Featured Archives

July 20, 2016November 27, 2016 by Matt Williams

How Fast Does Venus Rotate?

The planet Venus, as imaged by the Magellan 10 mission. Credit: NASA/JPL — The planet Venus, as imaged by the Magellan 10 mission. The planet's inhospitable surface makes exploration extremely difficult. Credit: NASA/JPL

Venus is often refereed to as “Earth’s sister planet”, thanks to the number of things it has in common with our planet. As a terrestrial planet, it is similarly composed of silicate rock and metals – which are differentiated between a metal core and a silicate crust and mantle. It also orbits within our Sun’s habitable zone, and had a similarly violent volcanic past.

But of course, there are also some major differences between our two planets. For one, Venus has an atmosphere that is incredibly dense (92 times that of Earth, in fact) and reaches temperatures that are hot enough to melt lead. In addition, the planet’s rotation is immensely slow by comparison, taking 243.025 days to complete a single rotation, and rotating backwards relative to Earth.

When discussing Venus’ rotation, it is important to note certain distinctions. Rotation is the time it takes for a planet to spin once on its axis. This is different from a planet’s revolution, which is the time it takes for a planet to orbit around another object (i.e. the Sun). So while it takes the Earth one day (24 hours) to rotate once on its axis, it takes one year (365.256 days) to revolve once around the Sun.

Earth and Venus' orbit compared. Credit: Sky and Telescope — *Earth and Venus’ orbit compared. Credit: Sky and Telescope*

Orbital Period:

In Venus’ case, things work a little differently. For starters, it orbits the Sun at an average distance of about 0.72 AU (108,000,000 km; 67,000,000 mi) with almost no eccentricity. In fact, with its farthest orbit (aphelion) of 0.728 AU (108,939,000 km) and closest orbit (perihelion) of 0.718 AU (107,477,000 km), it has the most circular orbit of any planet in the Solar System.

The planet completes a revolution around the Sun every 224.65 Earth days, which means that a year on Venus last about 61.5% as long as a year on Earth. Evey 584 days, Venus completes an interior conjunction, where it lies between Earth and the Sun. It is at this point that Venus makes the closest approach to Earth of any planet, at an average distance of 41 million km.

Rotational Period:

Unlike most other planets in the Solar System, which rotate on their axes in an counter-clockwise direction, Venus rotates clockwise (called “retrograde” rotation). It also rotates very slowly, taking 243.025 Earth days to complete a single rotation. This is not only the slowest rotation period of any planet, it also means that a single day on Venus lasts longer than a Venusian year.

Phases of Venus during 2004 photographed through a telescope. When very close to inferior conjunction (bottom right) the crescent is seen to extend fully around the planet. Credit: Statis Kalyva / Wikipedia

And, as noted earlier, Venus’ rotation is backwards, relative to Earth and the other bodies in the Solar System. Technically, this means that its rotational period is -243,025 days. It also means that if you could view the Solar System from the position above its celestial north pole, all of the planets (except for Uranus, which rotates on its side!) would appear to be rotating clockwise.

Venus, however, would appear to be rotating in a clockwise direction. Because of this, if you could stand on the surface of Venus, you would witness the Sun rising in the west and setting in the east. But you would be waiting a very long time to see this happen! Read on to find out why…

Sidereal vs. Solar Day:.

Another important thing to consider is the difference between a sidereal day and a solar day. A sidereal day corresponds to the amount of time it takes for a planet to rotate once on its axis, which in Venus’ case takes 243.025 Earth days. A solar day, by contrast, refers to the amount of time it takes for the Sun to reappear at the same point in the sky (i.e. between one sunrise/sunset and the next).

A Venusian (aka. Cytherean) Solar Day is the equivalent to 116.75 days on Earth, which means that it takes almost 117 days for the sun to rise, set, and return to the same place in the sky. Doing the math, we then see that a single year on Venus (224.65 Earth days) works out to just 1.92 Venusian (solar) days. Not exactly the basis for a good calendar system, is it?

Another view from the Solar Dynamics Observatory as Venus moves across the face of the Sun. Credit: NASA/SDO — *View of Venus from the Solar Dynamics Observatory. If viewed from the surface of Venus, the Sun would be moving from west to east in the sky. Credit: NASA/SDO*

Yes, when it comes to the planet Venus, things work quite differently than they do here on Earth. Not only does a day last over half a year on our “Sister Planet”, but the Sun rises and sets on the opposite horizons, and travels across the sky in the opposite direction. The reason for this, according to astronomers, is that billions of years ago (early in the planet’s history) Venus was impacted by another large planet.

The combined momentum between the two objects averaged out to the current rotational speed and direction, causing Venus to spin very slowly in its current retrograde motion. Someday, if human beings colonize there (perhaps in floating cities) they will have to learn to get used to a day that lasts over 2800 Earth hours, not to mention sunrises and sunsets happening on the wrong horizon!

We have written many interesting articles about Venus here at Universe Today. Here’s Interesting Facts About Venus, How Long is a Day on Venus?, How Long is a Year on Venus?, What is the Average Surface Temperature on Venus?, New Map Hints at Venus’ Wet, Volcanic Past and Venus Compared to Earth.

Want more information on Venus? Here’s a link to Hubblesite’s News Releases about Venus, and here’s a link to NASA’s Solar System Exploration Guide on Venus.

We have recorded a whole episode of Astronomy Cast that’s only about planet Venus. Listen to it here, Episode 50: Venus.

July 19, 2016February 22, 2017 by Fraser Cain

What Does the Universe Do When We’re Not Looking?

If you follow some of my other shows, like Astronomy Cast and the Weekly Space Hangout. Of course you do, what a ridiculous thing to say… “if”. Anyway, since you follow those other shows, you know I’m currently obsessed with an upcoming observatory called the Large Synoptic Survey Telescope.

Obsessions are best when they’re shared. So today, I invite you to become as obsessed as I am about the LSST.

In the past, astronomers focused on building bigger telescopes at more remote locations so they could peer more deeply into the past, to resolve the faintest objects, to see right to the edge of the observable Universe.

But there’s a whole other dimension to the Universe: time. And by taking advantage of time, astronomers have made some of the most momentous discoveries in the history of astronomy.

The Large Synoptic Survey Telescope is all about time. Watching the sky over and over, night after night, watching for anything that changes.

Credit: Large Synoptic Survey Telescope (CC-SA 4.0)

First, let’s talk about some of the kinds of discoveries that can be made when you’re watching the sky for changes.

Perhaps the best example of this is the Mira Variable. These are red giants at the very end of their stellar evolution, almost out of usable hydrogen to burn in their cores. As their stellar flame flickers out, the light pressure can no longer hold against the gravity pulling the star inward. The star compresses in on itself, raising the temperature and pressure, allowing more fusion. It flares up again, and brightens in our sky.

Astronomers discovered that there’s a very specific relationship to the brightness and rate that this brightening happens. In other words, if you know how often a Mira variable flares up, you know how intrinsically bright it is. And if you know how bright it is, you can calculate how far away it is. Even in other galaxies.

That’s what Edwin Hubble did when he surveyed Mira variables in other galaxies. He discovered that most galaxies are actually speeding away from us in all directions, leading to the theory of the Big Bang.

Thanks to time, we understand that we life in an expanding Universe that originated from a single point, 13.8 billion years ago.

Let me give you another example: the discovery of gamma ray bursts. In the 1960s, the US launched a group of satellites as part of the Vela Mission. They had no astronomical purpose, they were designed to watch for the specific gamma ray signature from an unauthorized nuclear weapons test. But instead of nuclear explosions, they detected massive blasts of gamma radiation coming from deep space. These blasts only last for a few seconds and then fade away, leaving a faint afterglow that also fades.

Artist’s impression of a gamma-ray burst. Credit: ESO/A. Roquette

We now know that gamma ray bursts mark the deaths of the largest stars in the Universe, and the formations of new black holes. Other gamma ray bursts signal the collisions of exotic stellar remnants, like neutron stars and white dwarfs.

I can give you many more examples, where the dimension of time lead to a discovery in astronomy:

In 1930, Clyde Tombaugh compared pairs of photographic plates, switching back and forth over and over, looking for any object that moved position. This was how he discovered Pluto. In fact, this same technique is used by astronomers to find other dwarf planets, asteroids and comets to this day.

Astronomers return again and again to galaxies in the night sky, looking for any that have a new star in them. This is a tell tale sign of a supernova, the explosion of a star much more massive than our Sun. Some of these supernovae allowed astronomers to discover dark energy, that the expansion of the Universe is accelerating.

This is what time can help us discover.

Artist rendering of the LSST observatory (foreground) atop Cerro Pachón in Chile. Credit: Large Synoptic Survey Telescope Project Office.

Now, on to the Large Synoptic Survey Telescope. The observatory is currently under construction in north-central Chile, where many of the world’s most powerful telescopes are located.

Its main mirror is 8.4 meters across. Just for comparison, ESO’s Very Large Telescopes are 8.2 metres across. The Gemini Observatories are 8.1 metres across. The Keck Observatory is 10 metres wide. What I’m saying here, is that the LSST is plenty big.

But that’s not its most important feature. LSST is fast. When I say fast, I’m saying this in the astronomical sense, which means that it can gather a lot of light over a wide area on the sky in a very short amount of time. While Keck, for example, can focus incredibly deeply at a tiny spot in the sky, LSST gulps light across a huge region of the sky.

It’ll be able to see 3.5-degrees of the sky, every time it takes a picture. The Sun and the Moon are about 0.5-degrees across in the sky, so imagine a grid 7 moons across and 7 moons high.

Suzanne Jacoby with the LSST focal plane array scale model. The image of the moon (30 arcminutes) is placed there for scale of the Field of View. Credit: Large Synoptic Survey Telescope (CC-SA 4.0)

It’ll take a 15-second exposure every 20 seconds. In the amount of time you’ll spend watching this video, the LSST could have taken dozens of high resolution images of the sky.

In fact, it’ll completely image the available sky every few nights. And then petabytes of data will be released onto the internet, available for astronomers to pore over.

Want to find asteroids, just look through the LSST records. Want to know how fast the Universe is expanding, dig through the data. LSST is going to look everywhere and anywhere every couple of nights, and then provide this data to scientists to make discoveries.

Assuming the construction isn’t delayed, the Large Synoptic Survey Telescope should see first light in 2019. Shortly after that, it’ll be disgorging mountains of astronomical data onto the internet.

And shortly after that, I suspect, we’ll start to hear everything the Universe was doing when we weren’t watching before. Because now, thanks to LSST, we’ll be watching all the time.

July 19, 2016July 23, 2016 by David Dickinson

See All Five Naked Eye Planets in the Dusk Sky at Once

Solar System — An Iphone solar system family portrait. Image credit and copyright: Andrew Symes (@Failedprotostar)

Hosting an evening star party this summer? You’re in for a treat. Starting later this week, all five naked eye planets (Mercury, Venus, Mars, Jupiter and Saturn) are visible in the evening sky at dusk for a brief few weeks. We had a similar lineup in the dawn sky earlier in 2016, as the Earth had all the inner planets in its forward-facing view — now, we see these same planets in our collective rear view mirror, as we lap Mars, Jupiter and Saturn on the inner track, while Mercury and Venus race to catch up with us.

Dusk on the evening of August 8th. Image credit: Stellarium. — Dusk on the evening of August 8th, looking to the southwest. Image credit: Stellarium.

At their narrowest, the planets from Saturn to Mercury fit within a span just 75 degrees wide in the last half of August. A wide field all-sky shot should catch ’em all in the same frame at once. This isn’t a ‘grand conjunction’ in a strict sense. To have all five planets visible, you need the slowest and outermost of the five — Jupiter and Saturn, with orbital periods of 11.9 and 29.5 years respectively — in the same general swath of sky. Both are headed towards conjunction on December 21^st, 2020, making such groupings more frequent as they race past the other three. The next true quintuple grand conjunction occurs on September 8^th, 2040, when all 5 planets span just 9.3 degrees of the sky… the closest span since September 18^th, 1186!

Can you see 'em? Five planets from Monte Mario in Rome on February 2nd, 2016. Image credit: Gianluca Masi/The Virtual Telescope project. — Can you see ’em? Five planets from Monte Mario in Rome on February 2nd, 2016. Image credit: Gianluca Masi/The Virtual Telescope project.

There’s a lot to watch out for in the next few weeks. Here’s a who’s who of planets this July and August, from east to west:

Saturn: shining at magnitude +0.4 in the constellation Ophiuchus, Saturn is fresh off of opposition on June 3rd. Riding high in the southeast at dawn, Saturn makes a close 4.4 degree pass near Mars on August 24^th, and the pair makes a straight line completed by the bright star Antares on the same date.

Mars: High to the south in the constellation Libra at dusk, Mars begins its slow dive into the dusk during the last half of 2016. Currently shining at a respectable magnitude -0.9, Mars passed opposition on May 22nd and is headed towards a grand opposition in 2018, nearly as close as the historic close pass of 2003.

Jupiter: Sitting in the constellation Leo, Jupiter shines at magnitude -1.6 and is about 20-30 degrees above the southwestern horizon at dusk. Jupiter passed quadrature 90 degrees east of the Sun on June 4^th and opposition for 2016 on March 8th.

Venus: The bashful planet of the group, Venus is slowly appearing from behind the Sun low in the dusk and headed for a brilliant dusk apparition later in 2016 and early 2017. Currently 3 degrees east of the Sun on July 31^st, Venus reaches greatest elongation 47 degrees east of the Sun on January 12^th, 2017. We’ve just been able to begin spying Venus using binocs last week from the rooftop of our Casablanca Air BnB. Follow that planet, as Venus makes a close 6′ pass near Jupiter on August 27th.

Mercury: And the innermost planet makes five, as Mercury reaches greatest elongation 27 degrees east of the Sun on August 16th. When can you first catch sight of Mercury, completing the fivesome? Jupiter and Venus actually make great bookends in the hunt, as +0.5 magnitude Mercury wanders between them through early August. It’s too bad dusk twilight obscured the view this past weekend, as both Mercury and Venus photobombed the Beehive Cluster M44 in Cancer. Mercury also passes 20′ from the bright star Regulus on July 30^th.

Looking west on the evening of July 19th, 2016. Credit Starry Night Education Software.

But wait, there’s more. The Moon passes New on August 2nd, entering back into the dusk sky. The one day old Moon will pass the grouping of Venus, Regulus and Mercury on the evening of August 4^th, actually occulting (passing in front of) Mercury for the southernmost tip of South America. The Moon then moves on to occult Jupiter for good measure on August 6^th for the South Pacific and southeast Asia in the daytime. Finally, the waxing gibbous Moon makes a wide pass near Mars, Antares and Saturn on the evening of August 12^th, on the same evening that the 2016 Perseids are due to occur.

The footprint of the August 4th occultation of Mercury by the Moon. Image credit: Occult 4.2 software.

The Moon also reaches the nearest apogee (think ‘closest far point’) of the year, at 404,265 kilometers from the Earth on August 10th and reaches Full on August 18^th, featuring a subtle penumbral eclipse and the start of eclipse season 2 of 2 for 2016.

More on all of these events in the coming weeks. So, if you find yourself out hunting Pokémon G0 creatures ’til the late dusk hours this summer, don’t forget to look up at the greatest show in the solar system!

July 18, 2016July 23, 2016 by Ken Kremer

SpaceX Nails Mesmerizing Midnight Launch and Land Landing of Falcon 9 Carrying Critical ISS Science and Docking Port

A team of engineers from the University of Glasgow and the Ukraine have created an engine that could cut costs by "eating itself". Credit: Ken Kremer/kenkremer.com

SpaceX Falcon 9 launches and lands over Port Canaveral in this streak shot showing rockets midnight liftoff from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida at 12:45 a.m. EDT carrying Dragon CRS-9 craft to the International Space Station (ISS) with almost 5,000 pounds of cargo and docking port. View from atop Exploration Tower in Port Canaveral. Credit: Ken Kremer/kenkremer.com — SpaceX Falcon 9 launches and lands over Port Canaveral in this streak shot showing rockets midnight liftoff from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida at 12:45 a.m. EDT on July 18, 2016 carrying Dragon CRS-9 craft to the International Space Station (ISS) with almost 5,000 pounds of cargo and docking port. View from atop Exploration Tower in Port Canaveral. Credit: Ken Kremer/kenkremer.com

KENNEDY SPACE CENTER, FL – In a breathtaking feat mesmerizing hordes of thrilled spectators, SpaceX nailed today’s (July 18) back to back post midnight launch and landing of the firms Falcon 9 first stage tasked to carry a cargo Dragon loaded with over two tons of critical science, supplies and a crew docking port to the space station for NASA.

Liftoff of the SpaceX Falcon 9 rocket in its upgraded, full thrust version and the Dragon CRS-9 resupply ship took place right on time at 12:45 a.m. EDT Monday, July 18, from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida.

SpaceX simultaneously successfully delivered over 5000 pounds (2200 kg) of research supplies to orbit for NASA in a commercial cargo Dragon ship, as the primary mission goal – and soft landed the approximately 60,000 pound Falcon 9 first stage on land, as the experimental secondary mission goal.

“The Falcon 9 first stage we landed is in excellent shape,” Hans Koenigsmann, SpaceX vice president of Flight Reliability, told Universe Today at the 2 a.m. EDT post launch and landing media briefing early this morning.

See my launch and landing streak shot and photos herein, including deployment of the four landing legs in the final seconds before propulsive touchdown.

The twin accomplishments will have far reaching implications for the exploration and exploitation of space for all humanity.

“Each commercial resupply flight to the space station is a significant event. Everything, from the science to the spare hardware and crew supplies, is vital for sustaining our mission,” said Kirk Shireman, NASA’s International Space Station Program manager.

“With equipment to enable novel experiments never attempted before in space, and an international docking adapter vital to the future of U.S. commercial crew spacecraft, we’re thrilled this Dragon has successfully taken flight.”

The CRS-9 mission is to support the resident six-person crew of men and women currently working on the station from the US, Russia and Japan.

The propulsive soft landing of the 156 foot tall Falcon 9 first stage of the Falcon 9 rocket on land at Cape Canaveral Air Force Station’s Landing Zone 1, located a few miles south of launch pad 40.

The dramatic ground landing at LZ -1 took place about 9 minutes after liftoff.

Moments before dramatic touchdown of SpaceX Falcon 9 1st stage at Landing Zone-1 (LX-1) accompanied by sonic booms after launching Dragon CRS-9 supply ship to orbit from Cape Canaveral Air Force Station, Florida at 12:45 a.m., bound for the International Space Station (ISS). Credit: Ken Kremer/kenkremer.com

The first and second stages separated about two and a half minutes after liftoff and were easily visible to any eyewitness watching – backdropped by the sunshine states dark skies.

As the second stage soared to orbit, the first stage reignited a first stage engine for a series of burns targeting a return to the Cape.

We spotted the first engine firing about two mintues before landing, as it descended directly overhead of myself and everyone in the Cape Canaveral region.

For a few moments it looked like it was headed right towards us, but then steered away as planned with engines blazing to slow the boosters descent to make a gentle landing at LZ-1.

Finally the Falcon landed, obscured by a big vapor cloud and sonic booms roaring around the space coast – and waking many local residents. Several folks told me they were suddenly woken by the shocking booms reverberating inside their homes.

Some area residents even called 911 not knowing the true nature of the noises.

Streak shot of launch and landing of SpaceX Falcon CRS-9 mission from Cape Canaveral Air Force Station, Florida to the ISS on July 18, 2016 at 12:45 a.m. EDT. View from Satellite Beach, FL. Credit: John Krauss/johnkraussphotos.com

Among the wealth of over 3900 pounds (1790 kg) of research investigations loaded on board Dragon is an off the shelf instrument designed to perform the first-ever DNA sequencing in space, and the first international docking adapter (IDA) that is absolutely essential for docking of the SpaceX and Boeing built human spaceflight taxis that will ferry our astronauts to the International Space Station (ISS) in some 18 months.

Blastoff of SpaceX Falcon 9 on Dragon CRS-9 resupply mission to the International Space Station (ISS) at 12:45 a.m. EDT on July 18, 2016. Credit: Ken Kremer/kenkremer.com

CRS-9 counts as the company’s ninth scheduled flight to deliver supplies, science experiments and technology demonstrations to the International Space Station (ISS).

The CRS-9 mission is for the crews of Expeditions 48 and 49 to support dozens of the approximately 250 science and research investigations in progress under NASA’s Commercial Resupply Services (CRS) contract.

Dragon reached its preliminary orbit about 10 minutes after launch. Then it deployed a pair of solar arrays and began a carefully choreographed series of thruster firings to reach the space station.

If all goes well, Dragon is scheduled to arrive at the orbiting outpost on Wednesday, July 20, after a 2 day orbital chase.

NASA astronaut Jeff Williams will then reach out with the station’s 57.7-foot-long Canadian-built robotic arm to grapple and capture the private Dragon cargo ship working from a robotics work station in the station’s cupola. NASA astronaut Kate Rubins will serve as Williams backup. She just arrived at the station last week on July 9 for a minimum 4 month stay, after launching to orbit on a Russian Soyuz on July 6 with two additional crew mates.

Ground commands will be sent from Houston to the station’s arm to install Dragon on the Earth-facing bottom side of the Harmony module for its stay at the space station. The crew expects to open the hatch a day later after pressurizing the vestibule in the forward bulkhead between the station and Dragon.

Live coverage of the rendezvous and capture July 20 will begin at 5:30 a.m. on NASA TV, with installation coverage set to begin at 9:45 a.m.

CRS-9 marks only the second time SpaceX has attempted a land landing of the 15 story tall first stage booster.

The history making first time successfully took place at Landing Zone 1 (LZ 1) on Dec. 22, 2015 as part of the ORBCOMM-2 mission. Landing Zone 1 is built on the former site of Space Launch Complex 13, a U.S. Air Force rocket and missile testing range.

SpaceX also successfully recovered first stages three times in a row at sea this year on an ocean going drone ship barge using the company’s OCISLY Autonomous Spaceport Drone Ship (ASDS) on April 8, May 6 and May 27.

Altogether SpaceX has successfully landed and recovered 5 first stage booster intact and upright.

The International Docking Adapter-2 was tested in the Space Station Processing Facility prior to being loaded for launch into space on the SpaceX CRS-9 mission set for July 18, 2016 from Cape Canaveral, Fl. Credits: NASA — The International Docking Adapter-2 was tested in the Space Station Processing Facility prior to being loaded for launch into space on the SpaceX CRS-9 mission [set for July 18, 2016 from Cape Canaveral, Fl. Credits: NASA

Watch for Ken’s onsite CRS-9 mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.

Here’s my launch pad video of the blastoff:

Video caption: SpaceX Falcon 9 lifts off with Dragon CRS-9 resupply ship bound for the International Space Station on July 18, 2016 at 12:45 a.m. EDT from Space Launch Complex 40 at Cape Canaveral Air Force Station, Fl, as seen in this up close video from Mobius remote camera positioned at the pad. Credit: Ken Kremer/kenkremer.com

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

………….

Learn more about Juno at Jupiter, SpaceX CRS-9 rocket launch, ISS, ULA Atlas and Delta rockets, Orbital ATK Cygnus, Boeing, Space Taxis, Mars rovers, Orion, SLS, Antares, NASA missions and more at Ken’s upcoming outreach events:

July 18, 26-28: “SpaceX launches to ISS on CRS-9, Juno at Jupiter, ULA Delta 4 Heavy and Atlas V spy satellite launches, SLS, Orion, Commercial crew, Curiosity explores Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

An illustration of how the IDA will look when attached to the International Space Station. Credits: NASA — An illustration of how the IDA will look when attached to the International Space Station.
Credits: NASA

Up close view of SpaceX Dragon CRS-9 resupply ship and solar panels atop Falcon 9 rocket at pad 40 prior to blastoff to the ISS on July 18, 2016 from Cape Canaveral Air Force Station, Florida. Credit: Ken Kremer/kenkremer.com

July 18, 2016September 20, 2016 by Matt Williams

ROCKY Exercise Device Will Help Keep Deep Space A Fit Place

NASA has unveiled a new exercise device that will be used by Orion crews to stay healthy on their mission to Mars. Credit: NASA

Going into space comes with its share of risks. In addition to the possibility of a catastrophic failure happening during take-off or landing, and having your craft pinholed by a micrometeorite, there are also the dangers of spending extended periods in space. Beyond that, there are also the slow, degenerative effects that spending an extended amount of time in a weightless environment can have on your body.

While astronauts on the ISS have enough space for the work-out equipment they need to help reduce these effects (i.e. muscle degeneration and loss of bone density), long-range missions are another matter. Luckily, NASA has plans for how astronauts can stay healthy during their upcoming “Journey to Mars“. It’s known as the Resistive Overload Combined with Kinetic Yo-Yo (ROCKY) device, which will be used aboard the Orion spacecraft.

For years, engineers at NASA and in the private sector have been working to create the components that will take astronauts to the Red Planet in the 2030s. These include the Space Launch System (SLS) and the Orion Multi Purpose Crew Capsule. At the same time, scientists and engineers at the Ohio-based Zin Technologies company – with the support of the NASA Human Research Program’s Exploration Exercise Equipment project – were busy developing the equipment needed to keep the Martian crews healthy and fit in space.

In this cutaway of the Orion crew module, the ROCKY exercise device in blue sits below the side hatch astronauts will use to get in and out of the spacecraft. Credit: NASA — *Cutaway of the Orion crew module, showing the ROCKY exercise device in blue, below the side hatch that astronauts will use to get in and out of the spacecraft. Credit: NASA*

One of the biggest challenges was making a device that is robust enough to provide a solid work-out, but still be compact and light-weight enough to fit inside the space capsule. What they came up with was ROCKY, a rowing machine-like tool that can accommodate both aerobic activity and strength training. Using loads that simulate up to 180 kg (400 pounds) of resistance, astronauts will be able to perform excises like squats, deadlifts and heel raises, as well as upper body exercises like bicep curls and upright rows.

In the past, astronauts aboard the ISS have relied on equipment like the Mini Exercise Device-2 or the Treadmill Vibration Isolation System (TVIS) to reduce the risks of bone-density loss and muscle degeneration. But as Gail Perusek – the deputy project manager for NASA’s Exploration Exercise Equipment project – explained, developing exercise equipment for the Journey to Mars required something new:

“ROCKY is an ultra-compact, lightweight exercise device that meets the exercise and medical requirements that we have for Orion missions. The International Space Station’s exercise devices are effective but are too big for Orion, so we had to find a way to make exercising in Orion feasible.”

The device can also be customized, and incorporates the best features from a second device known as the Device for Aerobic and Resistive Training (DART). These include a servo-motor programmed to deliver a load profile that feels very similar to free weights. The DART was developed by TDA Research, a Denver-based R&D company, with the support of NASA’s Small Business Innovation Research Program. It was evaluated alongside the ROCKY during the equipment selection process.

*The ROCKY device in action. Credit: NASA*

In addition to being used for the crewed mission to Mars, the ROCKY device is likely to become a permanent feature aboard the Orion capsule, which will make it a mainstay for all of NASA’s proposed long-duration missions.

As Cindy Haven, the project manager for the Exploration Exercise Equipment Project, explained: “Our long-term goal is to develop a device that’s going to work for us for exploration. Between now and the mission, we’ll have different phases where we’re going to evaluate it for functionality, usability and durability to refine its design.”

The ROCKY device will be tested for the first time on Exploration Mission-2 (EM-2), the first mission where the spacecraft will be launched with a crew aboard. Th ROCKY will be located near the side hatch of the spacecraft, which astronauts will use to get in and out of the capsule. After the Orion is launched, the crew’s seats will be collapsed to provide more interior space for the astronauts as they work out.

And while the early missions using the Orion capsule will span only a few weeks at a time, staying fit will be important in the unlikely event that the astronauts need to get out of the crew module unassisted after splashdown. In the meantime, NASA will be spending the next few years refining the device to optimize it not only for near-term crewed Orion missions, but for potential uses on future long-duration missions.

These will include the all-important launch where the Orion will dock with a habitat in the area of space around the moon. These missions are part of Phase II of NASA’s Mars mission, which is known as the “Proving Ground” phase. Scheduled to begin in 2030, this phase will involve the last elements of the mission being launched to cis-lunar orbit, and then all the equipment being sent to near-Mars space for pre-deployment.

The development team that will oversee future refinements will include engineers and scientists from Glenn Research Center in Cleveland, Ohio, and Johnson Space Center in Houston. In addition to building the hardware and ensuring that it is certified for flight, they will also be responsible for incorporating lessons learned from the development of equipment built for the ISS.

If all goes well in the coming years, the team even plans to include ROCKY into the International Space Station’s already impressive array of workout machines. Just another way for the astronauts to beat the slow, degenerative effects of floating freely in space!

Further Reading: NASA

July 18, 2016July 18, 2016 by Tammy Plotner

Messier 19 (M19) – The NGC 6273 Globular Cluster

Messier Object 19, as imaged with an amateur telescope.Credit: Hewholooks/Wikipedia Commons

Welcome back to Messier Monday! In our ongoing tribute to the great Tammy Plotner, we take a look at the Messier 19 globular star cluster. Enjoy!

In the 18th century, while searching the night sky for comets, French astronomer Charles Messier began noticing a series of “nebulous objects” in the night sky. Hoping to ensure that other astronomers did not make the same mistake, he began compiling a list of these objects,. Known to posterity as the Messier Catalog, this list has come to be one of the most important milestones in the research of Deep Sky objects.

One of these objects is Messier 19, a globular star cluster located in the constellation Ophiuchus. Of all the known globular clusters, M19 appears to be one of the most oblate (i.e. flattest) in the night sky. Discovered by William Herschel, this cluster is relatively difficult to spot with the naked eye, and appears as a fuzzy point of light with the help of magnification.

Description:

Speeding away from us at a rate of 146 kilometers per second, this gravitationally bound ball of stars measuring 140 light years in diameter, is one of the Messier globular clusters that has the distinction of being closest to the center of the Milky Way. At a little more than 5000 light-years from the intense gravitation of our own galactic core, it has played havoc on M19’s round shape.

In essence, Milky Way’s gravity has caused M19 to become one of the most oblate of all globular clusters, with twice as many stars along the major axis as along the minor. And, although it is 28,000 light-years from Earth, it’s actually on the opposite side of the galactic core. For all of its rich, dense mass, four RR Lyrae variable stars have been found in M19.

*The constellation Ophiuchis. Credit: iau.org*

Is Messier 19 unique? It has some stellar branch properties that are difficult to pinpoint. And even its age (though estimated at around 11.9 billion years old) is indeterminate. Says F. Meissner and A. Weiss in their 2006 study, “Global fitting of globular cluster age indicators“:

“The determination of globular cluster (GC) ages rests on the fact that colour-magnitude diagrams (CMDs) of single-age single composition stellar populations exhibit specific time-dependent features. Most importantly, this is the location of the turn-off (TO), which – together with the cluster’s distance – serves as the most straightforward and widely used age indicator. However, there are other parts of the CMD that change their colour or brightness with age, too. Since the sensitivity to time is different for the various parts of the cluster CMD, it is possible to use either the various indicators independently, or the differences in colour and brightness between pairs of them; these latter methods have the advantage of being independent of distance.”

What’s occurring is a horizontal branch gap – an not-quite explainable difference in the way the stars inside M19 are aging. However, science is looking for the answer. As G. Busso et al. explained in their 2008 paper titled “The Peculiar Horizontal Branch Morphology of the Galactic Globular Clusters NGC 6388 and NGC 6441“:

“I show that a possible solution of the puzzle is to assume that a small fraction of the stellar population in the two clusters is strongly helium enriched. The presence of two distinct stellar populations characterized by two different initial He contents can help in explaining the brightness difference between the red portion of the HB and the blue component.”

*The Messier 19 globular cluster, as viewed by the Two Micron All-Sky Survey (2MASS). Credit: 2MASS/ipac.caltech.edu*

Is helium the answer? Quite probably so. M. Salaris Astrophysics Research Institute and an international team of researchers explained in their 2004 study “The initial helium abundance of the Galactic globular cluster system“:

“Based on a recently updated set of stellar evolution models, we performed an accurate statistical analysis in order to assess whether GGCs show a statistically significant spread in their initial He abundances, and whether there is a correlation with the cluster metallicity. As in previous works on the subject, we do not find any significant dependence of the He abundance on the cluster metallicity; this provides an important constraint for models of Galaxy formation and evolution. Apart from GGCs with the bluest Horizontal Branch morphology, the observed spread in the individual helium abundances is statistically compatible with the individual errors. This means that either there is no intrinsic abundance spread among the GGCs, or that this is masked by the errors. In the latter case we have estimated a firm upper limit of 0.019 to the possible intrinsic spread. In case of the GGCs with the bluest Horizontal Branch morphology we detect a significant spread towards higher abundances inconsistent with the individual errors; this can be fully explained by additional effects not accounted for in our theoretical calibrations, which do not affect the abundances estimated for the clusters with redder Horizontal Branch morphology.”

History of Observation:

M19 was one of Charles Messier’s original discoveries, which he first observed on June 5th, 1764. In his notes, he wrote:

“I have discovered a nebula, situated on the parallel of Antares, between Scorpius and the right foot of Ophiuchus: that nebula is round & doesn’t contain any star; I have examined it with a Gregorian telescope which magnified 104 times, it is about 3 minutes of arc in diameter: one sees it very well with an ordinary refractor of 3 feet and a half. I have observed its passage of the Medirian, and compared it with that of the star Antares; I have determined the right ascension of that nebula of 252d 1′ 45″, and its declination of 25d 54′ 46″ south. The known star closest to that nebula is the 28th of the constellation Ophiuchus, after the catalog of Flamsteed, of sixth magnitude.”

Messier 19 and Antares. Credit: Wikisky — *The Messier 19 globular cluster, relative to M4, M80 and Antares. Credit: Wikisky*

While Charles didn’t resolve it, we must give him due credit for discovery, for its size wouldn’t make it a particularly easy object given his optics. Later, in 1784, William Herschel would become the first to open up its true identity:

“When the 19th of the Connoiss. is viewed with a magnifying power of 120, the stars are visible; the cluster is insulated; some of the small stars scattered in the neighborhood are near it; but they are larger than those belonging to the cluster. With 240 it is better resolved, and is much condensed in the centre. With 300 no nucleus or central body can be seen. The diameter with the 10 feet is 3’16”, and the stars in the centre are too accumulated to be separately seen. It will not be necessary to add that the two last mentioned globular clusters, viewed with more powerful instruments, are of equal beauty with the rest; and from what has been said it is obvious that here the exertion of a clustering power has brought the accumulation and artificial construction of these wonderful celestial objects to the highest degree of mysterious perfection.”

While you may – or may not – resolve Messier 19’s individual stars, even small telescopes can pick up on some of its ellipticity and larger telescopes will make out a definite blue tinge to its coloration. Before you yawn at viewing another globular cluster, remember that you are looking at the other side of our galactic center and think on the words about M19 from Admiral Symth.

“The whole vicinity,” he wrote, “afford a grand conception of the grandeur and richness even of the exterior creation; and indicate the beautious gradation and variety of the heaven of heavens. Truly has it been said, “Stars teach us as well as shine.” This is near the large opening or hole, about 4deg broad, in the Scorpion’s body, which WH [William Herschel] found almost destitute of stars.”

en:Messier 19 globular cluster by en:Hubble Space Telescope; 2.5? view en:NASA, en:STScI, en:WikiSky - en:WikiSky's — *The Messier 19 globular cluster, as imaged by the Hubble Space Telescope. Credit:NASA/STSc /HST/WikiSky*

Locating Messier 19:

Finding M19’s location in binoculars is quite easy – it’s less than a fistwidth (8 degrees) east of Antares (Alpha Scorpi). However, ‘seeing’ M19 in binoculars (especially smaller ones) is a little more problematic. The steadier the binoculars are, the better your chances, since it will appear almost stellar at first glance. A good indicator is to have optical double 26 Ophiuchi in the field at the 2:00 position and look for the star that won’t quite come to focus in the 8:00 position.

Star 26 also makes for a great finderscope lead when locating M19 in a telescope as well. Even for aperture sizes as small as 114mm, this globular cluster will show quite easily in a telescope and reveal its oblate nature. When aperture size increase to the 8″ range, it will begin resolution and as it nears 12″ or more, you’ll pick up on blue stars.

And for your convenience, here are the quick facts of M19:

Object Name: Messier 19
Alternative Designations: M19, NGC 6273
Object Type: Class VIII Globular Star Cluster
Constellation: Ophiuchus
Right Ascension: 17 : 02.6 (h:m)
Declination: -26 : 16 (deg:m)
Distance: 28.0 (kly)
Visual Brightness: 6.8 (mag)
Apparent Dimension: 17.0 (arc min)

We have written many interesting articles about Messier Objects here at Universe Today. Here’s Tammy Plotner’s Introduction to the Messier Objects, , M1 – The Crab Nebula, M8 – The Lagoon Nebula, and David Dickison’s articles on the 2013 and 2014 Messier Marathons.

Be to sure to check out our complete Messier Catalog. And for more information, check out the SEDS Messier Database.

July 17, 2016July 17, 2016 by Bob King

We’re Finally Sending Ears to Mars

Be patient. We'll soon be hearing from Mars. Left: Wikipedia CC BY-SA 3.0; right: NASA/JPL-Caltech

The Curiosity rover took this photo of the Martian landscape on July 12, 2016. Imagine if we could listen to it at the same time. NASA now plans to include a microphone on the upcoming Mars 2020 Mission. Credit: NASA/JPL-Caltech — The Curiosity rover took this photo of the Martian landscape on July 12, 2016. Imagine if we could hear the wind passing by. We will soon. NASA plans to include a microphone on the upcoming Mars 2020 Mission. Credit: NASA/JPL-Caltech

We all love that feeling of “being there” when it comes to missions to other planets. Juno’s arrival at Jupiter, New Horizons’ flyby of Pluto and the daily upload of raw images from the Mars Curiosity rover makes each of us an armchair explorer of alien landscapes. But there’s always been something missing. Something essential in shaping our environment — sound.

The microphone selected for the Mars 2020 Mission would be mounted It would be mounted on a tiny tube that protrudes from the warm electronics box, on the bracket that holds the window for the SuperCam instrument. Credit: S. Mauric et. all, 47th Lunar and Planetary Science Conference

NASA recently gave the go-ahead for the Mars 2020 rover that will bristle with a new suite of science instruments including a microphone. Hallelujah! Finally, we’ll get to listen to the sound of the Martian wind, the occasional whirl of dust devils, the crunch of rocks beneath the rover’s wheels and even sharp pops from laser-zapped rocks!

These photos show the microphones used in two earlier missions. Neither was ever used. On left, the Mars Descent Imager and microphone for the Phoenix lander; right, the device for the failed Mars Polar Lander. Credit: NASA/JPL-Caltech — Microphones were included on two earlier missions but never used. On left, the Mars Descent Imager and microphone for the Phoenix lander; right, the device for the failed Mars Polar Lander mission. Credit: NASA/JPL-Caltech

The staff and membership of The Planetary Society have been trying for 20 years to get a working microphone to the Red Planet. One flew aboard NASA’s Mars Polar Lander mission in 1998 but that probe crashed landed when its engine shut down prematurely during the descent phase. In 2008 the Society partnered with Malin Space Science Systems to include its next microphone in the descent imager package on the Mars Phoenix lander in 2008. While that mission was successful, the imager (along with its microphone) was turned off for fear it might cause an electrical problem with a critical landing system. Mission planners hoped it might be turned on later but whether it was a money issue or fear of shorting out other critical lander instruments, it never happened. Heartbreaking.

One sound souvenir we did get from Phoenix comes to us from the European Space Agency’s Mars which recorded the radio transmissions from the lander as it descended. The signals were then processed into audio within the range of human hearing. Give a listen, there’s a music to it.

The microphone for the upcoming Mars mission will be attached to the SuperCam, seen here in this illustration zapping a rock with its laser. Credit: NASA/JPL-Caltech — The microphone for the upcoming Mars mission will be attached to the rover’s SuperCam, seen here in this illustration zapping a rock with its laser. Credit: NASA/JPL-Caltech

The Mars 2020 mission, which is expected to launch in the summer of 2020 and land the following February, will search directly for signs of ancient Martian life as well as identify and cache samples and specimens at several locations on the surface for pick-up by later missions. The microphone would be housed with the rover’s SuperCam, a souped-up version of Curiosity’s ChemCam, which fires a laser at rocks and soils from a distance to analyze the resulting vapors for their elemental composition.

SuperCam will also shoot a laser to vaporize rocks and spectroscopy to tease out their molecular and mineral composition. The microphone would be mounted on a tube sticking out of the electronics box housing SuperCam and used for scientific purposes but I suspect for public outreach as well. One of its more intriguing uses will be to record the ‘snap’ or ‘pop’ when a rock is struck with the laser. Based on the volume of the sound, scientists can estimate the specimen’s mass.

NASA plans to land the 1-ton rover using the same sky crane method that settled Curiosity to the surface in dramatic fashion. While the rover will be busy photographing the entry, descent and landing sequence, the microphone will record the ambient sound. Synched together, this should make for one of the most compelling videos ever!

A beautiful dust devil recorded by NASA's Opportunity rover. Wouldn't it be wonderful to hear it at the same time as viewing the photo? Credit: NASA/JPL-Caltech/James Sorenson — A tall, beautiful dust devil recorded by NASA’s Opportunity rover. Wouldn’t it be wonderful to hear it at the same time as viewing the photo? Credit: NASA/JPL-Caltech/James Sorenson

The microphone will also be used to augment studies of Martian weather (the aforementioned winds and dust devils) and listen to the rover’s creaks, groans and whir of its motors as the car-sized machine rolls across the alternately sandy and rocky surface of Mars. The Planetary Society is collaborating with the SuperCam team to make the most of the microphone. Who knows what else we might hear? Exploding fireball overhead? Static electricity? Rhythmic winds? Blowing sand? Slime-slap of alien pseudopods? OK, probably not the last one, but new instruments often reveal completely unexpected phenomena.

It’s been hard as hell getting a microphone on a space mission. They’ve had to compete with other instruments considered more essential not to mention the precious space the device would take up and the burden of additional mass. Mission planners consider every fraction of a gram when building a space probe because getting it into Earth orbit and blasting it to a planet takes energy. Rockets only hold so much fuel!

Your Voice on Mars

You might wonder if Mars’ atmosphere is thick enough to carry sound. The good news is that it is, but unlike Earth’s much denser nitrogen-oxygen mix, Martian air is 100 times thinner and composed of 95% carbon dioxide. If you could snap off your helmet and talk out loud on the Red Planet, your voice would sound deeper and not travel as far. Scientists liken it to having a conversation at 100,000 feet (30,500 meters) above Earth’s surface. Check out the crazy video for a simulation.

Now that you’ve made it to the end of this story, sit back and pump up the volume. We’ll have ears on Mars soon!

Pump Up the Volume by M|A|R|R|S

July 16, 2016July 17, 2016 by Ken Kremer

SpaceX Midnight Launch Carrying Crucial Docking Port and Science to ISS Set for July 18, Plus Loud Land Landing – Watch Live

SpaceX conducts Falcon 9 Dragon CRS-9 mission static fire test ahead of planned 18 July 2016 liftoff from Cape Canaveral Air Force Station in Florida at 12:45 a.m. EDT. View from atop Launch Complex 39B at the Kennedy Space Center. Credit: Ken Kremer/kenkremer.com

KENNEDY SPACE CENTER, FL – The outlook is outstanding for a dramatic midnight blastoff of the next SpaceX commercial cargo Dragon jam packed with some 5000 pounds of critical payloads and research supplies for NASA and heading to the space station on Monday, July 18 – that also simultaneously features an experimental land landing that promises to rock loudly across the Florida space coast and one day slash launch costs.

Dragon is carrying a crucial crew docking port absolutely essential for conducting future human space missions to the orbiting outpost as well as a host of wide ranging science experiments essential for NASA exploiting the space environment for research in low earth orbit and deep space exploration.

Liftoff of the SpaceX Falcon 9 rocket in its upgraded, full thrust version and the Dragon CRS-9 resupply ship is targeted for 12:45 a.m. EDT Monday, July 18, from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida.

The CRS-9 mission is to support the resident six-person crew of men and women currently working on the station from the US, Russia and Japan.

Spectators are filling local area hotels in anticipation of a spectacular double whammy sky show comprising a thunderous nighttime launch streaking to orbit – followed minutes later by a brilliant rocket flash and night landing back at the Cape of the Falcon first stage that will send sonic booms roaring all around the coast and surrounding inland areas.

SpaceX has confirmed they are attempting the secondary mission of landing the 156 foot tall first stage of the Falcon 9 rocket on land at Cape Canaveral Air Force Station’s Landing Zone 1, located a few miles south of launch pad 40.

The weather and technical outlook for the 229 foot-tall (70 meter) Falcon 9 looks fantastic at this time, a day before liftoff.

The official weather forecast from Air Force meteorologists with the 45th Space Wing calls for a 90 percent chance of “GO” with extremely favorable conditions at launch time for liftoff of this upgraded, SpaceX Falcon 9.

The only concerns are for Cumulus clouds building up and a chance of precipitation.

And for added stargazers delight the night sky features a full moon.

The SpaceX/Dragon CRS-9 launch coverage will be broadcast on NASA TV beginning at 11:30 p.m. EDT Sunday, July 17, with additional commentary on the NASA launch blog.

SpaceX will also feature their own live webcast beginning approximately 20 minutes before launch at 12:25 a.m. EDT Monday, July 18

You can watch the launch live at NASA TV at – http://www.nasa.gov/nasatv

You can watch the launch live at SpaceX Webcast at – spacex.com/webcast

The launch window is instantaneous, meaning that any delays due to weather or technical issues will results in a minimum 2 day postponement.

If the launch does not occur Monday, a backup launch opportunity exists on 12 a.m. Wednesday, July 20, just seconds after midnight, with NASA TV coverage starting at 10:45 p.m. EDT Tuesday, July 19.

View of International Docking Adapter 2 (IDA-2) being processed inside the Space Station Processing Facility (SSPF) at NASA Kennedy Space Center for eventual launch to the ISS in the trunk of a SpaceX Dragon on the CRS-9 mission. It will be connected to the station to provide a port for Commercial Crew spacecraft carrying astronauts to dock to the orbiting laboratory as soon as 2017. The identical IDA-1 was destroyed during SpaceX CRS-7 launch failure on June 28, 2015. Credit: Ken Kremer/kenkremer.com

CRS-9 marks only the second time SpaceX has attempted a land landing of the 15 story tall first stage booster.

The history making first time took place at Landing Zone 1 (LZ 1) on Dec. 22, 2015 as part of the ORBCOMM-2 mission. Landing Zone 1 is built on the former site of Space Launch Complex 13, a U.S. Air Force rocket and missile testing range.

SpaceX issued a statement describing how local area residents could hear sonic booms – similar to those heard during landings of NASA’s space shuttles.

“There is the possibility that residents of northern and central Brevard County, Fla. may hear one or more sonic booms during landing. A sonic boom is a brief thunder-like noise a person on the ground hears when an aircraft or other vehicle flies overhead faster than the speed of sound,” said SpaceX.

Who could be affected?

“Residents of the communities of Cape Canaveral, Cocoa, Cocoa Beach, Courtenay, Merritt Island, Mims, Port Canaveral, Port St. John, Rockledge, Scottsmoor, Sharpes, and Titusville in Brevard County, Fla. are most likely to hear a sonic boom, although what residents experience will depend on weather conditions and other factors.”

The sights and sound are certain to be thrilling- so catch it if you can!

CRS-9 counts as the company’s ninth scheduled flight to deliver supplies, science experiments and technology demonstrations to the International Space Station (ISS).

SpaceX engineers conducted their standard static fire hold down test of the first stages Merlin 1D engines with the rocket erect at pad 40, this morning Saturday, July 16.

The customary test lasts a few seconds and was conducted with the Dragon bolted on top at about 9:30 a.m. I saw the test while visiting atop neighboring Launch Complex 39B at the Kennedy Space Center – see photo.

“All looks good,” reported Hans Koenigsmann, SpaceX vice president of Flight Reliability, at a media briefing this afternoon.

“We expect a GO for launch.”

Dragon will reach its preliminary orbit about 10 minutes after launch. Then it will deploy its solar arrays and begin a carefully choreographed series of thruster firings to reach the space station.

If all goes well, Dragon will arrive at the orbiting outpost on Wednesday, July 20, after a 2 day orbital chase.

Live coverage of the rendezvous and capture July 20 will begin at 5:30 a.m. on NASA TV, with installation coverage set to begin at 9:45 a.m.

Perhaps the most critical payload relating to the future of humans in space is the 1,020-pound international docking adapter known as IDA-2 or International Docking Adapter-2.

Here’s an early morning video view of Falcon 9 on the pad today.

Video Caption: Early morning shots of CRS-9 ready for flight on Monday July 18 at 12:45 AM. Credit: USLaunchReport

Watch for Ken’s onsite CRS-9 mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

………….

July 15-18: “SpaceX launches to ISS on CRS-9, Juno at Jupiter, ULA Delta 4 Heavy spy satellite, SLS, Orion, Commercial crew, Curiosity explores Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

Former astronaut Bob Cabana, director of NASA's Kennedy Space Center in Florida, surveys the IDA-2 inside the Space Station Processing Facility. Credits: NASA — Former astronaut Bob Cabana, director of NASA’s Kennedy Space Center in Florida, surveys the IDA-2 inside the Space Station Processing Facility. Credits: NASA

SpaceX Dragon CRS-9 mission logo. Credit: SpaceX

July 15, 2016September 20, 2016 by Matt Williams

Dark Energy Illuminated By Largest Galactic Map Ten Years In The Making

A section of the 3D map constructed by BOSS. The rectangle on the far left shows a cutout of 1000 sq. degrees in the sky containing nearly 120,000 galaxies, or roughly 10% of the total survey. Credit: Jeremy Tinker/SDSS-III

In 1929, Edwin Hubble forever changed our understanding of the cosmos by showing that the Universe is in a state of expansion. By the 1990s, astronomers determined that the rate at which it is expanding is actually speeding up, which in turn led to the theory of “Dark Energy“. Since that time, astronomers and physicists have sought to determine the existence of this force by measuring the influence it has on the cosmos.

The latest in these efforts comes from the Sloan Digital Sky Survey III (SDSS III), where an international team of researchers have announced that they have finished creating the most precise measurements of the Universe to date. Known as the Baryon Oscillation Spectroscopic Survey (BOSS), their measurements have placed new constraints on the properties of Dark Energy.

The new measurements were presented by Harvard University astronomer Daniel Eisenstein at a recent meeting of the American Astronomical Society. As the director of the Sloan Digital Sky Survey III (SDSS-III), he and his team have spent the past ten years measuring the cosmos and the periodic fluctuations in the density of normal matter to see how galaxies are distributed throughout the Universe.

An illustration of the concept of baryon acoustic oscillations, which are imprinted in the early universe and can still be seen today in galaxy surveys like BOSS (Illustration courtesy of Chris Blake and Sam Moorfield). — *An illustration of baryon acoustic oscillations, which are imprinted in the early universe and can still be seen today in galaxy surveys like BOSS. Credit: Chris Blake and Sam Moorfield*

And after a decade of research, the BOSS team was able to produce a three-dimensional map of the cosmos that covers more than six billion light-years. And while other recent surveys have looked further afield – up to distances of 9 and 13 billion light years – the BOSS map is unique in that it boasts the highest accuracy of any cosmological map.

In fact, the BOSS team was able to measure the distribution of galaxies in the cosmos, and at a distance of 6 billion light-years, to within an unprecedented 1% margin of error. Determining the nature of cosmic objects at great distances is no easy matter, due the effects of relativity. As Dr. Eisenstein told Universe Today via email:

“Distances are a long-standing challenge in astronomy. Whereas humans often can judge distance because of our binocular vision, galaxies beyond the Milky Way are much too far away to use that. And because galaxies come in a wide range of intrinsic sizes, it is hard to judge their distance. It’s like looking at a far-away mountain; one’s judgement of its distance is tied up with one’s judgement of its height.”

In the past, astronomers have made accurate measurements of objects within the local universe (i.e. planets, neighboring stars, star clusters) by relying on everything from radar to redshift – the degree to which the wavelength of light is shifted towards the red end of the spectrum. However, the greater the distance of an object, the greater the degree of uncertainty.

An artist's concept of the latest, highly accurate measurement of the Universe from BOSS. The spheres show the current size of the "baryon acoustic oscillations" (BAOs) from the early universe, which have helped to set the distribution of galaxies that we see in the universe today. Galaxies have a slight tendency to align along the edges of the spheres — the alignment has been greatly exaggerated in this illustration. BAOs can be used as a "standard ruler" (white line) to measure the distances to all the galaxies in the universe. Credit: Zosia Rostomian, Lawrence Berkeley National Laboratory — *An artist’s concept of the latest, highly accurate measurement of the Universe from BOSS. Credit: Zosia Rostomian/Lawrence Berkeley National Laboratory*

And until now, only objects that are a few thousand light-years from Earth – i.e. within the Milky Way galaxy – have had their distances measured to within a one-percent margin of error. As the largest of the four projects that make up the Sloan Digital Sky Survey III (SDSS-III), what sets BOSS apart is the fact that it relies primarily on the measurement of what are called “baryon acoustic oscillations” (BAOs).

These are essentially subtle periodic ripples in the distribution of visible baryonic (i.e. normal) matter in the cosmos. As Dr. Daniel Eisenstein explained:

“BOSS measures the expansion of the Universe in two primary ways. The first is by using the baryon acoustic oscillations (hence the name of the survey). Sound waves traveling in the first 400,000 years after the Big Bang create a preferred scale for separations of pairs of galaxies. By measuring this preferred separation in a sample of many galaxies, we can infer the distance to the sample.

“The second method is to measure how clustering of galaxies differs between pairs oriented along the line of sight compared to transverse to the line of sight. The expansion of the Universe can cause this clustering to be asymmetric if one uses the wrong expansion history when converting redshifts to distance.”

With these new, highly-accurate distance measurements, BOSS astronomers will be able to study the influence of Dark Matter with far greater precision. “Different dark energy models vary in how the acceleration of the expansion of the Universe proceeds over time,” said Eisenstein. “BOSS is measuring the expansion history, which allows us to infer the acceleration rate. We find results that are highly consistent with the predictions of the cosmological constant model, that is, the model in which dark energy has a constant density over time.”

An international team of researchers have produced the largest 3-D map of the universe to date, which validates Einstein's theory of General Relativity. Credit: NAOJ/CFHT/ SDSS — *Discerning the large-scale structure of the universe, and the role played by Dark Energy, is key to unlocking its mysteries. Credit: NAOJ/CFHT/ SDSS*

In addition to measuring the distribution of normal matter to determine the influence of Dark Energy, the SDSS-III Collaboration is working to map the Milky Way and search for extrasolar planets. The BOSS measurements are detailed in a series of articles that were submitted to journals by the BOSS collaboration last month, all of which are now available online.

And BOSS is not the only effort to understand the large-scale structure of our Universe, and how all its mysterious forces have shaped it. Just last month, Professor Stephen Hawking announced that the COSMOS supercomputing center at Cambridge University would be creating the most detailed 3D map of the Universe to date.

Relying on data obtained by the CMB data obtained by the ESA’s Planck satellite and information from the Dark Energy Survey, they also hope to measure the influence Dark Energy has had on the distribution of matter in our Universe. Who knows? In a few years time, we may very well come to understand how all the fundamental forces governing the Universe work together.

Further Reading: SDSIII

July 15, 2016September 20, 2016 by Evan Gough

A Dark Region Is Growing Eerily On The Sun’s Surface

NASA's Solar Dynamics Observatory has captured images of a growing dark region on the surface of the Sun. Called a coronal hole, it produces high-speed solar winds that can disrupt satellite communications. Image: Solar Dynamics Observatory / NASA

NASA has spotted an enormous black blotch growing on the surface of the Sun. It looks eerie, but this dark region is nothing to fear, though it does signal potential disruption to satellite communications.

The dark region is called a coronal hole, an area on the surface of the Sun that is cooler and less dense than the surrounding areas. The magnetic fields in these holes are open to space, which allows high density plasma to flow out into space. The lack of plasma in these holes is what makes them appear dark. Coronal holes are the origin of high-speed solar winds, which can cause problems for satellite communications.

The images were captured by the Solar Dynamics Observatory (SDO) on July 11th. Tom Yulsman at Discover’s ImaGeo blog created a gif from several of NASA’s images.

High-speed solar winds are made up of solar particles which are travelling up to three times faster than the solar wind normally does. Though satellites are protected from the solar wind, extremes like this can still cause problems.

Coronal holes may look like a doomsday warning; an enormous black hole on the surface of our otherwise placid looking Sun is strange looking. But these holes are a part of the natural life of the Sun. And anyway, they only appear in extreme ultraviolet and x-ray wavelengths.

The holes tend to appear at the poles, due to the structure of the Sun’s magnetosphere. But when they appear in more equatorial regions of the Sun, they can cause intermittent problems, as the high-speed solar wind they generate is pointed at the Earth as the Sun rotates.

In June 2012, a coronal hole appeared that looked Big Bird from Sesame Street.

The "Big Bird" coronal hole appeared on the Sun in June 2012. It caused a powerful storm that was considered a near miss for Earth. Image: NASA/AIA — The “Big Bird” coronal hole appeared on the Sun in June 2012. It was the precursor to a powerful storm that was considered a near miss for Earth. Image: NASA/AIA

The Big Bird hole was the precursor to an extremely powerful solar storm, the most powerful one in 150 years. Daniel Baker, of the University of Colorado’s Laboratory of Atmospheric and Space Physics, said of that storm, “If it had hit, we would still be picking up the pieces.” We were fortunate that it missed us, as these enormous storms have the potential to damage power grids on the surface of the Earth.

It seems unlikely that any solar wind that reaches Earth as a result of this current coronal hole will cause any disruption to us here on Earth. But it’s not out of the question. In 1989 a solar storm struck Earth and knocked out power in the province of Quebec in Canada.

It may be that the only result of this coronal hole, and any geomagnetic storms it creates, are more vivid auroras.

Those are something everyone can appreciate and marvel at. And you don’t need an x-ray satellite to see them.