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08/26/2016 04:36 PM
SpaceX Dragon Splashes Down with NASA’s Station Science Cargo

SpaceX Dragon CRS-9 returned to Earth with a splash down in the Pacific Ocean on Friday, Aug. 26, 2016 after more than a month stay at the International Space Station.  Credit: SpaceX

A SpaceX commercial Dragon cargo ship returned to Earth today, Friday, Aug. 26, 2016, by splashing down safely in the Pacific Ocean - thus concluding more than a month long stay at the International Space Station (ISS). The vessel was jam packed with some 1.5 tons of NASA cargo and critical science samples for eagerly waiting researchers.

The parachute assisted splashdown of the Dragon CRS-9 cargo freighter took place at 11:47 a.m. EDT today in the Pacific Ocean - located some 326 miles (520 kilometers) southwest of Baja California.

Dragon departed after spending more than five weeks berthed at the ISS.

It was loaded with more than 3,000 pounds of NASA cargo and critical research samples and technology demonstration samples accumulated by the rotating six person crews of astronauts and cosmonauts living and working aboard the orbiting research laboratory.

This station based research will contribute towards NASA's strategic plans to send astronauts on a 'Journey to Mars' by the 2030s.

It arrived at the station on July 20 ferrying over 2.5 tons of priceless research equipment, gear, spare parts and supplies, food, water and clothing for the station’s resident astronauts and cosmonauts as well as the first of two international docking adapters (IDAs) in its unpressurized cargo hold known as the “trunk.”

Dragon was launched on July 18 during a mesmerizing post midnight, back-to-back liftoff and landing of the SpaceX Falcon 9 rocket in its upgraded, full thrust version.

The SpaceX Falcon 9 blasted off at 12:45 a.m. EDT July 18, from Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida and successfully delivered the Dragon CRS-9 resupply ship to its preliminary orbit about 10 minutes later.

SpaceX also successfully executed a spellbinding ground landing of the Falcon 9 first stage back at Cape Canaveral Air Force Station’s Landing Zone 1, located a few miles south of launch pad 40.

The dramatic ground landing of the 156 foot tall Falcon 9 first stage at LZ -1 took place about 9 minutes after liftoff. It marked only the second time a spent, orbit class booster has touched down intact and upright on land.

The stage was set for today’s return to Earth when ground controllers robotically detached Dragon from the Earth-facing port of the Harmony module early this morning using the station’s 57.7-foot (17.6-meter) long Canadian-built robotic arm.

Expedition 48 Flight Engineers Kate Rubins of NASA and Takuya Onishi of the Japan Aerospace Exploration Agency (JAXA) then used Canadarm 2 to release Dragon from the grappling snares at about 6:10 a.m. EDT (1011 GMT) this morning.

“Houston, station, on Space to Ground Two, Dragon depart successfully commanded,” radioed Rubins.

The ISS was soaring some 250 miles over the Timor Sea, north of Australia.

“Congratulations to the entire team on the successful release of the Dragon. And thank you very much for bringing all the science, and all the important payloads, and all the important cargo to the station,” Onishi said. “We feel really sad to see it go because we had a great time and enjoyed working on all the science that the Dragon brought to us.”

Dragon then backed away and moved to a safe distance from the station via a trio of burns using its Draco maneuvering thrusters.

The de-orbit burn was conducted at 10:56 a.m. EDT (1456 GMT) to drop Dragon out of orbit and start the descent back to Earth.

SpaceX contracted recovery crews hauled Dragon aboard the recovery ship and are transporting it to a port near Los Angeles, where some time critical cargo items and research samples will be removed and returned to NASA for immediate processing.

SpaceX plans to move Dragon back to the firms test facility in McGregor, Texas, for further processing and to remove the remaining cargo cache.

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

During a spacewalk last week on Aug. 19, the initial docking adapter known as International Docking Adapter-2 (IDA-2) was installed Expedition 48 Commander Jeff Williams and Flight Engineer Kate Rubins of NASA.

Other science experiments on board included OsteoOmics to test if magnetic levitation can accurately simulate microgravity to study different types of bone cells and contribute to treatments for diseases like osteoporosis, a Phase Change Heat Exchanger to test temperature control technology in space, the Heart Cells experiments that will culture heart cells on the station to study how microgravity changes the human heart, new and more efficient three-dimensional solar cells, and new marine vessel tracking hardware known as the Automatic Identification System (AIS) that will aid in locating and identifying commercial ships across the globe.

The ring shaped IDA-2 unit was stowed in the Dragon’s unpressurized truck section. It weighs 1029 lbs (467 kg), measures about 42 inches tall and sports an inside diameter of 63 inches in diameter - so astronauts and cargo can easily float through. The outer diameter measures about 94 inches.

“Outfitted with a host of sensors and systems, the adapter is built so spacecraft systems can automatically perform all the steps of rendezvous and dock with the station without input from the astronauts. Manual backup systems will be in place on the spacecraft to allow the crew to take over steering duties, if needed,” says NASA.

"It's a passive system which means it doesn’t take any action by the crew to allow docking to happen and I think that's really the key," said David Clemen Boeing's director of Development/Modifications for the space station.

“Spacecraft flying to the station will use the sensors on the IDA to track to and help the spacecraft's navigation system steer the spacecraft to a safe docking without astronaut involvement.”

CRS-9 counts as the company’s ninth of 26 scheduled flight to deliver supplies, science experiments and technology demonstrations to the International Space Station (ISS).

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

Watch for Ken’s continuing SpaceX and CRS mission coverage where he reported onsite direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.

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

Ken Kremer

The post SpaceX Dragon Splashes Down with NASA’s Station Science Cargo appeared first on Universe Today.



08/26/2016 03:45 PM
What Are The Lagrange Points?

There are places in the Solar System where the forces of gravity balance out perfectly. Places we can use to position satellites, space telescopes and even colonies to establish our exploration of the Solar System. These are the Lagrange Points.

The post What Are The Lagrange Points? appeared first on Universe Today.



08/26/2016 02:14 PM
A New NASA Cumulative Time in Space Record

Astronaut Jeff Williams just established a new record for most time spent in space by a NASA astronaut. Credit: NASA

The International Space Station has provided astronauts and space agencies with immense opportunities for research during the decade and a half that it has been in operation. In addition to studies involving meteorology, space weather, materials science, and medicine, missions aboard the ISS has also provided us with valuable insight into human biology.

For example, studies conducted aboard the ISS' have provided us with information about the effects of long-term exposure to microgravity. And all the time, astronauts are pushing the limits of how long someone can healthily remain living under such conditions. One such astronauts is Jeff Williams, the Expedition 48 commander who recently established a new record for most time spent in space.

This record-breaking feat began back in 2000, when Williams spent 10 days aboard the Space Shuttle Atlantis for mission STS-101. At the time, the International Space Station was still under construction, and as the mission's flight engineer and spacewalker, Williams helped prepare the station for its first crew.

This was followed up in 2006, where Williams' served as part of Expedition 13 to the ISS. The station had grown significantly at this point with the addition of Russian Zvezda service module, the U.S. Destiny laboratory, and the Quest airlock. Numerous science experiments were also being conducted at this time, which included studies into capillary flow and the effects of microgravity on astronauts’ central nervous systems.

During the six months he was aboard the station, Williams was able to get in two more spacewalks, set up additional experiments on the station's exterior, and replaced equipment. Three years later, he would return to the station as part of Expedition 21, then served as the commander of Expedition 22, staying aboard the station for over a year (May 27th, 2009 to March 18th, 2010).

By the time Expedition 48's Soyuz capsule launched to rendezvous with the ISS on July 7th, 2016, Williams had already spent more than 362 days in space. By the time he returns to Earth on Sept. 6th, he will have spent a cumulative total of 534 days in space. He will have also surpassed the previous record set by Scott Kelly, who spent 520 days in space over the course of four missions.

On Wednesday, August 24th, the International Space Station raised its orbit ahead of Williams’ departure. Once he and two of his mission colleagues - Oleg Skripochka and Alexey Ovchinin - undock in their Soyuz TMA-20M spacecraft, they begin their descent towards Kazakhstan, arriving on Earth roughly three and a half hours later.

Former astronaut Scott Kelly was a good sport about the passing of this record, congratulating Williams in a video created by the Johnson Space Center (see below). Luckily, Kelly still holds the record for the longest single spaceflight by a NASA astronaut - which lasted a stunning 340 days.

And Williams may not hold the record for long, as astronaut Peggy Whitson is scheduled to surpass him in 2017 during her next mission (which launches this coming November). And as we push farther out into space in the coming years, mounting missions to NEOs and Mars, this record is likely to be broken again and again.

In the meantime, Williams and his crew will continue to dedicate their time to a number of crucial experiments. In the course of this mission, they have conducted research into human heart function, plant growth in microgravity, and executed a variety of student-designed experiments.

Like all research conducted aboard the ISS, the results of this research will be used to improve health treatments, have numerous industrial applications here on Earth, and will help NASA plan mission farther into space. Not the least of which will be NASA's proposed (and rapidly approaching) crewed mission to Mars.

In addition to spending several months in zero-g for the sake of the voyage, NASA will need to know how their astronauts will fair when conducting research on the surface of Mars, where the gravity is roughly 37% that of Earth (0.376 g to be exact).

And be sure to enjoy this video of Scott Kelly congratulating Williams on his accomplishment, courtesy of the Johnson Space Center:

https://youtu.be/_403HWLU6Uk

Further Reading: NASA

The post A New NASA Cumulative Time in Space Record appeared first on Universe Today.



08/26/2016 10:40 AM
What Can We Expect From Juno’s Return To Jupiter?

Illustration of NASA's Juno spacecraft firing its main engine to slow down and go into orbit around Jupiter. Lockheed Martin built the Juno spacecraft for NASA's Jet Propulsion Laboratory.  Credit: NASA/Lockheed Martin

The Juno spacecraft made history on July 4th, 2016, when it became the second spacecraft in history to achieve orbit around Jupiter for the sake of a long-term mission. Following in the footsteps of the Galileo mission, the probe will spend the next 20 months gathering data on Jupiter's atmosphere, clouds, interior and gravitational and magnetic fields, before purposefully crashing into the planet.

And on Saturday, August 27th, Juno will be making history once again. According to NASA, at precisely 12:51 UTC (5:51 a.m. PDT, 8:51 a.m. EDT) the spacecraft will be passing closer to the cloud tops of Jupiter than at any point in its main mission. And while the probe is expected to make 35 more close flybys of the gas giant before its mission ends in February of 2018, this particular one is expected to be especially revealing.

For one, it will be the first time that the probe has all of its scientific instruments online and surveying Jupiter's atmosphere as it swings past. And during the flyby, the probe will be passing Jupiter's cloud tops at a distance of 4,200 kilometers (2,500 miles) - closer than it will ever get again - while traveling at a speed of 208,000 km/hour (130,000 mph).

This will not only be the closest approach to Jupiter made by any probe, but it will pass over Jupiter's poles, which will give Juno the opportunity to get a look at some never-before-seen things. These will include infrared and microwave readings taken by Juno's suite of eight instruments, but also some choice photographs.

Yes, in addition to its sensor package, Juno's visible light imager (aka. JunoCam) will also be active and taking some close-up pictures of the atmosphere and poles. While the scientific information is expected to keep NASA scientists occupied for some time to come, the JunoCam images are expected to be released later next week.

According to NASA, these images will be the highest resolution photos of the Jovian atmosphere ever taken, not to mention the first glimpse of Jupiter's north and south poles ever. As Scott Bolton, principal investigator of Juno from the Southwest Research Institute in San Antonio, said in a NASA press release:

"This is the first time we will be close to Jupiter since we entered orbit on July 4. Back then we turned all our instruments off to focus on the rocket burn to get Juno into orbit around Jupiter. Since then, we have checked Juno from stem to stern and back again. We still have more testing to do, but we are confident that everything is working great, so for this upcoming flyby Juno’s eyes and ears, our science instruments, will all be open... This is our first opportunity to really take a close-up look at the king of our Solar System and begin to figure out how he works."

Ever since the Juno spacecraft launched on Aug. 5th, 2011, from Cape Canaveral, Florida, scientists and astronomers have been waiting for the day when it would start sending back information on the Solar System's greatest planet. By examining the atmosphere, interior, and magnetic environment of the gas giant, scientists hope to be able to answer burning questions about the history of the planet's formation.

For example, Jupiter’s interior structure and composition, as well as what drives its magnetic field, are still the subject of debate. In addition, there are some unanswered questions about when and where the planet formed. While it may have formed in its current orbit, some evidence suggests that it could have formed farther from the sun before migrating inward. All of these questions, it is hoped, are things the Juno mission will answer.

In so doing, scientists hope to be able to shed some additional light on the history of the Solar System as well. Like the other gas giants, it was assembled during the early phases, before our Sun had the chance to absorb or blow away the light gases in the huge cloud from which both were born. As such, Jupiter’s composition could tell us much about the early Solar System.

And this Saturday, the probe will be gathering what could prove to be the most crucial information its mission will produce. And of course, if all goes well, it will be taking the most detailed pictures of the Jovian giant to date! Godspeed, little Juno. You be careful out there!

https://youtu.be/SgEsf4QcR0Q

Further Reading: NASA

The post What Can We Expect From Juno’s Return To Jupiter? appeared first on Universe Today.



08/26/2016 07:04 AM
Citizen Scientists Help Crack 300 Year Old Mystery Of Eclipse Wind

Totality captured from the March 20, 2015 solar eclipse, as seen from the Svalbard Islands. Credit and Copyright: Tony Hoffman.

Being able to witness a solar eclipse is certainly a distinct experience. Even though the spectacle is mostly visual, there can be other effects as well. The air can cool, and observers may notice a decrease in wind speed or a change in wind direction. There might even be an eerie silence.

Experiences like this have been noted for centuries, and famed astronomer Edmund Halley wrote of the ‘Chill and Damp which attended the Darkness’ during an eclipse in 1715, which he noted caused ‘some sense of Horror’ among those who were witnessing the event.

While most people would describe an eclipse as ‘awe-inspiring’ (and not horrifying at all) the atmospheric changes noted by observers over the years has been called the “eclipse wind.” And now, based on the observations of over 4,500 citizen scientists in the UK during the partial eclipse on March 20, 2015, this effect is not just a figment of anyone’s imagination; it is a real phenomenon.

The National Eclipse Weather Experiment (NEWEx) was a UK-wide citizen science project for collecting atmospheric data during that eclipse. Members of the public – including about 200 schools – recorded weather changes such as air temperature, wind speed, wind direction and cloud cover every five minutes during the eclipse. That data, submitted online, was compared with official data from the UK’s Met office observations, the United Kingdom's national weather service.

“The NEWEx was, as far as we know, a world first, in measuring and analyzing eclipse changes in the weather on a national scale, in close to real time, through engagement of a network of citizen scientists,” wrote researchers Luke Barnard, Giles Harrison, Suzanne Gray and Antonio Portas from the University of Reading, in one of a series of new papers about eclipse meteorology published this week.

The data revealed that not only did the atmosphere cool during the eclipse – which is not surprising since solar radiation is being blocked by the Moon – but the winds and cloud cover also decreased. The cumulative effect is real, not just anecdotal, the team said.

The Data

NEWEx collected 15,606 meteorological observations from 309 locations within the UK and from those observations the science team was able to derive estimates of the near-surface air temperature, cloudiness and near-surface wind speed fields across many UK sites. The data submitted by citizen scientists were combined with Met Office surface weather stations and a network of roadside weather sensors that monitor highway conditions. The combination of data helped unravel the centuries-old mystery of the eclipse wind.

From analysis of the data, they found that the wind change is caused by variations to the "boundary layer" – the area of air that usually separates high-level winds from those at the ground.

“There have been lots of theories about the eclipse wind over the years, but we think this is the most compelling explanation yet,” said Harrison in a press release from the University of Reading in the UK. “As the sun disappears behind the moon the ground suddenly cools, just like at sunset. This means warm air stops rising from the ground, causing a drop in wind speed and a shift in its direction, as the slowing of the air by the Earth’s surface changes.”

The measurements from citizen scientists clearly showed temperature drops and a decrease in clouds. The team did note that because of the low velocity of winds and some areas where cloud cover change was small, it was difficult for the participants to make some of the measurements. But the high level of participation across the UK provided enough data for the team to make their conclusions.

“Halley also relied on combining eclipse observations from amateur investigators across Britain. We have continued his approach,” Harrison said.

A total of 16 new papers and reports were published this week in a special ‘eclipse meteorology’ issue of the world’s oldest scientific journal, Philosophical Transactions of the Royal Society A. The special issue is published 301 years after Halley’s report of the eclipse in London in 1715 – and in exactly the same journal.

The team wrote that they hope a similar citizen science effort might take place in August 2017, when a total solar eclipse will be visible from North America, providing another opportunity to study eclipse-induced meteorology changes.
“NEWEx serves as a useful example of the strengths and challenges of using a citizen science approach to study eclipse-induced meteorological changes, and could provide a template for a similar study for the August 2017 eclipse,” the team said.

Sources: Paper: The National Eclipse Weather Experiment: an assessment of citizen scientist weather observations, Philosophical Transactions of the Royal Society A, University of Reading.

The post Citizen Scientists Help Crack 300 Year Old Mystery Of Eclipse Wind appeared first on Universe Today.



08/25/2016 03:46 PM
What Does “Earthlike” Even Mean & Should It Apply To Proxima Centauri b?

Artist’s impression of the surface of the planet Proxima b orbiting the red dwarf star Proxima Centauri. The double star Alpha Centauri AB is visible to the upper right of Proxima itself. Credit: ESO

The ESO's recent announcement that they have discovered an exoplanet candidate orbiting Proxima Centauri - thus confirming weeks of speculation - has certainly been exciting news! Not only is this latest find the closest extra-solar planet to our own Solar System, but the ESO has also indicated that it is rocky, similar in size and mass to Earth, and orbits within the star's habitable zone.

However, in the midst of this news, there has been some controversy regarding certain labels. For instance, when a planet like Proxima b is described as "Earth-like", "habitable", and/or "terrestrial", there are naturally some questions as to what this really means. For each term, there are particular implications, which in turn beg for clarification.

For starters, to call a planet "Earth-like" generally means that it is similar in composition to Earth. This is where the term "terrestrial" really comes into play, as it refers to a rocky planet that is composed primarily of silicate rock and metals which are differentiated between a metal core and a silicate mantle and crust.

https://youtu.be/fuo3vWtSdqY

This applies to all planets in the inner Solar System, and is often used in order to differentiate rocky exoplanets from gas giants. This is important within the context of exoplanet hunting, as the majority of the 4,696 exoplanet candidates - of which 3,374 have been confirmed (as of August 18th, 2016) - have been gas giants.

What this does not mean, at least not automatically, is that the planet is habitable in the way Earth is. Simply being terrestrial in nature is not an indication that the planet has a suitable atmosphere or a warm enough climate to support the existence of liquid water or microbial life on its surface.

What's more, Earth-like generally implies that a planet will be similar in mass and size to Earth. But this is not the same as composition, as many exoplanets that have been discovered have been labeled as "Earth-sized" or "Super-Earths" - i.e. planets with around 10 times the mass of Earth - based solely on their mass.

This term also distinguishes an exoplanet candidate from those that are 15 to 17 masses (which are often referred to as "Neptune-sized") and those that are have masses similar to, or many times greater than that of Jupiter (i.e. Super-Jupiters). In all these cases, size and mass are the qualifiers, not composition.

https://youtu.be/y6g7c00v_nY

Ergo, finding a planet that is greater in size and mass than Earth, but significantly less than that of a gas giant, does not mean it is terrestrial. In fact, some scientists have recommended that the term "mini-Neptune" be used to describe planets that are more massive than Earth, but not necessarily composed of silicate minerals and metals.

And estimates of size and mass are not exactly metrics for determining whether or not a planet is "habitable". This term is especially sticky when it comes to exoplanets. When scientists attach this word to extra-solar planets like Proxima b, Gliese 667 Cc, Kepler-452b, they are generally referring to the fact that the planet exists within its parent star's "habitable zone" (aka. Goldilocks zone).

This term describes the region around a star where a planet will experience average surface temperatures that allow for liquid water to exist on its surface. For those planets that orbit too close to their star, they will experience intense heat that transforms surface waster into hydrogen and oxygen - the former escaping into space, the latter combining with carbon to form CO².

This is what scientists believe happened to Venus, where thick clouds of CO² and water vapor triggered a runaway greenhouse effect. This turned Venus from a world that once had oceans into the hellish environment we know today, where temperatures are hot enough to melt lead, atmospheric density if off the charts, and sulfuric acid rains from its thick clouds.

For planets that orbit beyond a star's habitable zone, water ice will become frozen solid, and the only liquid water will likely be found in underground reservoirs (this is the case on Mars). As such, finding planets that are just right in terms of average surface temperature is intrinsic to the "low-hanging fruit" approach of searching for life in our Universe.

But of course, just because a planet is warm enough to have water on its surface doesn't mean that life can thrive on it. As our own Solar System beautifully demonstrates, a planet can have the necessary conditions for life, but still become a sterile environment because it lacks a protective magnetosphere.

This is what scientists believe happened to Mars. Located within our Sun's Goldilocks zone (albeit on the outer edge of it), Mars is believed to have once had an atmosphere and liquid water on its surface. But today, atmospheric pressure on the surface of Mars is only 1% that of Earth's, and the surface is dry, cold, and devoid of life.

The reason for this, it has been determined, is because Mars lost its magnetosphere 4.2 Billion years ago. According to NASA's MAVEN mission, this resulted in Mars' atmosphere being slowly stripped away over the course of the next 500 million years by solar wind. What little atmosphere it had left was not enough to retain heat, and its surface water evaporated.

By the same token, planets that do not have protective magnetospheres are also subject to an intense level of radiation on their surfaces. On the Martian surface, the average dose of radiation is about 0.67 millisieverts (mSv) per day, which is about a fifth of what people are exposed to here on Earth in the course of a year.

We can expect similar situations on extra-solar planets where a magnetosphere does not exist. Essentially, Earth is fortunate in that it not only orbits in a pretty cushy spot around our Sun, but that its core is differentiated between a solid inner core and a liquid, rotating outer core. This rotation, it is believed, is responsible for creating a dynamo effect that in turn creates Earth's magnetic field.

However, using our own Solar System again as a model, we find that magnetic fields are not entirely uncommon. While Earth is the only terrestrial planet in our Solar System to have on (all the gas giants have powerful fields), Jupiter's moon Ganymede also has a magnetosphere of its own.

Similarly, there are orbital parameters to consider. For instance, a planet that is similar in size, mass and composition could still have a very different climate than Earth due to its orbit. For one, it may be tidally-locked with its star, which would mean that one side is permanently facing towards it, and is therefore much warmer.

On the other hand, it may have a slow rotational velocity, and a rapid orbital velocity, which means it only experiences a few rotations per orbit (as is the case with Mercury). Last, but certainly not least, its distance from its respective star could mean it receives far more radiation than Earth does - regardless of whether or not it has a magnetosphere.

This is believed to the be the case with Proxima Centauri b, which orbits its red dwarf star at a distance of 7 million km (4.35 million mi) – only 5% of the Earth’s distance from the Sun. It also orbits Proxima Centauri with an orbital period of 11 days, and either has a synchronous rotation, or a 3:2 orbital resonance (i.e. three rotations for every two orbits).

Because of this, the climate is likely to be very different than Earth's, with water confined to either its sun-facing side (in the case of a synchronous rotation), or in its tropical zone (in the case of a 3:2 resonance). In addition, the radiation it receives from its red dwarf star would be significantly higher than what we are used to here on Earth.

So what exactly does "Earth-like" mean? The short answer is, it can mean a lot of things. And in this respect, its a pretty dubious term. If Earth-like can mean similarities in mass, size, composition, and can allude to the fact that planet orbits within its star's habitable zone - but not necessarily all of the above - then its not a very reliable term.

In the end, the only way to keep things clear would be to describe a planet as "Earth-like" if it in fact shows similarities in terms of size, mass and composition, all at the same time. The word "terrestrial" can certainly be substituted in a pinch, but only where the composition of the planet is known with a fair degree of certainty (and not just its size and mass).

And words like "habitable" should probably only be used when chaperoned by words like "potentially". After all, being within a star's habitable zone certainly means there's the potential for life. But it doesn't not necessarily entail that life could have emerged there, or that humans could live there someday.

And should these words apply to Proxima b? Perhaps, but one should consider the fact that the ESO has announced the detection of a exoplanet using the Radial Velocity method. Until such time as it is confirmed using direct detection methods, its remains a candidate exoplanet (not a confirmed one).

But even these simple measures would likely not be enough to erase all the ambiguity or controversy. When it comes right down to it, planet-hunting - like all aspects of space exploration and science - is a divisive issue. And new findings always have a way of drawing criticism and disagreement from several quarters at once.

And you thought Pluto's classification confused things! Well, Pluto has got nothing on the exoplanet database! So be prepared for many years of classification debates and controversy!

Further Reading: NASA Exoplanet Archive

The post What Does “Earthlike” Even Mean & Should It Apply To Proxima Centauri b? appeared first on Universe Today.



08/25/2016 10:52 AM
Shields Up, Mr. Sulu! Cruising At 20% Speed Of Light Has Some Inherent Risks

Artist's impression of a directed-energy propulsion laser sail in action. Credit: Q. Zhang/deepspace.ucsb.edu

Back in April, Russian billionaire Yuri Milner and famed cosmologist Stephen Hawking unveiled Project Starshot. As the latest venture by Breakthrough Initiatives, Starshot was conceived with the aims of sending a tiny spacecraft to the neighboring star system Alpha Centauri in the coming decades.

Relying on a sail that would be driven up to relativistic speeds by lasers, this craft would theoretically be capable of making the journey is just 20 years. Naturally, this project has attracted its fair share of detractors. While the idea of sending a star ship to another star system in our lifetime is certainly appealing, it presents numerous challenges.

Not one to shy away from any potential problems, Breakthrough Starshot has begun funding the necessary research to make sure that their concept will work. The results of their first research effort appeared recently in arXiv, in a study titled "The interaction of relativistic spacecrafts with the interstellar medium".

Assessing the risks of interstellar travel, this paper addresses the greatest threat where relativistic speed is concerned: catastrophic collisions! To put it mildly, space is not exactly an empty medium (despite what the name might suggest). In truth, there are a lot of things out there on the "stellar highway" that can cause a fatal crash.

For instance, within interstellar space, there are clouds of dust particles and even stray atoms of gas that are the result of stellar formations and other processes. Any spacecraft traveling at 20% the speed of light (0.2 c) could easily be damaged or destroyed if it suffered a collision with even the tiniest of this particulate matter.

The research team was led by Dr. Chi Thiem Hoang, a postdoctoral fellow at Canadian Institute for Theoretical Astrophysics (CITA) at the University of Toronto. As Dr. Hoang told Universe Today via email:

"To evaluate the risks, we calculated the energy that each interstellar atom or dust grain transfers to the ship along the path of the projectile in the ship. This acquired energy rapidly heats a spot on the ship surface to high temperature, resulting in damage by reducing the material strength, melting or evaporation."

In short, the danger of a collision comes not from the physical impact, but from the energy that is generated due to the fact that the spaceship is traveling so fast. However, what they found was that while collisions with tiny dust grains are very likely, collisions with heavier atoms that can do the most damage would be more rare.

Nevertheless, the damage from so many tiny collisions will certainly add up over time. And it would only take one collision with a larger particle to end the mission. As Dr. Hoang explained:

"We found that the ship would be damaged by collision with heavy atoms and dust grains in the interstellar medium. Heavy atoms, mostly iron can damage the surface to a depth of 0.1mm. More importantly, the surface of the ship is eroded gradually by dust grains, to a depth of about 1mm. The ship may be completely destroyed if encountering a very big dust grain larger than 15micron, although it is extremely rare."

In terms of damage, what they determined was that each iron atom can produce a damage track of 5 nanometer across, whereas a typical dust silicate grain measuring just 0.1. micron across (and containing about one billion iron atoms) could produce a large crater on the ship's surface.

Over time, the cumulative effect of this damage would pose a major risk for the ship's survival. As a result, Dr. Hoang and his team recommended that some shielding would need to be mounted on the ship, and that it wouldn't hurt to "clear the road" a little as well.

"We recommended to protect the ship by putting a shield of about 1 mm thickness made of strong, high melting temperature material like graphite." he said. "We also suggested to destroy interstellar dust by using part of energy from laser sources."

Starshot is the latest in a long line of directed energy concepts that owe their existence to Professor Phillip Lubin. A professor from the University of California, Santa Barbara (UCSB), Lubin is also the mind behind the Directed Energy Propulsion for Interstellar Exploraiton (DEEP-IN) project and the Directed Energy Interstellar Study.

These projects, which are being funded by NASA, seek to harness the technology behind directed-energy propulsion to rapidly send missions to Mars and other locations within the Solar System in the future. Long-term applications include interstellar missions, similar to Starshot.

Other interesting projects overseen by Lubin and the UCSB lab include the Directed Energy System for Targeting of Asteroids and exploRation (DE-STAR). This system calls for the use of lasers to deflect asteroids, comets, and other near-Earth objects (NEO) that pose a credible risk of impact.

In all cases, directed-energy technology is being proposed as the solution to the problems posed by space travel. In the case of Starshot, these include (but are not limited to) inefficiency, mass, and/or the limited speeds of conventional rockets and ion engines.

As Professor Lubin told Universe Today via email, he and his colleagues are in general agreement with the research team and their findings:

"The recent paper by Hoang et al revisits the section (7) in our paper "A Roadmap to Interstellar Flight" that discusses our calculation for the effects of the ISM on the wafer scale spacecraft. Their general  conclusion on the effects of the gas and dust collisions were essentially the same as ours, namely that it is an issue, but not a fatal one, if one uses the spacecraft geometry we recommend in our paper, namely orient the spacecraft edge on (like a Frisbee in flight) and then use an edge coating (we use [Beryllium], they use graphite)."

"As for the sail interactions with the ISM we recommend either rotating the sail so it is edge on (lower cross section) or ejecting the sail after the initial few minutes of acceleration as it is no longer needed for acceleration. However. as we desire to use the sail as a reflector for the laser communications we prefer to keep it, though a secondary reflector could be deployed later in the mission if necessary. These detailed questions will be part of the evolving design phase."

Indeed, there are many safety hazards that have to be accounted for before any mission to interstellar space could be mounted. But as this recent study has shown - with which Professor Lubin agrees - they are not insurmountable, and a mission to Alpha Centauri (or, fingers crossed, Proxima Centauri!) could be performed if the proper precautions are taken.

Who knew the future of space travel would be every bit as cool as we've been led to believe - complete with lasers and shielding?

And be sure to enjoy this video from NASA 360, addressing directed-energy propulsion:

https://youtu.be/WCDuAiA6kX0

Further Reading: arXiv

The post Shields Up, Mr. Sulu! Cruising At 20% Speed Of Light Has Some Inherent Risks appeared first on Universe Today.



08/24/2016 09:59 AM
Potentially Habitable Exoplanet Confirmed Around Nearest Star!

Artist’s impression of the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. Credit: ESO/M. Kornmesser

For years, astronomers have been observing Proxima Centauri, hoping to see if this red dwarf has a planet or system of planets around it. As the closest stellar neighbor to our Solar System, a planet here would also be our closest planetary neighbor, which would present unique opportunities for research and exploration.

So there was much excitement when, earlier this month, an unnamed source claimed that the ESO had spotted an Earth-sized planet orbiting within the star's habitable zone. And after weeks of speculation, with anticipation reaching its boiling point, the ESO has confirmed that they have found a rocky exoplanet around Proxima Centauri - known as Proxima b.

Located just 4.25 light years from our Solar System, Proxima Centauri is a red dwarf star that is often considered to be part of a trinary star system - with Alpha Centauri A and B. For some time, astronomers at the ESO have been observing Proxima Centauri, primary with telescopes at the La Silla Observatory in Chile.

https://youtu.be/gxVk9QOjB-o

Their interest in this star was partly due to recent research that has shown how other red dwarf stars have planets orbiting them. These include, but are not limited to, TRAPPIST-1, which was shown to have three exoplanets with sizes similar to Earth last year; and Gliese 581, which was shown to have at least three exoplanets in 2007.

The ESO also confirmed that the planet is potentially terrestrial in nature (i.e. rocky), similar in size and mass to Earth, and orbits its star with an orbital period of 11 days. But best of all are the indications that surface temperatures and conditions are likely suitable for the existence of liquid water.

It's discovery was thanks to the Pale Red Dot campaign, a name which reflects Carl Sagan’s famous reference to the Earth as a "pale blue dot". As part of this campaign, a team of astronomers led by Guillem Anglada-Escudé - from Queen Mary University of London - have been observing Proxima Centauri for signs of wobble (i.e. the Radial Velocity Method).

After combing the Pale Red Dot data with earlier observations made by the ESO and other observatories, they noted that Proxima Centauri was indeed moving. With a regular period of 11.2 days, the star would vary between approaching Earth at a speed of 5 km an hour (3.1 mph), and then receding from Earth at the same speed.

This was certainly an exciting result, as it indicated a change in the star's radial velocity that was consistent with the existence of a planet. Further analysis showed that the planet had a mass at least 1.3 times that of Earth, and that it orbited the star at a distance of about 7 million km (4.35 million mi) - only 5% of the Earth's distance from the Sun.

The discovery of the planet was made possible by the La Silla's regular observation of the star, which took place star  between mid-January and April of 2016, using the 3.6-meter telescope's HARPS spectrograph. Other telescopes around the world conducted simultaneous observation in order to confirm the results.

One such observatory was the San Pedro de Atacama Celestial Explorations Observatory in Chile, which relied on its ASH2 telescope to monitor the changing brightness of the star during the campaign. This was essential, as red dwarfs like Proxima Centauri are active stars, and can vary in ways that would mimic the presence of the planet.

Guillem Anglada-Escudé described the excitement of the past few months in an ESO press release:

"I kept checking the consistency of the signal every single day during the 60 nights of the Pale Red Dot campaign. The first 10 were promising, the first 20 were consistent with expectations, and at 30 days the result was pretty much definitive, so we started drafting the paper!"

Two separate papers discuss the habitability of Proxima b and its climate, both of which will be appearing soon on the Institute of Space Sciences (ICE) website. These papers describe the research team's findings and outline their conclusions on how the existence of liquid water cannot be ruled out, and discuss where it is likely to be distributed.

Though there has been plenty of excitement thanks to words like "Earth-like", "habitable zone", and "liquid water" being thrown around, some clarifications need to be made. For instance, Proxima b's rotation, the strong radiation it receives from its star, and its formation history mean that its climate is sure to be very different from Earth's.

For instance, as is indicated in the two papers, Proxima b is not likely to have seasons, and water may only be present in the sunniest regions of the planet. Where those sunny regions are located depends entirely on the planet's rotation. If, for example, it has a synchronous rotation with its star, water will only be present on the sun-facing side. If it has a 3:2 resoncance rotation, then water is likely to exist only in the planet's tropical belt.

In any case, the discovery of this planet will open the door to further observations, using both existing instruments and the next-generation of space telescopes. And as Anglada-Escudé states, Proxima Centauri is also likely to become the focal point in the search for extra-terrestrial life in the coming years.

"Many exoplanets have been found and many more will be found, but searching for the closest potential Earth-analogue and succeeding has been the experience of a lifetime for all of us," he said. "Many people’s stories and efforts have converged on this discovery. The result is also a tribute to all of them. The search for life on Proxima b comes next..."

As we noted in a previous article on the subject, Project Starshot is currently developing a nanocraft that will use a laser-driven sail to make the journey to Alpha Centauri in 20 years time. But a mission to Proxima Centuari would take even less time (19.45 years at the same speed), and could study this newly-found exoplanet up-close.

One can only hope they are planning on altering their destination to take advantage of this discovery. And one can only imagine what they might find if and when they get to Proxima b!

A paper describing this milestone finding will be published in the journal Nature on August 25th, 2016, titled "A terrestrial planet candidate in a temperate orbit around Proxima Centauri".

https://youtu.be/59ClESB1AqA

Further Reading: ESO

The post Potentially Habitable Exoplanet Confirmed Around Nearest Star! appeared first on Universe Today.



08/24/2016 07:38 AM
Experience the Glorious Night Sky Over Yellowstone National Park

A still from the timelapse video 'Hades Exhales,'  a timelapse journey through several of Yellowstone National Park's geyser basins.  Credit and copyright: Harun Mehmedinovic/Skyglow Productions.

Tomorrow, August 25, 2016, the US National Park Service celebrates its 100th anniversary, and the NPS has been celebrating all year with their "Find Your Park" promotion. But the first national park, Yellowstone National Park, was created 144 years ago. Yellowstone is known for its dramatic canyons, lush forests, and flowing rivers, but might be most famous for its hot springs and gushing geysers.

This new timelapse offers you a chance to "find your dark skies" at Yellowstone, and features the many geysers there, showing the dramatic geothermal features under both day and night skies. But the night skies over these geyser explosions steal the show! It was filmed by Harun Mehmedinovicas part of the Skyglow Project, an ongoing crowdfunded project that explores the effects and dangers of urban light pollution in contrast with some of the most incredible dark sky areas in North America.

SKYGLOWPROJECT.COM : HADES EXHALES from Harun Mehmedinovic on Vimeo.

The Skyglow Project works in collaboration with International Dark-Sky Association, a nonprofit organization fighting to educate the public about light pollution and to preserve the dark skies around the world.

Coming up this weekend, you can enjoy free admission to all 412 national parks from August 25-28, 2016. You can "find your park" and read about special events happening all around the country at FindYourPark.com

Many thanks to Harun Mehmedinovic and Gavin Heffernan of Sunchaser Pictures for continuing their great work with the Skyglow Project and for sharing their incredible videos with Universe Today. Consider supporting their work, as all donations go towards the creation of more videos and images.

The post Experience the Glorious Night Sky Over Yellowstone National Park appeared first on Universe Today.



08/24/2016 03:00 AM
Tales of Two Asteroid Occultations: Io, Nemausa Cast Shadows Over North America

Don't blink... an artist's conception of an asteroid blocking out a distant star. Image credit: NASA.

Up for a challenge? Over the next two weekends, two asteroid occultations pass over North America. These are both occulting (passing in front of) +7th magnitude stars, easy targets for even binoculars or a small telescope. These events both have a probability score of 99-100%, meaning the paths are known to a high degree of accuracy. These are also two of the more high profile asteroid occultations for 2016.

Here's the lowdown on both events:

On the morning of Saturday, August 27th , the +10th magnitude asteroid 85 Io occults a +7.5 magnitude star (TYC 0517-00165-1). the maximum predicted duration for the event is 28 seconds, and the maximum predicted brightness drop is expected to be 3 magnitudes. The 'shadow' will cross North America from the northeast to the southwest starting over Quebec at 4:27 Universal Time (UT), crossing Ontario and Michigan's upper peninsula at 4:30 UT, and heading south over Oklahoma, Texas, and Mexico at 4:36 UT. The action takes place in the constellation Aquarius, with the Moon at a 28% waning crescent.

Discovered by C.H.F. Peters on September 19th, 1865, 85 Io is about 180 kilometers in diameter, as measured by an occultation in late 1995.

Next, on the morning of Saturday, September 3rd, the +11.5 magnitude asteroid 51 Nemausa occults a +7.6 mag star (HIP 8524). The maximum duration of the event along the centerline is expected to be 32 seconds in duration, with a maximum drop of four magnitudes. Said shadow will cross western Canada at9:42 UT, and the U.S. crossing runs from 9:49 to 9:55 UT. The action takes place in the constellation Pisces. The Moon phase is a slim 4% waxing crescent during the event.

Discovered in 1858 by A. Laurent observing from Nîmes, France, 51 Nemausa occulted a bright star in 1979. In fact, there's evidence from previous occultation to suggest the 51 Nemausa may possess a tiny moon... could it show up again during the September 3rd event?

Observing asteroid occultations is really a modern sub-specialty of amateur and even professional astronomy. To predict such an occurrence, the orbit of the asteroid or occulting body and the precise position of the star need to be known to a pretty high degree of precision. This required the advent of modern astrometry and massive computing power. If any casual sky observer noticed a naked eye star wink out way back when pre-mid 20th century, it's lost to history.

The first successfully predicted and observed occultation of a star by an asteroid was the +8.2 magnitude star SAO 112328 by 3 Juno on February 19, 1958. Less than two dozen such events were observed right up through to 1980. Today, hundreds of such events are predicted worldwide each year.

Next month's expected data release from the ESA's Gaia mission should refine our stellar position and parallax knowledge even further, and fine-tune predictions of future asteroid occultations.

And speaking of occultations, some great observations were made of the July 29th, 2016 lunar grazing occultation of Aldebaran across the United States. The Moon occults Aldebaran for every lunation in 2016 into 2017, and we get another shot favoring the southern U.S. in the daytime on August 25th.

Observing an asteroid occultation is a challenge, requiring an observer acquiring and monitoring the correct star at the precise time of the event. If possible (i.e. weather permitting) familiarize yourself with the star field a night or two prior to the event. I usually have a precise audio time signal such as WWV radio running in the background.

Why occultations? Well, if enough observations can be gathered, a sort of shadow profile of the occulting space rock can be made, with each observation representing a chord. Even negative 'misses' along the edge of the path help. Tiny moons of asteroids have even been discovered this way, as the distant star winks out multiple times.

The International Occultation Timing Association wants your observation. You can, with a little practice, make usable observations visually, though most observers tend to video record events.

Don't miss these asteroid occultations and more, coming to a sky worldwide near you!

The post Tales of Two Asteroid Occultations: Io, Nemausa Cast Shadows Over North America appeared first on Universe Today.




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