Universe Today

November 4, 2016 by Matt Williams

SpaceX’s Fueling Process Makes NASA Queasy

SpaceX and NASA find themselves at odds over the company's fueling policy. Credit: SpaceX

On September 1st, 2016, SpaceX experienced a rather public setback when one of their Falcon 9 rockets exploded on its launchpad at the Cape Canaveral Launch Complex in Florida. Though the accident resulted in no fatalities or injuries, this accident has since raised concerns over at NASA concerning the company’s safety standards.

Such was the conclusion reached by NASA’s Space Station Advisory Committee, which met on Monday, Oct. 31st, to discuss the accident and make recommendations. In a statement, the committee indicated that SpaceX’s policy of fueling rockets immediately before launch could pose a serious threat to crewed missions.

These concerns have been expressed before, but have become all the more relevant in light of the recent accident. At the time of the explosion, the rocket was already outfitted with its cargo capsule (which contained the Spacecom Amos-6 communications satellite). In the future, SpaceX hopes to send crewed missions into space, which means crews’ lives could be at risk in the event that a similar accident takes place during fueling.

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 — SpaceX Launch Complex-40, as seen from the VAB roof after the fueling test explosion destroyed the Falcon 9 rocket and AMOS-6 payload at Cape Canaveral Air Force Station. Credit: Ken Kremer/kenkremer.com

Lt. General Thomas Stafford (USAF), who chaired the committee, was especially emphatic about the need for SpaceX to review its fueling policy. According to The Wall Street Journal, this is the second time that Lt. Gen. Stafford has expressed concerns. The last time was in 2015, when he sent a letter to NASA arguing that the company’s policy of fueling a rocket with its cargo already on board went against decades of procedure.

In the past, NASA has always maintained a policy where a rocket’s cargo is added only after the rocket is fueled. The same goes for crewed missions, where astronauts would board the rocket or Shuttle only after all pre-flight procedures were finished. But in the age of NewSpace, and with private companies offering launch services, things work a little differently.

For example, SpaceX Falcon 9 rocket relies on a combination of liquid oxygen and rocket-grade kerosene propellant, which has less mass than conventional rocket fuel. This lets them pack more fuel into their rockets, and to be able to place larger payloads into orbit. However, this method requires that the rocket be immediately fueled before launch so that the fuel does not have time to warm up and expand.

As a result, future missions – which include crewed ones – will have to be fueled immediately before launch in order to ensure that the rocket’s fuel and lift capacity are not compromised. The Advisory Committee’s recommendations could therefore have a significant impact on how SpaceX does business. However, there recommendations might be a bit premature as far as crewed missions go.

For instance, the Dragon V2 has a crew abort system that was specifically designed for this kind of situation. Relying on the capsule’s eight side-mounted SuperDraco engines, this system is programmed to conduct a propulsive firing in the event of a catastrophic failure on the launchpad. The capsule also comes with a landing chute which will deploy once the rockets are depleted to ensure that it makes a soft landing.

In May of 2015, the company tested this system at the Cape Canaveral Launch Complex, followed by a “propulsive hovering test” in November of that same year. Both tests were successful and demonstrated how the SuperDraco engines are capable of launching the capsule to safety, and that they were capable of keeping the capsule in a state of equilibrium above the ground (see video above).

In addition, SpaceX responded to news of the Advisory Panel and expressed confidence in its procedures, which included fueling and their launch abort system. In an official statement, the full text of which was procured by Universe Today via email, the company said that:

“SpaceX has designed a reliable fueling and launch process that minimizes the duration and number of personnel exposed to the hazards of launching a rocket. As part of this process, the crew will safely board the Crew Dragon, ground personnel will depart, propellants will be carefully loaded over a short period, and then the vehicle will launch. During this time the Crew Dragon launch abort system will be enabled. Over the last year and a half, NASA and SpaceX have performed a detailed analysis of all potential hazards with this process.”

*A Falcon 9 test firing its nine first-stage Merlin engines at Cape Canaveral Air Force Station in Feb of 2015. Credit: NASA/Frankie Martin*

In addition, they cited that prior to the Sept.1st accident, all safety protocols had been followed and NASA had signed off on the launch. But of course, they also expressed that they would continue to comply with all safety procedures, which could include any changes based on the Advisory Committee’s recommendations:

“The hazard report documenting the controls was approved by the NASA’s Safety Technical Review Board in July 2016. As with all hazard analyses across the entire system and operations, controls against those hazards have been identified, and will be implemented and carefully verified prior to certification. There will be continued work ahead to show that all of these controls are in place for crewed operations and that the verifications meet NASA requirements. These analyses and controls will be carefully evaluated in light of all data and corrective actions resulting from the anomaly investigation. As needed, any additional controls will be put in place to ensure crew safety, from the moment the astronauts reach the pad, through fueling, launch, and spaceflight, and until they are brought safely home.”

In the meantime, SpaceX investigators are still attempting to find out exactly what went wrong with the Sept.1st launch. The most recent update (which was made on Oct. 28th) indicated that the company is making headway, and hoping to return to normal operations during the month of November.

“SpaceX’s efforts are now focused on two areas – finding the exact root cause, and developing improved helium loading conditions that allow SpaceX to reliably load Falcon 9,” it states. “With the advanced state of the investigation, we also plan to resume stage testing in Texas in the coming days, while continuing to focus on completion of the investigation.”

Further Reading: WSJ

November 4, 2016March 3, 2017 by Fraser Cain

Astronomy Cast Ep. 427: Click Bait vs Clear Science

Did you hear that Dark Energy doesn’t exist any more? Neither does Dark Matter? It turns out that NASA recalculated the Zodiac and now you’re an Ophiuchan! Science is hard enough, but communicating that science out to the public when there are publications hungry for traffic is even harder! Here’s how to parse the click-bait science titles.

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 4, 2016March 27, 2017 by Fraser Cain

Weekly Space Hangout – November 4, 2016: Mars and Where to Land on it with Dr. Matt Golombek

Host: Fraser Cain (@fcain)

Special Guest:
Dr. Matt Golombek, Senior Research Scientist at the JPL; Mars Exploration Rover Project Scientist; Mars Exploration Program Landing Site Scientist.

Guests:

Kimberly Cartier ( KimberlyCartier.org / @AstroKimCartier )
Nicole Gugliucci (cosmoquest.org / @noisyastronomer)
Paul M. Sutter (pmsutter.com / @PaulMattSutter)

Their stories this week:

The entire sky mapped via hydrogen

First light on VLT’s adaptive optics mirror

JWST’s sunshield completed

We use a tool called Trello to submit and vote on stories we would like to see covered each week, and then Fraser will be selecting the stories from there. Here is the link to the Trello WSH page (http://bit.ly/WSHVote), which you can see without logging in. If you’d like to vote, just create a login and help us decide what to cover!

If you would like to join the Weekly Space Hangout Crew, visit their site here and sign up. They’re a great team who can help you join our online discussions!

If you would like to sign up for the AstronomyCast Solar Eclipse Escape, where you can meet Fraser and Pamela, plus WSH Crew and other fans, visit our site linked above and sign up!

We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Universe Today, or the Universe Today YouTube page.

November 4, 2016November 23, 2016 by Bob King

Monster Meteorite Found in Texas

Clarendon (c) meteorite. Credit: Ruben Garcia

Deedee and Frank Hommel and the 345 kilogram Clarendon (c) meteorite Frank and his horse discovered on their land. The stony meteorite may be the second largest single meteorite ever found in the United States. It displays nice fusion crust on the topside; the bottom side, which faced down in the soil, is covered with caliche (ka-LEE-chee), a cement-like mineral deposit made of calcium carbonate. Credit: Ruben Garcia — DeeDee and Frank Hommel pose with the 760 pound (345 kilogram) Clarendon (c) meteorite discovered on their land. The stony meteorite may be the second largest single chondrite ever found in the United States. It displays dark fusion crust on the topside; the bottom side, which faced down in the soil, is covered with caliche (ka-LEE-chee), a cement-like mineral deposit of calcium carbonate. Credit: Ruben Garcia

On April 6, 2015, Frank Hommel was leading a group of guests at his Bar H Working Dude Ranch on a horseback ride. The horses got thirsty, so Hommel and crew rode cross-country in search of a watering hole. Along the way, his horse Samson suddenly stopped and refused to go any further. Ahead of them was a rock sticking out of the sandy soil. Hommel had never seen his horse act this way before, so he dismounted to get a closer look at the red, dimpled mass. Something inside told him this strange, out of place boulder had to be a meteorite.

This photo was taken of the Clarendon (c) meteorite before it was removed from the ground. There appear to be several broken fragments at lower left. Credit: Frank and Deedee Hommel — This photo was taken of the Clarendon (c) meteorite before it was removed from the ground. There appear to be several broken fragments at lower and center left. The meteorite is a chondrite, composed of rock found in the crust of asteroids. Credit: Frank and DeeDee Hommel

Here’s the crazy thing — Hommel’s hunch was correct. Lots of people pick up an odd rock now and then they think might be a meteorite, but in nearly every case it isn’t. Meteorites are exceedingly rare, so you’re chances of happening across one are remote. But this time horse and man got it right.

The rock that stopped Samson that April day was the real deal and would soon be classified and named the Clarendon (c) stony meteorite. Only the top third of the mass broke the surface; there was a lot more beneath the soil. Hommel used a tractor to free the beast and tow it to his home. Later, when he and his wife DeeDee got it weighed on the feed store scale, the rock registered a whopping 760 pounds (345 kilograms). Hommel with others returned to the site and recovered an additional 70 pounds (32 kilograms) of loose fragments scattered about the area.

This view show of the 760-pound meteorite shows relatively fresh fusion crust from melting of the outer millimeter or two of the meteoroid during its heated passage through Earth's atmosphere. You can also see lots of thumbprints or regmaglypts, which form when softer materials in the rock are ablated away by heat and high pressure experienced during the fall. Credit: Ruben Garcia — This view of the 760-pound meteorite shows relatively fresh fusion crust from melting of the outer millimeter or two of the meteoroid during its heated passage through Earth’s atmosphere. You can also see lots of thumbprints or regmaglypts (left side), which form when softer materials in the rock are ablated away by brief but intense heat and pressure experienced during the fall. Credit: Ruben Garcia

At this point, Frank and DeeDee couldn’t be certain it was a meteorite. Yes, it attracted a magnet, a good sign, but the attraction was weak. Frank had his doubts. To prove one way or another whether this rusty boulder came from space or belonged to the Earth, DeeDee sent a photo of it to Eric Twelker of Juneau, Alaska, a meteorite seller who maintains the Meteorite Market website. Twelker thought it looked promising and wrote back saying so. Six months later, the family sent him a sample which he arranged to have tested by Dr. Tony Irving at the University of Washington.

The dude ranch run by Deedee and Frank Hommel, finders of the Clarendon (c) meteorite. Credit: Ruben Garcia — The Bar H Dude Ranch run by DeeDee and Frank Hommel, finders of the Clarendon (c) meteorite. Credit: Ruben Garcia

Irving’s analysis revealed bright grains of iron-nickel metal and an abundance of chondrules, round grains composed of minerals that were flash-heated into a “fiery rain” in the solar nebula 4.5 billion years ago. When they cooled, the melted material congealed into small solid spheres several millimeters across that were later incorporated into the planetary embryos that grew into today’s planets and asteroids. Finding iron-nickel and chondrules proved beyond a shadow that the Hommels’ rock was a genuine stone from space.

In an e-mail communication, Twelker recounted his part of the story:

“I get about six to a dozen inquiries on rocks every day. I try to answer all of them — and give a rock ID if possible. I have to say my patience gets tried sometimes after looking at slag, basalt, and limestone day after day. But if I am in the right mood, then it is fun. This one made it fun. Over the years, I’ve probably had a half dozen discoveries this way, but this is by far the most exciting.”

This is a small slice of Northwest Africa 2793, an L4 chondrite similar to Clarendon (c). Credit: Bob King — This small slice of Northwest Africa 2793, an L4 chondrite, is similar to Clarendon (c). Flecks of iron-nickel metal give the cut surface a sparkly appearance. Several round chondrules are visible, especially near the bottom edge. Credit: Bob King

Irving pigeonholed it as an L4 chondrite meteorite. L stands for low-iron and chondrite indicates it still retains its ancient texture of chondrules that have been little altered since their formation. No one knows how long the meteorite has sat there, but the weathering of its surface would seem to indicate for a long time. That said, Hommel had been this way before and never noticed the rock. It’s possible that wind gradually removed the loosely-bound upper soil layer — a process called deflation — gradually exposing the meteorite to view over time.

Once a meteorite has been analyzed and classification, the information is published in the Meteorite Bulletin along with a chemical analysis and circumstances of its discovery. Meteorites are typically named after the nearest town or prominent geographical feature where they’re discovered or seen to fall. Because it was found on the outskirts of Clarendon, Texas, the Hommels’ meteorite took the town’s name. The little “c” in parentheses after the name indicates it’s the third unique meteorite found in the Clarendon area. Clarendon (b) turned up in 1981 and Clarendon (a) in 1979. Both are H5 (high metal) unrelated stony chondrites.

Ruben Garcia a.k.a. Mr. Meteorite arranged the sale of the Clarendon (c) meteorite to Texas Christian University. Courtesy of Ruben Garcia — Ruben Garcia, a.k.a. Mr. Meteorite, arranged the sale of the Clarendon (c) meteorite to Texas Christian University. Courtesy of Ruben Garcia

When Clarendon (c) showed up in the Bulletin late last month, meteorite hunter, dealer and collector Ruben Garcia, better known as Mr. Meteorite, quickly got wind of it. Garcia lives in Phoenix and since 1998 has made his livelihood buying and selling meteorites. He got into the business by first asking himself what would be the funnest thing he could do with his time. The answer was obvious: hunt meteorites!

These rusty rocks, chips off asteroids, have magical powers. Ask any meteorite collector. Touch one and you’ll be transported to a time before life was even a twinkle in evolution’s eye. Their ancientness holds clues to that deepest of questions — how did we get here? Scientists zap them with ion beams, cut them into translucent slices to study under the microscope and even dissolve them in acid in search of clues for how the planets formed.

Garcia contacted the Hommels and posed a simple question:

“Hey, you have a big meteorite on your property. Do you want to sell it?”

They did. So Mr. Meteorite put the word out and two days later Texas Christian University made an offer to buy it. After a price was agreed upon, Garcia began making plans to return to Clarendon soon, load up the massive missive from the asteroid belt on his trailer and truck it to the university where the new owner plans to put it on public display, a centerpiece for all to admire.

Visit the largest chondrite ever found in Texas

“How amazing to walk into a dude ranch and see a museum quality specimen,” said Garcia on his first impression of the stone. “I’ve never seen a meteorite this big outside of a museum or gem show.” Ruben joined Frank to collect a few additional fragments which he plans to put up for sale sometime soon.

So how does Clarendon (c) rank weigh-wise to other meteorite falls and finds? Digging through my hallowed copy of Monica Grady’s Catalogue of Meteorites, it’s clear that iron meteorites take the cake for record weights among all meteorites.

10x closeup of a very thin section through a chondrule in the meteorite NWA 4560. Crystals of olivine (bright colors) and pyroxene are visible. Credit: Bob King — A singe chondrule in a thin section of the meteorite NWA 4560 is seen through a polarizing microscope at a magnification of 10x. Crystals of olivine (bright colors) and pyroxene (darker) are visible. Astronomers believe chondrules were among the first solid material to form in the early solar system when some form of flash heating melted nebular dust. The dust congealed into tiny spheres that were later incorporated into planetesimals and ultimately the planets. Credit: Bob King

But when it comes to stony chondrites, Clarendon (c) is by far the largest individual space rock to come out of Texas. It also appears to be the second largest individual chondrite meteorite ever found in the United States. Only the Paragould meteorite, which exploded over Arkansas in 1930, dropped a larger individual — 820 pounds (371.9 kg) of pure meteorite goodness that’s on display at the Arkansas Center for Space and Planetary Sciences in Fayetteville. There’s truth to the saying that everything’s bigger in Texas.

Every meteorite has a story. Some are witnessed falls, while others fall unnoticed only to be discovered decades or centuries later. The Clarendon meteorite parent body spent billions of years in the asteroid belt before an impact broke off a fragment that millions of years later found its way to Earth. Did this chip off the old block bury itself in Texas soil 100 years ago, a thousand? No one can say for sure yet. But one April afternoon in 2015 they stopped a man and his horse dead in their tracks.

*** If you’d like tips on starting your own meteorite collection, check out my new book, Night Sky with the Naked Eye. It covers all the wonderful things you can see in the night sky without special equipment plus additional topics including meteorites. The book publishes on Nov. 8, but you can pre-order it right now at these online stores. Just click an icon to go to the site of your choice — Amazon, Barnes & Noble or Indiebound. It’s currently available at the first two outlets for a very nice discount:

November 3, 2016November 11, 2016 by Evan Gough

Somebody Get This Supermassive Black Hole A Towel

Artist's conception of how the "nearly naked" supermassive black hole originated. On the left panel, the black hole begins its encounter with another, larger black hole. In the middle panel, the stars are stripped away. On the right, the black hole emerges from the encounter with only the remnants of its galaxy intact. Credit: Bill Saxton, NRAO/AUI/NSF.

Most galaxies have a super-massive black hole at their centre. As galaxies collide and merge, the black holes merge too, creating the super-massives we see in the universe today. But one team of astronomers went looking for super-massives that aren’t at the heart of galaxies. They looked at over 1200 galaxies, using the National Science Foundation’s (NSF) Very Long Baseline Array (VLBA), and almost all of them had a black hole right where it should be, in the middle of the galaxy itself.

But they did find one hole, in a cluster of galaxies more than two billion light years away from Earth, that was not at the centre of a galaxy. They were surprised too see that this black hole had been stripped naked of surrounding stars. Once they identified this black hole, now called B3 1715+425, they used the Hubble and the Spitzer to follow up. And what they found tells an unusual story.

“We’ve not seen anything like this before.” – James Condon

The super-massive black hole in question, which we’ll call B3 for short, was a curiosity. It was far brighter than anything near it, and it was also more distant than most of the holes they were studying. But a black hole this bright is typically situated at the heart of a large galaxy. B3 had only a remnant of a galaxy surrounding it. It was naked.

James Condon, of the National Radio Astronomy Observatory (NRAO) described what happened.

“We were looking for orbiting pairs of supermassive black holes, with one offset from the center of a galaxy, as telltale evidence of a previous galaxy merger,” said Condon. “Instead, we found this black hole fleeing from the larger galaxy and leaving a trail of debris behind it,” he added.

“We concluded that our fleeing black hole was incapable of attracting that many stars on the way out to make it look like it does now.” – James Condon

Condon and his team concluded that B3 was once a super-massive black hole at the heart of a large galaxy. B3 collided with another, larger galaxy, one with an even larger black hole. During this collision B3 had most of its stars stripped away, except for the ones closest to it. B3 is still speeding away, at more than 2000 km per second.

Nearly Naked Black Hole from NRAO Outreach on Vimeo.

B3 and what’s left of its stars will continue to move through space, escaping their encounter with the other galaxy. It probably won’t escape from the cluster of galaxies it’s in though.

“What happens to a galaxy when most of its stars have been stripped away, but it still has an active super-massive black hole at the middle?” – James Condon

Condon outlines the likely end for B3. It won’t have enough stars and gas surrounding it to trigger new star birth. It also won’t be able to attract new stars. So eventually, the remnant stars of B3’s original galaxy will travel with it, growing progressively dimmer over time.

B3 itself will also grow dimmer, since it has no new material to “feed” on. It will eventually be nearly impossible to see. Only its gravitational effect will betray its position.

“In a billion years or so, it probably will be invisible.” – James Condon

How many B3s are there? If B3 itself will eventually become invisible, how many other super-massive black holes like it are there, undetectable by our instruments? How often does it happen? And how important is it in understanding the evolution of galaxies, and of clusters of galaxies. Condon asks these questions near the end of the clip. For now, at least, we have no answers.

Condon and his team used the NRAO‘s VLBA to search for these lonely holes. The VLBA is a radio astronomy instrument made up of 10 identical 25m antennae around the world, and controlled at a center in New Mexico. The array provides super sharp detail in the radio wave part of the spectrum.

Their black hole search is a long term project, making use of filler time available at the VLBA. Future telescopes, like the Large Synoptic Survey Telescope being built in Chile, will make Condon’s work easier.

Condon worked with Jeremy Darling of the University of Colorado, Yuri Kovalev of the Astro Space Center of the Lebedev Physical Institute in Moscow, and Leonid Petrov of the Astrogeo Center in Falls Church, Virginia. They will report their findings in the Astrophysical Journal.

November 3, 2016November 11, 2016 by Matt Williams

Beautiful Planetary Rings Are Dead Dwarf Planets! Dead Dwarf Planets!!!

This portrait looking down on Saturn and its rings was created from images obtained by NASA's Cassini spacecraft on Oct. 10, 2013. Credit: NASA/JPL-Caltech/Space Science Institute/G. Ugarkovic

In 1655, astronomer Christiaan Huygens became the first person to observe the beautiful ring system that surrounds Saturn. And while they are certainly the most spectacular, astronomers have since discovered that all the gas and ice giants of the Solar System (i.e. Jupiter, Saturn, Uranus and Neptune) have their own system of rings.

These systems have remained a source of fascination for astronomers, largely because their origins are still something of a mystery. But thanks to a recent study by researchers from the Tokyo Institute of Technology and Kobe University, the origins of these rings may be solved. According to their study, the rings are pieces of Dwarf Planets that got torn off in passing, which were then ripped to pieces!

This research could help to resolve many of the burning questions about the ring systems around our system’s giant planets, as well as details about the Solar Systems past. For the sake of their study – titled “Ring Formation around Giant Planets by Tidal Disruption of a Single Passing Large Kuiper Belt Object” – the Japanese team of researchers considered a number of factors.

The Kuiper Belt was named in honor of Dutch-American astronomer Gerard Kuiper, who postulated a reservoir of icy bodies beyond Neptune. The first Kuiper Belt object was discovered in 1992. We now know of more than a thousand objects there, and it's estimated it's home to more than 100,000 asteroids and comets there over 62 miles (100 km) across. Credit: JHUAPL — *The Kuiper Belt was named in honor of Dutch-American astronomer Gerard Kuiper, who postulated a reservoir of icy bodies beyond Neptune. Credit: JHUAPL*

First, they considered the diversity of the various ring systems in our Solar System. For instance, Saturn’s rings are massive (about 100,000 trillion kg!) and composed overwhelmingly (90-95%) of water ice. In contrast, the much less massive rings of Uranus and Neptune are composed of darker material, and are believed to have higher percentages of rocky material in them.

To shed some light on this, the team looked to the Nice Model – a theory of Solar System formation that states that the gas giant migrated to their present location during the Late Heavy Bombardment. This period took place between 4 and 3.8 billion years ago, and was characterized by a disproportionately high number of asteroids from Trans-Neptunian space striking planets in the Inner Solar System.

They then considered other recent models of Solar System formation which postulate that the giant planets experienced close encounters with Pluto-sized objects during this time. From this, they developed the theory that the rings could be the result of some of these objects getting trapped and ripped apart by the gas giants’ gravity. To test this theory, they performed a number of computer simulations to see what would happen in these instances.

As Ryuki Hyodo – a researcher at the Department of Planetology, Kobe University, and the lead author on the paper – told Universe Today via email:

“We performed two simulations. First, using SPH (Smoothed-particle hydrodynamics) simulations, we investigated tidal disruption of Pluto-sized objects during the close encounters with giant planets and calculated the amount of fragments that are captured around giant planets. We found enough mass/fragments to explain current rings is captured. Then, we performed the longer-term evolution of the captured mass/fragments by using N-body simulations. We found that the captured fragments can collide each other with destruction and form thin equatorial circular rings around giant planets.”

A composite image of Uranus in two infrared bands, showing the planet and its ring system. Picture taken by the Keck II telescope and released in 2007. Credit: W. M. Keck Observatory (Marcos van Dam) — *A composite image of Uranus in two infrared bands, showing the planet and its ring system. Credit: W. M. Keck Observatory (Marcos van Dam)*

The results of these simulation were consistent with the mass of the ring systems observed around Saturn and Uranus. This included the inner regular satellites of both planets – which would have also been the product of the past encounters with KBOs. It also accounted for the differences in the rings’ composition, showing how the planet’s Roche limits can influence what kind of material can be effectively captured.

This study is especially significant because it offers verifiable evidence for one of the enduring mysteries of our Solar System. And as Hyodo points out, it could come in mighty handy when it comes time to examine extra-solar planetary systems as well.

“Our theory suggested that, in the past, we had two possible epochs to form rings,” he said. “One is during the planet accretion phase and the other is during the Late heavy bombardment. Also, our model is naturally applicable to other planetary systems. So, our theory predicts that exoplanets also have massive rings around them.”

In the meantime, some might find the idea that ring systems are the corpses of Dwarf Planets troublesome. But I think we can all agree, a Soylent Green allusion might be just a bit over the top!

Further Reading: arXiv

November 3, 2016November 11, 2016 by Nancy Atkinson

China Just Launched Its Largest Rocket Ever

China's brand-new heavy-lift Long March-5 rocket blasts off from Wenchang Space Launch on Nov. 3, 2016. Credit: Xinhua/Li Gang.

China’s newest and biggest heavy-lift rocket was successfully launched today, Nov 3, 2016, testing out China’s latest rocket along with bringing an experimental satellite designed to test electric-propulsion technology.

The Long March 5 rocket blasted off from the Wenchang launch center on Hainan Island, off China’s southern coast, at 8:43 a.m. EDT (12:43:14 UTC; 8:43 p.m. Beijing time).

Although Chinese space officials have not released many details about the mission or the new rocket, reportedly the Long March-5, (or the Chang Zheng-5, CZ-5) gives China a launch vehicle with similar launch capability to the Delta 4 Heavy or ESA’s Ariane 5, which is twice the capability of China’s Long March-3 (CZ-3).

The 187-foot-tall (57-meter) Long March-5 is powered by 10 liquid-fueled engines, which reportedly generate about 2.4 million pounds of thrust.

The increase in capability is seen as essential for China’s long-range space goals for a bigger and permanently-staffed space station, missions to the Moon, a robotic mission to Mars and the launch of commercial satellites.

The @ChinaSpaceflight Twitter account tweeted this image the launch control center when the YZ-2 upper stage fired:

pic.twitter.com/njACqpIbCj

— ChinaSpaceflight (@cnspaceflight) November 3, 2016

The Long March-5 is a large, two-stage rocket with a payload capacity of 25 tons to low-Earth orbit. According to the China Aerospace Science and Technology Corporation (CASC), the developer of the Long March-5, the rocket uses kerosene, liquid oxygen and liquid hydrogen, moving away from more toxic propellants like hydrazine and nitrogen tetroxide. This makes the new rocket not only less expensive to launch but more environmental friendly.

Today’s launch is the second from the new Wenchang launch complex. This past summer, on June 25, China’s new medium-sized Long March-7 made its initial launch from the site.

Source: Xinhuanet

November 2, 2016November 2, 2016 by Matt Williams

What is the World’s Deepest Ocean?

Earth, seen from space, above the Pacific Ocean. Credit: NASA

One look at planet Earth on a map, or based on an image taken from space, ought to convey just how immense and important our oceans are. After all, they cover 72% of the planet’s surface, occupy a total volume of around 1.35 billion cubic kilometers (320 million cu mi), and are essential to life as we know it. And in their great depths, many mysteries still wait to be discovered.

Thanks to modern science and improvement exploration vehicles, one of the most obvious has been tackled – which is the mystery of where the deepest ocean in the world lies. This is none other than the Pacific Ocean, which averages approximately 4,280 meters (14,042 ft) in depth and contains the deepest known part of any ocean – the Mariana Trench.

Methodology:

Of course, determining the depth of an ocean is tricky business, and for obvious reasons. Ocean floors are extremely extensive, and vary widely in terms of elevation. Much like continental land masses, they have mountain ranges and trenches that throw off the curve. And in some cases, the trenches are much deeper than the average depth.

Oceans — *The view of the Pacific Ocean from the ISS. Credit: NASA*

However, in terms of average depth, the Pacific Ocean is the deepest. Though calculations vary, it is estimated that the entire ocean floor averages about 4,280 meters (14,042 ft), which is over 500 m (1640 ft) deeper than the global average of 3,700 meters (12,100 ft). Part of the reason for this is due to the Marian Trench, which is significantly deeper!

Characteristics:

The Marian Trench is located in the western Pacific Ocean near the Mariana Islands, almost equally distant from both the Philippines and Japan. The trench is crescent shaped, and measures roughly 2,550 kilometers (1,580 mi) long with an average width of 69 kilometers (43 mi).

It reaches a maximum-known depth of 10,994 meters (36,070 ft) – with a margin of error of 40 metes (130 ft) – at a small slot-shaped valley in its floor known as the Challenger Deep, located at its southern end. Countries near the trench include Japan, Papua New Guinea, Indonesia and the Philippines.

The geological feature is the result of subduction that occurs at the boundary between two tectonic plates – the Filipino and the Pacific Plate. This results in what is known as the Izu-Bonin-Mariana subduction system, where the western edge of the Pacific Plate is subducted (pushed under) the smaller Mariana plate (part of the Filipino Plate).

Location of the Mariana Trench. Credit: Wikipedia Commons/Kmusser

The movement of the Pacific and Mariana Plates also led to the formation of the Mariana Islands, which are volcanic in nature. They formed as a result of flux melting – i.e. where water cools hot lava – due to the release of water that was trapped in the subducted portion of the Pacific Plate.

To put just how deep the Mariana Trench is into perspective, let’s consider comparing it to Mount Everest. If you placed Mt. Everest inside the Mariana Trench, there would still be over 2,000 meters (6562 ft) of water covering the mountain.

The water pressure in the Mariana Trench is also 15,750 psi, which is more than 1000 times greater than the standard atmospheric pressure at sea level. This means that if you could stand at the bottom of the Mariana Trench, the pressure could literally crush you!

Measurement:

Numerous measurements of the trench have been taken over the years using different methods. The first mission was the Challenger expedition, which took place between 1872 and 1876. Using the sounding technique, they measured the deepest point of Mariana Trench to 9,636 meters (31,614 ft).

This was followed by the HMS Challenger, which conducted the Challenger II survey in 1931. Here, surveyors relied on the more accurate technique of echo-sounding, and retrieved a deepest measurement of 10,900 meters (35,760 ft). This area came to be known as the Challenger Deep.

During the latter half of the 20th century, multiple missions would be conducted. In 1957, the Soviet vessel Vityaz obtained depth readings of 11,034 meters (36,201 ft) at a location named “the Mariana Hollow”. This was followed in 1962 by the US merchant vessel Spencer F. Baird, which recorded a maximum depth of 10,915 meters (35,810 ft) using precision depth gauges.

In 1984, the Japanese survey vessel Takuyo used a narrow, multi-beam echo sounder and reported a maximum depth of 10,924 meters (35,840 ft). In 1995, another Japanese vessel – the remotely operated vehicle KAIKO – reached the deepest area of the Mariana trench, thus establishing the deepest diving record of 10,911 meters (35,797 ft).

In 2009, the US research vessel Kilo Moana conducted the most accurate measurements of the Mariana Trench to date. This involved using sonar to map the Challenger Deep, which located a spot with a maximum depth of 10,971 meters (35,994 ft).

Rear view of the research vessel Kilo Moana. NOAA — *Rear view of the research vessel* Kilo Moana. NOAA

Exploration:

Four missions have been made into the Mariana Trench. The first was the Trieste, a Swiss-designed, Italian-built, and US Navy-owned self-propelled submersible craft. On January 23rd, 1960, the craft and its two-man crew reached the bottom of the Trench, having reached a depth of 10,916 m (35,814 ft). This was followed by the unmanned Kaiko craft in 1996 and the autonomous craft Nereus in 2009.

The first three expeditions directly measured very similar depths of 10,902 to 10,916 m (35,768 to 35,814 ft). The fourth mission took place in 2012, where Canadian film director James Cameron mounted a mission using the submersible Deepsea Challenger. On March 26th, he reached the bottom of the Mariana Trench.

Several more missions have been planned as of February of 2012. These include Triton Submarines, a Florida-based company that designs and manufactures private submarines; and DOER Marine, a marine technology company based near San Francisco that plans to send a two or three-person sub to the seabed.

Beyond the coastlines, the world’s oceans are deep and unfathomable. Much of it remains unexplored and the life that scientists have found there is quite exotic (and may even provide insight into life on other worlds). Somehow, it seems appropriate that life in “inner space” would help us to understand life in “outer space”.

We have written many interesting articles about the Pacific Ocean here at Universe Today. Here’s How Many Oceans are there in the World?, What Causes Tides?, Did Comets Create the Earth’s Oceans?, and What Percentage of Earth is Water?

If you are looking for more information, you should try this article from National Geographic on life in the Mariana Trench and this website on the Mariana Trench.

Astronomy Cast has an episode on the subject – Episode 51: Earth.

Sources:

November 2, 2016November 2, 2016 by Evan Gough

NASA’s New Asteroid Alert System Gives 5 Whole Days of Warning

An asteroid strike that could wreak some serious havoc against Earth may be statistically unlikely. But it's not like there's no precedent for one. Artist's Image: . Credit: NASA

Everyone knows it was a large asteroid striking Earth that led to the demise of the dinosaurs. But how many near misses were there? Modern humans have been around for about 225,000 years, so we must have come close to death by asteroid more than once in our time. We would have had no clue.

Of course, it’s the actual strikes that are cause for concern, not near misses. Efforts to predict asteroid strikes, and to catalogue asteroids that come close to Earth, have reached new levels. NASA’s newest tool in the fight against asteroids is called Scout. Scout is designed to detect asteroids approaching Earth, and it just passed an important test. Scout was able to give us 5 days notice of an approaching asteroid.

Here’s how Scout works. A telescope in Hawaii, the Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) detected the asteroid, called 2016 UR36, and then alerted other ‘scopes. Three other telescopes confirmed 2016 UR36 and were able to narrow down its trajectory. They also learned its size, about 5 to 25 meters across.

The Pan STARRS telescope in Hawaii. Image: Institute for Astronomy, University of Hawaii.

After several hours, we knew that UR 36 would come close to us, but was not a threat to impact Earth. UR 36 would pass Earth at a distance of about 498,000 km. That’s about 1.3 times further away than the Moon.

The key part of this is that we had 5 days notice. And five days notice is a lot more than the few hours that we usually have. The approach of 2016 UR36 was the first test for the Scout system, and it passed the test.

Asteroids that come close to Earth are called Near Earth Objects (NEOs) and finding them and tracking them has become a growing concern for NASA. In fact NASA has about 15,000 NEOs catalogued, and they’re still finding about 5 more every night.

NASA is getting much better at discovering and detecting NEOs. Image: NASA/NEO Program.

Not only does NASA have the Scout system, whose primary role is to speed up the confirmation process for approaching asteroids, but they also have the Sentry program. Sentry’s role is a little different.

Sentry’s job is to focus on asteroids that are large enough to wipe out a city and cause widespread destruction. That means NEOs that are larger than about 140 metres. Sentry has over 600 large NEOs catalogued, and astronomers think there are a lot more of them out there.

NASA also has the Planetary Defense Coordination Office (PDCO), which has got to be the greatest name for an office ever. (Can you imagine having that on your business card?) Anyway, the PDCO has the over-arching role of preparing for asteroid impacts. The Office is there to make emergency plans to deal with the impact aftermath.

5 days notice for a small asteroid striking Earth is a huge step for preparedness. Resources can be mobilized, critical infrastructure can be protected, maybe things like atomic power plants can be shut down if necessary. And, of course, people can be evacuated.

We haven’t always had any notice for approaching asteroids. Look at the Chelyabinsk meteor from 2013. It was a 10,000 ton meteor that exploded over the Chelyabinsk Oblast, injuring 1500 people and damaging an estimated 3,000 building in 6 cities. If it had been a little bigger, and reached the surface of the Earth, the damage would have been widespread. 5 days notice would likely have saved a lot of lives.

Smaller asteroids may be too small to detect when they’re very far away. But larger ones can be detected when they’re still 10, 20, even 30 years away. That’s enough time to figure out how to stop them. And if you can reach them when they’re that far away, you only need to nudge them a little to deflect them away from Earth, and maybe to the Sun to be destroyed.

Large asteroids with the potential to cause widespread destruction are the attention-getters. Hollywood loves them. But it may be more likely that we face numerous impacts from smaller asteroids, and that they could cause more damage overall. Scout’s ability to detect these smaller asteroids, and give us several days notice of their approach, could be a life-saver.

November 2, 2016 by David Dickinson

Watch Asteroid 2016 VA Pass Through Earth’s Shadow

Mining asteroids might be necessary for humanity to expand into the Solar System. But what effect would asteroid mining have on the world's economy? Credit: ESA.

Holy low-flying space rocks, Batman.

Newly discovered asteroid 2016 VA snuck up on us last night, and crossed through the Earth’s shadow to boot.

Discovered just yesterday by the Mount Lemmon Sky Survey based outside of Tucson Arizona, 2016 VA passed just 58,600 miles (93,700 kilometers) from the surface of the Earth this morning at 00:42 Universal Time (UT). That’s a little over 20% of the distance from the Earth to the Moon, and just over twice the distance to the ring of geosynchronous and geostationary satellites around the Earth.

This sort of close pass of a newly discovered asteroid happens a few times a year. What made 2016 VA’s passage unusual, however, was its transit through the Earth’s shadow. The discovery was announced yesterday by the Minor Planet Center, and astronomer Gianluca Masi soon realized that the Virtual Telescope Project had a unique opportunity to capture the asteroid on closest approach.

The passage of asteroid 2016 VA. Image credit: The Virtual Telescope Project. — Asteroid 2016 VA. Image credit: The Virtual Telescope Project.

Gianluca Masi explained how the difficult capture was done:

“The image is a 60-second exposure, remotely taken with “Elena” (a PlaneWave 17” +Paramount ME+SBIG STL-6303E robotic unit) available at the Virtual Telescope project. The robotic mount tracked the extremely fast apparent motion of the asteroid, so stars are trailing. The asteroid is perfectly tracked; it is the sharp dot in the center, marked with two white segments. At imaging time, asteroid 2016 VA was at about 200,000 kilometers from us and approaching.”

Catching a fast-moving asteroid such as 2016 VA on closest approach isn’t easy. First off, there’s an amount of uncertainty surrounding the orbit of a newly discovered object until more observations can be made. 2016 VA passed close enough to the Earth that our planet’s gravity substantially altered the tiny asteroid’s future orbit. Also, a house-sized Earth-crosser like 2016 VA is really truckin’ across the sky on closest approach: 2016 VA was moving at 1500” a minute through Earth’s shadow – that’s 25” a second, fast enough to cross the apparent diameter of a Full Moon in just 72 seconds.

Masi also notes:

“During its flyby, asteroid 2016 VA was also eclipsed by the Earth. We covered the spectacular event, clearly capturing the penumbral effects. The movie is an amazing document showing the eclipse. Each frame comes from a 5-second integration.”

Watch as 2016 VA winks out as it hits Earth's shadow... Image credit: The Virtual Telescope Project. — Watch as 2016 VA winks out as it hits Earth’s shadow… Image credit: The Virtual Telescope Project.

At an estimated 16 to 19 meters in size, 2016 VA shined at 13^th magnitude as it crossed the southern hemisphere constellation of Sculptor on closest approach. It crossed through the Earth’s shadow for 11 minutes from 23:23 to 23:34 UT last night, just over an hour before closest approach. You can see the dimming effect of the Earth’s outer penumbral shadow in the video, just before the asteroid strikes the inner dark umbra and emerges back into eternal sunshine once again. Sitting on 2016 VA, and observer would have seen a total solar eclipse, as the bulk of the Earth passed between the asteroid and the Sun in an event not witnessed by the tiny world for thousands of years.

Such transits of asteroid through the Earth’s shadow have been observed before: 2012 XE54 crossed through the Earth’s shadow a few years back, and 2008 TC3 crossed through the Earth’s shadow before striking the Nubian desert in the early morning hours of October 7^th, 2008.

Satellites in geostationary orbit also pull a similar vanishing act right around either equinox as well.

The orbit of 2016 VA. Iimage credit: NASA/JPL. — The orbit of 2016 VA. Image credit: NASA/JPL.

2016 VA is also a similar size to another famous space rock: the 20 metre asteroid that exploded over the city of Chelyabinsk the day after Valentine’s Day in 2013. 2016 VA gave us a miss, and won’t make another pass as close to the Earth again for this century.

To our knowledge, such a video capture of an asteroid crossing through Earth’s shadow is a first, or at least the first that we’ve seen circulated on ye ole Web.

The light curve of 2016 as it passed through the Earth's shadow. Image credit: Peter Birtwhistle, Great Shefford Observatory. — The light curve of 2016 as it passed through the Earth’s shadow. Image credit: Peter Birtwhistle, Great Shefford Observatory.

Congrats to the good folks at the Virtual Telescope Project for swinging into action so quickly, and providing us with an amazing view!

-Catch the closest Full Moon of the year (and for many years to come!) on November 14^th live courtesy of the Virtual Telescope Project.