Universe Today

November 10, 2016November 21, 2016 by Matt Williams

Was Physics Really Violated By EM Drive In “Leaked” NASA Paper?

A model of the EmDrive, by NASA/Eagleworks. Credit: NASA Spaceflight Forum/emdrive.com

Ever since NASA announced that they had created a prototype of the controversial Radio Frequency Resonant Cavity Thruster (aka. the EM Drive), any and all reported results have been the subject of controversy. And with most of the announcements taking the form of “leaks” and rumors, all reported developments have been naturally treated with skepticism.

And yet, the reports keep coming. The latest alleged results come from the Eagleworks Laboratories at the Johnson Space Center, where a “leaked” report revealed that the controversial drive is capable of generating thrust in a vacuum. Much like the critical peer-review process, whether or not the engine can pass muster in space has been a lingering issue for some time.

Given the advantages of the EM Drive, it is understandable that people want to see it work. Theoretically, these include the ability to generate enough thrust to fly to the Moon in just four hours, to Mars in 70 days, and to Pluto in 18 months, and the ability to do it all without the need for propellant. Unfortunately, the drive system is based on principles that violate the Conservation of Momentum law.

Aerial Photography of Johnson Space Center site and facilities. Credit: NASA/James Blair — *Aerial photograph of NASA’s Johnson Space Center, where the Eagleworks Laboratory is located. Credit: NASA/James Blair*

This law states that within a system, the amount of momentum remains constant and is neither created nor destroyed, but only changes through the action of forces. Since the EM Drive involves electromagnetic microwave cavities converting electrical energy directly into thrust, it has no reaction mass. It is therefore “impossible”, as far as conventional physics go.

The report, titled “Measurement of Impulsive Thrust from a Closed Radio Frequency Cavity in Vacuum“, was apparently leaked in early November. It’s lead author is predictably Harold White, the Advanced Propulsion Team Lead for the NASA Engineering Directorate and the Principal Investigator for NASA’s Eagleworks lab.

As he and his colleagues (allegedly) report in the paper, they completed an impulsive thrust test on a “tapered RF test article”. This consisted of a forward and reverse thrust phase, a low thrust pendulum, and three thrust tests at power levels of 40, 60 and 80 watts. As they stated in the report:

“It is shown here that a dielectrically loaded tapered RF test article excited in the TM212 mode at 1,937 MHz is capable of consistently generating force at a thrust level of 1.2 ± 0.1 mN/kW with the force directed to the narrow end under vacuum conditions.”

Ionic propulsion is currently the slowest, but fmost fuel-efficient, form of space travel. Credit: NASA/JPL — *Ionic propulsion is currently the slowest, but most fuel-efficient, form of space travel. Credit: NASA/JPL*

To be clear, this level of thrust to power – 1.2. millinewtons per kilowatt – is quite insignificant. In fact, the paper goes on to place these results in context, comparing them to ion thrusters and laser sail proposals:

“The current state of the art thrust to power for a Hall thruster is on the order of 60 mN/kW. This is an order of magnitude higher than the test article evaluated during the course of this vacuum campaign… The 1.2 mN/kW performance parameter is two orders of magnitude higher than other forms of ‘zero propellant’ propulsion such as light sails, laser propulsion and photon rockets having thrust to power levels in the 3.33-6.67 [micronewton]/kW (or 0.0033 – 0.0067 mN/kW) range.”

Currently, ion engines are considered the most fuel-efficient form of propulsion. However, they are notoriously slow compared to conventional, solid-propellant thrusters. To offer some perspective, NASA’s Dawn mission relied on a xenon-ion engine that had a thrust to power generation of 90 millinewtons per kilowatt. Using this technology, it took the probe almost four years to travel from Earth to the asteroid Vesta.

The concept of direct-energy (aka. laser sails), by contrast, requires very little thrust since it involves wafer-sized craft – tiny probes which weight about a gram and carry all their instruments they need in the form of chips. This concept is currently being explored for the sake of making the journey to neighboring planets and star systems within our own lifetimes.

Two good examples are the NASA-funded DEEP-IN interstellar concept that is being developed at UCSB, which attempts to use lasers to power a craft up to 0.25 the speed of light. Meanwhile, Project Starshot (part of Breakthrough Initiatives) is developing a craft which they claim will reach speeds of 20% the speed of light, and thus be able to make the trip to Alpha Centauri in 20 years.

Compared to these proposals, the EM Drive can still boast the fact that it does not require any propellant or an external power source. But based on these test results, the amount of power that would be needed to generate a significant amount of thrust would make it impractical. However, one should keep in mind that this low power test was designed to see if any thrust detected could be attributed to anomalies (none of which were detected).

The report also acknowledges that further testing will be necessary to rule out other possible causes, such as center of gravity (CG) shifts and thermal expansion. And if outside causes can again be ruled out, future tests will no doubt attempt to maximize performance to see just how much thrust the EM Drive is capable of generating.

But of course, this is all assuming that the “leaked” paper is genuine. Until NASA can confirm that these results are indeed real, the EM Drive will be stuck in controversy limbo. And while we’re waiting, check out this descriptive video by astronomer Scott Manley from the Armagh Observatory:

Further Reading: Science Alert

November 10, 2016November 11, 2016 by Matt Williams

Discovery Of A Nearby Super Earth With Only 5 Times Our Mass

Artists impression of a Super-Earth, a class of planet that has many times the mass of Earth, but less than a Uranus or Neptune-sized planet. Credit: NASA/Ames/JPL-Caltech

Red dwarf stars have proven to be a treasure trove for exoplanet hunters in recent years. In addition to multiple exoplanets candidates being detected around stars like TRAPPIST-1, Gliese 581, Gliese 667C, and Kepler 296, there was also the ESO’s recent discovery of a planet orbiting within the habitable zone of our Sun’s closest neighbor – Proxima Centauri.

And it seems the trend is likely to continue, with the latest discovery comes from a team of European scientists. Using data from the ESO’s High Accuracy Radial velocity Planet Searcher (HARPS) and HARPS-N instruments, they detected an exoplanet candidate orbiting around GJ 536 – an M-class red dwarf star located about 32.7 light years (10.03 parsecs) from Earth.

According to their study, “A super-Earth Orbiting the Nearby M-dwarf GJ 536“, this planet is a super-Earth – a class of exoplanet that has between more than one, but less than 15, times the mass of Earth. In this case, the planet boasts a minimum of 5.36 ± 0.69 Earth masses, has an orbital period of 8.7076 ± 0.0025 days, and orbits its sun at a distance of 0.06661 AU.

Artist's impression of a system of exoplanets orbiting a low mass, red dwarf star. Credit: NASA/JPL — *Artist’s impression of a system of exoplanets orbiting a low mass, red dwarf star. Credit: NASA/JPL*

The team was led by Dr. Alejandro Suárez Mascareño of the Instituto de Astrofísica de Canarias (IAC). The discovery of the planet was part of his thesis work, which was conducted under Dr Rafael Rebolo – who is also a member of the IAC, the Spanish National Research Council and a professor at the University of Laguna. And while the planet is not a potentially habitable world, it does present some interesting opportunities for exoplanet research.

As Dr. Mascareño shared with Universe Today via email:

“GJ 536 b is a small super Earth discovered in a very nearby star. It is part of the group of the smallest planets with measured mass. It is not in the habitable zone of its star, but its relatively close orbit and the brightness of its star makes it a promising target for transmission spectroscopy IF we can detect the transit. With a star so bright (V 9.7) it would be possible to obtain good quality spectra during the hypothetical transit to try to detect elements in the atmosphere of the planet. We are already designing a campaign for next year, but I guess we won’t be the only ones.”

The survey that found this planet was part of a joint effort between the IAC (Spain) and the Geneva Observatory (Switzerland). The data came from the HARPS and HARPS-N instruments, which are mounted on the ESO’s 3.6 meter telescope at the La Silla Observstory in Chile and the 3.6 meter telescope at the La Palma Observatory in Spain. This was combined with photometric data from the All Sky Automated Survey (ASAS), which has observatories in Chile and Maui.

The research team relied on radial velocity measurements from the star to discern the presence of the planet, as well as spectroscopic observations of the star that were taken over a 8.6 year period. For all this, they not only detected an exoplanet candidate with 5 times the mass of Earth, but also derived information on the star itself – which showed that it has a rotational period of about 44 days, and magnetic cycle that lasts less than three years.

Artist's depiction of the interior of a low-mass star, such as the one seen in an X-ray image from Chandra in the inset. Credit: NASA/CXC/M.Weiss — *Artist’s depiction of the interior of a low-mass star, such as the one seen in an X-ray image from Chandra in the inset. Credit: NASA/CXC/M.Weiss*

By comparison, our Sun has a rotational period of 25 days and a magnetic cycle of 11 years, which is characterized by changes in the levels of solar radiation it emits, the ejection of solar material and in the appearance of sunspots. In addition, a recent study from the the Harvard Smithsonian Center for Astrophysics (CfA) showed that Proxima Centauri has a stellar magnetic cycle that lasts for 7 years.

This detection is just the latest in a long line of exoplanets being discovered around low-mass, low-luminosity, M-class (red dwarf) stars. And looking ahead, the team hopes to continue surveying GJ 536 to see if there is a planetary system, which could include some Earth-like planets, and maybe even a few gas giants.

“For now we have detected only one planet, but we plan to continue monitoring the star to search for other companions at larger orbital separations,” said Dr. Mascareño. “We estimate there is still room for other low-mass or even Neptune-mass planets at orbits from a hundred of days to a few years.”

The research also included scientists from the Astronomical Observatory at the University of Geneva, the University of Grenoble, The Astrophysical and Planetological Insitute of Grenoble, Institute of Astrophysics and Space Sciences in Portugal, and the University of Porto, Portugal.

Further Reading: arXiv

November 10, 2016March 3, 2017 by Fraser Cain

Astronomy Cast Ep. 428: The Moons of Mars

We begin a miniseries on Mars. How many episodes will we do? Who knows? But we start today with a discussion of the two Mars moons, Phobos and Deimos.

Visit the Astronomy Cast Page to subscribe to the audio podcast!

We usually record Astronomy Cast as a live Google+ Hangout on Air every Friday at 1:30 pm Pacific / 4:30 pm Eastern. You can watch here on Universe Today or from the Astronomy Cast Google+ page.

November 10, 2016 by Mark Mortimer

Rock Legends – the Asteroids and Their Discoverers

Artist's concept of Trojan asteroids, small bodies that dominate our solar system. Credit: NASA

If we are indeed stardust, then what will our future hold? And what happened to all that other dust that isn’t in people or planets? These are pretty heady questions perhaps best left for late at night. Since the age of Galileo and perhaps even beforehand these inquisitive night goers have sought an understanding of “What’s out there?” Paul Murdin in his book “Rock Legends – the Asteroids and Their Discoverers” doesn’t answer the big questions directly but he does shed some capricious light upon what the night time reveals and what the future may hold.

We’re pretty confident that our solar system evolved from a concentration of dust. Let’s leave aside the question about where the dust came from and assume that, at a certain time and place, there was enough free dust that our Sun was made and so too all the planets. In a nice, orderly universe all the dust would have settled out. However, as we’ve discovered since at least the time of Galileo this didn’t happen. There are a plethora of space rocks — asteroids — out wandering through our solar system.

And this is where Murdin’s book steps up. Once people realized that there more than just a few asteroids out there, they took to identifying and classifying them. The book takes a loosely chronological look at this classification and at our increasing knowledge of the orbits, sizes, densities and composition of these space wanderers.

Fortunately this book doesn’t just simply list discovery dates and characteristics. Rather, it includes significant amounts of its contents on the juicy human story that tags along, especially with the naming. It shows that originally these objects were considered special and refined and thus deserved naming with as much aplomb as the planets; i.e. using Greek and Roman deities. Then the number of discovered asteroids outpaced the knowledge of ancient lore, so astronomers began using the names of royalty, friends and eventually pets. Today with well over a million asteroids identified setting a name to an asteroid doesn’t quite have the same lustre, as the author is quick to point out with his own asteroid (128562) Murdin. Yet perhaps there’s not much else to do while waiting for a computer program to identify a few hundred more accumulations of dust, so naming some of the million nameless asteroids could happily fill in some time.

With the identifying of the early asteroid discoverers and the fun names they chose, this part of the book is quite light and simple. It expands the fun by wandering a bit just like the asteroids. From it you learn of the discovery of palladium, the real spelling of Spock’s name and the meaning of YORP. Sometimes the wandering is quite far, as with the origins of the Palladium Theatre, the squabbling surrounding the naming of Ceres and the status of the Cubewanos. Yet it is this capriciousness that gives the book its flavour and makes it great for a budding astronomer or a reference for a generalist. The occasional bouts of reflection on the future of various asteroids and even of the Earth add a little seriousness to an otherwise pleasant prose.

So if you’re wondering about the next occultation of Eris or the real background of the name (3512) Eriepa then you’re into asteroids. And perhaps you’re learning how to survive on a few hours of sleep so you can search for one more faint orbiting mote. Whether that’s the case or you’re just interested in how such odd names came to represent these orbiting rocks then Paul Murdin’s book “Rock Legends – the Asteroids and Their Discoverers” will be a treat. Read it and maybe you can use it to place your own curve upon an asteroid’s name.

The book is available on Springer. Find out more about author Paul Murdin here.

November 10, 2016February 3, 2017 by David Dickinson

Preview: Comet 45P/Honda–Mrkos–Pajdušáková Brightens in December

Comet 45P/Honda-Mrkos-Pajdušáková From October 1st, 2011 taken with a 10"/3.8 Newtonian and CCD imager. Image credit and copyright: Michael Jäger.

Looking for a good binocular comet? Well, if luck is on our side, we should be getting our first looks at periodic Comet 45P/Honda-Mrkos-Pajdušáková as it tops +10th magnitude in dusk skies over the next few weeks.

The swift path of Comet 45P/Honda-Mrkos-Pajdušáková on the nights of February 9th to February 12th. Image credit: Starry Night.

Comet 45P/Honda-Mrkos-Pajdušáková is expected to reach maximum brightness around late February 2017. Discovered independently by astronomers Minoru Honda, Antonin Mrkos and L’udmila Pajdušáková on December 3^rd, 1948, Comet 45P/Honda-Mrkos-Pajdušáková orbits the Sun once every 5.25 years on a short period orbit. Comet 45P/Honda-Mrkos-Pajdušáková is set to break binocular +10^th magnitude brightness in mid-December 2017, and may reach a maximum brightness of magnitude +7 from January through February 2017.

Slovak astronomer ?udmila Pajdušáková, co-discoverer of 5 comets, including Comet 45P/Honda-Mrkos-Pajdušáková. Image credit: The Skalnaté Pleso Observatory.

Currently and through the end of 2016, the comet sits towards the center of the Milky Way Galaxy in Sagittarius at a faint +15^th magnitude in the evening sky. The comet may break +10^th magnitude and become very briefly visible in the first few weeks of December before getting too close to the Sun to observe in late 2016 and crossing into the morning sky in early 2017.

The path of Comet 45/P from mid-November through December 15th, 2016. Image credit: Starry Night.

Visibility prospects: At its brightest, Comet 45P/Honda-Mrkos-Pajdušáková will be passing through the constellation Hercules during closest approach on February 11^th. The comet then passes through the constellations of Corona Borealis, Boötes, Canes Venatici, Ursa Major into Leo through to the end of February as it recedes. In the second week of February, the comet is visible in the dawn sky 82 degrees west of the Sun at maximum brightness. This apparition favors the northern hemisphere. The comet will reach perihelion on December 29^th, 2016 at 0.53 Astronomical Units (AU) from the Sun, and the comet passes just 0.08 AU (7.4 million miles) from the Earth on February 11^th at 14:44 UT. The comet made a slightly closer pass in 2011, and was a fine binocular object that time around. At its closest, the comet will cross nine degrees of sky from one night to the next. Some notable dates for comet 45P/Honda-Mrkos-Pajdušáková are:

November 23^rd: Venus passes 6′ from the comet.

December 12^th: May break 10^th magnitude.

December 14^th: Passes near M75.

December 15^th: Crosses into the constellation Capricornus.

January 4^th: Passes near the +4^th magnitude star Theta Capricorni

January 10^th: Crosses the ecliptic northward.

January 16^th: Passes into Aquarius.

January 22^nd: Passes near NGC 7009, M72 and M73.

January 25^th: Passes 8 degrees from the Sun and into the dawn sky.

January 28^th: Crosses into Aquila.

February 3^rd: Crosses the celestial equator northward.

February 4^th: Passes 4′ from the star +3.3 magnitude star Delta Aquilae.

February 6^th: Crosses the Galactic equator.

February 7^th: Crosses into Ophiuchus.

February 9^th: Crosses into Hercules.

February 16^th: makes a wide pass near M3.

February 19^th: Drops back below +10^th magnitude.

The path of Comet 45P/Honda-Mrkos-Pajdušáková through the inner solar system. Image credit: NASA/JPL.

This is the final close (less than 0.1 AU) passage of Comet 45P/Honda-Mrkos-Pajdušáková near the Earth for this century.

On July 1^st 1770, Comet D/1770 L1 Lexell passed 0.0151AU from the Earth; a comet in 1491 may have passed closer. Next year’s passage of 45P/Honda-Mrkos-Pajdušáková ranks as the 21^st closest passage of a comet near the Earth.

The light curve of Comet 45/P Honda-Mrkos-Pajdušáková. Credit: Seiichi Yoshida’s *Weekly Information About Bright Comets.*

Why do comets end up with such cumbersome names? Well, comets derive their names from the first three discovers that submit the find within a 24 hour period to the Minor Planet Center’s Central Bereau for Astronomical Telegrams, which, in fact, received its last ‘telegram’ during the discovery of Comet Hale-Bopp around two decades ago. Increasingly, comets are receiving names of all sky surveys such as LINEAR and PanSTARRS from robotic competition against amateur hunters. It does seem like you need an umlaut or the chemical symbol for boron to in your moniker to qualify these days… rare is the ‘Comet Smith.’ But hey, it’s still fun to watch science journalists try and spell the Icelandic volcano Eyjafjallajökull and comet Churyumov-Gerasimenko over and over… Perhaps, we should insist that our first comet discovery is actually spelled Comet Dîckînsðn…

And Comet 45/P is just one of the fine binocular comets on deck for 2017. We’re also expecting Comet 41P/Tuttle-Giacobini-Kresák, 2/P Encke, C/2015 ER61 PanSTARRS Comet C/2015 V2 Johnson to break +10^th magnitude next year… and the next great naked eye ‘Comet of the Century’ could light up the skies at any time.

Goldstone radar pings comet 45/P back in 2011. Image credit: NASA.

Binoculars are the best tool to observe bright comets, as they allow you to simply sweep the star field and admire the full beauty of a comet, coma, tail(s) and all. Keep in mind, a comet will often appear visually fainter than its quoted brightness… this is because, like nebulae, that intrinsic magnitude is ‘smeared out’ over an extended area. To my eye, a binocular comet often looks like a fuzzy, unresolved globular cluster that stubbornly refuses to snap into focus.

Don’t miss your first looks at Comet 45/P 45P/Honda-Mrkos-Pajdušáková, as it spans 2016 into 2017.

November 9, 2016November 11, 2016 by Matt Williams

Where Will President-Elect Trump Take American Space Endeavours?

Given the fiscal policies of his party, and his own stances on Climate Change, there is concern about how a Trump administration will affect NASA. Credit: Wikipedia Commons/Gage Skidmore

With the 2016 election now finished and Donald Trump confirmed as the president-elect of the United States, there are naturally some concerns about what this could means for the future of NASA. Given the administration’s commitment to Earth science, and its plans for crewed missions to near-Earth Orbit and Mars, there is understandably some worry that the budget environment might be changing soon.

At this juncture, it is not quite clear how a Trump presidency will affect NASA’s mandate for space exploration and scientific research. But between statements made by the president-elect in the past, and his stances on issues like climate change, it seems clear that funding for certain types of research could be threatened. But there is also reason to believe that larger exploration programs might be unaffected.

Back in September, the Senate Committee on Commerce, Science, and Transportation passed the NASA Transition Authorization Act of 2016. This bill granted $19.5 billion in funding for NASA for fiscal year 2017, thus ensuring that NASA’s proposed activities would not be affected by the transition in power. Central to this bill was the continued funding of operations that NASA considered to be central to its “Journey to Mars“.

Looking forward, it is unclear how the new administration will affect NASA's plans for space exploration. Credit: NASA/AESP — Looking forward, it is unclear how the new administration will affect NASA’s plans for space exploration. Credit: NASA/AESP

Beyond FY 2017, though, the picture is unclear. When it comes to things like NASA’s Earth Science program, the administration of a president that denies the existence of Climate Change is expected to mean budget cuts. For instance, back in May, Trump laid out his vision for an energy policy. Central to this was a focus on oil, natural gas and coal, the cancellation of the Paris Agreement, and the cessations of all payments to the UN Green Climate Fund.

This could signal a possible reverse of policies initiated by the Obama administration, which increased funding for Earth science research by about 50 percent. And as NASA indicated in a report issued on Nov. 2nd by the Office of the Inspect General – titled “NASA’s Earth Science Mission Portfolio” – this has resulted in some very favorable developments.

Foremost among these has been the increased in the number of products delivered to users by NASA, going from 8.14 million in 2000 to 1.42 billion in 2015. In other words, usage of NASA resources has increased by a factor of 175, and in the space of just 15 years (much of that in the last 8). Another major benefit has been the chance for collaboration and lucrative partnerships. From the report:

“Government agencies, scientists, private entities, and other stakeholders rely on NASA to process raw information received from Earth observation systems into useable data. Moreover, NASA’s Earth observation data is routinely used by government agencies, policy makers, and researchers to expand understanding of the Earth system and to enhance economic competitiveness, protect life and property, and develop policies to help protect the planet. Finally, NASA is working to address suggestions that it use commercially provided data to augment its Earth observation data. However, NASA must reconcile its policy that promotes open sharing of data at minimal cost to users with a commercial business model under which fees may create a barrier to use.”

Much of NASA's research into Climate Change takes place through the Earth Sciences Directorate. Credit: NASA — *Much of NASA’s research into Climate Change takes place through the Earth Science division of the Mission Directorate. Credit: NASA*

Unfortunately, it has been this same increase in funding that prompted Congressional Republicans, in the name of fiscal responsibility, to demand changes and new standards. These sentiments were voiced back in March of 2015 during NASA’s budget request for 2016. As Senator Ted Cruz – currently one of the Trump campaign’s backers – said at the time:

“We’ve seen a disproportionate increase in the amount of federal funds going to the earth sciences program at the expense of funding for exploration and space operations, planetary sciences, heliophysics, and astrophysics, which I believe are all rooted in exploration and should be central to NASA’s core mission. We need to get back to the hard sciences, to manned space exploration, and to the innovation that has been integral to NASA.

While Trump himself has little to say about space during his long campaign, his team did manage to recruit Robert Walker – a former Republican congressman from Pennsylvania – this past October to draft a policy for them. In an op-ed to SpaceNews in late October, he echoed Cruz’s sentiments about cutting back on Earth sciences to focus on space exploration:

“NASA should be focused primarily on deep space activities rather than Earth-centric work that is better handled by other agencies. Human exploration of our entire solar system by the end of this century should be NASA’s focus and goal. Developing the technologies to meet that goal would severely challenge our present knowledge base, but that should be a reason for exploration and science.”

“It makes little sense for numerous launch vehicles to be developed at taxpayer cost, all with essentially the same technology and payload capacity. Coordinated policy would end such duplication of effort and quickly determine where there are private sector solutions that do not necessarily require government investment.“

NASA's Journey to Mars. NASA is developing the capabilities needed to send humans to an asteroid by 2025 and Mars in the 2030s. Credit: NASA/JPL — *NASA is developing the capabilities needed to send humans to an asteroid by 2025 and Mars in the 2030s. Credit: NASA/JPL*

Next, there is the issue of NASA’s long-term goals, which (as noted) seem more secure for the time being. In May of 2016, Trump was issued the Aerospace America Questionnaire – a series of ten questions issued by NASA to determine the stances of the candidates on space exploration. On the subject of a crewed mission to Mars in the future, Trump’s campaign indicated that things would depend upon the state of the country’s economy:

“A lot of what my administration would recommend depends on our economic state. If we are growing with all of our people employed and our military readiness back to acceptable levels, then we can take a look at the timeline for sending more people into space.“

However, they also professed an admiration for NASA and a commitment to its overall goal:

“NASA has been one of the most important agencies in the United States government for most of my lifetime. It should remain so. NASA should focus on stretching the envelope of space exploration for we have so much to discover and to date we have only scratched the surface.”

From all of this, a general picture of what NASA’s budget environment will look like in the near future begins to emerge. In all likelihood, the Earth Science division (and other parts of NASA) are likely to find their budgets being scrutinized based on newly-developed criteria. Essentially, unless it benefits space exploration and research beyond Earth, it’s not likely to see continued funding.

*NASA Administrator Charles Bolden. Credit: NASA*

But regardless of the results of the election, it appears at this juncture that NASA is looking forward with cautious optimism. Addressing the future, NASA Administrator Charles Bolden issued an internal memo on Wednesday, Nov. 9th. Titled “Reaching for New Heights in 2017 and Beyond“, Bolden expressed positive thoughts about the transition of power and what it would mean:

“In times when there has been much news about all the things that divide our nation, there has been noticeable bipartisan support for this work, our work – support that not only reaches across the aisle, but across the public, private, academic and non-profit sectors.

“For this reason, I think we can all be confident that the new Trump Administration and future administrations after that will continue the visionary course on which President Barack Obama has set us, a course that all of you have made possible.”

For NASA’s sake, I hope Bolden’s words prove to be prophetic. For no matter who holds of the office of the President of the United States, the American people – and indeed, all the world’s people – depend upon the continued efforts of NASA. As the leader in space exploration, their presence is essential to humanity’s return to space!

Further Reading: Planetary Society

November 9, 2016November 9, 2016 by David Dickinson

November’s Supermoon 2016 – Closest of a Lifetime?

The 2015 Supermoon. Image credit and copyright: Wils 888.

What’s that, rising in the sky?

By now, you’ve heard the news. We’ll spare you the “it’s a bird, it’s a plane…” routine to usher in the Supermoon 2016. This month’s Full Moon is not only the closest for the year, but the nearest Full Moon for a 80 year plus span.

Like Blue and Black Moons, a Supermoon is more of a cultural phenomenon than a true astronomical event. The Moon’s orbit is elliptical, taking it from 362,600 to 405,400 km from the Earth in the course of its 27.55 day anomalistic orbit from one perigee to the next. For the purposes of this week’s discussion, we consider a Supermoon as when the Full Moon occurs within 24 hours of perigee, and a Minimoon as when the Full Moon occurs within 24 hours of apogee. From the Earth, the Moon varies in apparent size from 29.3” to 34.1” across. This month, the Moon reaches perigee on November 14^th at 356,511 kilometers distant, 2 hours and 22 minutes before Full.

A perigee 'Supermoon' versus an apogee 'Minimoon'. Image credit and copyright: Raven Yu. — A perigee ‘Supermoon’ versus an apogee ‘Minimoon’. Image credit and copyright: Raven Yu.

This is the closest perigee Moon for 2016, beating out the April 7^th, 2016 perigee Moon by just 652 kilometers. Perigee can vary over a span of 2,800 kilometers. In the 21^st century, the farthest lunar perigee (think the ‘most distant near point’) occurs on January 3^rd, 2100 at 370,356 kilometers distant, while the closest perigee of the century (356,425 kilometers) occurs on December 6^th , 2052.

When the Moon reaches Full on November 14^th at 13:51 UT, it’s just 356,520 kilometers distant, (that is , as measured from the Earth’s center) the closest Full Moon since January 26^th, 1948 (356,490 km) and until November 25^th , 2034 (356,446 km) losing out to either dates by just 21 kilometers.

Why does perigee vary? Well, as the Moon orbits the Earth, the Sun tugs our large natural satellite’s orbit around as well, in an 8.85 year cycle known as the precession of the line of apsides. Earth’s orbit is elliptical as well, and the tugging of the Sun (and to a much lesser degree, the other planets in the solar system) alters the perigee and apogee points slightly based on where the Earth-Moon pair fall in their swing about a common barycenter.

The November Full Moon is also known as the Full Beaver Moon by the Algonquin Native Americans, a good time to ensure a supply of winter furs before the swamps froze over. A good sign that even in 2016, ‘Winter is Coming.’

Does the Moon look any larger to you than usual as it rises to the east opposite to the setting Sun on Monday night? When the Moon reaches Full, it passes the zenith as seen from the central Indian Ocean region just south of Sri Lanka, 354,416 km distant. Of course, as the Moon rises, it’s actually one full Earth radii more distant than when straight overhead at the zenith.

A side-by-side 'Super' vs 'Minimoon.' Image credit and copyright: Marco Langbroek. — A side-by-side ‘Super’ vs ‘Minimoon.’ Image credit and copyright: Marco Langbroek.

Would you notice any difference in the size of the November Full Moon, if you didn’t know better? The 4′ odd difference between an apogee and perigee Full Moon is certainly discernible in side-by-side images… but it’s interesting to note that early cultures did not uncover the elliptical nature of the Moon’s motion, though it certainly would have been possible. Crystalline spheres ruled the day, a sort of perfection that was just tough to break in the minds of many.

Be sure to enjoy the rising Full Moon on Monday night, the largest for many years to come.

November 8, 2016August 25, 2021 by Matt Williams

What are Active Galactic Nuclei?

An artist's impression of the accretion disc around the supermassive black hole that powers an active galaxy. Astronomers want to know if the energy radiated from a black hole is caused by jets of material shooting away from the hole, or by the accretion disk of swirling material near the hole. Credit: NASA/Dana Berry, SkyWorks Digital

In the 1970s, astronomers became aware of a compact radio source at the center of the Milky Way Galaxy – which they named Sagittarius A. After many decades of observation and mounting evidence, it was theorized that the source of these radio emissions was in fact a supermassive black hole (SMBH). Since that time, astronomers have come to theorize that SMBHs at the heart of every large galaxy in the Universe.

Most of the time, these black holes are quiet and invisible, thus being impossible to observe directly. But during the times when material is falling into their massive maws, they blaze with radiation, putting out more light than the rest of the galaxy combined. These bright centers are what is known as Active Galactic Nuclei, and are the strongest proof for the existence of SMBHs.

Description:

It should be noted that the enormous bursts in luminosity observed from Active Galactic Nuclei (AGNs) are not coming from the supermassive black holes themselves. For some time, scientists have understood that nothing, not even light, can escape the Event Horizon of a black hole.

Instead, the massive burst of radiations – which includes emissions in the radio, microwave, infrared, optical, ultra-violet (UV), X-ray and gamma ray wavebands – are coming from cold matter (gas and dust) that surround the black holes. These form accretion disks that orbit the supermassive black holes, and gradually feeding them matter.

The incredible force of gravity in this region compresses the disk’s material until it reaches millions of degrees kelvin. This generates bright radiation, producing electromagnetic energy that peaks in the optical-UV waveband. A corona of hot material forms above the accretion disc as well, and can scatter photons up to X-ray energies.

A large fraction of the AGN’s radiation may be obscured by interstellar gas and dust close to the accretion disc, but this will likely be re-radiated at the infrared waveband. As such, most (if not all) of the electromagnetic spectrum is produced through the interaction of cold matter with SMBHs.

The interaction between the supermassive black hole’s rotating magnetic field and the accretion disk also creates powerful magnetic jets that fire material above and below the black hole at relativistic speeds (i.e. a significant fraction of the speed of light). These jets can extend for hundreds of thousands of light-years, and are a second potential source of observed radiation.

Types of AGN:

Typically, scientists divide AGN into two categories, which are referred to as “radio-quiet” and “radio-loud” nuclei. The radio-loud category corresponds to AGNs that have radio emissions produced by both the accretion disk and the jets. Radio-quiet AGNs are simpler, in that any jet or jet-related emission are negligible.

Carl Seyfert discovered the first class of AGN in 1943, which is why they now bear his name. “Seyfert galaxies” are a type of radio-quiet AGN that are known for their emission lines, and are subdivided into two categories based on them. Type 1 Seyfert galaxies have both narrow and broadened optical emissions lines, which imply the existence of clouds of high density gas, as well as gas velocities of between 1000 – 5000 km/s near the nucleus.

Type 2 Seyferts, in contrast, have narrow emissions lines only. These narrow lines are caused by low density gas clouds that are at greater distances from the nucleus, and gas velocities of about 500 to 1000 km/s. As well as Seyferts, other sub classes of radio-quiet galaxies include radio-quiet quasars and LINERs.

Low Ionisation Nuclear Emission-line Region galaxies (LINERs) are very similar to Seyfert 2 galaxies, except for their low ionization lines (as the name suggests), which are quite strong. They are the lowest-luminosity AGN in existence, and it is often wondered if they are in fact powered by accretion on to a supermassive black hole.

Artist's representation of an active galactic nucleus (AGN) at the center of a galaxy. Credit: NASA/CXC/M.Weiss — Artist’s representation of an active galactic nucleus (AGN) at the center of a galaxy. Credit: NASA/CXC/M.Weiss

Radio-loud galaxies can also be subdivded into categories like radio galaxies, quasars, and blazars. As the name suggests, radio galaxies are elliptical galaxies that are strong emitters of radiowaves. Quasars are the most luminous type of AGN, which have spectra similar to Seyferts.

However, they are different in that their stellar absorption features are weak or absent (meaning they are likely less dense in terms of gas) and the narrow emission lines are weaker than the broad lines seen in Seyferts. Blazars are a highly variable class of AGN that are radio sources, but do not display emission lines in their spectra.

Detection:

Historically speaking, a number of features have been observed within the centers of galaxies that have allowed for them to be identified as AGNs. For instance, whenever the accretion disk can be seen directly, nuclear-optical emissions can be seen. Whenever the accretion disk is obscured by gas and dust close to the nucleus, an AGN can be detected by its infra-red emissions.

Then there are the broad and narrow optical emission lines that are associated with different types of AGN. In the former case, they are produced whenever cold material is close to the black hole, and are the result of the emitting material revolving around the black hole with high speeds (causing a range of Doppler shifts of the emitted photons). In the former case, more distant cold material is the culprit, resulting in narrower emission lines.

Image taken by the Hubble Space Telescope of a 5000-light-year-long jet ejected from the active galaxy M87. The blue synchrotron radiation contrasts with the yellow starlight from the host galaxy. Credit: NASA/The Hubble Heritage Team (STScI/AURA) — *Image taken by the Hubble Space Telescope of a 5000-light-year-long jet ejected from the active galaxy M87. Credit: NASA/The Hubble Heritage Team (STScI/AURA)*

Next up, there are radio continuum and x-ray continuum emissions. Whereas radio emissions are always the result of the jet, x-ray emissions can arise from either the jet or the hot corona, where electromagnetic radiation is scattered. Last, there are x-ray line emissions, which occur when x-ray emissions illuminate the cold heavy material that lies between it and the nucleus.

These signs, alone or in combination, have led astronomers to make numerous detections at the center of galaxies, as well as to discern the different types of active nuclei out there.

The Milky Way Galaxy:

In the case of the Milky Way, ongoing observation has revealed that the amount of material accreted onto Sagitarrius A is consistent with an inactive galactic nucleus. It has been theorized that it had an active nucleus in the past, but has since transitioned into a radio-quiet phase. However, it has also been theorized that it might become active again in a few million (or billion) years.

When the Andromeda Galaxy merges with our own in a few billion years, the supermassive black hole that is at its center will merge with our own, producing a much more massive and powerful one. At this point, the nucleus of the resulting galaxy – the Milkdromeda (Andrilky) Galaxy, perhaps? – will certainly have enough material for it to be active.

The discovery of active galactic nuclei has allowed astronomers to group together several different classes of galaxies. It’s also allowed astronomers to understand how a galaxy’s size can be discerned by the behavior at its core. And last, it has also helped astronomers to understand which galaxies have undergone mergers in the past, and what could be coming for our own someday.

We have written many articles about galaxies for Universe Today. Here’s What Fuels the Engine of a Supermassive Black Hole?, Could the Milky Way Become a Black Hole?, What is a Supermassive Black Hole?, Turning on a Supermassive Black Hole, What Happens when Supermassive Black Holes Collide?.

For more information, check out Hubblesite’s News Releases on Galaxies, and here’s NASA’s Science Page on Galaxies.

Astronomy Cast also has episodes about galactic nuclei and supermassive black holes. Here’s Episode 97: Galaxies and Episode 213: Supermassive Black Holes.

Source:

November 8, 2016November 8, 2016 by Ken Kremer

SpaceX Aims for Mid-December Falcon 9 Launch Resumption: Musk

SpaceX Falcon 9 rocket moments after catastrophic explosion destroys the rocket and Amos-6 Israeli satellite payload at launch pad 40 at Cape Canaveral Air Force Station, FL, on Sept. 1, 2016. A static hot fire test was planned ahead of scheduled launch on Sept. 3, 2016. Credit: USLaunchReport

Hoping to recover quickly after suffering a calamitous launch pad explosion of their Falcon 9 rocket at Cape Canaveral some two months ago, SpaceX is aiming to resume launches of the booster in mid-December, said company founder and CEO Elon Musk in a recent televised interview on Nov. 4.

Musk further indicated in the Nov. 4 interview with CNBC that they have discovered the problem that suddenly triggered the catastrophic Falcon 9 launch pad explosion that suddenly destroyed the rocket and $200 million Israeli Amos-6 commercial payload during a routine fueling and planned static fire engine test on Sept. 1.

“I think we’ve gotten to the bottom of the problem,” Musk said. “It was a really surprising problem. It’s never been encountered before in the history of rocketry.”

Musk said the issue related to some type of interaction between the liquid helium bottles , carbon composites and solidification of the liquid oxygen propellant in the SpaceX Falcon 9 second stage.

“It basically involves a combination of liquid helium, advanced carbon fiber composites, and solid oxygen, Musk elaborated.

“Oxygen so cold that it enters the solid phase.”

“Turning out to be the most difficult and complex failure we have ever had in 14 years,” Musk previously tweeted on Sept. 9.

“It’s never happened before in history. So that’s why it took us awhile to sort it out,” Musk told CNBC on Nov. 4.

SpaceX founder and CEO Elon Musk. Credit: Ken Kremer/kenkremer.com

The explosion took place without warning as liquid oxygen and RP-1 propellants were being loaded into the second stage of the 229-foot-tall (70-meter) Falcon 9 during a routine fueling test and engine firing test at SpaceX’s Space Launch Complex-40 launch facility at approximately 9:07 a.m. EDT on Sept. 1 on Cape Canaveral Air Force Station, Fl.

But the rocket blew up during the fueling operations and the SpaceX launch team never even got to the point of igniting the first stage engines for the static fire test.

Launch of the AMOS-6 comsat from pad 40 had been scheduled to take place two days later.

In company updates posted to the SpaceX website on Sept. 23 and Oct 28, the company said the anomaly appears to be with a “large breach” in the cryogenic helium system of the second stage liquid oxygen tank – but that the root cause had not yet been determined.

“The root cause of the breach has not yet been confirmed, but attention has continued to narrow to one of the three composite overwrapped pressure vessels (COPVs) inside the LOX tank.”

“Through extensive testing in Texas, SpaceX has shown that it can re-create a COPV failure entirely through helium loading conditions.”

The helium loading is “mainly affected by the temperature and pressure of the helium being loaded.”

“This was the toughest puzzle to solve that we’ve ever had to solve,”Musk explained to CNBC.

After the Sept. 1 accident, SpaceX initiated a joint investigation to determine the root cause with the FAA, NASA, the US Air Force and industry experts who have been “working methodically through an extensive fault tree to investigate all plausible causes.”

“We have been working closely with NASA, and the FAA [Federal Aviation Administration] and our commercial customers to understand it,” says Musk.

SpaceX is renovating Launch Complex 39A at the Kennedy Space Center for launches of the Falcon Heavy and human rated Falcon 9. Credit: Ken Kremer/kenkremer.com

Musk was not asked and did not say from which launch pad the Falcon 9 would launch or what the payload would be.

“It looks like we’re going to be back to launching around mid-December,” he replied.

SpaceX maintains launch pads on both the US East and West coasts.

“Pending the results of the investigation, we continue to work towards returning to flight before the end of the year. Our launch sites at Kennedy Space Center, Florida, and Vandenberg Air Force Base, California, remain on track to be operational in this timeframe,” SpaceX said on Oct 28.

At KSC launches will initially take place from pad 39A, the former shuttle pad that SpaceX has leased from NASA.

Pad 40 is out of action until extensive repairs and testing are completed.

Aerial view of pad and strongback damage at SpaceX Launch Complex-40 as seen from the VAB roof on Sept. 8, 2016 after fueling test explosion destroyed the Falcon 9 rocket and AMOS-6 payload at Cape Canaveral Air Force Station, FL on Sept. 1, 2016. Credit: Ken Kremer/kenkremer.com

The Sept. 1 calamity was the second Falcon 9 failure within 15 months time and will call into question the rockets overall reliability.

The first Falcon 9 failure involved a catastrophic mid air explosion in the second stage about two and a half minutes after liftoff, during the Dragon CRS-9 cargo resupply launch for NASA to the International Space Station on June 28, 2015 – and witnessed by this author.

Although both incidents involved the second stage, SpaceX maintains that they are unrelated – even as they continue seeking to determine the root cause.

SpaceX must determine the root cause before Falcon 9 launches are allowed to resume. Effective fixes must be identified and effective remedies must be verified and implemented.

Overview schematic of SpaceX Falcon 9. Credit: SpaceX

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

Ken Kremer

November 8, 2016November 8, 2016 by Evan Gough

Mars One Merges With Mobile Payment Company In Odd Restructuring

An artist's illustration of a Mars settlement. Image: Bryan Versteeg/MarsOne — An artist's illustration of an early Mars settlement. Credit: Bryan Versteeg/MarsOne

“Pssst. Hey you! Want to go to Mars? No, you won’t be able to come back, you’ll die there. No, we don’t have a ship. No, we don’t have any plans for life support, or for growing food to eat while you there. But we do have our own mobile payment app!”

So goes the sales pitch from Mars One, the oddball of the space exploration world.

In a move that can charitably be described as “puzzling”, Mars One is merging with Swiss mobile payment company InFin Innovative Finance AG. InFin is a small player in a mobile payment field dominated by huge entities like Google, Apple, and Samsung. So, other than ensuring that Mars One astronauts will be able to complete their online shopping without hassle, what is behind this merger?

Money.

In case you don’t know, Mars One is the Netherlands-based company proposing to send astronauts to Mars and set up a human colony there. There would be no returning to Earth, and the “lucky” people chosen by Mars One to be the first to go, would die there. Mars One has been roundly criticized by the aerospace community at large for its lack of detail and its lack of technical capability.

This latest move is unlikely to quell any of the criticism.

Artist's concept of a Martian astronaut standing outside the Mars One habitat. Credit: Bryan Versteeg/Mars One — Artist’s concept of a Martian astronaut standing outside the Mars One habitat. Credit: Bryan Versteeg/Mars One

Mars One has had no problem attracting a huge number of applicants to become astronauts and colonists. Over 200,000 people applied, and that number has been whittled down to 100. They’ve been able to attract applicants, and a lot of attention, but one thing they haven’t been able to attract is money.

Mars One say they need $6 billion to establish their colony on Mars, but they’ve only raised about $1 million so far, mostly from donations, astronaut application fees, and from t-shirt sales and other merchandise. Yes, t-shirts.

“Mars One is very pleased to have been acquired by InFin. This step provides the opportunity to raise capital through the listing on the Frankfurt Stock Exchange.” – Bas Lansdorp

Clearly, Mars One needs cash, and this merger gives Mars One access to capital. You see, InFin is traded on the Frankfurt Stock Exchange, and once the two entities have merged, Mars One will be publicly traded. It’s difficult to see how any institutional investors would ever go anywhere near Mars One stock, but it may be an investment for novelty-seekers, space enthusiasts, or true believers. Who knows?

In a press release, Mars One CEO and co-founder Bas Lansdorp said “This listing also supports our aim to attract international support to establish a permanent human settlement on Mars: our global followers will have the opportunity to be part of this adventure and to literally own a piece of this historic venture.”

A cynic might say that Mars One was just created by Lansdorp as a way to generate some cash from the interest surrounding human travel to Mars. This latest move just adds to the cynicism, since there’s no apparent synergy between a space travel company and a mobile payment company.

If the fact that they sell t-shirts to raise money for their Mars colony doesn’t make you question how capable and serious Mars One is, then this latest move surely will.

Or, maybe we’re being too hard on Mars One. It’s not like NASA or the ESA has ever inspired a line of clothing, or an opera.

Maybe Mars One is an innovator, and is thinking outside the box. Just because space exploration has always been done one way, doesn’t mean it can’t be done in another. Maybe in the final analysis, Mars One will be a successful endeavour, and will show others how unorthodox approaches can work. Only the future knows, and we’re still waiting for the future to tell us.

In the meantime, want to buy a t-shirt?