Universe Today

November 17, 2017November 19, 2017 by Matt Williams

When James Webb Finally Reaches Space, Here’s What it’ll be Hunting

Artist conception of the James Webb Space Telescope. Credit: NASA

Ever since the project was first conceived, scientists have been eagerly awaiting the day that the James Webb Space Telescope (JWST) will take to space. As the planned successor to Hubble, the JWST will use its powerful infrared imaging capabilities to study some of the most distant objects in the Universe (such as the formation of the first galaxies) and study extra-solar planets around nearby stars.

However, there has been a lot of speculation and talk about which targets will be the JWST’s first. Thankfully, following the recommendation of the Time Allocation Committee and a thorough technical review, the Space Telescope Science Institute (STScI) recently announced that it has selected thirteen science “early release” programs, which the JWST will spend its first five months in service studying.

As part of the JWST Director’s Discretionary Early Release Science Program (DD-ERS), these thirteen targets were chosen by a rigorous peer-review process. This consisted of 253 investigators from 18 counties and 106 scientific institutions choosing from over 100 proposals. Each program has been allocated 500 hours of observing time, once the 6-month commissioning period has ended.

*The JWST’s Optical Telescope element/Integrated Science instrument module (OTIS) undergoing testing at NASA’s Johnson Space Center. Credit: NASA/Desiree Stover*

As Ken Sembach, the director of the Space Telescope Science Institute (STScI), said in an ESA press statement:

“We were impressed by the high quality of the proposals received. These programmes will not only generate great science, but will also be a unique resource for demonstrating the investigative capabilities of this extraordinary observatory to the worldwide scientific community… We want the research community to be as scientifically productive as possible, as early as possible, which is why I am so pleased to be able to dedicate nearly 500 hours of director’s discretionary time to these early release science observations.”

Each program will rely on the JWST’s suite of four scientific instruments, which have been contributed by NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA). These include the the Near-Infrared Spectrograph (NIRSpec) and the Mid-Infrared Instrument (MIRI) developed by the ESA, as well as the Near-Infrared Camera (NIRCam) developed by NASA and the STScI, and the Near-Infrared Imager and Slitless Spectrograph (NIRISS) developed by the CSA.

The thirteen programs selected include “Through the looking GLASS“, which will rely on the astronomical community’s experience using Hubble to conduct slitless spectroscopy and previous surveys to gather data on galaxy formation and the intergalactic medium, from the earliest epochs of the Universe to the present day. The Principal Investigator (PI) for this program is Tommaso Treu of the University of California Los Angeles.

*Once deployed, the JWST will conduct a variety of science missions aimed at improving our understanding of the Universe. Credit: NASA/STScI*

Another is the Cosmic Evolution Early Release Science (CEERS) program, which will conduct overlapping observations to create a coordinated extragalactic survey. This survey is intended to let astronomers see the first visible light of the Universe (ca. 240,000 to 300,000 years after the Big Bang), as well as information from the Reionization Epoch (ca. 150 million to 1 billion years after the Big Bang) and the period when the first galaxies formed. The PI for this program is Steven Finkelstein of the University of Texas at Austin.

Then there’s the Transiting Exoplanet Community Early Release Science Program, which will build on the work of the Hubble, Spitzer, and Kepler space telescopes by conducting exoplanet surveys. Like its predecessors, this will consist of monitoring stars for periodic dips in brightness that are caused by planets passing between them and the observer (aka. Transit Photometry).

However, compared to earlier missions, the JWST will be able to study transiting planets in unprecedented detail, which is anticipated to reveal volumes about their respective atmospheric compositions, structures and dynamics. This program, for which the PI is Imke de Pater from the University of California Berkeley, is therefore expected to revolutionize our understanding of planets, planet formation, and the origins of life.

Also focused on the study of exoplanets is the High Contrast Imaging of Exoplanets and Extraplanetary Systems program, which will focus on directly imaged planets and circumstellar debris disks. Once again, the goal is to use the JWST’s enhanced capabilities to provide detailed analyses on the atmospheric structure and compositions of exoplanets, as well as the cloud particle properties of debris disks.

*Artist’s impression of the planet orbiting a red dwarf star. Credit: ESO/M. Kornmesser*

But of course, not all the programs are dedicated to the study of things beyond our Solar System, as is demonstrated by the program that will focus on Jupiter and the Jovian System. Adding to the research performed by the Galileo and Juno missions, the JWST will use its suite of instruments to characterize and produce maps of Jupiter’s cloud layers, winds, composition, auroral activity, and temperature structure.

This program will also focus on some of Jupiter’s largest moons (aka. the “Galilean Moons”) and the planet’s ring structure. Data obtained by the JWST will be used to produce maps of Io’s atmosphere and volcanic surface, Ganymede’s tenuous atmosphere, provide constrains on these moons thermal and atmospheric structure, and search for plumes on their surfaces. As Alvaro Giménez, the ESA Director of Science, proclaimed:

“It is exciting to see the engagement of the astronomical community in designing and proposing what will be the first scientific programs for the James Webb Space Telescope. Webb will revolutionize our understanding of the Universe and the results that will come out from these early observations will mark the beginning of a thrilling new adventure in astronomy.”

During its mission, which will last for a minimum of five years (barring extensions), the JWST will also address many other key topics in modern astronomy, probing the Universe beyond the limits of what Hubble has been capable of seeing. It will also build on observations made by Hubble, examining galaxies whose light has been stretched into infrared wavelengths by the expansion of space.

*The James Webb Space Telescope’s 18-segment primary mirror, a gold-coated beryllium mirror has a collecting area of 25 square meters. Credit: NASA/Chris Gunn*

Beyond looking farther back in time to chart cosmic evolution, Webb will also examine the Supermassive Black Holes (SMBH) that lie at the centers of most massive galaxies – for the purpose of obtaining accurate mass estimates. Last, but not least, Webbwill focus on the birth of new stars and their planets, initially focusing on Jupiter-sized worlds and then shifting focus to study smaller super-Earths.

John C. Mather, the Senior Project Scientist for the JWST and a Senior Astrophysicist at NASA’s Goddard Space Flight Center, also expressed enthusiasm for the selected programs. “I’m thrilled to see the list of astronomers’ most fascinating targets for the Webb telescope, and extremely eager to see the results,” he said. “We fully expect to be surprised by what we find.”

For years, astronomers and researchers have been eagerly awaiting the day when the JWST begins gathering and releasing its first observations. With so many possibilities and so much waiting to be discovered, the telescope’s deployment (which is scheduled for 2019) is an event that can’t come soon enough!

Further Reading: ESA, STScI

November 16, 2017November 17, 2017 by Matt Williams

Antarctica has a Huge Mantle Plume Beneath it, Which Might Explain Why its Ice Sheet is so Unstable

Illustration of flowing water under the Antarctic ice sheet. Blue dots indicate lakes, lines show rivers. Marie Byrd Land is part of the bulging "elbow" leading to the Antarctic Peninsula, left center. Credits: NSF/Zina Deretsky

Beneath the Antarctic ice sheet, there lies a continent that is covered by rivers and lakes, the largest of which is the size of Lake Erie. Over the course of a regular year, the ice sheet melts and refreezes, causing the lakes and rivers to periodically fill and drain rapidly from the melt water. This process makes it easier for Antarctica’s frozen surface to slide around, and to rise and fall in some places by as much as 6 meters (20 feet).

According to a new study led by researchers from NASA’s Jet Propulsion Laboratory, there may be a mantle plume beneath the area known as Marie Byrd Land. The presence of this geothermal heat source could explain some of the melting that takes place beneath the sheet and why it is unstable today. It could also help explain how the sheet collapsed rapidly in the past during previous periods of climate change.

The study, titled “Influence of a West Antarctic mantle plume on ice sheet basal conditions“, recently appeared in the Journal of Geophysical Research: Solid Earth. The research team was led by Helene Seroussi of the Jet Propulsion Laboratory, with support from researchers from the Department of Earth and Planetary Sciences at Washington University and the Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research in Germany.

*Glaciers seen during NASA’s Operation IceBridge research flight to West Antarctica on Oct. 29, 2014. Credit: NASA/Michael Studinger*

The motion of Antarctica’s ice sheet over time has always been a source of interest to Earth scientists. By measuring the rate at which the ice sheet rises and falls, scientists are able to estimate where and how much water is melting at the base. It is because of these measurements that scientists first began to speculate about the presence of heat sources beneath Antarctica’s frozen surface.

The proposal that a mantle plume exists under Marie Byrd Land was first made 30 years ago by Wesley E. LeMasurier, a scientist from the University of Colorado Denver. According to the research he conducted, this constituted a possible explanation for regional volcanic activity and a topographic dome feature. But it was only more recently that seismic imaging surveys offered supporting evidence for this mantle plume.

However, direct measurements of the region beneath Marie Byrd Land is not currently possible. Hence why Seroussi and Erik Ivins of the JPL relied on the Ice Sheet System Model (ISSM) to confirm the existence of the plume. This model is essentially a numerical depiction of the physics of the ice sheet, which was developed by scientists at the JPL and the University of California, Irvine.

To ensure that the model was realistic, Seroussi and her team drew on observations of changes in altitude of the ice sheet made over the course of many years. These were conducted by NASA’s Ice, Clouds, and Land Elevation Satellite (ICESat) and their airborne Operation IceBridge campaign. These missions have been measuring the Antarctic ice sheet for years, which have led tot he creation of very accurate three-dimensional elevation maps.

*A view of mountains and glaciers in Antarctica’s Marie Byrd Land seen during the Nov. 2nd, 2014, IceBridge survey flight. Credit: NASA / Michael Studinger*

Seroussi also enhanced the ISSM to include natural sources of heating and heat transport that result in freezing, melting, liquid water, friction, and other processes. This combined data placed powerful constrains on the allowable melt rates in Antarctica, and allowed the team to run dozens of simulations and test a wide range of possible locations for the mantle plume.

What they found was that the heat flux caused by the mantle plume would not exceed more than 150 milliwatts per square meter. By comparison, regions where there is no volcanic activity typically experience a feat flux of between 40 and 60 milliwatts, whereas geothermal hotspots – like the one under Yellowstone National Park – experience an average of about 200 milliwatts per square meter.

Where they conducted simulations that exceeded 150 millwatts per square meter, the melt rate was too high compared to the space-based data. Except in one location, which was an area inland of the Ross Sea, which is known to experience intense flows of water. This region required a heat flow of at least 150 to 180 milliwatts per square meter to align with its observed melt rates.

In this region, seismic imaging has also shown that heating might reach the ice sheet through a rift in the Earth’s mantle. This too is consistent with a mantle plume, which are thought to be narrow streams of hot magma rising through the Earth’s mantle and spreading out under the crust. This viscous magma then balloons under the crust and causes it to bulge upward.

*Temperature changes in the Antarctic ice sheet over the last 50 years, measured in degrees Celsius. Credit: NASA/GSFC Scientific Visualization Studio*

Where ice lies over top of the plume, this process transfers heat into the ice sheet, triggering significant melting and runoff. In the end, Seroussi and her colleagues provide compelling evidence – based on a combination of surface and seismic data – for a surface plume beneath the ice sheet of West Antarctica. They also estimate that this mantle plume formed roughly 50 to 110 million years ago, long before the West Antarctic ice sheet came into existence.

Roughly 11,000 years ago, when the last ice age ended, the ice sheet experienced a period of rapid, sustained ice loss. As global weather patterns and rising sea levels began to change, warm water was pushed closer to the ice sheet. Seroussi and Irvins study suggests that the mantle plume could be facilitating this kind of rapid loss today, much as it did during the last onset of an inter-glacial period.

Understanding the sources of ice sheet loss under West Antarctica is important as far as estimating the rate at which ice may be lost there, which is essentially to predicting the effects of climate change. Given that Earth is once again going through global temperature changes – this time, due to human activity – it is essential to creating accurate climate models that will let us know how rapidly polar ice will melt and sea levels will rise.

It also informs our understanding of how our planet’s history and climate shifts are linked, and what effect these had on its geological evolution.

Further Reading: NASA, Journal of Geophysical Research

November 16, 2017 by Susie Murph

Carnival of Space #535

Carnival of Space. Image by Jason Major.

This week’s Carnival of Space is hosted by Gadi Eidelheit at his The Venus Transit blog.

Click here to read Carnival of Space #535.
Continue reading “Carnival of Space #535”

November 15, 2017November 16, 2017 by Ken Kremer

Ownerless Super Secret Zuma Spysat Set for Dark Veiled Dark Night SpaceX Blastoff and Land Landing Nov. 16: Watch Live

SpaceX Falcon 9 stands erect topped with super secret Zuma spysat claimed by no US government entity on Launch Complex 39A at the Kennedy Space Center, FL, poised for liftoff on 16 Nov 2017. As seen from inside the pad perimeter. Credit: Ken Kremer/Kenkremer.com

KENNEDY SPACE CENTER, FL – The super secret ‘Zuma’ spysat mission claimed by no U.S. government entity – not even the elusive NRO spy agency ! – and whose goals are veiled in virtually complete darkness– is poised for a dark of night blastoff on a SpaceX Falcon rocket Thursday evening, Nov. 16, from the Florida Space Coast. Update: Delayed to Friday 8 PM

An unclassified aspect of the mission codenamed ‘Zuma’ is that SpaceX will also attempt to recover the 16 story tall first stage booster with a soft landing on the ground back at Cape Canaveral Air Force Station. So expect some extremely loud sonic booms to rock the space coast region about eight minutes after liftoff.

Zuma is a total mystery, to the delight of the spymasters.

One of the very few tidbits of information we can absolutely confirm (and not deny) is that the clandestine and ownerless ‘Zuma’ Spysat is now targeted for a nighttime launch on a SpaceX Falcon 9 rocket from seaside Launch Complex 39A at NASA’s Kennedy Space Center in Florida during a lengthy 2 hour window.

We can also confirm that the launch contract was arranged as a commercial enterprise under the auspices of Northrop Grumman Corporation – as a means to significantly slash launch costs for whatever U.S government entity is responsible for Zuma.

That goal is completely in line with SpaceX founder and CEO Elon Musk’s entire company-wide goal in developing the Falcon and Dragon family of rockets and spaceships.

“The U.S. Government assigned Northrop Grumman the responsibility of acquiring launch services for this mission,” Lon Rains, Northrop Grumman Director of Communications, told Universe Today.

“We have procured the Falcon 9 launch service from SpaceX.”

The launch window at pad 39A opens at 8 p.m. EST (0100 GMT). It extends for two full hours until 10 p.m. EST (0300 GMT).

We can further confirm that the launch was postponed a day to Thursday from the originally slated Wednesday night target – ostensibly to deal with last minute ‘mission assurance issues to insure the rocket and payload are ready for a launch upon which SpaceX’s reputation is on the line for future high value national security payloads of the most critical importance to the US governments Defense and Spy agencies

“SpaceX is now targeting Thursday, Nov. 16 for launch of the Zuma mission,” said SpaceX spokesman John Taylor.

“Both Falcon 9 and the payload remain healthy; teams will use the extra day to conduct some additional mission assurance work in advance of launch.”

Covert Zuma spysat is encapsulated inside the nose cose at the top of the SpaceX Falcon 9 rocket in this up-close view from Launch Complex 39A at the Kennedy Space Center, FL, taken on Nov. 16, 2017. Launch reset to Nov. 17, 2017. Credit: Ken Kremer/Kenkremer.com

You can watch the launch live on a SpaceX dedicated webcast starting about 10 minutes prior to the 8 p.m. EDT (0100 GMT) liftoff time.

Watch the SpaceX broadcast live at: SpaceX.com/webcast

The launch window for the newly built booster extends for two hours until it closes at 10 p.m. EDT (0300 GMT).

The weather outlook is rather favorable along the Florida Space Coast with a 90% chance of favorable conditions at launch time according to U.S. Air Force meteorologists with the 45th Space Wing Weather Squadron at Patrick Air Force Base.

The primary concerns on Nov. 16 are only for the Cumulous Cloud Rule.

The odds get even high at greater than 90% favorable for the 24 hour scrub turnaround day Nov 17.

The launch window remains the same on Nov 17 at 8 to 10 p.m.

SpaceX Falcon 9 booster deploys quartet of landing legs moments before precision propulsive ground touchdown at Landing Zone 1 on Canaveral Air Force Station barely nine minutes after liftoff from Launch Complex 39A on 3 June 2017 from the Kennedy Space Center in Florida on the Dragon CRS-11 resupply mission to the International Space Station for NASA. Credit: Ken Kremer/Kenkremer.com

Furthermore the two stage 229-foot-tall (70-meter-tall) Falcon 9 rocket was raised to vertical launch position later today Wednesday afternoon Nov. 15 – so everything seems to be in place for a Thursday evening launch attempt.

The first stage landing legs attached to the side of the Falcon 9 booster are seen up close as the rocket awaits blastoff with the unclaimed Zuma surveillance satellite from Launch Complex 39A at the Kennedy Space Center, FL, set for liftoff on Nov. 17, 2017. Credit: Ken Kremer/Kenkremer.com

However we don’t know anything about the ‘Zuma’ payloads characteristics and vital statistics – despite the seemingly endless leaks streaming out of Washington these days.

“The Zuma payload is a restricted payload,” Rains told me.

So quite naturally we’re all curious for any nugget of information from which we might draw some reasonable conclusions based on the scientific method of analysis.

The little bits we do know is that the launch services for the ownerless government payload are being procured by Northrop Grumman Corporation under a commercial contract with a stated goal to find a develop a “cost effective approach”

“Northrop Grumman is proud to be a part of the Zuma launch,” Rains added.

“This event represents a cost effective approach to space access for government missions.”

One juicy tidbit we do know is that it is intended for launch to low Earth orbit (LEO).

“It will be launched into Low Earth Orbit,” Rains informed me.

Low Earth Orbit extends upwards to roughly 1200 miles altitude and includes the ISS orbit for example at approx. 250 miles.

“As a company, Northrop Grumman realizes this is a monumental responsibility and we have taken great care to ensure the most affordable and lowest risk scenario for Zuma.”

In addition to launch services Northrop Grumman Corporation may have manufactured the Zuma payload – although that’s not even known.

SpaceX Falcon 9 stands erect at sunrise with KoreaSat5A DTH TV commercial comsat atop Launch Complex 39A at the Kennedy Space Center, FL, poised for Halloween eve liftoff on 30 Oct 2017. As seen from inside the pad perimeter. Credit: Ken Kremer/Kenkremer.com

SpaceX has successfully launched a pair of diverse national security payloads this year already with identified customers. Namely the NROL-76 surveillance satellite for the NRO on May 1, 2017 and the OTV-5 military spaceplane for the USAF on Sept. 7.

SpaceX Falcon 9 rocket carrying classified NROL-76 surveillance satellite for the National Reconnaissance Office successfully launches shortly after sunrise from Launch Complex 39A on 1 May 2017 from NASA’s Kennedy Space Center in Florida. 1st stage accomplished successful ground landing at the Cape nine minutes later. Credit: Ken Kremer/Kenkremer.com

The long launch window should significantly increase the chance of launching Zuma and removing any errant or intentional boaters and flyers from the restricted airspace around the launch pads.

That’s increasingly important these days given that a pair of critical NASA science mission this week and in the past 3 days were scrubbed near T Zero on both US East and West coast launch pads in Virginia for the Orbital ATK Antares rocket and in California for the ULA Delta II rocket.

‘Homeless’ government satellites not even claimed by the NRO are rather rare.

A recent example is Clio, an unclaimed mission from Lockheed Martin.

Clio launched at night on a ULA Atlas V on September 16, 2014 from Space Launch Complex-41 on Cape Canaveral Air Force Station, Fl.

Mysterious CLIO payload shrouded beneath 4-meter-diameter payload fairing in this up close view of the top of the United Launch Alliance (ULA) Atlas V rocket prior to launch from Space Launch Complex-41 on Cape Canaveral Air Force Station, Fla. Credit: Ken Kremer – kenkremer.com

Watch for Ken’s continuing onsite coverage of SpaceX Zuma, KoreaSat-5A & SES-11, ULA NROL-52 and NASA and space 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

………….

Ken’s upcoming outreach events:

Learn more about the upcoming SpaceX Falcon 9 Zuma launch on Nov 16, 2017, upcoming Falcon Heavy and CRS-13 resupply launches, NASA missions, ULA Atlas & Delta launches, SpySats and more at Ken’s upcoming outreach events at Kennedy Space Center Quality Inn, Titusville, FL:

Nov 17: “SpaceX Falcon 9 Zuma launch, ULA Atlas NRO NROL-52 spysat launch, SpaceX SES-11, CRS-13 resupply launches to the ISS, Intelsat35e, BulgariaSat 1 and NRO Spysat, SLS, Orion, Commercial crew capsules from Boeing and SpaceX , Heroes and Legends at KSCVC, GOES-R weather satellite launch, OSIRIS-Rex, Juno at Jupiter, InSight Mars lander, SpaceX and Orbital ATK cargo missions to the ISS, ULA Delta 4 Heavy spy satellite, Curiosity and Opportunity explore Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

USAF X-37B military spaceplane blasts off with picturesque water reflections at 10 a.m. EDT (1400 UTC) Sept. 7, 2017 on a SpaceX Falcon 9 rocket from Launch Complex 39A at the Kennedy Space Center. Credit: Ken Kremer/kenkremer.com

Zuma satellite mission patch. Credit: SpaceX/Northrop Grumman

United Launch Alliance (ULA) Atlas V rocket carrying the CLIO mission for Lockheed Martin Space Systems Company launched at 8:10 p.m. EDT September 16, 2014 from Space Launch Complex-41 on Cape Canaveral Air Force Station, Fla. Credit: Ken Kremer – kenkremer.com

November 15, 2017 by Matt Williams

Closest Potentially-Habitable World Found Around “Quiet” Star

This artist's impression shows the temperate planet Ross 128 b, with its red dwarf parent star in the background. Credit: ESO/M. Kornmesser

In August of 2016, the European Southern Observatory (ESO) announced the discovery of a terrestrial (i.e. rocky) extra-solar planet orbiting within the habitable zone of the nearby Proxima Centauri star system, just 4.25 light-years away. Naturally, news of this was met with a great deal of excitement. This was followed about six months later with the announcement of a seven-planet system orbiting the nearby star of TRAPPIST-1.

Well buckle up, because the ESO just announced that there is another potentially-habitable planet in our stellar neighborhood! Like Proxima b, this exoplanet – known as Ross 128b – is relatively close to our Solar System (10.8 light years away) and is believed to be temperate in nature. But on top of that, this rocky planet has the added benefit of orbiting a quiet red dwarf star, which boosts the likelihood of it being habitable.

The discovery paper, titled “A temperate exo-Earth around a quiet M dwarf at 3.4 parsecs“, was recently released by the ESO. The discovery team was led by Xavier Bonfils of the University of Grenoble Alpes, and included members from the Geneva Observatory, the National Scientific and Technical Research Council (CONICET), the University of Buenos Aires, the University of Laguna, the Instituto de Astrofísica de Canarias (IAC), and the University of Porto.

The discovery was made using the ESO’s High Accuracy Radial velocity Planet Searcher (HARPS), located at the La Silla Observatory in Chile. This observatory relies on measurements of a star’s Doppler shift in order to determine if it moving back and forth, a sign that it has a system of planets. Using the HARPS data, the team determined that a rocky planet orbits Ross 128 (an M-type red dwarf star) at a distance of about 0.05 AU with a period of 9.9 days.

Despite its proximity to its host star, Ross 128b receives only 1.38 times more irradiation than the Earth. This is due to the cool and faint nature of red dwarf stars like Ross 128, which has a surface temperature roughly half that of our Sun. From this, the discovery team estimated that Ross 128b’s equilibrium temperature is likely somewhere between -60 and 20°C – i.e. close to what we experience here on Earth.

As Nicola Astudillo-Defru of the Geneva Observatory – and a co-author on the discovery paper – indicated in an ESO press release:

“This discovery is based on more than a decade of HARPS intensive monitoring together with state-of-the-art data reduction and analysis techniques. Only HARPS has demonstrated such a precision and it remains the best planet hunter of its kind, 15 years after it began operations.”

But what is most encouraging is the fact that Ross 128 is the “quietest” nearby star that is also home to an exoplanet. Compared to other classes of stars, M-type red dwarfs are particularly low in mass, dimmer and cooler. They are also the most common type of star in the Universe, accounting for 70% of the stars in spiral galaxies and more than 90% of all stars in elliptical galaxies.

Unfortunately, they are also variable and unstable compared to other classes of star, which means they experience regular flare ups. This means that any planets which orbit them will be periodically subjected to deadly ultraviolet and X-ray radiation. In comparison, Ross 128 is much quieter, meaning it experiences less in the way of flare activity, and planets orbiting it are therefore exposed to less radiation over time.

This means that, relative to Proxima b or those planets located within TRAPPIST-1’s habitable zone – Ross 128b is more likely to retain an atmosphere and support life. For those who are engaged in searches for exoplanets around M-type stars – or are of the opinion that red dwarfs are the best bet for finding habitable worlds – this latest discovery would seem to confirm that they are looking in the right spots!

As noted, red dwarfs are the most common in the Universe, and in recent years, many rocky planets (sometimes even a multi-planet system) have been found orbiting these stars. Combined with their natural longevity – which can remain in their main sequence phase for up to 10 trillion years – red dwarf stars have understandably become a popular target for exoplanet-hunters.

In fact, lead author Xavier Bonfils named their HARPS program “The Shortcut to Happiness” for this very reason. As he and his colleagues indicated, it is easier to detect small cool planets of Earth around smaller, dimmer M-type stars than it is around stars that are more similar to the Sun.

However, many in the scientific community have remained skeptical about the likelihood that any of these planets could be habitable (again, due to their variable nature). But this most recent discovery, along with recent research that indicates how tidally-locked planets that orbit red dwarf stars could hold onto their atmospheres, is another possible indication that these fears may be for naught.

Being at a distance of about 11 light-years from Earth, Ross 128b is currently the second-closest exoplanet to our Sun. However, Ross 128 itself is slowly moving closer towards us and will become our nearest stellar neighbor in roughly 79,000 years. At this point, Ross 128b will replace Proxima b and become the closest exoplanet to Earth!

But of course, much remains to be found about this latest exoplanet. While the discovery team consider Ross 128b to be a temperate planet based on its orbit, it remains uncertain as to whether it lies within, beyond, or on the cusp of the star’s habitable zone. However, further studies are expected to shed more light on this and other questions relating this potentially-habitable world.

Astronomers also anticipate that more temperature exoplanets will be discovered in the coming years, and that future surveys will be able to determine a great deal more about their atmospheres, composition and chemistry. Instruments like the James Webb Space Telescope (JWST) and the ESO’s Extremely Large Telescope (ELT) are expected to play a major role.

Not only will these and other instrument help turn up more exoplanet candidates, they will also be used in the hunt for biosignatures in planet’s atmospheres (i.e. oxygen, nitrogen, water vapor, etc.). As Bonfils concluded:

“New facilities at ESO will first play a critical role in building the census of Earth-mass planets amenable to characterization. In particular, NIRPS, the infrared arm of HARPS, will boost our efficiency in observing red dwarfs, which emit most of their radiation in the infrared. And then, the ELT will provide the opportunity to observe and characterize a large fraction of these planets.”

At this juncture, the process of exoplanet discovery is moving beyond detection and getting into the process of characterization and detailed study. Even so, it is nice that we are still making groundbreaking discoveries in the field of detection. In the coming years, we may transition from looking for an Earth 2.0 to a point where weare actively studying several at once!

Further Reading: ESO, ESO (2)

November 15, 2017November 16, 2017 by Ken Kremer

S.S Gene Cernan Honoring Last Moonwalker Arrives at International Space Station Carrying Tons of Research Gear and Supplies

The Canadarm2 robotic arm is seen grappling the Orbital ATK S.S. Gene Cernan Cygnus resupply ship on Nov. 14, 2017 for berthing to the the International Space Station. Credit: NASA TV

The S.S. Gene Cernan Cygnus spacecraft named in honor of the Apollo 17 lunar landing commander and launched by Orbital ATK from the eastern shore of Virgina at breakfast time Sunday, Nov. 12, arrived at the International Space Station early Tuesday morning, Nov 14, carrying over 3.7 tons of research equipment and supplies for the six person resident crew.

Soon thereafter at 5:04 a.m., Expedition 53 Flight Engineer Paolo Nespoli of ESA (European Space Agency) assisted by NASA astronaut Randy Bresnik successfully captured Orbital ATK’s Cygnus cargo freighter using the International Space Station’s 57.7-foot-long (17.6 meter-long) Canadarm2 robotic arm.

The station was orbiting 260 statute miles over the South Indian Ocean at the moment Nespoli grappled the S.S. Gene Cernan Cygnus spacecraft with the Canadian-built robotic arm.

Nespoli and Bresnik were working at a robotics work station inside the seven windowed domed Cupola module that offers astronauts the most expansive view outside to snare Cygnus with the robotic arms end effector.

The Cygnus cargo freighter – named after the last man to walk on the Moon – reached its preliminary orbit nine minutes after blasting off early Sunday atop the upgraded 230 version of the Orbital ATK Antares rocket from NASA’s Wallops Flight Facility in Virginia.

The flawless liftoff of the two stage Antares rocket took place shortly after sunrise Sunday at 7:19 a.m. EST, Nov. 12, rocket from Pad-0A at NASA’s Wallops Flight Facility in Virginia.

Orbital ATK Antares rocket blasts off from the ‘On-Ramp’ to the International Space Station on Nov. 12, 2017 carrying the S.S. Gene Cernan Cygnus OA-8 cargo spacecraft from Pad 0A at NASA’s Wallops Flight Facility in Virginia. Credit: Ken Kremer/kenkremer.com

Sunday’s spectacular Antares launch delighted spectators – but came a day late due to a last moment scrub on the originally planned Veteran’s Day liftoff, Saturday, Nov. 11, when a completely reckless pilot flew below radar into restricted airspace just 5 miles away from the launch pad – forcing a sudden and unexpected halt to the countdown under absolutely perfect weather conditions.

After a carefully choreographed series of intricate thruster firings to raise its orbit over the next two days, the Cygnus spacecraft on the OA-8 resupply mission for NASA arrived in the vicinity of the orbiting research laboratory.

With Cygnus firmly in the grip of the robots hand, ground controllers at NASA’s Mission Control at the Johnson Space Center in Texas, maneuvered the arm towards the exterior hull and berth the cargo ship at the Earth-facing port of the stations Unity module.

1st stage capture was completed at 7:08 a. EST Nov 14.

After driving in the second stage gang of bolts, hard mate and capture were completed at 7:15 a.m.

The station was flying 252 miles over the North Pacific in orbital night at the time of berthing.

The Cygnus spacecraft dubbed OA-8 is Orbital ATK’s eighth contracted cargo resupply mission with NASA to the International Space Station under the unmanned Commercial Resupply Services (CRS) program to stock the station with supplies on a continuing and reliable basis.

NASA TV provided live coverage of the rendezvous and grappling.

Including Cygnus there are now five visiting vehicle spaceships parked at the space station including also the Russian Progress 67 and 68 resupply ships and the Russian Soyuz MS-05 and MS-06 crew ships.

International Space Station Configuration. Five spaceships are parked at the space station including the Orbital ATK Cygnus after Nov. 14, 2017 arrival, the Progress 67 and 68 resupply ships and the Soyuz MS-05 and MS-06 crew ships. Credit: NASA

Cygnus will remain at the space station until Dec. 4, when the spacecraft will depart the station and deploy several CubeSats before its fiery re-entry into Earth’s atmosphere as it disposes of several tons of trash.

On this flight, the Cygnus OA-8 spacecraft is jam packed with its heaviest cargo load to date!

Altogether over 7,400 pounds of science and research, crew supplies and vehicle hardware launched to the orbital laboratory and its crew of six for investigations that will occur during Expeditions 53 and 54.

The S.S. Gene Cernan manifest includes equipment and samples for dozens of scientific investigations including those that will study communication and navigation, microbiology, animal biology and plant biology. The ISS science program supports over 300 ongoing research investigations.

Among the experiments flying aboard Cygnus are the coli AntiMicrobial Satellite (EcAMSat) mission, which will investigate the effect of microgravity on the antibiotic resistance of E. coli, the Optical Communications and Sensor Demonstration (OCSD) project, which will study high-speed optical transmission of data and small spacecraft proximity operations, the Rodent Research 6 habitat for mousetronauts who will fly on a future SpaceX cargo Dragon.

Cernan was commander of Apollo 17, NASA’s last lunar landing mission and passed away in January at age 82. He set records for both lunar surface extravehicular activities and the longest time in lunar orbit on Apollo 10 and Apollo 17.

The prime crew for the Apollo 17 lunar landing mission are: Commander, Eugene A. Cernan (seated), Command Module pilot Ronald E. Evans (standing on right), and Lunar Module pilot, Harrison H. Schmitt (left). They are photographed with a Lunar Roving Vehicle (LRV) trainer. Cernan and Schmitt used an LRV during their exploration of the Taurus-Littrow landing site. The Apollo 17 Saturn V Moon rocket is in the background. This picture was taken during October 1972 at Launch Complex 39A, Kennedy Space Center (KSC), Florida. Credit: Julian Leek

Under the Commercial Resupply Services-1 (CRS-1) contract with NASA, Orbital ATK will deliver approximately 66,000 pounds (30,000 kilograms) of cargo to the space station. OA-8 is the eighth of these missions.

The Cygnus OA-8 spacecraft is Orbital ATK’s eighth contracted cargo resupply mission with NASA to the International Space Station under the unmanned Commercial Resupply Services (CRS) program to stock the station with supplies on a continuing basis.

Beginning in 2019, the company will carry out a minimum of six cargo missions under NASA’s CRS-2 contract using a more advanced version of Cygnus.

Watch for Ken’s continuing Antares/Cygnus mission and launch reporting from on site at NASA’s Wallops Flight Facility, VA during the launch campaign.

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

Ken Kremer

Launch of Apollo17, NASA’s final lunar landing mission, on December 7, 1972, as seen from the KSC press site. Credit: Mark and Tom Usciak

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Ken’s upcoming outreach events:

Nov 15, 17: “SpaceX Falcon 9 Zuma launch, ULA Atlas NRO NROL-52 spysat launch, SpaceX SES-11, CRS-13 resupply launches to the ISS, Intelsat35e, BulgariaSat 1 and NRO Spysat, SLS, Orion, Commercial crew capsules from Boeing and SpaceX , Heroes and Legends at KSCVC, GOES-R weather satellite launch, OSIRIS-Rex, Juno at Jupiter, InSight Mars lander, SpaceX and Orbital ATK cargo missions to the ISS, ULA Delta 4 Heavy spy satellite, Curiosity and Opportunity explore Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

Portrait of NASA astronaut Gene Cernan and floral wreath displayed during the Jan. 18, 2017 Remembrance Ceremony at the Kennedy Space Center Visitor Complex, Florida, honoring his life as the last Man to walk on the Moon. Credit: Ken Kremer/kenkremer.com

The next Orbital ATK Cygnus supply ship was christened the SS John Glenn in honor of Sen. John Glenn, one of NASA’s original seven astronauts as it stands inside the Payload Hazardous Servicing Facility at NASA’s Kennedy Space Center. Credit: Ken Kremer/Kenkremer.com

Orbital ATK’s eighth contracted cargo delivery flight to the International Space Station successfully launched at 7:19 a.m. EST on an Antares rocket from Pad 0A at NASA’s Wallops Flight Facility in Virginia, Sunday, Nov. 12, 2017 carrying the Cygnus OA-8 resupply spacecraft. Credit: Ken Kremer/kenkremer.com

Sunset launchpad view of Orbital ATK Antares rocket and Cygnus OA-8 resupply spaceship the evening before blastoff to the International Space Station on Nov. 11, 2017. Credit: Ken Kremer/kenkremer.com

November 14, 2017 by Matt Williams

NASA’s Next-Generation Spaceplane Passes Free Flight Test

Sierra Nevada Corp’s Dream Chaser lands on Edwards Air Force Base in California. The spacecraft went through preparations for flight at NASA’s Armstrong Flight Research Center. Credits: NASA/Carla Thomas

It’s called the Dream Chaser, a reusable spaceplane that will one day transport cargo and crews to the International Space Station. For the past ten years, the Sierra Nevada Corporation and NASA have been developing and testing this next-generation space vehicle. When it is ready, this vehicle will not only provide a more cost-effective way of servicing the ISS, it will also help restore domestic launch capability to the United States.

On Saturday, November 11th, the Dream Chaser passed an important milestone by conducting a successful free flight test. This took place at Edwards Air Force Base in California, and verified the spaceplane’s ability to glide and land autonomously. This, in addition to verifying several key avionic and flight systems, is a strong indication that the spaceplane will be capable of conducting runs to and from Low-Earth Orbit (LEO) in the near future.

This test involved the spaceplane being lifted to an altitude of 3,780 meters (12,400 feet) and then let go to glide freely. It then deployed its landing gears and touched down on the Edwards Air Force Base runway before coming to a full stop. This runway, it should be noted, is very similar to the Kennedy Space Center Shuttle Landing Facility runway that the Dream Chaser will land on once it is operational.

This flight test validated the performance of the Dream Chaser during what is arguably the most critical part of a mission – the approach and landing phase – which will be the final phase of future flights from the ISS. The ability to conduct automated landings is central to the spaceplane’s reusability, which operates in much the same way as the now-retired Space Shuttle did.

This process entails the craft being launched into orbit aboard a rocket (Atlas V or Ariane 5), maneuvering under its own power while in orbit so that it can dock with the ISS (or other orbiting facilities), and then re-entering the atmosphere and returning to a landing strip. As Mark Sirangelo, the corporate vice president of SNC’s Space System business area, said in a company press release:

“The Dream Chaser flight test demonstrated excellent performance of the spacecraft’s aerodynamic design and the data shows that we are firmly on the path for safe, reliable orbital flight.”

The flight test also helped advance the vehicle as part of NASA’s Commercial Crew Program and prepare it for service under Commercial Resupply Services 2 program. These programs consist of NASA working closely with private aerospace companies to develop new spacecraft and launch systems that will be capable of carrying crews to locations in LEO and to the ISS.

Front-end view of the Dream Chaser spaceplane. Credit: Sierra Nevada Corporation

This approach and landing test expands on the phase one flight test, which took place back in October of 2013. For this free-flight test, the vehicle was released from a “skycrane” helicopter and flew a short flight, touching down less than a minute later. Just prior to landing, the left main landing gear failed to deploy resulting in a crash landing. However, the vehicle and its crew compartment were left intact.

For the second flight test, SNC and NASA incorporated orbital vehicle avionics and flight software for the first time. The trajectory also included specific program test inputs which, together with the added software, provided validations for orbital vehicle operations. Over the coming days and weeks, SNC and NASA will be evaluating all the data obtained during the flight, which includes the Dream Chaser aerodynamic and integrated system performance.

The data that SNC gathers from this test campaign will help inform the final design of the cargo Dream Chaser, which will be capable of transporting crews of six astronauts to the ISS. As Fatih Ozmen, the CEO of SNC, exclaimed:

“I’m so proud of the Dream Chaser team for their continued excellence. This spacecraft is the future and has the ability to change the way humans interact with space, and I couldn’t be happier with SNC’s dedicated team and the results of the test.”

If all goes well, SNC and NASA are hoping to begin conducting cargo deliveries by 2019. By 2024, it is hoped that a total of six cargo delivery missions will take place. No indications have been given as to when the crewed variant could start bringing astronauts to the ISS. But once that is possible, NASA will no longer be forced to rely on Roscosmos and their fleet of Soyuz rockets to send astronauts into space.

Be sure to check out this video of the Dream Chaster Cargo System, courtesy of Sierra Nevada Corporation:

Further Reading: NASA, Sierra Nevada

November 14, 2017November 15, 2017 by Ken Kremer

Despite Merlin Engine Testing Anomaly SpaceX Forges Ahead With Ambitious Year End Launch Schedule Commencing Nov. 15

A Falcon 9 Merlin 1D engine during hot fire engine test firing on a test stand in McGregor, Texas in this February 2012 file photo. Credit: SpaceX

KENNEDY SPACE CENTER, FL – Despite suffering a significant engine testing “anomaly” and fire during test protocols with a Merlin engine that powers both stages of SpaceX’s Falcon 9 rocket, the Elon Musk founded company is forging ahead with an ambitious year end launch schedule that commences this week with blastoff of the secretive Zuma mission on Wednesday evening, Nov. 15. Clearly Musk & Co. feel it is safe to proceed.

While preparing to conduct a test firing of the most advanced Merlin engine of the type that will launch astronauts to the International Space Station (ISS) as soon as next year, something sparked the outbreak of a fire in a test bay earlier this month on a SpaceX engine test stand at their rocket development facility in McGregor, Texas, SpaceX spokesman John Taylor confirmed to Universe Today.

The resulting fire in a McGregor, Texas test bay apparently did not involve an engine explosion as technicians were getting ready to conduct an actual hot fire test. The fire may have occurred as a result of a leak while setting the Merlin engine up on a test stand during pre-test procudures. Details have not been released.

“We do not expect this to have any impact on our launch cadence,” SpaceX spokesman John Taylor told Universe Today.

“SpaceX is committed to our current manifest.”

Since the fire involved the most advanced Block 5 version of the Merlin rather than the currently used Block 4 version, SpaceX engineers and management decided they can safely and responsibly move forward with the upcoming jam packed schedule of Falcon 9 and Falcon Heavy launches, while simultaneously continuing the anomaly investigation.

2017 has been a banner year thus far for SpaceX involving 16 missions to date that ties a ULA record established in 2009.

The most recent launch took place of Oct. 30 delivering KoreaSat-5A to its intended orbit – along with a magnificent soft landing and recovery of the first stage booster on an oceangoing platform that floated ‘back in town’ days later.

SpaceX Falcon 9 blasts off with KoreaSat-5A commercial telecomsat atop Launch Complex 39A at the Kennedy Space Center, FL, on Halloween eve 30 Oct 2017. As seen from inside the pad perimeter. Credit: Ken Kremer/Kenkremer.com

The fire took place on Nov. 4, as first reported by the Washington Post on Nov. 9.

“On November 4, SpaceX experienced an anomaly during a Qualification test set up of a Merlin engine at our rocket development facility in McGregor, Texas,” SpaceX spokesman Taylor told me.

With a slew of critical launches looming starting tomorrow, Nov. 15, SpaceX had to decide quickly whether to pause or move ahead with their final planned launches of 2017 – numbering at least 4 or more and possibly including the long-awaited and long-delayed mammoth Falcon Heavy. It utilizes 27 Merlin 1D engines in the first stage cores.

SpaceX has decided to move ‘Full Speed Ahead’ – after an initial review of the fire incident which is still ongoing.

Seemingly, the fire happened during the set up period for the Merlin engine before the actual qualification engine test had begun. A leak may have occurred around the test stand and caused the fire to brake out.

Although 2017 has been a great year, SpaceX has suffered two catastrophic rocket accidents in 2015 and 2016 as a result of unrelated failures traced to the second stage which slowed down the launch pace as engineers raced to identify and rectify the root causes.

Engineers were conducting a pre-test operation when the test bay fire broke out. It may take a few weeks or more to repair the test stand and resume hot fire testing.

SpaceX has notified customers such as NASA, the FAA and the USAF about the incident – for which SpaceX plans a Dragon cargo resupply mission to the ISS launching as soon as Dec. 4 from Cape Canaveral Air Force Station, FL.

“We are now conducting a thorough and fully transparent investigation of the root cause.”

Fortunately there were no injuries to any personal.

“No one was injured and all safety protocols were followed during the time of this incident,” Taylor explained.

The Merlin engine about to be tested involved the most advanced type known as the Block 5 version that will be used to propel astronauts to orbit inside the SpaceX Crew Dragon.

Up close look as technicians quickly work to detach all 4 landing legs from the recovered SpaceX Falcon 9 Koreasat-5A booster on Nov. 3, 2017 after it sailed into Port Canaveral the day before. Credit: Ken Kremer/Kenkremer.com

The Falcon 9 is currently powered by 9 Merlin 1D engines of the Block 4 version.

Altogether they generate a combined 1.7 million pounds of liftoff thrust.

SpaceX can continue launches with the less advanced Merlin 1D version because testing of Block 4 is still happening.

Meanwhile launch preparations are in full swing for Wednesday’s nighttime blastoff of the mysterious Zuma mission for the U.S. government at 8 p.m. EST on Nov. 15 from pad 39A on NASA’s Kennedy Space Center.

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

Ken Kremer

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Learn more about the upcoming SpaceX Falcon 9 Zuma launch on Nov 15, 2017, upcoming Falcon Heavy and CRS-13 resupply launches, NASA missions, ULA Atlas & Delta launches, SpySats and more at Ken’s upcoming outreach events at Kennedy Space Center Quality Inn, Titusville, FL:

Nov 14, 16: “SpaceX Falcon 9 Zuma launch, ULA Atlas NRO NROL-52 spysat launch, SpaceX SES-11, CRS-13 resupply launches to the ISS, Intelsat35e, BulgariaSat 1 and NRO Spysat, SLS, Orion, Commercial crew capsules from Boeing and SpaceX , Heroes and Legends at KSCVC, GOES-R weather satellite launch, OSIRIS-Rex, Juno at Jupiter, InSight Mars lander, SpaceX and Orbital ATK cargo missions to the ISS, ULA Delta 4 Heavy spy satellite, Curiosity and Opportunity explore Mars, Pluto and more,” Kennedy Space Center Quality Inn, Titusville, FL, evenings

SpaceX Falcon 9 first stage booster is hoisted off OCISLY droneship after being towed through the channel of Port Canaveral, FL on Nov. 2. It successfully launched KoreaSat-5A telecomsat to orbit on Oct. 30, 2017. Credit: Ken Kremer/Kenkremer.com

November 14, 2017 by Matt Williams

Triton’s Arrival was Chaos for the Rest of Neptune’s Moons

Artist's impression of what the surface of Triton may look like. Credit: ESO

The study of the Solar System’s many moons has revealed a wealth of information over the past few decades. These include the moons of Jupiter – 69 of which have been identified and named – Saturn (which has 62) and Uranus (27). In all three cases, the satellites that orbit these gas giants have prograde, low-inclination orbits. However, within the Neptunian system, astronomers noted that the situation was quite different.

Compared to the other gas giants, Neptune has far fewer satellites, and most of the system’s mass is concentrated within a single satellite that is believed to have been captured (i.e. Triton). According to a new study by a team from the Weizmann Institute of Science in Israel and the Southwest Research Institute (SwRI) in Boulder, Colorado, Neptune may have once had a more massive systems of satellites, which the arrival of Triton may have disrupted.

The study, titled “Triton’s Evolution with a Primordial Neptunian Satellite System“, recently appeared in The Astrophysical Journal. The research team consisted of Raluca Rufu, an astrophysicist and geophysicist from the Weizmann Institute, and Robin M. Canup – the Associate VP of the SwRI. Together, they considered models of a primordial Neptunian system, and how it may have changed thanks to the arrival of Triton.

*Neptune and its large moon Triton as seen by Voyager 2 on August 28th, 1989. Credit: NASA*

For many years, astronomers have been of the opinion that Triton was once a dwarf planet that was kicked out of the Kuiper Belt and captured by Neptune’s gravity. This is based on its retrograde and highly-inclined orbit (156.885° to Neptune’s equator), which contradicts current models of how gas giants and their satellites form. These models suggest that as giant planets accrete gas, their moons form from a surrounding debris disk.

Consistent with the other gas giants, the largest of these satellites would have prograde, regular orbits that are not particularly inclined relative to their planet’s equator (typically less than 1°). In this respect, Triton is believed to have once been part of a binary made up of two Trans-Neptunian Objects (TNOs). When they swung past Neptune, Triton would have been captured by its gravity and gradually fell into its current orbit.

As Dr. Rufu and Dr. Canup state in their study, the arrival of this massive satellite would have likely caused a lot of disruption in the Neptunian system and affected its evolution. This consisted of them exploring how interactions – like scattering or collisions – between Triton and Neptune’s prior satellites would have modified Triton’s orbit and mass, as well as the system at large. As they explain:

“We evaluate whether the collisions among the primordial satellites are disruptive enough to create a debris disk that would accelerate Triton’s circularization, or whether Triton would experience a disrupting impact first. We seek to find the mass of the primordial satellite system that would yield the current architecture of the Neptunian system.”

*Montage of Neptune’s largest moon, Triton and the planet Neptune showing the moon’s sublimating south polar cap (bottom) and enigmatic “cantaloupe terrain”. Credit: NASA*

To test how the Neptunian system could have evolved, they considered different types of primordial satellite systems. This included one that was consistent with Uranus’ current system, made up of prograde satellites with a similar mass ration as Uranus’ largest moons – Ariel, Umbriel, Titania and Oberon – as well as one that was either more or less massive. They then conducted simulations to determine how Triton’s arrival would have altered these systems.

These simulations were based on disruption scaling laws which considered how non-hit-and-run impacts between Triton and other bodies would have led to a redistribution of matter in the system. What they found, after 200 simulations, was that a system that had a mass ratio that was similar to the current Uranian system (or smaller) would have been most likely to produce the current Neptunian system. As they state:

“We find that a prior satellite system with a mass ratio similar to the Uranian system or smaller has a substantial likelihood of reproducing the current Neptunian system, while a more massive system has a low probability of leading to the current configuration.”

They also found that the interaction of Triton with an earlier satellite system also offers a potential explanation for how its initial orbit could have been decreased fast enough to preserve the orbits of small irregular satellites. These Nereid-like bodies would have otherwise been kicked out of their orbits as tidal forces between Neptune and Triton caused Triton to assume its current orbit.

*The moons of Uranus and Neptune as imaged during the 2011 opposition season. Credit: Rolf Wahl Olsen.*

Ultimately, this study not only offers a possible explanation as to why Neptune’s system of satellites differs from those of other gas giants; it also indicates that Neptune’s proximity to the Kuiper Belt is what is responsible. At one time, Neptune may have had a system of moons that were very much like those of Jupiter, Saturn, and Uranus. But since it is well-situated to pick up dwarf planet-sized objects that were kicked out of the Kuiper Belt, this changed.

Looking to the future, Rufu and Canup indicate that additional studies are needed in order to shed light on Triton’s early evolution as a Neptunian satellite. Essentially, there are still unanswered questions concerning the effects the system of pre-existing satellites had on Triton, and how stable its irregular prograde satellites were.

These findings were also presented by Dr, Rufu and Dr. Canup during the 48th Lunar and Planetary Science Conference, which took place in The Woodlands, Texas, this past March.

Further Reading: The Astronomical Journal, USRA

November 13, 2017 by Matt Williams

Dinosaur Killing Asteroid hit Earth in Exactly the Wrong Spot

Earth and possibly its Moon were hit by impactors that killed off the dinosaurs — Artistic rendition of the Chicxulub impactor striking ancient Earth, with Pterosaur observing. Could pieces of the same impact swarm have hit the Moon, too? Credit: NASA

Sixty-six million years ago, an asteroid struck Earth in what is now the Yucatan Peninsula in southern Mexico. This event, known as the Chicxulub asteroid impact, measured 9 km in diameter and caused extreme global cooling and drought. This led to a mass extinction, which not only claimed the lives of the dinosaurs, but also wiped out about 75% of all land and sea animals on Earth.

However, had this asteroid impacted somewhere else on the planet, things could have turned out very differently. According to a new study produced by a team of Japanese researchers, the destruction caused by this asteroid was due in large part to where it impacted. Had the Chicxulub asteroid landed somewhere else on the planet, they argue, the fallout would not have been nearly as severe.

The study, which recently appeared in the journal Scientific Reports, is titled “Site of asteroid impact changed the history of life on Earth: the low probability of mass extinction“, and was conducted by Kunio Kaiho and Naga Oshima of Tohoku University and the Meteorological Research Institute, respectively. For the sake of their study, the pair considered how geological conditions in the Yucatan region were intrinsic to mass extinction that happened 66 million years ago.

*Satellite views of the Chicxulub impact site in the Yucutan Peninsula, southern Mexico. Image credit: NASA/JPL*

Dr. Kaiho and Dr. Oshima began by considering recent studies that have shown how the Chicxulub impact heated the hydrocarbon and sulfur content of rocks in the region. This is what led to the formation of stratospheric soot and sulfate aerosols which caused the extreme global cooling and drought that followed. As they state in their study, it was this (not the impact and the detritus it threw up alone) that ensured the mass extinction that followed:

“Blocking of sunlight by dust and sulfate aerosols ejected from the rocks at the site of the impact (impact target rocks) was proposed as a mechanism to explain how the physical processes of the impact drove the extinction; these effects are short-lived and therefore could not have driven the extinction. However, small fractions of stratospheric sulfate (SO4) aerosols were also produced, which may have contributed to the cooling of the Earth’s surface.“

Another issue they considered was the source of the soot aerosols, which previous research has indicated were quite prevalent in the stratosphere during the Cretaceous/Paleogene (K–Pg) boundary (ca. 65 million years ago). This soot is believed to coincide with the asteroid impact since microfossil and fossil pollen studies of this period also indicate the presence of iridium, which has been traced to the Chicxulub asteroid.

Previously, this soot was believed to be the result of wildfires that raged in the Yucatan as a result of the asteroid impact. However, Kaiho and Oshima determined that these fires could not have resulted in stratospheric soot; instead positing that they could only be produced by the burning and ejecting of hyrdocarbon material from rocks in the impact target area.

When an asteroid struck the Yucatan region about 66 million years ago, it wiped out the dinosaurs, and most of life on Earth. If it had hit elsewhere, the dinosaurs might well have survived. Credit: NASA/Don Davis

The presence of these hydrocarbons in the rocks indicate the presence of both oil and coal, but also plenty of carbonate minerals. Here too, the geology of the Yucatan was key, since the larger geological formation known as the Yucatan Platform is known to be composed of carbonate and soluble rocks – particularly limestone, dolomite and evaporites.

To test just how important the local geology was to the mass extinction that followed, Kaiho and Oshima conducted a computer simulation that took into account where the asteroid struck and how much aerosols and soot would be produced by an impact. Ultimately, they found that the resulting ejecta would have been sufficient to trigger global cooling and drought; and hence, an Extinction Level Event (ELE).

This sulfur and carbon-rich geology, however, is not something the Yucatan Peninsula shares with most regions on the planet. As they state in their study:

“Here we show that the probability of significant global cooling, mass extinction, and the subsequent appearance of mammals was quite low after an asteroid impact on the Earth’s surface. This significant event could have occurred if the asteroid hit the hydrocarbon-rich areas occupying approximately 13% of the Earth’s surface. The site of asteroid impact, therefore, changed the history of life on Earth.”

*Mass extinction only occurred when the asteroid having 9-km diameter hit the orange areas. Credit: Kunio Kaiho*

Basically, Kaiho and Oshima determined that 87% of Earth would not have been able to produce enough sulfate aerosols and soot to trigger a mass extinction. So if the Chicxulub asteroid struck just about anywhere else on the planet, the dinosaurs and most of the world’s animals would have likely survived, and the resulting macroevolution of mammals probably would not have taken place.

In short, modern hominids may very well owe their existence to the fact that the Chicxulub asteroid landed where it did. Granted, the majority of life in the Cretaceous/Paleogene (K–Pg) was wiped out as a result, but ancient mammals and their progeny appear to have lucked out. The study is therefore immensely significant in terms of our understanding of how asteroid impacts affect climatological and biological evolution.

It is also significant when it comes to anticipating future impacts and how they might affect our planet. Whereas a large impact in a sulfur and carbon-rich geological region could lead to another mass extinction, an impact anywhere else could very well be containable. Still, this should not prevent us from developing appropriate countermeasures to ensure that large impacts don’t happen at all!

Further Reading: Science Reports