Universe Today

October 19, 2016 by Matt Williams

Forget Mars, Now You Can Kickstart an Antimatter Propulsion System to Another Star!

Artist's concept of Antimatter propulsion system. Credit: NASA/MFSC

When it comes to the future of space exploration, one of the biggest questions is, “how and when will we travel to the nearest star?” And while space agencies have been pondering this question and coming up with proposals for decades, none of them have advanced beyond the theory stage. For the most part, their efforts has been focused on possible missions to Mars and the outer Solar System.

But there are some people, like Dr. Gerald Jackson, who are working towards making an interstellar mission possible in the near future. He and his research team, which have been funded by NASA in the past, are looking to create an antimatter engine that will be capable of reaching (or exceeding) 5% the speed of light. Towards this end, they have launched a Kickstarter campaign to fund their efforts.

As advanced propulsion concepts go, antimatter has quite a lot going for it. As propulsion goes, it has the highest specific energy of any known method, 100 times more than fission/fusion reactions, and 10 billion times more than chemical propellants. It is also the most fuel-efficient, requiring mere milligrams of antimatter to produce the same amount of energy as tons of chemical fuel.

Typically, this theoretical concept relies on the collision between hydrogen and antihydrogen (which have the same mass but opposite charge) to generate thrust. This process unleashes energy and a shower of particles (pions and muons), which can be channeled by a magnetic nozzle to generate thrust.

And while laboratories like CERN have been producing antimatter, and research is being conducted on large-scale storage, no propulsion systems exist that could turn antimatter into thrust. Dr. Jackson, a graduate of Cornell University, is hoping to change that. Before entering the private sector, Jackson worked as an accelerator physicist at the Fermi National Accelerator Laboratory for 14 years.

In 2002, he co-founded a limited-liability company (HBar Technologies) for the sake of developing commercial markets for antimatter. In 2002, NASA’s Institute for Advanced Concepts (NIAC) awarded Dr. Jackson and his company $75,000 to develop a mission concept that could traverse 250 AUs of space within 10 years time, and with a fuel supply of 10 kg.

These specifications essentially called for the creation of an antimatter rocket that could travel as far as the heliopause within a decade’s time. The result was a propulsion concept that relied on a beam that would fire focused antiprotons onto a sail to generate propulsion. This sail would measure 5 meters in diameter and be composed of a carbon backing on one side and uranium foil on the other (measuring 15 and 296 microns thick, respectively).

The solar system and its nearby galactic neighborhood are illustrated here on a logarithmic scale extending (from < 1 to) 1 million Astornomical Units (AU). Credit: NASA/JPL — *Illustration of the solar system and its nearby galactic neighborhood on a logarithmic scale extending (from < 1 to) 1 million AU. Credit: NASA/JPL*

When a pulse of antiprotons is annihilated against a small section of the uranium side, the resulting fission causes momentum. As Dr. Jackson explained to Universe Today via email:

“Note that antiprotons have a negative electrical charge, similar to an electron. When the antiprotons enter the sail, they displace an electron orbiting an uranium nucleus. Because antiprotons and electrons do not share any quantum numbers, the antiproton immediately cascades down into the atomic ground state, causing a high probability of interaction between the antiproton and either a proton or neutron within the nucleus.

“On average, a fission event results in the creation of two daughter nuclei of roughly equal mass. These daughters travel in opposite directions with a kinetic energy of 1 MeV per proton or neutron. Because the daughters are charged, the one travelling further into the sail is absorbed and transfers is forward momentum. The other daughter flies into space with an exhaust velocity of 4.6% of lightspeed. This selective transfer of momentum is thrust.”

Unfortunately, due to the budget environment of the time, the NIAC was forced to cancel its funding after a second round had been granted. Because of this, Dr. Jackson and his colleagues are now seeking public support so that they may finish their work on the experimental sail and prepare it for exposure to an antiproton beam.

Diagram showing Hbar's concept for a antimatter-driven propulsion system. Credit: antimatterdrive.org — *Diagram showing Hbar’s concept for a antimatter-driven propulsion system. Credit: antimatterdrive.org*

Much like Project Starshot (whom they acknowledge on their campaign page), Jackson and his team are looking to produce an interstellar mission proposal that does not involve shortcuts (i.e. warp drive, wormholes, star gates, etc.). Starshot, as you may recall, calls for a wafer craft and a laser-driven lightsail that would be capable of reaching speeds of up to 20% the speed of light, thus making the journey to Alpha Centauri in 20 years.

In the same vein, a antiproton-driven sail that could reach speeds of 5% the speed of light or more would be capable of making it to Alpha Centauri (or Proxima Centauri) in about 90 years time. All the while, the science behind it would remain within the realm of established physics, being consistent with Newton’s Laws of Motion and Einstein’s Theory of Special Relativity.

“The revolutionary aspect of the antimatter-driven sail is that the antimatter is not the fuel, but rather the spark plug that initiates fission reactions,” said Jackson. “Because the fission reactions can produce thrust without heavy shielding or other structures, the mass of the propulsion system can be comparable to the mass of the instrument package.”

Project Starshot, an initiative sponsored by the Breakthrough Foundation, is intended to be humanity's first interstellar voyage. Credit: breakthroughinitiatives.org — *Project Starshot, an initiative sponsored by the Breakthrough Foundation, is another concept for making humanity’s first interstellar voyage. Credit: breakthroughinitiatives.org*

To see their project through, Jackson and his colleagues are hoping to raise $200,000. Should they prove successful, they hope to mount follow-up campaigns to finance a series of validation experiments, storage demonstrations, and mission details. In the end, their goal is nothing less than making antimatter propulsion a reality, which they hope will one day lead interstellar mission.

“We expect that these campaigns will provide the data needed to convince people to fund full scale antimatter production and an actual mission to a nearby solar system,” Jackson added. “The goal of those early interstellar missions is to provide information about these other solar systems, such as whether they are habitable or inhabited. If the latter, we will want to study or interact with those life forms in follow-on missions. If habitable and not inhabited, we need sufficient information to assure the success of a manned migratory mission.”

As of the penning of this article, Jackson and his colleagues have raised $672 of their $200,000 goal. However, the campaign launched only a few days ago and will remain open for another 25 days. For those interesting in following their progress, or have an interest in donating to their cause, check out the links below.

Further Reading: Kickstarter, Antima:tterDrive

October 19, 2016October 20, 2016 by Evan Gough

Either Stars are Strange, or There Are 234 Aliens Trying to Contact Us

The Sloan Digital Sky Survey telescope stands out against the breaktaking backdrop of the Sacramento Mountains. 234 stars out of the Sloan's catalogue of over 2.5 million stars are producing an unexplained pulsed signal. Image: SDSS, Fermilab Visual Media Services

We all want there to be aliens. Green ones, pink ones, brown ones, Greys. Or maybe Vulcans, Klingons, even a being of pure energy. Any type will do.

That’s why whenever a mysterious signal or energetic fluctuation arrives from somewhere in the cosmos and hits one of our many telescopes, headlines erupt across the media: “Have We Finally Detected An Alien Signal?” or “Have Astronomers Discovered An Alien Megastructure?” But science-minded people know that we’re probably getting ahead of ourselves.

Skepticism still rules the day when it comes to these headlines, and the events that spawn them. That’s the way it should be, because we’ve always found a more prosaic reason for whatever signal from space we’re talking about. But, being skeptical is a balancing act; it doesn’t mean being dismissive.

What we’re talking about here is a new study from E.F. Borra and E. Trottier, two astronomers at Laval University in Canada. Their study, titled “Discovery of peculiar periodic spectral modulations in a small fraction of solar type stars” was just published at arXiv.org. ArXiv.org is a pre-print website, so the paper itself hasn’t been peer reviewed yet. But it is generating interest.

The two astronomers used data from the Sloan Digital Sky Survey, and analyzed the spectra of 2.5 million stars. Of all those stars, they found 234 stars that are producing a puzzling signal. That’s only a tiny percentage. And, they say, these signals “have exactly the shape of an ETI signal” that was predicted in a previous study by Borra.

A portion of the 234 stars that are sources of the pulsed ETI-like signal. Note that all the stars are in the narrow spectral range F2 to K1, very similar to our own Sun. Image: Ermanno F. Borra and Eric Trottier

Prediction is a key part of the scientific method. If you develop a theory, your theory looks better and better the more you can use it to correctly predict some future events based on it. Look how many times Einstein’s predictions based on Relativity have been proven correct.

The 234 stars in Borra and Trottier’s study aren’t random. They’re “overwhelmingly in the F2 to K1 spectral range” according to the abstract. That’s significant because this is a small range centred around the spectrum of our own Sun. And our own Sun is the only one we know of that has an intelligent species living near it. If ours does, maybe others do too?

The authors acknowledge five potential causes of their findings: instrumental and data reduction effects, rotational transitions in molecules, the Fourier transform of spectral lines, rapid pulsations, and finally the ETI signal predicted by Borra (2012). They dismiss molecules or pulsations as causes, and they deem it highly unlikely that the signals are caused by the Fourier analysis itself. This leaves two possible sources for the detected signals. Either they’re a result of the Sloan instrument itself and the data reduction, or they are in fact a signal from extra-terrestrial intelligences.

This graph shows the number of detected signals by Spectral Type of star. Image: Ermanno F. Borra and Eric Trottier

The detected signals are pulses of light separated by a constant time interval. These types of signals were predicted by Borra in his 2012 paper, and they are what he and Trottier set out to find in the Sloan data. It may be a bit of a red flag when scientist’s find the very thing they predicted they would find. But Trottier and Borra are circumspect about their own results.

As the authors say in their paper, “Although unlikely, there is also a possibility that the signals are due to highly peculiar chemical compositions in a small fraction of galactic halo stars.” It may be unlikely, but lots of discoveries seem unlikely at first. Maybe there is a tiny subset of stars with chemical peculiarities that make them act in this way.

To sum it all up, the two astronomers have found a tiny number of stars, very similar to our own Sun, that seem to be the source of pulsed signals. These signals are the same as predicted if a technological society was using powerful lasers to communicate with distant stars.

We all want there to be aliens, and maybe the first sign of them will be pulsed light signals from stars like our own Sun. But it’s all still very preliminary, and as the authors acknowledge, “…at this stage, this hypothesis needs to be confirmed with further work.”

That further work is already being planned by the Breakthrough Listen Initiative, a project that searches for intelligent life in the cosmos. They plan to use the Automated Planet Finder telescope at the Lick Observatory to further observe some of Borra’s 234 stars.

The Breakthrough team don’t seem that excited about Borra’s findings. They’ve already poured cold water on it, trotting out the old axiom that “Extraordinary claims require extraordinary evidence” in a statement on Borra’s paper. They also give Borra’s findings a score of 0 to 1 on the Rio Scale. The Rio Scale is something used by the international SETI community to rank detections of phenomena that could indicate advanced life beyond Earth. A rating of 0 to 1 means its insignificant.

Better reign in the headline writers.

October 19, 2016October 20, 2016 by Bob King

Europe’s Orbiter is Safely at Mars, but No Word from the Lander

This artist's view shows the European Space Agency's Schiaparelli lander on Mars. It's unclear whether the landing was successful. Signals were received during its descent but then suddenly cut off. Mission control is working on the data now and will have an update on the status of the probe tomorrow morning Oct. 20. Credit: ESA/ATG medialab

Schiaparelli on Mars. Credit: ESA/ATG medialab — This artist’s view shows the European Space Agency’s Schiaparelli lander on Mars. It’s unclear whether the landing was successful. Signals were received during its descent but then suddenly cut off. Mission control is working on the data now and will have an update on the status of the probe tomorrow morning Oct. 20. Credit: ESA/ATG medialab

Good news and bad news. First the good. After a seven-month and 300 million mile (483 million km) journey, the Trace Gas Orbiter (TGO) successfully achieved orbit around Mars today. A signal spike appeared out of the noise about 12:35 p.m. EDT to great applause and high-fives at ESA’s European Space Operations Center in Darmstadt, Germany.

Hugs in the control room when the signal from the Trace Gas Orbiter was received this morning, signaling that the spacecraft had achieved orbit around Mars. Credit: ESA Livestream — Joy in the control room when the signal from the Trace Gas Orbiter was received this morning, signaling that the spacecraft had achieved orbit around Mars. Credit: ESA Livestream

Two hours later, news of the lander arrived. Not so good but to be fair, it’s still too early to tell. Schiaparelli broadcast a signal during its descent to the Red Planet that was received here on Earth and by the orbiting Mars Express. All well and good. But then mid-transmission, the signal cut out.

Paolo Ferri, head of ESA’s mission operations department, called the news “not good signs” but promised that his team would be analyzing the data through the night to determine the status of the lander. Their findings will be shared around mid-morning Friday Central European Time (around 5 a.m. EDT).

Three days ago, Schiaparelli separated from the orbiter and began a three-day coast to Mars. It entered the atmosphere today at an altitude of 76 miles (122 km) and speed of 13,049 mph (21,000 km/hr), protected from the hellish heat of re-entry by an aerodynamic heat shield.

Simulated sequence of the 15 images that the descent camera Schiaparelli module should have taken during its descent to Mars this morning. In the simulated images shown here, the first was made from 3 km up. The camera took images every 1.5 seconds with the final image in this at ~1.5 km. Depending on Schiaparelli’s actual descent speed, the final image may have been snapped closer to the surface. The views were generated from images taken by NASA’s Mars Reconnaissance Orbiter of the center of Schiaparelli's landing ellipse, and represent the views expected at each altitude. Copyright spacecraft: ESA/ATG medialab; simulated views based on NASA MRO/CTX images (credit: NASA/JPL/MRO); landing ellipse background image: Mars Odyssey; simulation: ESA — Simulated sequence of the 15 images that the descent camera Schiaparelli module should have taken during its descent to Mars this morning. In the simulated images shown here, the first was made from 3 km up. The camera had planned to take images every 1.5 seconds with the final image in this at ~1.5 km. Depending on Schiaparelli’s actual descent speed, the final image may have been snapped closer to the surface. The views were generated from images taken by NASA’s Mars Reconnaissance Orbiter of the center of Schiaparelli’s landing ellipse, and represent the views expected at each altitude. Copyright spacecraft: ESA/ATG medialab; simulated views from NASA images (credit: NASA/JPL/MRO); landing ellipse background image: Mars Odyssey; simulation: ESA

If all went well, at 6.8 miles (11 km) altitude, it would have deployed its parachute and moments later, dropped the heat shield. At 0.7 miles (1.2 km) above the surface, the lander would have jettisoned the chute and rear protective cover and fired its nine retrorockets while plummeting to the surface at 155 mph (255 mph). 29 seconds later, the thrusters would have shut off with Schiaparelli dropping the remaining 6.5 feet (2 meters) to the ground. Total elapsed time: just under 6 minutes.

For now, have hope. Given that Schiaparelli was primarily a test of landing technologies for future Mars missions, whatever happened, everything we learn from this unexpected turn of events will be invaluable. You can continue to follow updates on ESA’s Livestream.

** Update Oct. 20: It appears that the thrusters on Schiaparelli may have cut out too soon, causing the lander to drop from a higher altitude. In addition, the ejection of the parachute and back heat shield may have happened earlier than expected.

This from ESA:

“The data have been partially analyzed and confirm that the entry and descent stages occurred as expected, with events diverging from what was expected after the ejection of the back heat shield and parachute. This ejection itself appears to have occurred earlier than expected, but analysis is not yet complete.

The thrusters were confirmed to have been briefly activated although it seems likely that they switched off sooner than expected, at an altitude that is still to be determined.”

October 19, 2016March 3, 2017 by Fraser Cain

Astronomy Cast Ep. 425: Naming Spacecraft

Have you ever noticed spacecraft missions have some pretty cool names? How does anyone decide what to call these things?

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.

October 19, 2016October 19, 2016 by Nancy Atkinson

Watch Live: ExoMars Arrival and Landing

Artist's view of the Schiaparelli lander descending to Mars on October 19. Credit: ESA

After a seven month flight, ESA’s ExoMars mission arrives at the Red Planet today, October 19. You can watch live here as the Trace Gas Orbiter (TGO) and Schiaparelli lander make their historic entry into orbit and landing.

The action starts at 9:09am ET (1:09pm GMT) when TGO fires its main engines for 134 minutes for its Mars Orbit Insertion. That burn should put the orbiter in a highly elliptical orbit which will be refined over the next few months.

Then, at 10:42am EDT (2:42pm GMT), the Schiaparelli lander will begin its six-minute entry, descent and landing through Mars’ atmosphere, coming at about 13,000 mph (21,000 kph). The aeroshell will slow the craft enough for a parachute to deploy, and at about 1 km above the surface, three hydrazine thrusters will ignite and slow Schiaparelli until it is about 6.5 feet (2 meters) above the surface. The lander will then be dropped to the Martian surface.

ESA has put together a video of what a successful landing looks like:

The ExoMars 2016 mission is a collaboration between the European Space Agency (ESA) and Roscosmos. ExoMars will continue the search for biological and geologic activity on Mars, which may have had a much warmer, wetter climate in the past. The TGO orbiter is equipped with a payload of four science instruments supplied by European and Russian scientists that will investigate the source and precisely measure the quantity of the methane and other trace gases.

Artist's impression depicting the separation of the ExoMars 2016 entry, descent and landing demonstrator module, named Schiaparelli, from the Trace Gas Orbiter, and heading for Mars. Credit: ESA/ATG medialab — Artist’s impression depicting the separation of the ExoMars 2016 entry, descent and landing demonstrator module, named Schiaparelli, from the Trace Gas Orbiter, and heading for Mars. Credit: ESA/ATG medialab

Methane is interesting because it can be produced by biology, volcanoes, natural gas and hydrothermal activity. TGO will investigate how methane is produced on Mars, as well as make follow up on measurements from NASA’s Curiosity rover and other instruments and telescopes that have detected methane on Mars.

The 2016 lander will carry an international suite of science instruments and test European entry, descent and landing (EDL) technologies for the 2nd ExoMars mission, which will bring an advanced lander to Mars in 2018.

The battery powered Schiaparelli lander is expected to operate for up to eight days until the battery is depleted.

Schiaparelli lander descent sequence. Image: ESA/ATG medialab

October 18, 2016October 18, 2016 by Nancy Atkinson

Latest Results from New Horizons: Clouds on Pluto, Landslides on Charon

This image of haze layers above Pluto’s limb was taken by the Ralph/Multispectral Visible Imaging Camera (MVIC) on NASA’s New Horizons spacecraft. About 20 haze layers are seen; the layers have been found to typically extend horizontally over hundreds of kilometers, but are not strictly parallel to the surface. For example, scientists note a haze layer about 3 miles (5 kilometers) above the surface (lower left area of the image), which descends to the surface at the right. Credit: NASA/JHUAPL/SwRI.

By the end of this week, all the data gathered by the New Horizons spacecraft during its July 2015 flyby of the Pluto system will have finished downloading to Earth and be in the hands of the science team. Bonnie Buratti, a science team co-investigator said they have gone from being able to look at the pretty pictures to doing the hard work required to study the data. During today’s press briefing from the Division of Planetary Sciences conference, the New Horizons team shared a few interesting and curious findings they’ve found in the data so far.

While the famous global view of Pluto appears to show a cloud-free dwarf planet, Principal investigator Alan Stern said the team has now take a closer look and found handful of potential clouds in images taken with New Horizons’ cameras.

“Clouds are common in the atmospheres of the solar system,” Stern said during the briefing, “ and a natural question was whether Pluto, with a nitrogen atmosphere, has any clouds.”

Stern said they’ve known since flyby that Pluto has haze layers, as seen in the backlit lead image above, as New Horizons flew away from Pluto. “They stretch more than 200 km into the sky, and we’ve counted over two dozen concentric layers,” he said.

While hazes are not clouds, Stern said they have identified candidates for clouds in high-phase images from the Long Range Reconnaissance Imager and the Multispectral Visible Imaging Camera.

Candidates for possible clouds on Pluto, in images from the New Horizons Long Range Reconnaissance Imager and Multispectral Visible Imaging Camera, during the spacecraft's July 2015 flight through the Pluto system. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute — Candidates for possible clouds on Pluto, in images from the New Horizons Long Range Reconnaissance Imager and Multispectral Visible Imaging Camera, during the spacecraft’s July 2015 flight through the Pluto system. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

“The seven candidates are all similar in that they are very low altitude,” Stern said, and they are all low-lying, isolated small features, so no broad cloud decks or fields. When we map them over the surface, they all lie near the terminator, so they occur near dawn or dusk. This is all suggestive they are clouds because low-lying regions and dawn or dusk provide cooler conditions where clouds may occur.”

Stern told Universe Today that these possible, rare condensation clouds could be made of ethane, acetylene, hydrogen cyanide or methane under the right conditions. Stern added these clouds are probably short-lived phenomena – again, likely occurring only at dawn or dusk. A day on Pluto is 6.4 days on Earth.

“But if there are clouds, it would mean the weather on Pluto is even more complex than we imagined,” Stern said.

Disappointingly, the New Horizons team has no way of confirming if these are clouds or not. “None of them can be confirmed as clouds because they are very low lying and we don’t have stereo images to tell us more,” Stern said, adding that the only way to confirm if there are condensation clouds on Pluto would be to return with an orbiter mission.

Landslides on Charon

Signs of a long run-out landslide on Pluto's largest moon, Charon. This perspective view of Charon's informally named Serenity Chasm shows a 200-meter thick lobate landslide that runs up against a 6 km high ridge. The images were taken by New Horizons, Long Range Reconnaissance Imager (LORRI) and Multispectral Visible Imaging Camera (MVIC) during the spacecraft’s July 2015 flyby of the Pluto system. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute — Signs of a long run-out landslide on Pluto’s largest moon, Charon. This perspective view of Charon’s informally named Serenity Chasm shows a 200-meter thick lobate landslide that runs up against a 6 km high ridge. The images were taken by New Horizons, Long Range Reconnaissance Imager (LORRI) and Multispectral Visible Imaging Camera (MVIC) during the spacecraft’s July 2015 flyby of the Pluto system. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

While Pluto shows many kinds of activity, one surface process scientists haven’t seen on the dwarf planet is landslides. Surprisingly, though, they have been spotted on Pluto’s largest moon, Charon.

“We’ve seen similar landslides on other rocky and icy planets, such as Mars and Saturn’s moon Iapetus, but these are the first landslides we’ve seen this far from the sun, in the Kuiper Belt,” said Ross Beyer, a science team researcher from Sagan Center at the SETI Institute and NASA Ames Research Center, California. “The big question is will they be detected elsewhere in the Kuiper Belt?”

Long runout landslides seen on Charon’s Serenity Chasm shows a 200-meter thick lobate landslide that runs up against a 6 km high ridge.

“With our images, we can just resolve a smooth apron and the deposit as a whole,” said Beyer, “we can’t see individual grains. But given the cold conditions on Charon, the deposit likely made of boulders of ice and rock.”

Beyer said earthquakes or an impact could have jump started the landslide on regions that were ready to slide. “The boulders may have melted and the edges and got slippery enough to begin to slide down the slope,” he said.

The images of Serenity Chasma were taken by New Horizons’ Long Range Reconnaissance Imager (LORRI) on July 14, 2015, from a distance of 48,912 miles (78,717 kilometers).

Beyer added that while Pluto doesn’t have landslides, it does have material that appears to be moving downhill as rock falls and glacier-like flows.

Scientists from NASA's New Horizons mission have spotted signs of long run-out landslides on Pluto's largest moon, Charon. Arrows mark indications of landslide activity. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute. — Scientists from NASA’s New Horizons mission have spotted signs of long run-out landslides on Pluto’s largest moon, Charon. Arrows mark indications of landslide activity. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute.

Bright and active

New Horizons data shows that portions of Pluto’s large heart-shaped region, Sputnik Planitia, are among the most reflective in the solar system. “That brightness indicates surface activity,” said Buratti, “similar to how Saturn’s moon Enceladus is very reflective, about 100% reflective, and is very active with plumes and geysers. Because we see a pattern of high surface reflectivity equating to activity, we can infer that the dwarf planet Eris, which is known to be highly reflective, is also likely to be active.”

Next Target

New Horizons is now making a beeline for its next target, KBO 2014 MU69. Cameras on the New Horizons spacecraft have been taking long range images and MU69 is the smallest KBO to have its color measured: it has a reddish tint. Scientists have used that data to confirm this object is part of the so-called cold classical region of the Kuiper Belt, which is believed to contain some of the oldest, most prehistoric material in the solar system.

“The reddish color tells us the type of Kuiper Belt object 2014 MU69 is,” said Amanda Zangari, a New Horizons post-doctoral researcher from Southwest Research Institute. “The data confirms that on New Year’s Day 2019, New Horizons will be looking at one of the ancient building blocks of the planets.”

Zangari added that they will be using the Hubble Space Telescope to better understand MU69.

“We would like to use Hubble to its find rotation rate and better understand its shape, as far as planning,” she said. “We would like to know ahead of time, if it is oblong, we would like to fly when the longest point is facing the telescope.”

Several times during the briefing, Stern indicated how having a future mission that orbited Pluto would answer so many outstanding questions the team has. He outlined one potential mission that is in the very earliest stages of study where a spacecraft could be launched on NASA’s upcoming Space Launch System (SLS) and the spacecraft could have an RTG-powered ion engine that would allow a fast-moving spacecraft the ability to slow down and go into orbit (unlike New Horizons). This type of architecture would allow for a flight time of 7.5 years to Pluto, quicker than New Horizons’ nearly 9.5 years.

October 18, 2016October 18, 2016 by Matt Williams

What Is an Earthquake?

The "Global Tectonic and Volcanic Activity of the Last One Million Years" map. Credit: NASA/DTAM

For people who live on or near an active fault line – such as the San Andreas Fault in California, the Median Tectonic Line in Japan, or the Sunda Megathrust of southeast Asia – earthquakes are a regular part of life. Oftentimes, they can take the form of minor tremors that come and go without causing much damage.

But at other times, they are cataclysmic, causing widespread destruction and death tolls in the thousands or more. But what exactly is an earthquake? What geological forces lead to this destructive force? Where do they typically happen, and how many different types are there? And most importantly, how can we be better prepared for them?

Definition:

An earthquake is defined as a perceptible tremor in the surface of the Earth, which is caused by seismic waves resulting from the sudden release of energy in the Earth’s crust. Sometimes, they are detected because of the transfer of this energy to structures, causing noticeable shaking and noise. At other times, they can be violent enough to throw people and level entire cities.

*Global earthquake epicenters, 1963–1998. Credit: NASA/DTAM*

Generally, the term is used to describe any seismic event that generates seismic waves. An earthquake’s point of initial rupture is called its focus or hypocenter, while the point on the Earth directly above it (i.e. the most immediately-effected area) is called the epicenter.

Causes:

The structure of the Earth’s crust, which is divided into several “tectonic plates”, is responsible for most earthquakes. These plates are constantly in motion due to convection in the Earth’s semi-viscous upper mantle. Over time, these plates will separate and crash into each other, creating visible boundaries called faults.

When plates collide, they remain locked until enough pressure builds that one of them is forced under the other (a process known as subduction). This process occurs over the course of millions of years, and occasionally results in a serious release of energy, frictional heating and cracking along the fault lines (aka. an earthquake).

The energy waves that result are divided into two categories – surface waves and body waves. Surface waves are so-named because they are the energy that reaches the surface of the Earth, while body waves refer to the energy that remains within the planet’s interior.

The Earth's Tectonic Plates. Credit: msnucleus.org — *Map of the Earth’s Tectonic Plates. Credit: msnucleus.org*

It is estimated that only 10% or less of an earthquake’s total energy is radiated as seismic energy, while the rest is used to power the fracture growth or is converted into friction heat. However, what reaches the surface triggers all of the effects that we humans associate with earthquakes – i.e. tremors that vary in duration and intensity.

Occasionally, earthquakes can happen away from fault lines. These are due to some plate boundaries being located in regions of continental lithosphere, where deformation is spread out over a much larger area than the plate boundary. Under these conditions, earthquakes are related to strains developed within the broader zone of deformation.

Earthquakes within a plate (called “intraplate earthquakes”) can also happen as a result of internal stress fields, which are caused by interaction with neighboring plates, as well as sedimentary loading or unloading.

Aside from naturally occurring earthquakes (aka. tectonic earthquakes) that occur along tectonic plate lines (fault lines), there are also those that fall under the heading of “human-made earthquakes”. These are all the result of human activity, which is most often the result of nuclear testing.

A 23 kiloton tower shot called BADGER, fired on April 18, 1953 at the Nevada Test Site, as part of the Operation Upshot–Knothole nuclear test series. Credit: NNSA — *Earthquakes can also be caused by human-made factors, such as nuclear testing. Credit: NNSA*

This type of earthquake can been felt all from considerable distance after the detonation of a nuclear weapon. There is very little actual data that is readily available on this type of earthquake, but, compared to tectonic activity, it can be easily predicted and controlled.

Measurements:

Scientists measure earthquakes using seismometers, which measures sound waves through the Earth’s crust. There is also a method of measuring the intensity of an earthquake. It is known as the Richter Scale, which grades earthquakes from 1 to 10 based on their intensity.

Although there is no upper limit to the scale, most people set ten as the upper limit because no earthquakes equal to or greater than ten have been recorded. Scientist hypothesize that level 10 earthquakes were probably more common in prehistoric times, especially as the result of meteor impacts.

Effects of Earthquakes:

Earthquakes can happen on land or at sea, and can therefore trigger other natural disasters. In the case of those that take place on land, displacement of the ground is often the result, which can cause landslides or even volcanoes. When they take place at sea, the displacement of the seabed often results, causing a tsunami.

Map of major earthquakes around the world. Credit: USGS / Google Maps / AJAX / SODA — *Map of earthquakes around the world in a seven day period. Credit: USGS / Google Maps / AJAX / SODA*

Even though major earthquakes do not happen that often, they can cause substantial damage. In addition to the aforementioned natural disasters they can cause, earthquakes can also trigger fires when gas or electrical lines are damaged and floods when dams are destroyed.

Some of the most devastating earthquakes in history include the 1556 Shaanxi earthquake, which occurred on January 1556 in China. This quake resulted in widespread destruction of housing in the region – most of the housing being dwellings carved directly out of the silt stone mountain – and led to over 830,000 deaths.

The 1976 Tangshan earthquake, which took place in north-eastern China, was the deadliest of the 20th century, leading to he deaths of between 240,000 and 655,000 people. The 1960 Chilean earthquake is the largest earthquake that has been measured on a seismograph, reaching 9.5 magnitude on May 22nd, 1960.

And then there was the 2004 Indian Ocean earthquake, a seismic event that also triggered a massive tsunami that caused devastation throughout southeast Asia. This quake reached 9.1 – 9.3 on the Richter Scale, struck coastal communities with waves measuring up to 30 meters (100 ft) high, and caused the deaths of 230,000 people in 14 countries.

A village near the coast of Sumatra that was devastated by the 2004 Tsunami. Credit: US Navy — *A village near the coast of Sumatra that was devastated by the 2004 Tsunami. Credit: Wikipedia Commons/US Navy*

Warning Systems:

More than 3 million earthquakes occur each year, which works out to about 8,000 earthquakes each day. Most of these occur in specific regions, mainly because they usually happen along the borders of tectonic plates. Despite being difficult to predict (except where human agency is the cause) some early warning methods have been devised.

For instance, using seismological data obtained in well-understood fault regions, earthquakes can be reasonably predicted weeks or months in advance. Regional notifications are also used whenever earthquakes are in progress, but before the shocks have struck, allowing people time to seek shelter in time.

Much like volcanoes, tornadoes, and debris flows, earthquakes are a force of nature that is not to be taken lightly. While they are a regular feature of our planet’s geological activity, they have had a considerable impact on human societies. And just like the eruption that buried Pompeii or the Great Flood, they are remembered long after they strike!

We have written many interesting articles about earthquakes here at Universe Today. Here’s Famous Earthquakes, What Causes Earthquakes?, What are Earthquake Fault Lines?, What are the Different Types of Earthquakes? and The Sun Doesn’t Cause Earthquakes,

For more information, you should check out earthquakes and how earthquakes work.

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

Sources:

October 18, 2016October 18, 2016 by Fraser Cain

What Are Cosmic Voids?

Clearly I need to learn to be more specific when I write these articles. Everything time I open my mouth, I need to prepare for the collective imagination of the viewers.

We did a whole article about the biggest things in the Universe, and identified superclusters of galaxies as the best candidate. Well, the part of superclusters actually gravitationally bound enough to eventually merge together in the future. But you had other ideas, including dark energy, or the Universe itself as the biggest thing. Even love? Aww.

One intriguing suggestion, though, is the idea of the vast cosmic voids between galaxies. Hmm, is the absence of something a thing? Whoa, time to go to art school and talk about negative space.

Ah well, who cares? It’s a super interesting topic, so let’s go ahead and talk about voids.

When most people imagine the expansion of the Universe after the Big Bang, they probably envision an equally spaced smattering of galaxies zipping away from one another. And that’s pretty accurate at the smallest scales.

Credit: NASA, ESA, and E. Hallman (University of Colorado, Boulder)

But at the largest scales, like when you can see billions of light-years in a cube that fits on your computer screen, then a larger structure starts to take shape.

It looks less like an explosion, and more like a tasty tasty sponge cake, with huge filaments, walls, and the vast gaps in between. The gaps, the voids, the supervoids, are the point of today’s article, but to understand the gaps, we’ve got to understand why the Universe is clumped up the way it is.

Run the Universe clock backwards, all the way to the beginning, to a fraction of a second after the Big Bang. When the entire cosmos was compressed down into a tiny region of superheated plasma.

Although it was mostly uniform in density, there were slight variations – quantum fluctuations in spacetime itself. And as the Universe expanded, those differences were magnified. What started out as tiny differences in the density of matter at the smallest scale, turned into regions of higher and lower density of matter in the Universe.

Here we are, 13.8 billion years after the Big Bang, and we can see how the microscopic variations at the beginning of time were magnified to the largest scales. Instead of individual galaxies, we see huge walls containing thousands of galaxies; filaments of galaxies connect in nodes. These structures are huge; hundreds of millions of light-years across, containing thousands of galaxies. But the gaps, the voids, between these clusters can be even larger.

Astronomers first started thinking about these voids back in the 1970s, when the first large-scale surveys of the Universe were made. By measuring the redshift of galaxies, and determining how fast they were speeding away from us, astronomers started to realize that the distribution of galaxies wasn’t even.

Some galaxies were relatively close, but then there were huge gaps in distance, and then another cluster of galaxies collected together.

Over the last few decades, astronomers have built sophisticated 3-dimensional models that map out the Universe in the largest scales. The Sloan Digital Sky Survey, updated in 2009, has provided the most accurate map so far. The Large Synoptic Survey Telescope, destined for first light in a few years will take this to the next level.

The largest void that we currently know of is known as the Giant Void (original, I know), and it’s located about 1.5 billion light-year away. It has a diameter of 1 billion to 1.3 billion light-years across.

To be fair, these regions aren’t really completely empty. They just have less density than the regions with galaxies. In general, they’ve got about a tenth the density of matter that’s average for the Universe.

Galaxy MCG+01-02-015 is so isolated that if our galaxy, the Milky Way, were to be situated in the same way, we would not have known of the existence of other galaxies until the 1960s Credit: ESA/Hubble & NASA and N. Gorin (STScI). Acknowledgement: Judy Schmidt — Galaxy MCG+01-02-015 is so isolated that if our galaxy, the Milky Way, were to be situated in the same way, we would not have known of the existence of other galaxies until the 1960s
Credit: ESA/Hubble & NASA and N. Gorin (STScI). Acknowledgement: Judy Schmidt

Which means that there’s still gas and dust in these regions, as well as dark matter. There will still be stars and galaxies out in the middle of those voids. Even the Giant Void has 17 separate galaxy clusters inside it.

You might imagine continuing to scale outward. Maybe you’re wondering if the this spongy distribution of matter is actually just the next step to an even larger structure, and so on, and so on. But it isn’t. In fact, astronomers call this “the End of Greatness”, because it doesn’t seem like there’s any larger structure to the Universe.

As the expansion of the Universe continues, these voids are going to get even larger. The walls and filaments connecting clusters of galaxies will stretch and break. The voids will merge with each other, and only gravitationally bound galaxy clusters will remain as islands, adrift in the expanding emptiness.

The full scale of the observable Universe is truly mind boggling. We’re here in this tiny corner of the Local Group, which is part of the Virgo Supercluster, which is perched on the precipice of vast cosmic voids. So much to explore, so let’s get to work.

October 18, 2016 by David Dickinson

Photobomb: The Moon Occults Aldebaran Wednesday

An occultation of Aldebaran by the Moon: before and after. Image credit and copyright: Eliot Herman.

How about that Hunter’s Supermoon this past weekend, huh? Follow that Moon, as it’s meeting up with the Hyades again this week, and occults (passes in front of) Aldebaran Tuesday night into Wednesday morning.

Here’s the lowdown on the event:

The 86% illuminated waning gibbous Moon occults the +0.9 magnitude star Aldebaran across North America, the Northern Atlantic and Europe. The Moon is three days past Full during the event. Both are located 136 degrees west of the Sun at the time of the event. The central time of conjunction is ~6:40 Universal Time (UT). The event occurs during the daylight hours over western Europe and northwestern Africa and under darkness for southeastern North America, including the eastern United States and Mexico. The Moon will next occult Aldebaran on November 15^th, 2016. This is occultation 24 in the current series of 49 running from January 29^th, 2015 to September 3^rd 2018.

The occultation of Aldebaran by the Moon as seen from London on December 23rd, 2015. Image credit and copyright: Roger Hutchinson.

The graze line is of particular interest during this event. We’re talking about the very edge of the footprint of the Moon’s ‘shadow’ cast by Aldebaran, running through Canada and bisecting the United States. Observers based along this line could see a spectacular ‘grazing occultation’ of Aldebaran by the Moon. We usually think of the limb of the Moon as a smooth curve, but it’s actually jagged. What you may see is Aldebaran wink in and out as light shines down those lunar valleys and is alternately blocked out behind peaks and crater rims. This is an unforgettable sight, and makes for great video. A record of a grazing occultation by multiple observers can also be used to create a profile of the lunar limb. That light from Aldebaran took 65 years to get here, only to be blocked by our Moon at the very last second.

The occultation footpring for tonight's event. The solid lines denote where the occultation occurs under dark night time skies, while the blue lines denote twilight and the broken lines describe where the event occurs in the daytime. Image credit: Occult 4.2. — The occultation footprint for tonight’s event. The solid lines denote where the occultation occurs under dark nighttime skies, while the blue lines denote twilight, and the broken lines describe where the event occurs in the daytime. Image credit: Occult 4.2.

And observers (myself one of them) based in Europe shouldn’t count themselves out. Like brighter planets, you can spy a +1 magnitude star such as Aldebaran near the daytime Moon using binoculars or a telescope… if, of course, you have a high contrast deep blue sky and know exactly where to look for it. The International Occultation Timing Association has a page for the event with a complete list of ingress and egress times for key cities on three continents in the path. We’ll be watching the Wednesday event – clear skies willing — from our present basecamp in the Andalusian foothills just outside of Jimena de la Frontera, Spain.

The northern graze line for tonight's occultation. Note that several major cities lie along the crucial path. Image credit: Dave Dickinson. — The northern graze line for tonight’s occultation. Note that several major cities lie along the crucial path. Image credit: Dave Dickinson.

During our current epoch, the Moon can only occult four +1^st magnitude stars: Regulus, Spica, Antares and Aldebaran. The slow motion movement of the Moon, the Earth and the background stars make this prestigious A-list change over time: until about two millennia ago, you could also count the bright star Pollux in Gemini among them.

In the current century, (2001-2100 AD) the Moon occults Aldebaran 247 times, topped only by Antares (386 times) and barely beating out Spica (220 times).

Timing an occultation is fun and as easy as shooting video of the Moon through a telescope at the appointed time of ingress or egress. Practice on framing the dazzling Moon first well in advance — probably the toughest part is getting the exposure of the bright limb stopped down enough to still see and image the star. We find that shooting anywhere from 1/100^th to 1/500^th frame rate for a gibbous Moon is about right. Don’t be afraid to crank up the magnification a bit, so you can place the bulk of the Moon out of view. Also, catching occultations of stars and planets during waning Moon phases are more challenging than waxing, as the star will ingress behind the bright leading limb and later reappear behind the dark trailing limb (waxing is vice versa).

Observing: Running an audible time hack in the background such as WWV radio out of Fort Collins, Colorado can provide a precise record of the occultation.

But wait, there’s more. When the Moon occults Aldebaran, its also crossing the background V-shaped open star cluster known as the Hyades. Worldwide the waning gibbous Moon also occults Gamma, 51, and Theta^1 and Theta^2, SAO 93975, and 119 Tauri. Chances are, there’s an occultation for YOU to catch this week, regardless of your location.

Want more? Well, the Moon continues to occult Aldebaran every lunation through 2017, and will also start a cycle of passes in front of Regulus on December 18^th. In fact, the next occultation of Aldebaran on November 15th favors central Asia, and the event two lunations from now on December 13^th brings the path back around the North America.

A great close out for 2016, for sure. Don’t miss this week’s occultation!

October 18, 2016October 19, 2016 by Ken Kremer

Antares ‘Return to Flight’ Blastoff Soars to Stellar Success

The Orbital ATK Antares rocket topped with the Cygnus cargo spacecraft launches from Pad-0A, Monday, Oct. 17, 2016 at NASA’s Wallops Flight Facility in Virginia. Orbital ATK’s sixth contracted cargo resupply mission with NASA to the International Space Station. Credit: Ken Kremer/kenkremer

NASA WALLOPS FLIGHT FACILITY, VA – The ‘Return to Flight’ blastoff of Orbital ATK’s upgraded Antares rocket soared to a stellar success this evening, Oct. 17, on a space station bound mission to stock the orbiting outpost with two and a half tons of science and supplies.

The re-engined Orbital ATK Antares/Cygnus OA-5 mission lifted off at 7:45 p.m. EDT, tonight from the Mid-Atlantic Regional Spaceport pad 0A at NASA’s Wallops Flight Facility on Virginia’s picturesque Eastern shore spewing about 1.2 million pounds of liftoff thrust and brilliantly lighting up the evening skies in every direction.

Sporting a pair of more powerful new RD-181 engines, Antares roared off the launch pad somewhat more swiftly than the previous launches and consequently reached its preliminary orbit about one minute earlier.

Cygnus separated from the second stage as planned about 9 minutes after liftoff. The launch marked the first nighttime liftoff of Antares.

“It’s great to see launches to the International Space Station happening again from the Virginia coast – and it shows what can be accomplish with a close partnership of federal and state agencies, along with the U.S. industry, all working together,” said NASA Administrator Charles Bolden.

“I am incredibly proud of what you have all done,” said Bolden in post launch remarks to the launch team at Wallops Launch Control Center. “Thank you for all your hard work.”

Antares launch on Oct. 17, 2016 from NASA's Wallops Flight Facility in Virginia. Credit: © Patrick J. Hendrickson / Highcamera.com — Antares launch on Oct. 17, 2016 from NASA’s Wallops Flight Facility in Virginia. Credit: © Patrick J. Hendrickson / Highcamera.com

This was the first Antares launch in two years following the rockets catastrophic failure just moments after liftoff on Oct. 28, 2014, which doomed the Orb-3 resupply mission to the space station – as witnessed by this author.

The weather was absolutely perfect at 100% GO by launch time and consequently was visible to millions of East Coast residents from the Carolinas to Maine as well as inland regions.

Visibility was aided by cloudless evening skies that afforded a spectacular long distance view of the engine firings for both the first and second stages, as the rocket accelerated to orbit in a southeastwardly direction before arcing over towards the African continent.

The power producing and life giving solar arrays were deployed and unfurled about two hours after liftoff, finished at about 9:40 p.m.

Cygnus is loaded with over 5,100 pounds of science investigations, food, supplies and hardware for the space station and its crew.

After Cygnus arrives at the ISS on Sunday, Oct. 23, Expedition 49 Flight Engineers Takuya Onishi of the Japan Aerospace Exploration Agency and Kate Rubins of NASA will grapple the spacecraft with the space station’s 57 foot long Canadian-built robotic arm. It will take hold of the Cygnus,

Ground controllers will then command the station’s arm to rotate and install it on the bottom of the station’s earth facing Unity module.

The Cygnus spacecraft will spend about five weeks attached to the space station. Cygnus will remain at the space station until November, when the spacecraft will depart the station and begin a fire experiment dubbed Saffire-II.

The 14 story tall commercial Antares rocket launched for the first time in the upgraded 230 configuration – powered by a pair of the new Russian-built RD-181 first stage engines.

For the OA-5 mission, the Cygnus advanced maneuvering spacecraft was loaded with approximately 2,425 kg (5,346 lb.) of supplies and science experiments for the International Space Station (ISS). The cargo was packed inside 56 cargo bags of multiple sizes.

The experiments will support dozens of new and existing investigations as the space station crews of Expeditions 49 and 50 contribute to about 250 science and research studies.

Among the science payloads aboard the Cygnus OA-5 mission is the Saffire II payload experiment to study combustion behavior in microgravity. Data from this exp,eriment will be downloaded via telemetry. In addition, a NanoRack deployer will release Spire Cubesats used for weather forecasting. These secondary payload operations will be conducted after Cygnus departs the space station.

Here is the Cygnus payload manifest:

Payloads:
• Spacecraft Fire Experiment-II (Saffire-II)
• Fast Neuron Spectrometer
• ACM and Experiment Tray
• SLMMD
Cargo:
• ISS Experiment Hardware
• EVA Equipment– EMU Repair Kit– EVA Supplies
• Emergency Equipment
• Photo/TV and Computer Resources– Computer – iPad Air 2
– Laptop – T61P and Connectors – Camera – Nikon D4
• ISS Hardware and Spare ORUs – Cupola Scratch Panes
– Water ORU
• Food, Crew Supplies and Crew Provisions
• Flight Crew Equipment
• Cargo Environment SensorsAdditional payload details can be found at www.nasa.gov/iss-science.

Streak shot of Orbital ATK Antares rocket carrying Cygnus supply ship soars to orbit on Oct. 17, 2016 from Pad-0A at NASA’s Wallops Flight Facility in Virginia. Credit: Ken Kremer/kenkremer

The Cygnus spacecraft for the OA-5 mission is named the S.S. Alan G. Poindexter in honor of former astronaut and Naval Aviator Captain Alan Poindexter.

Under the Commercial Resupply Services (CRS) contract with NASA, Orbital ATK will deliver approximately 28,700 kilograms of cargo to the space station. OA-5 is the sixth of these missions.

Watch for Ken’s continuing Antares/Cygnus mission and launch reporting. He is 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