# Astronomy & Science

## TheSky App

Sky&Telescope -

Software Bisque Inc.

862 Brickyard Circle, Golden, CO 80403-8058

303-278-4478; www.bisque.com

Software Bisque announces its long-anticipated expansion into the app market with the release of TheSky Mobile ($14.99) for the iPhone and TheSky HD for the iPad ($29.99). Both include an extensive feature set tailored to the intermediate and advanced amateur. TheSky for iOS integrates popular features from the desktop editions, including field-of-view indicators for many telescope, eyepiece, and camera combinations; large astronomical databases (including satellites and minor planets); integrated photos of popular astronomical objects; and much more. TheSky’s Wi-Fi telescope control (a Wi-Fi-to-serial adapter is required and sold separately) offers a powerful and elegant alternative to your Go To telescope’s hand paddle, allowing you to control their telescopes directly with your iPhone or iPad device. TheSky HD for the iPad also integrates with DC-3 Dreams ACP Observatory Control Software, enabling users to plan, submit to ACP, and execute their observing session without having to exit TheSky. Additional catalog plug-ins can be downloaded from the manufacturers website free of charge.

SkyandTelescope.com's New Product Showcase is a reader service featuring innovative equipment and software of interest to amateur astronomers. The descriptions are based largely on information supplied by the manufacturers or distributors. Sky & Telescope assumes no responsibility for the accuracy of vendors statements. For further information contact the manufacturer or distributor. Announcements should be sent to nps@SkyandTelescope.com. Not all announcements will be listed.

The post TheSky App appeared first on Sky & Telescope.

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## Inside the September 2014 Issue

Sky&Telescope -

PURCHASE PRINT ISSUE | PURCHASE DIGITAL ISSUE | DOWNLOAD BACK ISSUES | SUBSCRIBE

Martian Mysteries and Reliving History

How did Mars lose its rich atmosphere and planet-wide magnetic field? Our cover story, written by S&T assistant editor Camille M. Carlisle, previews NASA's Maven mission, due to arrive at the Red Planet in late September to investigate these ongoing mysteries. Elsewhere in the solar system, history lives again in the project authors Rod Pommier and Richard Smith undertook when they measured the 2012 transit of Venus. Plus, read an amateur astronomer's account on surviving the medical maze of cataract surgery, learn about the potential of interplanetary nanosatellite explorers, and explore deep-sky treasures in Cygnus the Swan.

Feature Articles

Rick Schrantz

Deciphering Mars
NASA's new mission to the Red Planet will help reveal why our neighboring world went red and dead.
By Camille M. Carlisle

Reliving History
The authors observed the 2012 transit of Venus to replicate experiments from past centuries.
By Rod Pommier & Richard Smith

Clearing the Clouds: Cataract Surgery for Astronomers
One amateur's journey through the medical maze of cataract surgery has lessons for any observer facing the same condition.
By Kathy & Jerry Oltion

20 Fun Naked-Eye Double Stars
From easy to challenging, here are some star pairs every skywatcher should know.
By Jerry Lodriguss

Get the most out of this powerful technique in PixInsight.
By Rogelio Bernal Andreo

Beyond the Printed Page

ISEE 3

New Life for Kepler by Maria Temming
Get the full story behind the revamping of NASA's crippled Kepler spacecraft.

How Amateurs Snagged a Spacecraft by Kelly Beatty
Watch a video of the long-retired ISEE 3's simulated trajectory and capture.

Inflation Evidence Inconclusive by Camille M. Carlisle
Read the original papers that show why this year's biggest cosmology result may not be what it seems.

Lunar Librations by Sean Walker
Librations and other lunar data for September 2014.

ALSO IN THIS ISSUE

Uranus
Sean Walker

Mars Meets Its Rival
The Red Planet has a fine conjunction with Antares this month.
By Fred Schaaf

Ice-Giant Spotting
Uranus and Neptune are in reach of binoculars as they go their separate ways.
By Alan MacRobert

The Violet Sun
A K-line filter can reveal solar activity normally hidden from view.
By Howard Eskildsen

See what else September's issue has to offer.

The post Inside the September 2014 Issue appeared first on Sky & Telescope.

## NASA Gears Up for Mars 2020 Rover

Sky&Telescope -

The seven scientific instruments to be built for NASA's Mars 2020 rover will pave the way for human exploration of the Red Planet.

Artist's rendering of Mars 2020 rover.
NASA/JPL-Caltech

Six years from now, there will be a new NASA robot heading to the Red Planet: the Mars 2020 rover. On July 31st mission planners unveiled their picks for the rover’s seven scientific instruments. What immediately stands out about these instruments is not just the high-tech science they’ll accomplish, but that they’re geared to pave the way for human exploration of Mars.

The Mars 2020 rover is a Curiosity 2.0. NASA’s Mars Science Laboratory (“Curiosity”) touched down in 2012 and has determined that Mars once hosted a habitable environment. (That’s not the same thing as saying life lived there—just that it could have survived there if present.) Mars 2020 will expand that research by not only searching for potential signatures of ancient life on Mars, but also studying the environmental factors that will affect a future human presence on the planet. “This is really going to take our understanding of Mars to the next level,” NASA Chief Scientist Ellen Stofan stated in the NASA press conference on Thursday.

In January, NASA received 58 proposals for the instruments onboard Mars 2020 from scientists and engineers worldwide. Since then, mission planners have weeding through the proposals to determine which ones will best enable them to pursue the mission’s objectives. That process culminated in last week’s announcement, when NASA representatives announced which seven instrument packages they decided will be built for the rover.

Image of tear in one of Curiosity’s wheels taken on Dec. 22, 2013 NASA/JPL/MSSS/Ken Kremer -kenkremer.com/Marco Di Lorenzo

Each of the selected instruments for Mars 2020 is either an improved version of something used on Curiosity or is brand new to Mars. Although the new rover will have the same basic architecture as Curiosity, NASA scientists and engineers are working to improve that design however they can for Mars 2020—even down to the wheels, which they might redesign to better withstand damage from the Red Planet’s rough terrain.

Much of the instrumentation on Mars 2020 is devoted to studying the planet’s chemical composition and mineralogy, as well as detecting organic compounds that could hint at past life on Mars. The rover will also image the landscape, as well as the subsurface of Mars as deep as half a kilometer using a ground-penetrating radar.

Humans Breathing on Mars?

One particularly exciting function of the new rover is its Mars Oxygen ISRU Experiment (MOXIE), which will convert the carbon dioxide in Mars’s atmosphere into oxygen. According to Michael Hecht, Principal Investigator of the MOXIE instrument, MOXIE will be like a “fuel cell run in reverse.” Whereas normal fuel cells combine fuel with an oxidizer (usually oxygen) to produce electricity, MOXIE consumes electricity and carbon dioxide to produce oxygen.

MOXIE might serve as the prototype for a large-scale system of oxygen production on Mars, which would be crucial not only for the respiration of human pioneers, but also the rocket fuel for a return trip to Earth.

The information gleaned from Mars 2020’s instruments will help scientists better understand the risks involved with human excursions on Mars and will certainly inform future mission designs. “Human exploration of Mars will be a seminal event for the next generation, the same way the Moon landing was for my generation,” Hecht stated in an MIT press release. “I welcome this opportunity to move us closer to that vision.”

Of Sample Collection and Boston Cream Pie

Mars 2020 will also collect samples of Martian rock to be retrieved on future (but as-yet unplanned) missions. Unlike Curiosity, which grinds Martian material to inspect its chemical composition, Mars 2020 will be equipped with a coring system that removes whole chunks of rock.

Artist's concept of Mars rover.
NASA/JPL-Caltech

Michael Meyer, Lead Scientist for NASA’s Mars Exploration Program, offers an analogy: Say you want to analyze a slice of Boston cream pie. The coring system would preserve the carefully laid layers of custard and chocolate, whereas the grinding system would provide you a light brown paste. By maintaining the structure of the rock, scientists can learn more about the history and environment of the rock’s formation, explains Meyer. There are currently no definitive plans to retrieve the samples Mars 2020 collects, but sealed samples can be stored for upwards of 20 years.

Mars 2020 is an international effort involving more than 50 institutions around the world. The entire mission will cost approximately $1.9 billion U.S., with$130 million devoted to developing the seven instruments onboard. That’s a big chunk of change, but it’s worth noting that the Curiosity mission cost nearly \$2.5 billion. NASA mission planners explain that reproducing the basic infrastructure of Curiosity for Mars 2020, including using leftover parts, will significantly decrease the cost of the new mission.

You can learn more about the function of Mars 2020’s individual instruments in the NASA press release.

Interested in Mars? There's more to discover about the Red Planet inside Sky & Telescope's special "Mysteries of Mars" issue.

The post NASA Gears Up for Mars 2020 Rover appeared first on Sky & Telescope.

## Dark Shuttle Approaching

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What's that approaching?

## NGC 7023: The Iris Nebula

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These clouds of interstellar dust and gas

## Tetons and Snake River, Planet Earth

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Tetons and Snake River, Planet Earth

## This Week’s Sky at a Glance, August 1 – 9

Sky&Telescope -

Watch night to night as the waxing Moon moves eastward past the lineup of Spica, Mars, and then Saturn. (The blue 10° scale is about the size of your fist held at arm's length. The Moon is plotted for the middle of North America, and it's shown three times actual apparent size.)

Friday, August 1

At dusk this evening, the Moon forms the lower-right end of a very long, curving line of celestial objects. Counting to the Moon's upper left, these are Spica, Mars, and Saturn, as shown here.

Today is Lammas Day or Lughnasadh, one of the four traditional "cross-quarter" days midway between the solstices and equinoxes. More or less. The actual midpoint between the June solstice and the September equinox this year comes at 2:40 a.m. August 7th Eastern Daylight Time (6:40 UT). That will be the exact center of (astronomical) summer.

Saturday, August 2

The Moon shines about midway between Spica and Mars this evening, as shown here.

Sunday, August 3

The first-quarter Moon shines between Mars and Saturn as seen from the Americas and Europe, as shown above (plotted for the middle of North America). The Moon will occult (cover) Saturn as seen from Australia, where the local date will be August 4th. Watch live via Slooh starting at 11:00 UT August 4th (7 a.m. August 4th Eastern Daylight Time in the US).

Monday, August 4

Now the Moon forms the left end of a ragged line with Saturn, Mars, and Spica to its right. To the Moon's lower left are the vertical row of stars forming the head of Scorpius (highlighted by Delta Scorpii, labeled below), and then Antares.

The Moon posing over Scorpius.

Tuesday, August 5

Look below the Moon this evening for the red supergiant Antares, as shown at right. Around Antares and to its right are other stars of upper Scorpius.

Wednesday, August 6

Antares is well to the lower right of the Moon this evening, as shown here. More than twice as far to the Moon's upper left shines Altair.

Thursday, August 7

Vega is the brightest star very high in the east after dusk. The brightest in the southeast is Altair, almost as bright. Altair is flagged by little Tarazed (3rd magnitude) a finger-width above it: an orange giant far in Altair's background.

Friday, August 8

Look northeast as the stars come out for W-shaped Cassiopeia. It's still not as high as the Big Dipper is in the northwest, but the two are on their way to their dusk balance point week by week. Get a preview of this by checking on them around 11 p.m. (depending on your location).

Saturday, August 9

If you're in the Earth's mid-northern latitudes, bright Vega crosses close by the zenith around 10 or 11 p.m. (depending on where you are east-west in your time zone). Wherever you are, Deneb always passes the zenith two hours later.

Want to become a better astronomer? Learn your way around the constellations. They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope.

This is an outdoor nature hobby; for an easy-to-use constellation guide covering the whole evening sky, use the big monthly map in the center of each issue of Sky & Telescope, the essential guide to astronomy. Or download our free Getting Started in Astronomy booklet (which only has bimonthly maps).

The Pocket Sky Atlas plots 30,796 stars to magnitude 7.6 — which may sound like a lot, but it's still less than one per square degree on the sky. Also plotted are many hundreds of telescopic galaxies, star clusters, and nebulae.

Once you get a telescope, to put it to good use you'll need a detailed, large-scale sky atlas (set of charts). The standards are the little Pocket Sky Atlas, which shows stars to magnitude 7.6; the larger and deeper Sky Atlas 2000.0 (stars to magnitude 8.5); and once you know your way around, the even larger Uranometria 2000.0 (stars to magnitude 9.75). And read how to use sky charts with a telescope.

You'll also want a good deep-sky guidebook, such as Sue French's Deep-Sky Wonders collection (which includes its own charts), Sky Atlas 2000.0 Companion by Strong and Sinnott, the bigger Night Sky Observer's Guide by Kepple and Sanner, or the beloved if dated Burnham's Celestial Handbook.

Can a computerized telescope replace charts? Not for beginners, I don't think, and not on mounts and tripods that are less than top-quality mechanically (able to point with better than 0.2° repeatability, which means fairly heavy and expensive). As Terence Dickinson and Alan Dyer say in their Backyard Astronomer's Guide, "A full appreciation of the universe cannot come without developing the skills to find things in the sky and understanding how the sky works. This knowledge comes only by spending time under the stars with star maps in hand."

This Week's Planet Roundup

Christopher Go took this extraordinarily sharp image of Saturn during excellent seeing on June 1st using a 14-inch scope. It's a stack of many selected video frames, de-rotated and expertly processed. South is up. Note the growing shadow of the globe on the rings (just off the globe's lower-right edge), and the shadow of the rings on the globe (just above the rings' edge at top).

Mercury (about magnitude –1.5) sinks very deep into the glow of sunrise this week, farther and farther to the lower left of much-brighter Venus. Scan for it with binoculars. Mercury and Jupiter are in conjunction, 1° apart, on Saturday morning August 2nd.

Venus (magnitude –3.8) shines low in the east-northeast during dawn.

Mars (magnitude +0.5, in Virgo) is in the southwest at dusk. It's about midway between Saturn to its upper left and Spica to its lower right. In a telescope Mars's tiny gibbous disk is only 8 arcseconds tall.

Jupiter (magnitude –1.8) is just beginning to emerge from the glare of sunrise far to the lower left of Venus. Jupiter and Mercury are in conjunction, 1° apart, on the morning of August 2nd; bring binoculars.

On August 18th, Jupiter will reach a much more striking conjunction with Venus higher in the dawn.

Saturn (magnitude +0.5, in Libra) shines in the southwest in twilight to the upper left of Mars.

Uranus (magnitude 5.8 in Pisces) and Neptune (magnitude 7.8 in Aquarius) are well placed in the southern sky in the early-morning hours. Use our finder charts for Uranus and Neptune.

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All descriptions that relate to your horizon — including the words up, down, right, and left — are written for the world's mid-northern latitudes. Descriptions that also depend on longitude (mainly Moon positions) are for North America.

Eastern Daylight Time (EDT) is Universal Time (UT, UTC, or GMT) minus 4 hours.

The post This Week’s Sky at a Glance, August 1 – 9 appeared first on Sky & Telescope.

## Tour August’s Sky: Sagittarius and Scorpius

Sky&Telescope -

Late summer offers the Teapot of Sagittarius and the nearby arc of the Scorpion's Tail in the evening, the Perseid meteor shower, and a spectacular pairing of Venus and Jupiter before dawn.

August will be a busy skywatching month in the evening sky. Two bright planets, Mars and Saturn, are low in the west at dusk. They’re joined by the star Spica. Look for a line of three obvious “stars,” all about the same brightness. The one on the left is Saturn, on the right is Spica, and Mars is in between.

Find the Teapot of Sagittarius and the Tail of Scorpius low in the south after it gets dark during August.
Sky & Telescope diagram

Swing your gaze well to the left, arcing over and past the Saturn-Mars-Spica lineup. Look for a medium-bright star above the southern horizon. That’s Antares, the heart of the constellation Scorpius. Shift your gaze to the left of Antares by a bit more than two fists away. You’re looking for a group of eight medium-bright stars in the shape of a teapot. The handle is on the left and the spout, tipped down a bit, is on the right. Now when astronomers carved up the sky they didn’t call this the Teapot constellation. Instead, you’ve found the main stars of Sagittarius, the Archer. The regions around Sagittarius and Scorpius are rich with star clusters and nebulae.

Meanwhile, if you can manage to rise before the Sun on August 18th, you’ll be rewarded with a view of Venus and Jupiter — the two brightest planets — spectacularly close together not far above the horizon. They’ll be separated by less than ½°. You’ll be able to cover them both with the tip of your little finger on an outstretched arm.

And August is well known for the Perseid meteor shower, which should reach its peak late on Tuesday night, August 12th, and Wednesday morning, the 13th. Unfortunately this year the shower peaks just a couple of days after a full Moon on the 10th. You might see a Perseid or two as early as 9 or 10 p.m., but the shower doesn’t really get going until after 11 or midnight local time, after Perseus rises high in the northeast — and by then the Moon will be up.

And there's even more great skywatching advice in the August issue of Sky & Telescope magazine.

The post Tour August’s Sky: Sagittarius and Scorpius appeared first on Sky & Telescope.

## Novae Surprise with Gamma Rays

Sky&Telescope -

Astronomers have detected gamma-ray emission from three classical novae, an unexpected discovery that has left them perplexed.

Some days, it seems like everything is dumped on you. As the pressure builds, you finally hit a point at which you just lose it and explode.

In a classical nova, a white dwarf siphons material off a companion star, piling up material on its surface until thermonuclear processes kick off, creating a brilliant outburst.
NASA / JPL-Caltech

White dwarfs can have the same problem. When one of these stellar corpses funnels gas off a companion star, the white dwarf builds up a layer of material on its own surface until the temperature and pressure are so high that they trigger a thermonuclear explosion. The bright outburst, called a nova, can blaze for months. And unlike their brighter cousins the supernovae, novae don’t destroy the star and can actually repeat.

Observations with NASA’s Fermi Gamma-ray Space Telescope now show that nova-ing white dwarfs throw a surprisingly energetic fit when they’ve had enough. Fermi observations of three “classical” novae — V959 Monocerotis 2012, V1324 Scorpii 2012, and V339 Delphini 2013 — reveal that these eruptions produce gamma rays, heretofore unexpected from this type of system.

Each of the three novae emitted gamma rays over 2 to 3 weeks, with the gamma-ray peak following the optical peak by a couple of days. (The Fermi-LAT collaboration can’t confirm the delay for V959 Mon, because the nova was too close to the Sun for optical observations when detected with Fermi in June 2012.)

The gamma-ray delay happens because the material the white dwarf ejects initially blocks the high-energy photons from escaping, and the gamma rays can only get out when the material expands and thins.

Amateur astronomers actually helped confirm that two of the three transient gamma-ray signals came from novae. Amateurs fought the dawn to pick up the optical glow from V959 Mon in August, confirming the gamma-ray outburst was from a nova. After that, cooperation with spectroscopy-savvy amateurs enabled the Fermi collaboration to plan their observations of V339 Del after an amateur discovered that nova as well. The third nova was found by a professional team.

Mysterious Gamma Rays

An artist's portrayal of a symbiotic recurrent nova like V407 Cygni. Astronomers detected gamma rays from V407 Cygni in 2010; now they're finding that another class of novae also produce gamma rays. Click here for a larger version.
Credit: David A. Hardy http://www.astroart.org & Science and Technology Facilities Council

The first and only other nova detected in gamma rays is V407 Cygni, reported in 2010. That system’s white dwarf closely orbits a swollen red giant star, which spews out a thick wind. Astronomers think V407 Cyg created its gamma rays when the nova blast hit this wind material, creating a shock wave that accelerated the charged particles (electrons, protons) that then created the gamma rays.

But the three new novae are from systems that don’t have these hefty winds — there’s ostensibly nothing for the blast wave to crash into.

“It was thus a complete surprise to see gamma-rays from classical novae,” explains Brian Metzger (Columbia University), who works on high-energy and stellar astrophysics. Although radio and X-ray observations have long hinted that shocks exist, this is the first “irrefutable evidence” of particle acceleration at such shocks, he says.

Yet without a companion’s wind to crash into, the ejected material needs to be hitting something to create the shock. That suggests the outflow from the white dwarf’s surface might have first been slow and then fast, with the fast wave smacking into the slower-moving stuff. But current theory doesn’t explain why that change would happen, Metzger says.

Given the similarity of the gamma-ray signals from the three novae, the same process likely creates the emission for all three objects, says study coauthor Teddy Cheung (Naval Research Laboratory). “This is satisfying but puzzling at the same time,” he says, “because it implies there is some general mechanism operating in thermonuclear explosions that make high-energy gamma rays, despite differences in the systems” — differences such as the mass and composition of the white dwarfs and the binary system itself.

Cheung agrees that shocks are a plausible explanation, but any shocks involved in making gamma rays would need to be stronger and shorter lived than the ones that create radio and X-ray emission. They’d also likely be more localized, because the radio and X-ray emission tend to occur over larger volumes in the nova ejecta, he adds.

“The origin and location of the gamma ray emission is the key open question,” he sums up. The explosion definitely starts with the thermonuclear runaway on the white dwarf’s surface, he explains, but it’s still unclear where and when the gamma rays are produced.

Reference: Fermi-LAT Collaboration. "Fermi establishes classical novae as a distinct class of gamma-ray sources." Science. August 1, 2014.

Prepare for next year's astronomical fun with our 2015 wall calendar.

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