

kilometers) from Saturn. Image scale is 51 miles (82

kilometers) per pixel.

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3. Arecibo Observatory Gets $19 Million NASA Grant to Help Protect

Earth from Asteroids

The Arecibo Observatory in Puerto Rico. (Image: © Arecibo Observatory/NSF)

Knowledge is power and NASA has just invested $19 million into the Arecibo Observatory in Puerto Rico to

gain a lot of knowledge about asteroids.

NASA awarded the University of Central Florida (which manages the site on behalf of National Science

Foundation) the four-year grant to observe and characterize near-Earth objects (NEO) that pose a potential

hazard to Earth or that could be candidates for future space missions.

The observatory is home to the most powerful and most sensitive planetary radar system in the world, which

means it is also a unique tool available to analyze NEOs, such as asteroids and comets. The knowledge helps

NASA determine which objects pose significant risks and when and what to do to mitigate them. NASA officials

can also use the information to determine which objects are the most viable for science missions – landing on

an asteroid is not equally easy for all of them. Information the observatory provided about asteroid Bennu, for

example, is one of the factors that led NASA to select the OSIRIS-REx mission for funding.

UCF manages the NSF facility under a cooperative agreement with Universidad Ana G. Méndez and Yang

Enterprises, Inc. The NASA grant will be used for operations, maintenance and upgrades to the radar system

that directly relate to the Arecibo Planetary Radar Group, which leads this work. The group will spend up to

800 hours a year analyzing NEOs during the grant period.

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The award also includes money to support STEM education among high school students in Puerto Rico. The

Science, Technology and Research (STAR) Academy brings together 30 local high-school students per

semester once a week for 16 classes to learn about science and research at the observatory.

“The S-band planetary radar system on the 305-m William E. Gordon telescope at Arecibo Observatory is the

most sensitive planetary radar system in the world,” says the Arecibo planetary radar program’s principal

investigator Anne Virkki. She received her doctorate degree in astronomy from the University of Helsinki,

Finland, and leads the planetary radar group at the observatory. “This is why Arecibo is such an amazing tool

for our work. Our radar astrometry and characterization are critical for identifying objects that are truly

hazardous to Earth and for the planning of mitigation efforts. We can use our system to constrain the size,

shape, mass, spin state, composition, binarity, trajectory, and gravitational and surface environments of NEOs

and this will help NASA to determine potential targets for future missions.”

Arecibo has played a role in analyzing NEOs since the mid-90s, observing 60-120 objects per year. Congress

made NEOs a priority when it directed NASA in 2005 to seek out and characterize at least 90 percent of near-

Earth objects larger than 140 meters by 2020.

“Arecibo plays an important role in discovery and advancing our knowledge of our solar system and our

universe,” says Francisco Cordova, director of the facility. “We also play a critical role in helping to protect our

planet through providing knowledge and unique expertise. It’s part of our mission and one of the reasons we

are so passionate about our work.”

The international team of asteroid observers at the observatory includes: Flaviane Venditti from Brazil; Sean

Marshall from the U.S.; Dylan Hickson from Canada, and Luisa Zambrano-Marin from Colombia. Co-

investigators include Noemi Pinilla-Alonso from the Florida Space Institute; Yanga Fernandez from UCF; Patrick

Taylor and Edgard Rivera-Valentin from the Lunar and Planetary Institute; Michael Nolan and Ellen Howell

from the University of Arizona; Tracy Becker from the Southwest Research Institute, and Chris Magri from the

University of Maine.

Source: University of Central Florida Return to Contents

Lead scientist Anne

Virkki (center) reviews

images with research

scientist Flaviane

Venditti (left) and

postdoctoral scientist

Sean Marshall (right).

They are part of the

team working on the

NASA project at the

Arecibo Observatory.

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The Night Sky

Thursday, Sept. 5

• First-quarter Moon (exact at 11:10 p.m. EDT). It poses in an interesting setting. As the stars come out, you'll find

Jupiter shining a few degrees to the Moon's left (for North America) and dimmer orange Antares twinkling farther

below it. See the top of this page.

Friday, Sept. 6

• The two brightest stars (not planets) of September evenings are Vega high overhead and Arcturus in the west,

both magnitude 0.

Draw a line from Vega down to Arcturus. A third of the way down you cross the dim Keystone of Hercules.

Two thirds of the way down you cross the dim semicircle of Corona Borealis with its one modestly bright star:

Alphecca, the gem of the crown.

Well to the right of Arcturus, in the northwest, the Big Dipper is turning more and more level.

Saturday, Sept. 7

• Look left of the gibbous Moon at dusk for Saturn, as shown at the top of this page. Below the Moon, can you

piece out the Sagittarius Teapot?

Source: Sky and Telescope Return to Contents

Tuesday, Sept. 3

• Even with a modest telescope under

a mediocre sky, did you know you can

see the black-hole microquasar Cygnus

X-1 — or rather the 9th-magnitude star

feeding it? It's 0.4° east of 4th-

magnitude Eta Cygni high overhead.

Celestial north there is up and east is

to the left.

Wednesday, Sept. 4

• The Moon at dusk hangs left of

Jupiter, Antares, and the head of

Scorpius, as shown at the top of this

page.

• A winter preview: Step out before

the first light of dawn this week, and

the sky displays the starry panorama it

will after dinnertime in late January

and early February. Orion strides up in

the southeast, with Aldebaran and

then the Pleiades high above it. Sirius

sparkles far below Orion. The Gemini

twins are lying on their sides well up in

the east.

The waxing Moon will step eastward past Jupiter and Saturn, over Scorpius and Sagittarius. (The blue 10° scale

is about the size of your fist at arm's length.)

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ISS Sighting Opportunities (from Denver)

Date Visible Max Height Appears Disappears

Wed Sep 4, 4:32 AM 2 min 16° 16° above NNW 10° above NNE

Wed Sep 4, 6:09 AM < 1 min 10° 10° above N 10° above N

Thu Sep 5, 3:45 AM < 1 min 12° 12° above NNE 10° above NNE

Thu Sep 5, 5:19 AM 2 min 10° 10° above NNW 10° above NNE

Fri Sep 6, 4:31 AM 2 min 11° 11° above NNW 10° above NNE

Fri Sep 6, 6:07 AM 3 min 13° 10° above NNW 11° above NNE

Sat Sep 7, 3:44 AM < 1 min 10° 10° above NNE 10° above NNE

Sat Sep 7, 5:19 AM 2 min 11° 10° above NNW 10° above

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

NASA-TV Highlights (all times Eastern Time Zone)

September 4, Wednesday

6:30 a.m. – Video B-Roll of Training for Expedition 61-62 astronaut Jessica Meir of NASA (All Channels)

7 – 8:15 a.m. – Live Interviews with Expedition 61-62 astronaut Jessica Meir of NASA – Johnson Space Center

via the Gagarin Cosmonaut Training Center in Star City, Russia (All Channels)

September 5, Thursday

10 a.m. – International Space Station Expedition Expedition 60 in-flight event with NASA astronauts Nick Hague

and Andrew Morgan (All Channels)

4 p.m. - Replay of the International Space Station Expedition 61-62 crew news conference at the Gagarin

Cosmonaut Training Center in Star City, Russia (Skripochka, Meir, Almansoori) (All Channels)

4:45 p.m. – Video file of the International Space Station Expedition 61-62 crew’s ceremonial visit to the Gagarin

Museum at the Gagarin Cosmonaut Training Center and visit to Red Square and the Kremlin in Moscow

(Skripochka, Meir, Almansoori) (Media Channel)

September 6, Friday

9:45 a.m. – International Space Station Expedition 60 In-Flight Event for the European Space Agency for the

Space19+ Forum in Cernobbio, Italy and ESA astronaut Luca Parmitano (Public Channel with interpretation;

Media Channel in native language)

1:45 p.m. – Coverage of the undocking of the unpiloted International Space Station Soyuz MS-14 spacecraft

from the International Space Station. Undocking is scheduled at 2:13 p.m. EDT; no coverage of landing in

Kazakhstan (All Channels)

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

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Space Calendar

Sep 03 - Mercury Passes 0.7 Degrees from Mars

Sep 03 - Apollo Asteroid 2018 DE1 Near-Earth Flyby (0.033 AU)

Sep 03 - Apollo Asteroid 2019 OF2 Near-Earth Flyby (0.046 AU)

Sep 03 - Apollo Asteroid 137052 Tjelvar Closest Approach To Earth (0.671 AU)

Sep 03 - Lecture: The Astronomer's Toolkit, Baltimore, Maryland

Sep 03-05 - 5th Workshop in Binary Asteroids, Fort Collins, Colorado

Sep 03-06 - 8th CSA-IAA Conference on Space Technology Innovation, Shanghai, China

Sep 03-06 - Conference: Geometry and Strings 2019, Oxford, United Kingdom

Sep 03-06 - Conference: GeoInformation for Disaster Management (Gi4DM), Prague, Mauritania

Sep 04 - Apollo Asteroid 2019 QX3 Near-Earth Flyby (0.029 AU)

Sep 04 - Aten Asteroid 2006 SE6 Near-Earth Flyby (0.072 AU)

Sep 04 - Colloquium: Astrophysics Origin of the Elements in the Periodic Table, Trieste, Italy

Sep 04 - Colloquium: Measurement of the Luminosity Function of Fast Radio Bursts, Sydney, Australia

Sep 04 - September Satuccino Event, Didcot, United Kingdom

Sep 04-05 - 7th International Conference on Sustainable Development (ICSD 2019), Rome, Italy

Sep 04-05 - Resources 2019 Conference, Trondheim, Norway

Sep 04-06 - Workshop: Dynamics and Physics of Asteroids, TNOs and Natural Satellites in the New Era of Gaia Data, Antalya, Turkey

Sep 04-06 - 7th International Colloquium on Scientific and Fundamental Aspects of GNSS, Zurich, Switzerland

Sep 04-06 - Workshop: Variable Galactic Gamma-Ray Sources (VGGRS), Barcelona, Spain

Sep 04-06 - 3rd PocketQube Workshop, Glasgow, United Kingdom

Sep 04-06 - Meeting: Panel on Compact Objects and Energetic Phenomena (Astro2020), Washington DC

Sep 04-06 - Irish National Astronomy Meeting (INAM), Armagh, Northern Ireland

Sep 04-17 - 2019 European School of High-Energy Physics (ESHEP 2019), St. Petersburg, Russia

Sep 05 - Apollo Asteroid 2019 QE1 Near-Earth Flyby (0.034 AU)

Sep 05 - Lecture: Searching for Life Beyond Earth, Newark, California

Sep 05 - Colloquium: Getting Under Europa’s Skin, Ithaca, New York

Sep 05-06 - Workshop: Precision Spectroscopy 2019 - Rotation, Magnetic Activity and Lithium, Sao Paulo, Brazil

Sep 05-06 - 2019 URSI-Japan Radio Science Meeting, Tokyo, Japan

Sep 06 - Chandrayaan 2, Moon Landing

Sep 06 - Apollo Asteroid 465617 (2009 EK1) Near-Earth Flyby (0.057 AU)

Sep 06 - Apollo Asteroid 1566 Icarus Closest Approach To Earth (0.439 AU)

Sep 06 - Apollo Asteroid 4660 Nereus Closest Approach To Earth (0.781 AU)

Sep 06 - Lecture: Observing Black Holes, Pasadena, California

Sep 06-07 - Meeting: Astrophysics with GW Detections, Warsaw, Poland

Sep 06-13 - IRAM 30m Summer school 2019, Pradollano, Spain

Source: JPL Space Calendar Return to Contents

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Food for Thought

A Possible Solution to Mars’s Methane Problem

There are several ways to add methane to Mars's atmosphere (and take it away again). Although microbes are the most

exciting possibility, other likely sources include reactions between water and the minerals olivine or pyroxene, or solar

ultraviolet radiation breaking up meteoritic dust on the planet's surface. NASA / JPL-Caltech / SAM-GSFC / Univ. of

Michigan

For the last 20 years, scientists have been trying to determine if the Martian atmosphere contains methane. The

presence of the molecule could reveal processes happening belowground, such as chemical reactions between liquid

water and iron-rich minerals or even microbial activity. However, orbiters and even the Curiosity rover have

provided conflicting measurements as to whether the gas is present at all.

Now, a study appearing in the August 20th Geophysical Research Letters proposes a solution that could resolve the

dispute — though the debate isn’t over yet.

The Methane Debate

The quest for methane has become a source of heated debate among scientists as measurements obtained from

different instruments have yielded conflicting results. On the one hand, NASA’s Curiosity rover has observed a

seasonal pattern repeated over three Mars years, where methane abundance varies from 0.2 to 0.7 parts per billion

by volume (ppbv). The rover has also detected here-and-gone peaks in methane concentration, known as plumes.

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In 2013 one of these plumes reached 5.78 ppbv. Moreover, the Planetary Fourier Spectrometer (PFS) onboard the

European Space Agency (ESA) orbiter, Mars Express, confirmed the plume from orbit.

On the other hand, in April 2019, researchers operating the most sensitive spacecraft ever deployed to study the

Martian atmosphere, the ExoMars Trace Gas Orbiter, reported that they had failed to find signs of methane after

several months of operations. A collaborative project between ESA and Roscosmos, the Russian space agency,

ExoMars TGO carries two independently operating spectrometers, the European NOMAD and the Russian ACS. They

can detect vanishingly small concentrations of trace gases in the upper atmosphere (more than 5 kilometers off the

ground), but neither one found any methane. Scientists on the ExoMars team concluded that if any methane is

present, it must be less than 0.05 ppbv.

This illustration shows a proposed cycle in the methane levels on Mars, as seen by Curiosity (points), along with the ways

in which the gas might find its way to the Martian surface from below. Potential methane sources include methanogenesis

by microbes, ultraviolet degradation of organics, or water-rock chemistry. The methane could be later destroyed by

atmospheric photochemistry or surface reactions, as examples. Seasons refer to the northern hemisphere.

NASA / JPL-Caltech

What’s curious is that if methane were leaking into the Martian atmosphere at the rate found by Curiosity and Mars

Express, it should build up over time. Current models predict that methane molecules can survive in the Martian

atmosphere for about 300 years before being destroyed by sunlight. Therefore, even though instruments on the

three craft explore different parts of the atmosphere, scientists can’t explain why TGO would see not even a hint of

methane.

A Possible Resolution?

Scientists have now come up with an explanation that could reconcile the disparate measurements. Modeling the

diffusion of gases in the Martian atmosphere over daily and seasonal cycles, they have determined that a tiny but

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constant methane release within the Gale Crater, where Curiosity roves, could explain its measurements. Curiosity’s

instruments are designed to measure methane at night, when the atmosphere is relatively still. A more stable

atmosphere could more easily hold onto any molecules that slip out from an underground source. This explains why

the rover detected methane. TGO, on the other hand, measures methane abundance around sunset after a day of

Sun-driven atmospheric mixing, when methane has already become too diluted to pick up.

John Moores (York University, Canada) and his colleagues have calculated that if local sources at Gale Crater were

generating less than 2.8 kilograms of methane every day, that would explain Curiosity’s overnight measurements

but wouldn’t increase global levels above TGO’s 0.05 ppbv detection limit. The researchers estimate that less than

27,000 square kilometers of Martian surface might be spewing methane at this low rate. “This is indeed a very small

amount of methane!” Moores says. “It’s about 20,000 times less than the smallest seeps found on Earth.”

It’s important to note that this tiny rate of methane production doesn’t rule out any possible explanations of its

origin, Moores adds. “For solutions that involve degradation of organic carbon by whatever means, Mars has much

less of this material than does the Earth, so you would anticipate that the amount of methane produced would be

much smaller,” Moores says. “For water-rock reactions these too could proceed slowly, resulting in very little

methane.”

Marco Giuranna (National Institute of Astrophysics, Italy), the principal investigator of the Mars Express PFS

instrument, says these results are consistent with his own findings. He has suggested that the methane observed by

Curiosity, and confirmed by Mars Express in 2019, was emitted from a region 500 km east of the crater. One

possible mechanism he has proposed is that a layer of buried ice traps methane underground, then releases it in

sudden bursts.

“From my perspective, the most befuddling aspect of the methane question is not, why is there so much, but why is

there so little?” Moores says. Hundreds of tons of organic carbon fall on Mars every year in the form of

interplanetary dust particles, he explains. “When we put this material under UV illumination in a lab here on Earth it

generates tremendous amounts of methane, enough so that the atmosphere of Mars should contain 10 ppbv of

methane all the time!” Considering that models show that any gas should be quickly distributed throughout the

atmosphere, the small amount of methane is puzzling, though Giuranna argues that the daily changes in

atmospheric mixing could help explain it.

The Debate Continues

The atmospheric mixing explanation only works for the long-term methane observations — the short-lived plumes

are a different question. They could be unrelated to the constant seeping from underground. “I’m of the opinion

that the plumes and the background are separate processes, so one does not preclude the other,” Moores says.

“The background seepage is continuous and happens in the absence of other effects.”

But other scientists don’t think that the proposed solution to the methane question is feasible. “Curiosity is reporting

levels between 0.4 and 0.5 ppbv, but that’s ten times more than we know there isn’t,” says Jose Juan Lopez-

Moreno (Andalusian Institute of Astrophysics, Spain), co-principal investigator of the TGO’s NOMAD instrument.

“Methane doesn’t hide.”

Instead, Lopez-Moreno proposes a different resolution to the debate: “There isn’t a Mars methane mystery because

there isn’t any methane.”

Definitive answers will only come from more frequent measurements, notes Moores, preferably from landers or rovers. “My paper is based on 12 data points collected over 7 years on Mars,” he explains. “We once believed that methane concentrations changed on the order of centuries. Then we saw with TLS [instrument aboard Curiosity] that they change over the course of the seasons. Now it looks like methane concentrations can change over the course of the day.” Maybe the next generation of rovers, starting with Mars 2020, can settle the controversy.

Source: Sky and Telescope Return to Contents

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Space Image of the Week

M45: The Pleiades Star Cluster Image Credit & Copyright: Marco Lorenzi (Glittering Lights))

Explanation: Have you ever seen the Pleiades star cluster? Even if you have, you probably have never seen it as dusty as this. Perhaps the most famous star cluster on the sky, the bright stars of the Pleiades can be seen without binoculars from even the depths of a light-polluted city. With a long exposure from a dark location, though, the dust cloud surrounding the Pleiades star cluster becomes very evident. The featured exposure took over 12 hours and covers a sky area several times the size of the full moon. Also known as the Seven Sisters and M45, the Pleiades lies about 400 light years away toward the constellation of the Bull (Taurus). A common legend with a modern twist is that one of the brighter stars faded since the cluster was named, leaving only six stars visible to the unaided eye. The actual number of Pleiades stars visible, however, may be more or less than seven, depending on the darkness of the surrounding sky and the clarity of the observer's eyesight.

Source: NASA APOD Return to Contents