Posted on by Ken Kremer

Secret X-37B Military Mini-Shuttle Set for SpaceX Blastoff/Landing Sept. 7 as Cat 5 Hurricane Irma Forces Florida State of Emergency – Watch Live

SpaceX Falcon 9 rocket rolls horizontally up incline at Launch Complex 39A at the Kennedy Space Center on 6 Sept. 2017. The rocket is being processed for liftoff of the X-37B OTV-5 mini-shuttle mission scheduled for Sept. 7, 2017. Credit: Ken Kremer/kenkremer.com
SpaceX Falcon 9 rocket rolls horizontally up incline at Launch Complex 39A at the Kennedy Space Center on 6 Sept. 2017. The rocket is being processed for liftoff of the X-37B OTV-5 mini-shuttle mission scheduled for Sept. 7, 2017. Credit: Ken Kremer/kenkremer.com

KENNEDY SPACE CENTER, FL – Although its far from sunny in the so called ‘Sunshine State’ the secret X-37B military mini-shuttle is set for a SpaceX blastoff and booster landing combo Thursday, Sept. 7 – even as the looming threat from Cat 5 Hurricane Irma forced Florida’s Governor to declare a statewide ‘State of Emergency.’

Launch preparations were in full swing today on Florida’s Space Coast for liftoff of the hi tech USAF X-37B reusable spaceplane- hoping to escape to orbit for the first time atop a SpaceX Falcon 9 rocket and just in the nick of time tomorrow, before the impending threat of monster storm Irma potentially lashes the launch pad at NASA’s Kennedy Space Center in the center of the states long peninsula.

Hurricane Irma Cone forecast on Sept 7, 2017 from the National Hurricane Center. Credit: NHC

Irma is packing winds of 185 mph and one of the strongest Atlantic storms ever. It is being closely tracked in incredibly high resolution by the new NASA/NOAA GOES-16 (GOES-R) satellite launched late last year on a ULA Atlas V in Nov 2016.

I witnessed the entire SpaceX Falcon 9 rocket and payload stack being rolled horizontally up the incline to the top of Launch Complex 39A late this afternoon, Sept. 6, during our media visit for up-close camera setup.

Up close head on view of SpaceX Falcon 9 rocket rolling horizontally up incline at Launch Complex 39A at the Kennedy Space Center on 6 Sept. 2017. The rocket is being processed for liftoff of the X-37B OTV-5 mini-shuttle mission scheduled for Sept. 7, 2017. Credit: Ken Kremer/kenkremer.com

Rather remarkably the relatively dismal weather forecast has brightened considerably in the final hours leading to Thursday’s scheduled launch and the forecast heavy rain showers and thunder have dissipated in the time remaining between now and liftoff.

The X-37B reusable mini-shuttle is a secretive technology testing spaceplane flying on its fifth mission overall.

Up close side view of SpaceX Falcon 9 rocket and nose cone housing the X-37B OTV-5 spaceplane slated for liftoff from Launch Complex 39A at the Kennedy Space Center on Sept. 7, 2017. Credit: Ken Kremer/kenkremer.com

The path to launch was cleared following the successful engine test firing of the Falcon 9 first stage I witnessed late last week, Thursday afternoon, Aug. 30.

During the hold down static fire test all nine Merlin 9 stage engine were ignited and fired up to full throttle for several seconds. See my static fire story here.

SpaceX conducts successful static fire test of the Falcon 9 first stage rocket at 4:30 p.m. EDT on Aug. 31, 2017 on Launch Complex 39A on NASA’s Kennedy Space Center, Fl., as seen from nearby Playalinda causeway. Liftoff of the USAF X-37B OTV-5 mini-shuttle mission is scheduled for Sept. 7, 2017. Credit: Ken Kremer/kenkremer.com

Although the exact launch time remains a closely guarded U.S. Air Force secret, liftoff of the X-37B is slated to occur sometime during a 5 hour long window.

The launch window for the X-37B on the OTV-5 mission opens at 9:50 a.m. EDT (13:50 UTC) and spans until 2:55 p.m. EDT (18:55 UTC) Sept. 7 from seaside Launch Complex 39A on NASA’s Kennedy Space Center.

SpaceX will offer their own live webcast beginning approximately 15 minutes before launch starting at about 9:35 a.m. EDT.

You can watch the launch live at NASA TV at the SpaceX hosted Webcast at – spacex.com/webcast

In the event of delay for any reason, the next launch opportunity is Friday, Sept 8 at approximately the same time and window.

However amidst the heavy duty Hurricane Irma preparations all around, nothing is certain. Local area schools in Brevard County have closed and local residents are preparing their homes and apartments to hunker down, buying food and essentials putting up storm shutters, topping off gas and energy supplies and more.

“If for any reason we cannot launch tomorrow we will reevaluate whether or not we can still support another attempt on Friday, said Wayne R. Monteith, Brig Gen, USAF, Commander, 45th Space Wing.

The weather forecast overall is about 50% chance of favorable conditions at launch time according to U.S. Air Force meteorologists with the 45th Space Wing Weather Squadron at Patrick Air Force Base. But the opportunity varies within the long window and the exact launch time is currently classified.

“Hurricane Irma is forecast to be approximately 900 miles southeast of the Spaceport during Thursday’s launch attempt, so while Irma certainly bears watching, the stalled boundary will be the main factor in Thursday’s weather,” noted the 45th Space Wing Weather Squadron.

The primary concerns on Sept. 7 are for cumulus clouds and for thick clouds in the flight path.

The odds drop to 40% favorable for the 24 hour scrub turnaround day on Friday, Sept 8

The USAF X-37B Orbital Test Vehicle is set for blastoff on Sept. 7, 2017, onboard a SpaceX Falcon 9 launch vehicle from Launch Complex 39A (LC-39A) at Kennedy Space Center in Florida. Photo: Boeing/USAF

Everything is currently on track for Thursday’s launch of the 230 foot tall SpaceX Falcon 9 on the X-37B OTV-5 mission.

“The Air Force Rapid Capabilities Office is undergoing final launch preparations for the fifth mission of the X-37B Orbital Test Vehicle [OTV],” the Secretary of the Air Force Public Affairs announced. “The OTV is scheduled to launch on Sept. 7, 2017, onboard a SpaceX Falcon 9 launch vehicle.

SpaceX Falcon 9 rocket rolls horizontally up incline at Launch Complex 39A at the Kennedy Space Center on 6 Sept. 2017 ahead of liftoff of the X-37B OTV-5 spaceplane mission on Sept. 7, 2017. Credit: Julian Leek

The X-37B will be launched for the fifth time on the OTV-5 mission atop a SpaceX Falcon 9 on Sept. 7 from Launch Complex 39A on the Kennedy Space Center Florida into low Earth orbit.

The Boeing-built X-37B is processed for flight at KSC using refurbished NASA space shuttle processing facilities now dedicated to the reusable mini-shuttle, also known as the Orbital Test Vehicle (OTV). It launches vertically like a satellite but lands horizontally like an airplane and functions as a reliable and reusable space test platform for the U.S. Air Force.

The OTV-5 mission marks the first launch of an X-37B spaceplane by SpaceX.

All four prior OTV missions launched on the United Launch Alliance Atlas V and ended with runway landings in either California or Florida.

“The many firsts on this mission make the upcoming OTV launch a milestone for the program,” said Randy Walden, the director of the Air Force Rapid Capabilities Office.

“It is our goal to continue advancing the X-37B OTV so it can more fully support the growing space community.”

Ground landing of SpaceX Falcon 9 first stage at Landing Zone-1 (LZ-1) after SpaceX launched its 12th resupply mission to the International Space Station from NASA’s Kennedy Space Center in Florida from pad 39A at 12:31 p.m. EDT on Monday, Aug. 14, 2017. Credit: Ken Kremer/Kenkremer.com

SpaceX will also attempt another land landing of the 156-foot-tall Falcon 9 first stage back at Landing Zone-1 (LZ-1) at the Cape.

The Falcon 9 first stage is equipped with a quartet of landing legs and grid fins to enable the rocket recycling plan.

Up close view of SpaceX Falcon 9 landing legs for the X-37B OTV-5 spaceplane slated for liftoff from Launch Complex 39A at the Kennedy Space Center on Sept. 7, 2017. Credit: Ken Kremer/kenkremer.com

This marks the 7th time SpaceX attempts a ground landing at the Cape.

The booster will touch down about 8 minutes after launch and generate multiple sonic booms screaming loudly across the surrounding region and beyond.

“The fifth OTV mission will also be launched into, and landed from, a higher inclination orbit than prior missions to further expand the X-37B’s orbital envelope.”

The daylight first stage precision guided landing should offer spectators a thrilling up close view of the rocket reusability technology envisioned by SpaceX’s billionaire CEO Elon Musk to drastically slash the high costs of launching to space.

Technicians work on the Air Force X-37B Orbital Test Vehicle 4, which landed at NASA’s Kennedy Space Center Shuttle Landing Facility in Florida May 7, 2017. Credit: Secretary of the Air Force Public Affairs.

The 11,000 pound (4990 kg) state-of -the art reusable OTV space plane is about a quarter the size of a NASA space shuttle. The vehicle measures 29 ft 3 in (8.9 m) in length with a wingspan of 14 ft 11 in (4.5 m).

The X-37B was originally developed by NASA but was transferred to the Defense Advanced Research Projects Agency (DARPA) in 2004.

Since then most but not all of the spaceplane’s goals have been shrouded in secrecy.

Watch for Ken’s continuing onsite X-37B OTV-5 and NASA mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.

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

Ken Kremer

Posted on by Matt Williams

The Orbit of Earth will be Hiding Earth 2.0

According to a new study, the motions of our Sun around its center of mass could make it impossible to detect another Earth in a distant star system. Credit: ESO

In the hunt for extra-solar planets, astronomers and enthusiasts can be forgiven for being a bit optimistic. In the course of discovering thousands of rocky planets, gas giants, and other celestial bodies, is it too much to hope that we might someday find a genuine Earth-analog? Not just an “Earth-like” planet (which implies a rocky body of comparable size) but an actual Earth 2.0?

This has certainly been one of the goals of exoplanet-hunters, who are searching nearby star systems for planets that are not only rocky, but orbit within their star’s habitable zone, show signs of an atmosphere and have water on their surfaces. But according to a new study by Alexey G. Butkevich – a astrophysicist from the Pulkovo Observatory in St. Petersburg, Russia – our attempts to discover Earth 2.0 could be hindered by Earth itself!

Butkevich’s study, titled “Astrometric Exoplanet Detectability and the Earth Orbital Motion“, was recently published in the Monthly Notices of the Royal Astronomical Society. For the sake of his study, Dr. Butkevich examined how changes in the Earth’s own orbital position could make it more difficult to conduct measurements of a star’s motion around its system’s barycenter.

Artist’s impression of how an Earth-like planet might look from space. Credit: ESO.

This method of exoplanet detection, where the motion of a star around the star system’s center of mass (barycenter), is known as the Astrometic Method. Essentially, astronomers attempt to determine if the presence of gravitational fields around a star (i.e. planets) are causing the star to wobble back and forth. This is certainly true of the Solar System, where our Sun is pulled back and forth around a common center by the pull of all its planets.

In the past, this technique has been used to identify binary stars with a high degree of precision. In recent decades, it has been considered as a viable method for exoplanet hunting. This is no easy task since the wobbles are rather difficult to detect at the distances involved. And until recently, the level of precision required to detect these shifts was at the very edge of instrument sensitivity.

This is rapidly changing, thanks to improved instruments that allow for accuracy down to the microarcsecond. A good example of this is the ESA’s Gaia spacecraft, which was deployed in 2013 to catalog and measure the relative motions of billions of stars in our galaxy. Given that it can conduct measurements at 10 microarcseconds, it is believed that this mission could conduct astrometric measurements for the sake of finding exoplanets.

But as Butkevich explained, there are other problems when it comes to this method. “The standard astrometric model is based on the assumption that stars move uniformly relative to the solar system barycentre,” he states. But as he goes on to explain, when examining the effects of Earth’s orbital motion on astrometric detection, there is a correlation between the Earth’s orbit and the position of a star relative to its system barycenter.

Kepler-22b, an exoplanet with an Earth-like radius that was discovery within the habitable zone of its host star. Credit: NASA

To put it another way, Dr. Butkevich examined whether or not the motion of our planet around the Sun, and the Sun’s motion around its center of mass, could have a cancelling effect on parallax measurements of other stars. This would effectively make any measurements of a star’s motion, designed to see if there were any planets orbiting it, effectively useless. Or as Dr. Butkevich stated in his study:

“It is clear from simple geometrical considerations that in such systems the orbital motion of the host star, under certain conditions, may be observationally close to the parallactic effect or even indistinguishable from it. It means that the orbital motion may be partially or fully absorbed by the parallax parameters.”

This would be especially true of systems where the orbital period of a planet was one year, and which had an orbit that placed it close to the Sun’s ecliptic – i.e. like Earth’s own orbit! So basically, astronomers would not be able to detect Earth 2.0 using astrometric measurements, because Earth’s own orbit and the Sun’s own wobble would make detection close to impossible.

As Dr. Butkevich states in his conclusions:

“We present an analysis of effects of the Earth orbital motion on astrometric detectability of exoplanetary systems. We demonstrated that, if period of a planet is close to one year and its orbital plane is nearly parallel to the ecliptic, orbital motion of the host may be entirely or partially absorbed by the parallax parameter. If full absorption occurs, the planet is astrometrically undetectable.”
Future surveys for exoplanets could be complicated by the Sun’s own motion around its barycenter. Credit: NASA

Luckily, exoplanet-hunters have a myriad of other methods too choose from, including direct and indirect measurements. And when it comes to spotting planets around neighboring stars, two of the most effective involve measuring Doppler shifts in stars (aka. the Radial Velocity Method) and dips in a star’s brightness (aka. the Transit Method).

Nevertheless, these methods suffer from their own share of drawbacks, and knowing their limitations is the first step in refining them. In that respect, Dr. Butkevich’s study has echoes of heliocentrism and relativity, where we are reminded that our own reference point is not fixed in space, and can influence our observations.

The hunt for exoplanets is also expected to benefit greatly from deployment of next-generation instruments like the James Webb Space Telescope, the Transiting Exoplanet Survey Satellite (TESS), and others.

Further Reading: arXiv

Posted on by Fraser Cain

Supermassive Black Holes or Their Galaxies? Which Came First?

Which Came First, Supermassive Black Holes of their Galaxies?
Which Came First, Supermassive Black Holes of their Galaxies?

There’s a supermassive black hole at the center of almost every galaxy in the Universe. How did they get there? What’s the relationship between these monster black holes and the galaxies that surround them?

Every time astronomers look farther out in the Universe, they discover new mysteries. These mysteries require all new tools and techniques to understand. These mysteries lead to more mysteries. What I’m saying is that it’s mystery turtles all the way down.

One of the most fascinating is the discovery of quasars, understanding what they are, and the unveiling of an even deeper mystery, where do they come from?

As always, I’m getting ahead of myself, so first, let’s go back and talk about the discovery of quasars.

Molecular clouds scattered by an intermediate black hole show very wide velocity dispersion in this artist’s impression. This scenario well explains the observational features of a peculiar molecular cloud CO-0.40-0.22. Credit: Keio University

Back in the 1950s, astronomers scanned the skies using radio telescopes, and found a class of bizarre objects in the distant Universe. They were very bright, and incredibly far away; hundreds of millions or even billion of light-years away. The first ones were discovered in the radio spectrum, but over time, astronomers found even more blazing in the visible spectrum.

The astronomer Hong-Yee Chiu coined the term “quasar”, which stood for quasi-stellar object. They were like stars, shining from a single point source, but they clearly weren’t stars, blazing with more radiation than an entire galaxy.

Over the decades, astronomers puzzled out the nature of quasars, learning that they were actually black holes, actively feeding and blasting out radiation, visible billions of light-years away.

But they weren’t the stellar mass black holes, which were known to be from the death of giant stars. These were supermassive black holes, with millions or even billions of times the mass of the Sun.

As far back as the 1970s, astronomers considered the possibility that there might be these supermassive black holes at the heart of many other galaxies, even the Milky Way.

The Whirlpool Galaxy (Spiral Galaxy M51, NGC 5194), a classic spiral galaxy located in the Canes Venatici constellation, and its companion NGC 5195. Credit: NASA/ESA

In 1974, astronomers discovered a radio source at the center of the Milky Way emitting radiation. It was titled Sagittarius A*, with an asterisk that stands for “exciting”, well, in the “excited atoms” perspective.

This would match the emissions of a supermassive black hole that wasn’t actively feeding on material. Our own galaxy could have been a quasar in the past, or in the future, but right now, the black hole was mostly silent, apart from this subtle radiation.

Astronomers needed to be certain, so they performed a detailed survey of the very center of the Milky Way in the infrared spectrum, which allowed them to see through the gas and dust that obscures the core in visible light.

They discovered a group of stars orbiting Sagittarius A-star, like comets orbiting the Sun. Only a black hole with millions of times the mass of the Sun could provide the kind of gravitational anchor to whip these stars around in such bizarre orbits.

Further surveys found a supermassive black hole at the heart of the Andromeda Galaxy, in fact, it appears as if these monsters are at the center of almost every galaxy in the Universe.

But how did they form? Where did they come from? Did the galaxy form first, and cause the black hole to form at the middle, or did the black hole form, and build up a galaxy around them?

Until recently, this was actually still one of the big unsolved mysteries in astronomy. That said, astronomers have done plenty of research, using more and more sensitive observatories, worked out their theories, and now they’re gathering evidence to help get to the bottom of this mystery.

Astronomers have developed two models for how the large scale structure of the Universe came together: top down and bottom up.

In the top down model, an entire galactic supercluster formed all at once out of a huge cloud of primordial hydrogen left over from the Big Bang. A supercluster’s worth of stars.

As the cloud came together it, it spun up, kicking out smaller spirals and dwarf galaxies. These could have combined later on to form the more complex structure we see today. The supermassive black holes would have formed as the dense cores of these galaxies as they came together.

Hubble image of Messier 54, a globular cluster located in the Sagittarius Dwarf Galaxy. Credit: ESA/Hubble & NASA

If you want to wrap your mind around this, think of the stellar nursery that formed our Sun and a bunch of other stars. Imagine a single cloud of gas and dust forming multiple stars systems within it. Over time, the stars matured and drifted away from each other.

That’s top down. One big event that leads to the structure we see today.

In the bottom up model, pockets of gas and dust collected together into larger and larger masses, eventually forming dwarf galaxies, and even the clusters and superclusters we see today. The supermassive black holes at the heart of galaxies were grown from collisions and mergers between black holes over eons.

In fact, this is actually how astronomers think the planets in the Solar System formed. By pieces of dust attracting one another into larger and larger grains until the planet-sized objects formed over millions of years.

Bottom up, small parts coming together.

Shortly after the Big Bang, the entire Universe was incredibly dense. But it wasn’t the same density everywhere. Tiny quantum fluctuations in density at the beginning evolved over billions of years of expansion into the galactic superclusters we see today.

Colliding galaxies can force the supermassive black holes in their cores together (NCSA)

I want to stop and let this sink into your brain for a second. There were microscopic variations in density in the early Universe. And these variations became the structures hundreds of millions of light-years across we see today.

Imagine the two forces at play as the expansion of the Universe happened. On the one hand, you’ve got the mutual gravity of the particles pulling one another together. And on the other hand, you’ve got the expansion of the Universe separating the particles from one another. The size of the galaxies, clusters and superclusters were decided by the balance point of those opposing forces.

If small pieces came together, then you’d get that bottom up formation. If large pieces came together, you’d get that top down formation.

When astronomers look out into the Universe at the largest scales, they observe clusters and superclusters as far as they can see – which supports the top down model.

On the other hand, observations show that the first stars formed just a few hundred million years after the Big Bang, which supports bottom up.

So the answer is both?

No, the most modern observations give the edge to the bottom up processes.

The key is that gravity moves at the speed of light, which means that the gravitational interactions between particles spreading away from each other needed to catch up, going the speed of light.

In other words, you wouldn’t get a supercluster’s worth of material coming together, only a star’s worth of material. But these first stars were made of pure hydrogen and helium, and could grow much more massive than the stars we have today. They would live fast and die in supernova explosions, creating much more massive black holes than we get today.

This illustration shows the final stages in the life of a supermassive star that fails to explode as a supernova, but instead implodes to form a black hole. Credit: NASA/ESA/P. Jeffries (STScI)

The first protogalaxies came together, collecting together these first monster black holes and the massive stars surrounding them. And then, over millions and billions of years, these black holes merged again and again, accumulating millions and even billions of times the mass of the Sun. This was how we got the modern galaxies we see today.

There was a recent observation that supports this conclusion. Earlier this year, astronomers announced the discovery of supermassive black holes at the center of relatively tiny galaxies. In our own Milky Way, the supermassive black hole is 4.1 million times the mass of the Sun, but accounts for only .01% of the galaxy’s total mass.

But astronomers from the University of Utah found two ultra compact galaxies with black holes of 4.4 million and 5.8 million times the mass of the Sun respectively. And yet, the black holes account for 13 and 18 percent of the mass of their host galaxies.

The thinking is that these galaxies were once normal, but collided with other galaxies earlier on in the history of the Universe, were stripped of their stars and then were spat out to roam the cosmos.

They’re the victims of those early merging events, evidence of the carnage that happened in the early Universe when the mergers were happening.

We always talk about the unsolved mysteries in the Universe, but this is one that astronomers are starting to puzzle out.

It seems most likely that the structure of the Universe we see today formed bottom up. The first stars came together into protogalaxies, dying as supernova to form the first black holes. The structure of the Universe we see today is the end result of billions of years of formation and destruction. With the supermassive black holes coming together over time.

Once telescopes like James Webb get to work, we should be able to see these pieces coming together, at the very edge of the observable Universe.

Posted on by Matt Williams

Now We Know When Stars Will Be Passing Through the Oort Cloud

A new study indicates that in about a million years, a star will pass close to our Solar System, sending comets towards Earth and the other planets. Credit: NASA/JPL-Caltech

To our Solar System, “close-encounters” with other stars happen regularly – the last occurring some 70,000 years ago and the next likely to take place 240,000 to 470,000 years from now. While this might sound like a “few and far between” kind of thing, it is quite regular in cosmological terms. Understanding when these encounters will happen is also important since they are known to cause disturbances in the Oort Cloud, sending comets towards Earth.

Thanks to a new study by Coryn Bailer-Jones, a researcher from the Max Planck Institute for Astronomy, astronomers now have refined estimates on when the next close-encounters will be happening. After consulting data from the ESA’s Gaia spacecraft, he concluded that over the course of the next 5 million years, that the Solar System can expect 16 close encounters, and one particularly close one!

For the sake of the study – which recently appeared in the journal Astronomy & Astrophysics under the title “The Completeness-Corrected Rate of Stellar Encounters with the Sun From the First Gaia Data Release” – Dr. Bailer Jones used Gaia data to track the movements of more than 300,000 stars in our galaxy to see if they would ever pass close enough to the Solar System to cause a disturbance.

Artist’s impression of the ESA’s Gaia spacecraft. Credit: ESA/ATG medialab; background: ESO/S. Brunier

As noted, these types of disturbances have happened many times throughout the history of the Solar System. In order to dislodge icy objects from their orbit in the Oort Cloud – which extends out to about 15 trillion km (100,000 AU) from our Sun – and send them hurling into the inner Solar System, it is estimated that a star would need to pass within 60 trillion km (37 trillion mi; 400,000 AU) of our Sun.

While these close encounters pose no real risk to our Solar System, they have been known to increase comet activity. As Dr. Bailer-Jones explained to Universe Today via email:

“Their potential influence is to shake up the Oort cloud of comets surrounding our Sun, which could result in some being pushed into the inner solar system where is chance they could impact with the Earth. But the long-term probability of one such comet hitting the Earth is probably lower than the probability the Earth is hit by a near-Earth asteroid. So they don’t pose much more danger.”

One of the goals of the Gaia mission, which launched back in 2013, was to collect precise data on stellar positions and motions over the course of its five-year mission. After 14 months in space, the first catalogue was released, which contained information on more than a billion stars. This catalogue also contained the distances and motions across the sky of over two million stars.

By combining this new data with existing information, Dr. Bailer-Jones was able to calculate the motions of some 300,000 stars relative to the Sun over a five million year period. As he explained:

“I traced the orbits of stars observed by Gaia (in the so-called TGAS catalogue) backwards and forwards in time, to see when and how close they would come to the Sun. I then computed the so-called ‘completeness function’ of TGAS to find out what fraction of encounters would have been missed by the survey: TGAS doesn’t see fainter stars (and the very brightest stars are also omitted at present, for technical reasons), but using a simple model of the Galaxy I can estimate how many stars it is missing. Combining this with the actual number of encounters found, I could estimate the total rate of stellar encounters (i.e. including the ones not actually seen). This is necessarily a rather rough estimate, as it involves a number of assumptions, not least the model for what is not seen.”

From this, he was able to come up with a general estimate of the rate of stellar encounters over the past 5 million years, and for the next 5 million. He determined that the overall rate is about 550 stars per million years coming within 150 trillion km, and about 20 coming closer than 30 trillion km. This works out to about one potential close encounter every 50,000 years or so.

Dr. Bailor-Jones also determined that of the 300,000 stars he observed, 97 of them would pass within 150 trillion km (93 trillion mi; 1 million AU) of our Solar System, while 16 would come within 60 trillion km. While this would be close enough to disturb the Oort Cloud, only one star would get particularly close. That star is Gliese 710, a K-type yellow dwarf located about 63 light years from Earth which is about half the size of our Sun.

Stars speeding through the Galaxy. Credit: ESA

According to Dr. Bailer-Jones’ study, this star will pass by our Solar System in 1.3 million years, and at a distance of just 2.3 trillion km (1.4 trillion mi; 16 ,000AU). This will place it well within the Oort Cloud, and will likely turn many icy planetesimals into long-period comets that could head towards Earth. What’s more, Gliese 710 has a relatively slow velocity compared to other stars in our galaxy.

Whereas the average relative velocity of stars is estimated to be around 100.000 km/h (62,000 mph) at their closest approach, Gliese 710 will will have a speed of 50,000 km/h (31,000 mph). As a result, the star will have plenty of time to exert its gravitational influence on the Oort Cloud, which could potentially send many, many comets towards Earth and the inner Solar System.

Over the past few decades, this star has been well-documented by astronomers, and they were already pretty certain that it would experience a close encounter with our Solar System in the future. However, previous calculations indicated that it would pass within 3.1 to 13.6 trillion km (1.9 to 8.45 trillion mi; 20,722 to 90,910 AU) from our star system – and with a 90% certainty. Thanks to this most recent study, these estimates have been refined to 1.5–3.2 trillion km, with 2.3 trillion km being the most likely.

Again, while it might sound like these passes are on too large of a timescale to be of concern, in terms of the astronomical history, its a regular occurrence. And while not every close encounter is guaranteed to send comets hurling our way, understanding when and how these encounters have happened is intrinsic to understanding the history and evolution of our Solar System.

Understanding when a close encounters might happen next is also vital. Assuming we are still around when another  takes place, knowing when it is likely to happen could allow us to prepare for the worst – i.e. if a comets is set on a collision course with Earth! Failing that, humanity could use this information to prepare a scientific mission to study the comets that are sent our way.

The second release of Gaia data is scheduled for next April, and will contain information on an estimated 1 billion stars. That’s 20 times as many stars as the first catalogue, and about 1% the total number of stars within the Milky Way Galaxy. The second catalog will also include information on much more distant stars, will which allow for reconstructions of up to 25 million years into the past and future.

As Dr. Bailer-Jones indicated, the release of Gaia data has helped astronomers considerably. “[I]t greatly improves on what we had before, in both number of stars and precision,” he said. “But this is really just a taster of what will come in the second data release in April 2018, when we will provide parallaxes and proper motions for around one billion stars (500 times as many as in the first data release).”

With every new release, estimates on the movements of the galaxy’s stars (and the potential for close encounters) will be refined further. It will also help us to chart when major comet activity took place within the Solar System, and how this might have played a role in the evolution of the planets and life itself.

Further Reading: ESA

Posted on by Fraser Cain

Big Solar Storm Coming Our Way, Now’s Your Chance to See Auroras

X9.3 Flare blasts off the Sun. Image credit: NASA/GSFC/SDO
X9.3 Flare blasts off the Sun. Image credit: NASA/GSFC/SDO

An X9.3 class solar flare flashes in the middle of the Sun on Sept. 6, 2017. Credit:NASA/GSFC/SDO
An X9.3 class solar flare flashes in the middle of the Sun on Sept. 6, 2017. Credit:NASA/GSFC/SDO

If you’re still riding that high from seeing the recent total solar eclipse and you want to keep the party going, now’s your chance to see another of the night sky’s wonders: an aurora. That said, a totally full Moon is going to try and wreck the party.

NASA announced that two powerful flares were just emitted on the surface of the Sun, casting coronal mass ejections in our direction. Over the course of the next couple of days, this should generate aurora activity in the sky outside the regular viewing areas. In other words, if you normally don’t see the Northern Lights where you live, you might want to spend a few hours outside tonight and tomorrow. Look up, you might see something.

The first flare, an X2.2 event, peaked on September 6 at 5:10 am EDT and the second X9.3 flare went off at 8:02 am. Both of which came from the sunspot group AR 2673. If you’ve still got those eclipse glasses, take a look at the Sun, and you should be able to see the sunspot group right now. There are two groups of sunspots close to one another, AR 2673 and AR 2674. This follows up the X4 flare emitted on September 4th.

Solar astronomers measure flares using a similar scale to other natural events, with a series of designations. The smallest are A-class, then B, C, M and finally X. Each level within the rating accounts for double the strength; it’s exponential. So, and X2 is twice as powerful as an X1, etc. The most powerful flare ever recorded was an X28 in 2003, so today’s flare is still comparatively weak to that monster.

Here's the flare in visible and ultraviolet. Credit: NASA/GSFC/SDO
Here’s the flare in visible and ultraviolet. Credit: NASA/GSFC/SDO

But, measuring in at X9.3, today’s flare is the strongest in almost a decade. The last one this strong was back in 2008. And NOAA is predicting that this flare could cause radio blackouts across the sun-facing side of the Earth. If you’re out at sea and depending on your radio transmissions, don’t be surprised if you’re getting a lot of static today.

How do you stand the best chance of seeing auroras? My favorite tool comes from NOAA’s 3-day aurora forecast. It shows you a 3-day predictive simulation for what the solar storm should do as it buffets the Earth’s magnetosphere. You can run the simulation backwards and forwards, and you’re looking glowing green areas to come across your part of the world.

But even if it doesn’t look like you’re going to see the auroras, I still think it’s worth trying. Even if you don’t get an aurora directly overhead, you can sometimes see it on the horizon, and it can be surprisingly beautiful.

Here’s my timelapse video of auroras on the horizon.

The big problem, of course, is the Moon. Tonight is also a full Moon, which means that awful glowing ball is going to rise just after sunset and blaze across the sky all night. You’re going to have a rough time seeing all but the brightest auroras. But I still think it’s worth trying.

If you want to maximize your chances of seeing an aurora, check out the Space Weather site on a regular basis. There are also services that’ll send you a text message when there’s a powerful aurora going on in your area (just Google “aurora alert text messages”. And of course, there are handy apps that’ll make your phone beep boop when there are auroras overhead. I use an app called Aurora Alert.

We’ve had three powerful flares in the last couple of days, which means that the Sun is feeling a little frisky. There could be more, and they could happen after the full Moon is over, and we’ve got some alone time with the dark sky. So stay on top of the current space weather, spend time outside, and keep your eyes on the sky. You might get a shot at seeing an aurora.

And once you’ve seen one, you’ll be hooked.

Source: NASA News Release

Posted on by Nancy Atkinson

NASA, NOAA Satellites Track Hurricane Irma’s Path

The Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite captured this nighttime view of the Category 5 Hurricane Irma in the early hours of September 5, 2017. When the image was acquired, the storm’s center was moving due west. A National Hurricane Center forecast called for the hurricane to turn west-northwest toward the northern Leeward Islands. Credit: NASA, NOAA, Suomi NPP - VIIRS.

Record-setting Hurricane Irma barreled over the Caribbean islands of St. Martin, St. Barthelemy and Anguilla early Wednesday, destroying buildings with its sustained winds of 185 mph (297 kph), with rains and storm surges causing major flooding. The US National Hurricane Center listed the Category 5 Irma as the strongest Atlantic hurricane ever recorded north of the Caribbean and east of the Gulf of Mexico. The storm continues to roar on a path toward the U.S. and British Virgin Islands, Puerto Rico and possibly Florida, or along the southeast coast of the US.

This animation of NOAA’s GOES East satellite imagery from Sept. 3 at 8:15 a.m. EDT (1215 UTC) to Sept. 6 ending at 8:15 a.m. EDT (1215 UTC) shows Category 5 Hurricane Irma as it moved west and track over St. Martin by 8 a.m. EDT on Sept. 6:

Different models have Irma traveling on slightly different paths and officials from all the areas that might possibly be hit are telling people to prepare and follow evacuation orders. National Hurricane Center scientist Eric Blake said via twitter that some models had the storm going one way, and some another. But he cautioned everyone in a potential path should take precautions. “Model trends can be quite misleading- could just change right back. It is all probabilistic at this point. It could still miss [one particular area]. But chances of an extreme event is rising.”

The fleet of Earth-observing satellites are providing incredible views of this monster storm, and even astronauts on board the International Space Station are capturing views:

While satellite views provide the most comprehensive view of Irma’s potential track, there’s also a more ‘hands-on’ approach to getting data on hurricanes. NOAA hurricane hunter Nick Underwood posted this video while his plane flew into Hurricane Irma yesterday. The plane’s specialized instruments can take readings on the storm that forecasters can’t get anywhere else:

But Irma isn’t the only storm to keep an eye on. Tropical storms Katia and Jose are also on the horizon:

In the meantime, a launch is scheduled from Cape Canaveral on Thursday, September 7. SpaceX is hoping to launch the US Air Force’s X-37B reusable spaceplane, but current forecasts put only a 50% chance of weather suitable enough on Thursday, and only 40% on Friday. We’ll keep you posted.

For the latest satellite views, the Twitter accounts above are posting regular updates.

On Sept. 4 at 17:24 UTC, NASA-NOAA’s Suomi NPP satellite captured this view of Hurricane Irma as a Category 4 hurricane approaching the Leeward Islands.
Credits: NOAA/NASA Goddard MODIS Rapid Response Team.
Posted on by Matt Williams

Another Monster Black Hole Found in the Milky Way

Molecular clouds scattered by an intermediate black hole show very wide velocity dispersion in this artist’s impression. This scenario well explains the observational features of a peculiar molecular cloud CO-0.40-0.22. Credit: Keio University

At the center of the Milky Way Galaxy resides the Supermassive Black Hole (SMBH) known as Sagittarius A*. This tremendous black hole measures an estimated 44 million km in diameter, and has the mass of over 4 million Suns. For decades, astronomers have understood that most larger galaxies have an SMBH at their core, and that these range from hundreds of thousands to billions of Solar Masses.

However, new research performed by a team of researchers from Keio University, Japan, has made a startling find. According to their study, the team found evidence of a mid-sized black hole in a gas cluster near the center of the Milky Way Galaxy. This unexpected find could offer clues as to how SMBHs form, which is something that astronomers have been puzzling over for some time.

The study, titled “Millimetre-wave Emission from an Intermediate-mass Black Hole Candidate in the Milky Way“, recently appeared in the journal Nature Astronomy. Led by Tomoharu Oka, a researcher from the Department of Physics and the School of Fundamental Science and Technology at Keio University, the team studied CO–0.40–0.22, a high-velocity compact gas cloud near the center of our galaxy.

This artist’s concept shows a galaxy with a supermassive black hole at its core. The black hole is shooting out jets of radio waves.Image credit: NASA/JPL-Caltech

This compact dust cloud, which has been a source of fascination to astronomers for years, measures over 1000 AU in diameter and is located about 200 light-years from the center of our galaxy. The reason for this interest has to do with the fact that gases in this cloud – which include hydrogen cyanide and carbon monoxide – move at vastly different speeds, which is something unusual for a cloud of interstellar gases.

In the hopes of better understanding this strange behavior, the team originally observed CO–0.40–0.22 using the 45-meter radio telescope at the Nobeyama Radio Observatory in Japan. This began in January of 2016, when the team noticed that the cloud had an elliptical shape that consisted of two components. These included a compact but low density component with varying velocities, and a dense component (10 light years long) with little variation.

After conducting their initial observations, the team then followed up with observations from the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. These confirmed the structure of the cloud and the variations in speed that seemed to accord with density. In addition, they observed the presence of radio waves (similar to those generated by Sagittarius A*) next to the dense region. As they state in their study:

“Recently, we discovered a peculiar molecular cloud, CO–0.40–0.22, with an extremely broad velocity width, near the center of our Milky Way galaxy. Based on the careful analysis of gas kinematics, we concluded that a compact object with a mass of about 105 [Solar Masses] is lurking in this cloud.”

Change image showing the area around Sgr A*, where low, medium, and high-energy X-rays are red, green, and blue, respectively. The inset box shows X-ray flares from the region close to Sgr A*. NASA: NASA/SAO/CXC

The team also ran a series of computer models to account for these strange behaviors, which indicated that the most likely cause was a black hole. Given its mass – 100,000 Solar Masses, or roughly 500 times smaller than that of Sagittarius A* – this meant that the black hole was intermediate in size. If confirmed, this discovery will constitute the second-largest black hole to be discovered within the Milky Way.

This represents something of a first for astronomers, since the vast majority of black holes discovered to date have been either small or massive. Studies that have sought to locate Intermediate Black Holes (IMBHs), on the other hand, have found very little evidence of them. Moreover, these findings could account for how SMBHs form at the center of larger galaxies.

In the past, astronomers have conjectured that SMBHs are formed by the merger of smaller black holes, which implied the existence of intermediate ones. As such, the discovery of an IMBH would constitute the first piece of evidence for this hypothesis. As Brooke Simmons, a professor at the University of California in San Diego, explained in an interview with The Guardian:

“We know that smaller black holes form when some stars die, which makes them fairly common. We think some of those black holes are the seeds from which the much larger supermassive black holes grow to at least a million times more massive. That growth should happen in part by mergers with other black holes and in part by accretion of material from the part of the galaxy that surrounds the black hole.

“Astrophysicists have been collecting observational evidence for both stellar mass black holes and supermassive black holes for decades, but even though we think the largest ones grow from the smallest ones, we’ve never really had clear evidence for a black hole with a mass in between those extremes.”

Artist’s impression of two merging black holes, which has been theorized to be a source of gravitational waves. Credit: Bohn, Throwe, Hébert, Henriksson, Bunandar, Taylor, Scheel/SXS

Further studies will be needed to confirm the presence of an IMBH at the center of CO–0.40–0.22. Assuming they succeed, we can expect that astrophyiscists will be monitoring it for some time to determine how it formed, and what it’s ultimate fate will be. For instance, it is possible that it is slowly drifting towards Sagittarius A* and will eventually merge with it, thus creating an even more massive SMBH at the center of our galaxy!

Assuming human beings are around to detect that merger, its fair to say that it won’t go unnoticed. The gravitational waves alone are sure to be impressive!

Further Reading: Nature Astronomy

Posted on by Ken Kremer

NASA’s Peggy Whitson Safely Returns Home in Soyuz from Record Breaking Stay in Space

The Soyuz MS-04 vehicle is pictured the moment it touches down with the Expedition 52 crew inside comprising NASA astronauts Peggy Whitson and Jack Fisher and Commander Fyodor Yurchikhin of Roscosmos on Sept. 3, 2017, Kazakhstan time. Credit: NASA/Bill Ingalls
The Soyuz MS-04 vehicle is pictured the moment it touches down with the Expedition 52 crew inside comprising NASA astronauts Peggy Whitson and Jack Fisher and Commander Fyodor Yurchikhin of Roscosmos on Sept. 3, 2017, Kazakhstan time. Credit: NASA/Bill Ingalls

NASA’s Peggy Whitson, America’s most experienced astronaut, returned to Earth safely and smiling Sunday morning on the steppes of Kazakhstan, concluding her record-breaking stay in space aboard the International Space Station (ISS) along with Soyuz crewmates Jack Fischer of NASA and Commander Fyodor Yurchikhin of Roscosmos.

The multinational trio touched down softly on Earth inside their Soyuz MS-04 descent capsule on Saturday evening, Sept. 2 at 9:21 p.m. EDT (shortly after sunrise 7:21 a.m. Kazakhstan time, Sept. 3), some 90 miles southeast of the remote town of Dzhezkazgan in Kazakhstan.

Whitson wrapped up a 288-day extended mission in obviously good health that began in November 2016, spanning 122.2 million miles and 4,623 orbits of Earth – completing her third long-duration stay on the orbiting science outpost spanning Expeditions 50, 51 and 52.

“A flawless descent and landing,” said NASA commentator Rob Navias during the live NASA TV coverage of the return of the ISS Expedition 52 crew Saturday afternoon and evening US time.

“The crew is back on Earth safe and sound.”

NASA astronaut Peggy Whitson, Russian cosmonaut Fyodor Yurchikhin of Roscosmos, and NASA astronaut Jack Fischer undergo routine initial medical checks after returning from their mission aboard the International Space Station at 9:21 p.m. EDT Saturday, Sept. 2, 2017 (7:21 a.m. Kazakhstan time, Sunday, Sept. 3), landing southeast of the remote town of Dzhezkazgan in Kazakhstan. Credits: NASA TV

She has now accrued a total of 665 days in space – more than any American astronaut – over the course of her illustrious career during which she set multiple U.S. space records spanning a total of three spaceflights.

Whitson’s 665 total accumulated days in space places her eighth on the all-time space endurance list – just 8 days behind her Russian crewmate and Soyuz Commander Fyodor Yurchikhin who now ranks 7th on the all-time list with 673 days in space on his five flights. She has exceeded the endurance record of her next closest NASA competitor by 131 days – namely NASA astronaut Jeff Williams.

The remarkable 57-year-old Ph.D biochemist by training has spent nearly 2 years of her entire life in space and she holds several other prestigious records as well – including more accumulated time in space than any other woman and the longest single spaceflight by a women – 288 days!

During this mission Whitson became the first woman to serve twice as space station commander. Indeed in 2008 Whitson became the first woman ever to command the space station during her prior stay on Expedition 16 a decade ago. Her second stint as station commander this mission began earlier this year on April 9.

Whitson also holds the record for the most spacewalks and the most time spent spacewalking by a female astronaut. Altogether she has accumulated 60 hours and 21 minutes of EVA time over ten spacewalks -ranking her third most experienced in the world.

Notably Soyuz Commander Yurchikhin ranks fourth in spacewalking experience. Only Russia’s Anatoly Solovyev and NASA’s Michael Lopez-Alegria have more spacewalking time to their credit.

NASA’s Jack Fischer completed his rookie spaceflight accumulating 136 days in space aboard the ISS.

Astronaut Peggy Whitson is pictured May 12, 2017, during the 200th spacewalk at the International Space Station. Credit: NASA

Whitson originally launched to the ISS on Nov 17, 2016 aboard the Russian Soyuz MS-03 spacecraft from the Baikonur Cosmodrome in Kazakhstan, as part of the three person Expedition 50 crew including flight engineers Oleg Novitskiy of Roscosmos and Thomas Pesquet of ESA (European Space Agency).

Her flight was unexpectedly extended in flight after the Russian government decided to cut back on the number of space station crew cosmonauts this year from three to two to save money. Thus a return seat became available on this Soyuz MS-04 return flight after NASA negotiated an extension with Rosmoscos in April enabling Whitson to remain on board the orbiting outpost an additional three months beyond her than planned June return home.

Whitson’s mission extension proved to be a boon for NASA and science research enabling the US/partner USOS crew complement to be enlarged from three to four full time astronauts much earlier than expected. This allowed NASA to about double the weekly time devoted to research aboard station – a feat not expected to happen until America’s commercial crew vehicles, namely Boeing Starliner and SpaceX Crew Dragon – finally begin inaugural launches next year from the Kennedy Space Center in mid-2018.

NASA Astronaut Peggy Whitson after safe return to Earth on Sept. 2, 2017 ET. Credit: NASA

Descending dramatically while hanging below a single gigantic orange-and-white parachute the scorched Russian Soyuz vehicle fired its braking rockets just moments before touchdown in Kazakhstan to cushion the crew for a gentle landing under beautifully sunny skies.

A live NASA TV video feed captured the thrilling descent for over 14 minutes after the main parachute deployed all the way to the ground under clear blue sunny Sunday morning weather conditions and comfortably local Kazakh temperatures of 77 degrees F.

“Everything today went in perfect fashion from the undocking, to the deorbit burn to landing,” said Navias. “It went by the book with no issues.”

“We saw a spectacular 14 minute long live video of the Soyuz descent and landing.”

The Soyuz MS-04 carrying NASA astronauts Peggy Whitson and Jack Fischer and Fyodor Yurchikin of Roscosmos back to Earth from the International Space Station touched down at at 9:21 p.m. EDT Saturday, Sept. 2 (7:21 a.m. Kazakhstan time, Sunday, Sept. 3), southeast of the remote town of Dzhezkazgan in Kazakhstan. Credits: NASA TV

Russian search and recovery forces quickly arrived via a cluster of MI-8 helicopters after the soft landing to begin their normal procedures to extract the three Expedition 52 crew members from their cramped Soyuz descent module.

Soyuz Commander Yurchikhin in the center seat was hauled out first, followed by Fischer in the left side seat and lastly Whitson in the right seat. All 3 were placed on reclining seats sitting side by side and appeared quite well, conversing and speaking via satellite phones.

A group of Russian and US medical teams were on hand to check the astronauts and cosmonauts health and help the crewmates begin readapting to the tug of Earth’s gravity they have not experienced after many months of weightlessness in space.

Whitson’s final planned news conference from space with the media to sum up her experiences this past Wednesday had to be cancelled due to the catastrophic flooding events from Hurricane Harvey impacting Houston and elsewhere in Texas – including Mission Control which was forced to close multiple days.

The crews had bid their final farewells earlier and closed the hatches between the Soyuz and station at 2:40 p.m. EDT Saturday.

After conducting final spacecraft systems checks the trio unhooked the latches and undocked from the International Space Station at 5:58 p.m. EDT to begin their voyage home through the scorching heats of reentry in the Earth’s atmosphere that reached over 2500 degrees F (1400 degrees C) on the outside.

“While living and working aboard the world’s only orbiting laboratory, Whitson and Fischer contributed to hundreds of experiments in biology, biotechnology, physical science and Earth science, welcomed several cargo spacecraft delivering tons of supplies and research experiments, and conducted a combined six spacewalks to perform maintenance and upgrades to the station,” said NASA.

“Among their scientific exploits, Whitson and Fischer supported research into the physical changes to astronaut’s eyes caused by prolonged exposure to a microgravity environment. They also conducted a new lung tissue study that explored how stem cells work in the unique microgravity environment of the space station, which may pave the way for future stem cell research in space.”

“Additional research included an antibody investigation that could increase the effectiveness of chemotherapy drugs for cancer treatment, and the study of plant physiology and growth in space using an advanced plant habitat. NASA also attached the Cosmic Ray Energetics and Mass Investigation (ISS CREAM) on the outside of the space station in August, which is now observing cosmic rays coming from across the galaxy.”

Astronaut Peggy Whitson signs her autograph near an Expedition 50 mission patch attached to the inside the International Space Station. Credit: NASA

ISS Expedition 53 began at the moment of undocking from the space station, now under the command of veteran NASA astronaut Randy Bresnik since the official change of command ceremony on Friday.

Along with his crewmates Sergey Ryazanskiy of Roscosmos and Paolo Nespoli of ESA (European Space Agency), the three-person crew will operate the station for the next 10 days until the imminent arrival of three new crew members.

The station will get back to a full complement of six crewmembers after the upcoming Sept. 12 launch and fast track 4 orbit 6 hour docking of NASA astronauts Mark Vande Hei and Joe Acaba of NASA and Alexander Misurkin of Roscosmos aboard the next Soyuz MS-06 spacecraft departing from the Baikonur Cosmodrome, Kazakhstan.

Meanwhile the next launch from the Kennedy Space Center is slated for this Thursday, Sept.7 is the SpaceX Falcon 9 carrying the USAF X-37B OTV-5 military mini-shuttle to low Earth orbit -detailed here.

Peggy Whitson set the record on Sept. 2, 2017, for most cumulative days living and working in space by a NASA astronaut at 665 days. Credit: NASA
Expedition 52 Flight Engineer Peggy Whitson of NASA, Commander Fyodor Yurchikhin of the Russian space agency Roscosmos and Flight Engineer Jack Fischer of NASA float through the Harmony module of the International Space Station. Credits: NASA

Watch for Ken’s continuing onsite X-37B OTV-5 and NASA mission reports direct from the Kennedy Space Center and Cape Canaveral Air Force Station, Florida.

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

Soyuz has split into 3 modules 139.8 km above Earth. Crew parachutes to landing inside Descent Module at 9:22 pm ET Sept. 2, 2017. Credit: NASA
Expedition 52 crew returns to Earth Sept. 2, 2017. Credit: NASA
Peggy Whitson @AstroPeggy is 3rd place all-time for cumulative spacewalk time with 10 spacewalks totaling 60 hours, 21 minutes. Credit: NASA
Posted on by Matt Williams

Researchers Tackle Question of How the Universe Became Filled With Light

A billion years after the big bang, hydrogen atoms were mysteriously torn apart into a soup of ions. Credit: NASA/ESA/A. Felid (STScI)).

In accordance with the Big Bang model of cosmology, shortly after the Universe came into being there was a period known as the “Dark Ages”. This occurred between 380,000 and 150 million years after the Big Bang, where most of the photons in the Universe were interacting with electrons and protons. As a result, the radiation of this period is undetectable by our current instruments – hence the name.

Astrophysicists and cosmologists have therefore been pondering how the Universe could go from being in this dark, cloudy state to one where it was filled with light. According to a new study by a team of researchers from the University of Iowa and the Harvard-Smithsonian Center for Astrophysics, it may be that black holes violently ejected matter from the early Universe, thus allowing light to escape.

Their study, titled “Resolving the X-ray emission from the Lyman continuum emitting galaxy Tol 1247-232“, recently appeared in the Monthly Notices of the Royal Astronomical Society. Led by Phillip Kaaret, a professor of Physics and Astronomy at the University of Iowa – and supported by an award from the Chandra X-ray Observatory – the research team arrived at this conclusion by observing a nearby galaxy from which ultraviolet light is escaping.

Milestones in the history of the Universe, from the Big Bang to the present day. Credit: NAOJ/NOAO

This galaxy, known as Tol 1247-232, is a small (and possibly elliptical) galaxy located 652 million light-years away, in the direction of the southern Hydra constellation. This galaxy is one of just nine in the local Universe (and one of only three galaxies close to the Milky Way) that has been shown to emit Lyman continuum photons – a type of radiation in the ultraviolet band.

Back in May of 2016, the team spotted a single X-ray source coming from a star-forming region in this galaxy, using the Chandra X-ray observatory. Based on their observations, they determined that it was not caused by the formation of a new star. For one, new stars do not experience sudden changes in brightness, as this x-ray source did. In addition, the radiation emitted by new stars does not come in the form of a point-like source.

Instead, they determined that what they were seeing had to be the result of a very small object, which left only one likely explanation: a black hole. As Philip Kaaret, a professor in the UI Department of Physics and Astronomy and the lead author on the study, explained:

“The observations show the presence of very bright X-ray sources that are likely accreting black holes. It’s possible the black hole is creating winds that help the ionizing radiation from the stars escape. Thus, black holes may have helped make the universe transparent.”

Where is the Nearest Black Hole
Artist concept of matter swirling around a black hole. Credit: NASA/Dana Berry/SkyWorks Digital

However, this also raised the question of how a black hole could be emitting matter. This is something that astrophysicists have puzzled over for quite some time. Whereas all black holes have tendency to consume all that is in their path, a small number of supermassive black holes (SMBHs) have been found to have high-speed jets of charged particles streaming from their cores.

These SMBHs are what power Active Galactic Nuclei, which are compact, bright regions that has been observed at the centers of particularly massive galaxies. At present, no one is certain how these SMBHs manage to fire off jets of hot matter. But it has been theorized that they could be caused by the accelerated rotational energy of the black holes themselves.

In keeping with this, the team considered the possibility that accreting X-ray sources could explain the escape of matter from a black hole. In other words, as a black hole’s intense gravity pulls matter inward, the black hole responds by spinning faster. As the hole’s gravitational pull increases, the speed creates energy, which inevitably causes charged particles to be pushed out. As Kaaret explained:

“As matter falls into a black hole, it starts to spin and the rapid rotation pushes some fraction of the matter out. They’re producing these strong winds that could be opening an escape route for ultraviolet light. That could be what happened with the early galaxies.”

Depiction of the tidal disruption event in F01004-2237. The release of gravitational energy as the debris of the star is accreted by the black hole leads to a flare in the optical light of the galaxy. Credit and copyright: Mark Garlick

Taking this a step further, the team hypothesized that this could be what was responsible for light escaping the “Dark Ages”. Much like the jets of hot material being emitted by SMBHs today, similarly massive black holes in the early Universe could have sped up due to the accretion of matter, spewing out light from the cloudiness and allowing for the Universe to become a clear, bright place.

In the future, the UI team plans to study Tol 1247-232 in more detail and locate other nearby galaxies that are also emitting ultraviolet light. This will corroborate their theory that black holes could be responsible for the observed point source of high-energy X-rays. Combined with studies of the earliest periods of the Universe, it could also validate the theory that the “Dark Ages” ended thanks to the presence of black holes.

Further Reading: Iowa Now, Monthly Notices of the Royal Astronomical Society

Posted on by Matt Williams

Preparations for Deployment of InSight Lander to Mars are Ramping Up!

Artist's conception of the NASA InSight Mars lander. Credit: NASA/JPL-Caltech

This summer has been a busy time for NASA. At present, the agency is making the final preparations for the Cassini mission‘s plunge into Saturn’s atmosphere, monitoring the large Near-Earth Asteroid that recently made a flyby of Earth, marking the 40th anniversary of the historic Voyager missions, and hosting the Summer of Mars at the Kennedy Space Center.

In addition to all that, engineers at the Jet Propulsion Laboratory in Pasadena, California, are busy preparing the Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) Lander for its scheduled launch in 2018. Once deployed to Mars, the lander will reveal things about Mars’ interior geology and composition, shedding new light on the history of the Red Planet’s formation and evolution.

Originally scheduled for launch in 2016, the lander’s deployment was delayed due to the failure of a key component – a chamber that housed the Seismic Experiment for Interior Structure (SEIS). Having finished work on a new vacuum enclosure for this instrument, the technicians at Lockheed Martin Space Systems are back at work, assembling and testing the spacecraft in a clean room facility outside of Denver, Colorado.

This artist’s concept from August 2015 depicts NASA’s InSight Mars lander fully deployed for studying the deep interior of Mars. Credit: NASA/JPL-Caltech

As Stu Spath, the spacecraft program manager at Lockheed Martin, said in a NASA press statement:

“Our team resumed system-level integration and test activities last month. The lander is completed and instruments have been integrated onto it so that we can complete the final spacecraft testing including acoustics, instrument deployments and thermal balance tests.”

Beyond the exploration of Mars, the InSight mission is also expected to reveal information about how all terrestrial (i.e. rocky) planets in the Solar System formed over four billion years ago. Mars is an especially opportune target for this type of research since it has been relatively inactive for the past three billion years. However, when the planet was still young, it underwent geological processes that were analogous to Earth’s.

In other words, because the interior of Mars has been subject to less convection over the past three billion years, it has likely preserved evidence about its early geological history better than Earth has. InSight will study this preserved history through a series of instruments that will measure the planet’s seismology, heat loss, and the state and nature of its core.

Once it reaches Mars, the stationary lander will set down near Mars’ equator and deploy its two fold-out solar cells, which kind of resemble large fans. Within a few weeks of making its landing, it will use a robotic arm to place its two main instruments onto the Martian surface – the aforementioned Seismic Experiment for Interior Structure (SEIS) and the Heat Flow and Physical Properties Probe (HP³).

Artist’s impression of the interior of Mars. Credit: NASA/JPL

The SEIS instrument – which was developed by France’s National Center for Space Studies (CNES) in collaboration with NASA and several European scientific institutions – has a sensitivity comparable to the best research seismometers here on Earth. This instrument will record seismic waves from “marsquakes” and meteor impacts, which will reveal things about the planet’s interior layers.

The HP³ probe, supplied by the German Aerospace Center (DLR), will use a Polish-made self-hammering mechanism to bury itself to a depth of 3 meters (10 feet) or more. As it descends, the probe will extend a tether that contains temperature sensors every ~10 cm, which measure the temperature profile of the subsurface. Combined with surface measurements, the instrument will determine the amount of heat escaping from the planet’s interior.

A third experiment, known as Rotation and Interior Structure Experiment (RISE), will also come into play. This instrument will use the lander’s X-band radio link to conduct Doppler tracking of the lander’s location, which will also allow it to measure variations in Mars’ rotation axis. Since these variations are primarily related to the size and state of Mars’ core, this experiment will shed light on one of Mars’ greatest mysteries.

Thanks to multiple missions that have studies Mars’ surface and atmosphere, scientists now know that roughly 4.2 billions of years ago, Mars lost its magnetic field. Because of this, Mars’ atmosphere was stripped away by solar wind during the next 500 million years. It is believed that it was this process that allowed the planet to go from being a warmer, wetter environment in the past to the cold, desiccated and irradiated place it is today.

NASA’s InSight Mars lander spacecraft in a Lockheed Martin clean room near Denver. Credit: NASA/JPL-Caltech/Lockheed Martin

As such, determining the state of Mars’ core – i.e. whether it is solid or liquid, or differentiated between a solid outer core and liquid inner core – will allow scientists to gain a more comprehensive understanding of the planet’s geological history. It will also allow them to answer with a fair degree of certainty how and when Mars lost its magnetic field (and hence, its denser, warmer atmosphere).

The spacecraft’s science payload is also on track for next year’s launch. At present, the mission is scheduled to launch on May 5th, 2018, though this window could be moved to anytime within a five-week period. Regardless of what day it launches, mission planners indicate that the flight will reach Mars on November 26th, 2018 (the Monday after Thanksgiving).

As noted, the mission was originally planned to launch in March of 2016, but was canceled due to the presence of a leak in the special metal container designed to maintain near-vacuum conditions around the SEIS’s main sensors. Now that a redesigned vacuum vessel has been built and tested (and integrated with the SEIS) the spacecraft is ready for its new launch date.

Back in 2010, the InSight mission was selected from a total of 28 proposals, which were made as part of the twelfth round of selections for NASA’s Discovery Program. In contrast to New Frontiers or Flagship programs, Discovery missions are small-budget enterprises that aid in larger scientific pursuits. Along with two other finalists – the Titan Mare Explorer (TiME) and the Comet Hopper (CHopper) – InSight was awarded funding for further development.

Bruce Banerdt of NASA’s Jet Propulsion Laboratory is the Principle Investigator (PI) for the InSight mission.

Be sure to check out this video of the InSight mission (courtesy of NASA JPL) as well:

Further Reading: NASA JPL