Universe Today

August 15, 2013December 23, 2015 by Tammy Plotner

Hubble Looks Back In Time To See Shape Of Galaxies 11 Billion Years Ago

This image shows "slices" of the Universe at different times throughout its history (present day, and at 4 and 11 billion years ago). Each slice goes further back in time, showing how galaxies of each type appear. The shape is that of the Hubble tuning fork diagram, which describes and separates galaxies according to their morphology. Credit: NASA, ESA, M. Kornmesser

What we’re gonna’ do here is go back. Way back into time. Back to when the only thing that existed was… galaxies? When astronomers employed the power of Hubble’s CANDELS survey to observe different galaxy types from the distant past, they expected to see a variety of spiral, elliptical, lenticular and peculiar structures, but what they didn’t expect was that things were a whole lot more “peculiar” a long time ago!

Known as the Hubble Sequence, astronomers use this classified system for listing galaxy sizes, shapes and colors. It also arranges galaxies according to their morphology and star-forming activity. Up to the present, the Hubble Sequence covered about 80% of the Universe’s history, but the latest information shows that the sequence was valid as much as 11 billion years ago! Out of what we currently know, there are two dominant galaxy types – spiral and elliptical – with the lenticular structure as a median. Of course, this is constrained to the regions of space which we can readily observe, but how true did the sequence hold back when the Universe theoretically began?

“This is a key question: when and over what timescale did the Hubble Sequence form?” says BoMee Lee of the University of Massachusetts, USA, lead author of a new paper exploring the sequence. “To do this you need to peer at distant galaxies and compare them to their closer relatives, to see if they too can be described in the same way.”

Using the Hubble Space Telescope, astronomers took on the sequence challenge to peer back 11 billion years in time to study galaxy structure. Up until now, researchers could confirm the sequence was valid as long ago as 8 billion years, but these new studies pushed CANDELS, the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, to the outer limits. It is simply the largest project ever, and soaked up 902 assigned orbits of observing time. Using the WFC3 and ACS cameras, the team examined structures that existed less than one billion years after the Big Bang. While earlier studies had aimed for lower-mass galaxies in this era, no study had really taken on serious observation of mature structures – ones similar to our own galaxy. Now the new CANDELS observations show us that all galaxies, regardless of size, fit into a totally different classification!

“This is the only comprehensive study to date of the visual appearance of the large, massive galaxies that existed so far back in time,” says co-author Arjen van der Wel of the Max Planck Institute for Astronomy in Heidelberg, Germany. “The galaxies look remarkably mature, which is not predicted by galaxy formation models to be the case that early on in the history of the Universe.”

Just what did this study see that’s so different? Just the power of two. Galaxies were either complex, with blue star forming regions and irregular structures, or they were like our nearby neighbors: massive red galaxies that exhibit no new star-formation. In the early Universe, galaxies like the Milky Way were uncommon. With so little to study, it was nearly impossible to get a large enough sample to sufficiently catalog their characteristics. Early research could only peer back in visible light, a format which emphasized star formation and revealed the red-shifted ultraviolet emission of the galaxies. This information was inconclusive because galaxy structure appeared disrupted and unlike the formations we see near to us. Through the use of infra-red, astronomers could observe the now red-shifted massive galaxies in their visible rest frame. Thanks to CANDELS lighting the way, astronomers were able to thoroughly sample a significantly larger amount of mature galaxies in detail.

“The huge CANDELS dataset was a great resource for us to use in order to consistently study ancient galaxies in the early Universe,” concludes Lee. “And the resolution and sensitivity of Hubble’s WFC3 is second to none in the infrared wavelengths needed to carry out this study. The Hubble Sequence underpins a lot of what we know about how galaxies form and evolve — finding it to be in place this far back is a significant discovery.”

Original Story Source: ” Hubble Explores the Origins of Modern Galaxies” – Hubble News Release.

August 15, 2013December 23, 2015 by Nancy Atkinson

IAU Revises Their Stance on Public Involvement in Naming of Exoplanets and Moons

Artistic representations of the only known planets around other stars (exoplanets) with any possibility to support life as we know it. Credit: Planetary Habitability Laboratory, University of Puerto Rico, Arecibo.

The International Astronomical Union issued a statement on August 14, 2013 that they have changed their official stance on two things: 1. assigning popular names to the numerous extrasolar planets being discovered, and 2. allowing the public to be involved in that naming process.

“It is therefore in line with a long-established global tradition and experience that the IAU fully supports the involvement of the general public, whether directly or through an independent organised vote, in the naming of planetary satellites, newly discovered planets and their host stars,” the online statement said.

This new stance came as a surprise to many.

“I was surprised by the IAU statement encouraging the general public input on naming astronomical objects,” said Professor Abel Mendez, director of the Planetary Habitability Laboratory at the University of Puerto Rico, in an email to Universe Today. “This is certainly something good. …So there is now a public naming procedure that includes the IAU validation but this does not exclude any other non-IAU public naming campaigns.”

As recently as late March, 2013, the IAU’s official word on naming exoplanets was, “the IAU sees no need and has no plan to assign names to these objects at the present stage of our knowledge.”

Their rationale was since there is seemingly going to be so many exoplanets, it will be difficult to name them all.

But then, on about March 24, the IAU added this to their website:

“…the IAU greatly appreciates and wishes to acknowledge the increasing interest from the general public in being more closely involved in the discovery and understanding of our Universe. As a result in 2013 the IAU Commission 53 Extrasolar Planets and other IAU members will be consulted on the topic of having popular names for exoplanets, and the results will be made public on the IAU website.”

Artistic rendition of a sunset view from the perspective of an imagined Earth-like moon orbiting the giant planet, PH2 b. Image Credit: H. Giguere, M. Giguere/Yale University — Artistic rendition of a sunset view
from the perspective of an imagined Earth-like moon orbiting the giant planet, PH2 b. Image Credit: H. Giguere, M. Giguere/Yale University

This new decision follows a line of events earlier this year where the SETI Institute and the space company Uwingu organized their own campaigns/contests for creating popular names of objects in space instead of the rather clinical, scientific names currently assigned to planets, such as HD 41004 Ab. Both events were wildly popular with the general public, but generated discussion about how “official” the names would be. The IAU issued a statement regarding the contests saying that while they welcomed the public’s interest in being involved in recent discoveries, as far as they are concerned, the IAU has the last word. Additionally, they were against “selling” names (Uwingu charged a fee to suggest a name and to vote as a fundraiser for space research.)

“In the light of recent events, where the possibility of buying the rights to name exoplanets has been advertised, the International Astronomical Union (IAU) wishes to inform the public that such schemes have no bearing on the official naming process. The IAU… would like to strongly stress the importance of having a unified naming procedure,” said the April 12, 2013 statement issued by the IAU.

The IAU’s new rules allow for individuals to suggest names of exoplanets and planetary satellites (moons) via email to the IAU (Click here for email address).

Public naming campaigns are also “sanctioned” given they follow a set of rules:

1. Prior to any public naming initiative, often a vote (hereafter “the process”), the IAU should be contacted from the start by Letter of Intent sent to the IAU General Secretary;
2. The process should be submitted in the form of a proposal to the IAU by an organization. Scientists or science communicators may be involved in the process;
3. The organization should list its legal or official representatives and its goals, and explain the reasons for initiating the process for naming a particular object or set of objects;
4. The process cannot request nor make reference to any revenues, for whatever purpose;
5. The process must guarantee a wide international participation;
6. The public names proposed (whether by individuals or in a naming campaign)should follow the naming rules and restrictions adopted for Minor Bodies of the Solar System, by the IAU and by the Minor Planet Center (see here and here
for more details.

Among other rules are that proposed names should be 16 characters or less in length, pronounceable in as many languages as possible, non-offensive in any language or culture, and that names of individuals, places or events principally known for political or military activities are unsuitable.

Also, the names must have the formal agreement of the discoverers.

The new statement also has its critics. People joked on Twitter this morning whether the name of our neighboring planet Mars, named for the god of war, will have to be changed due to the new restrictions on military nomenclature.

Astronomer Alan Stern, principal investigator of the New Horizons mission to Pluto and CEO of Uwingu said he was actually not surprised at the IAU’s new statement.

“Fundamentally it’s still about the public being subservient to IAU committees that pass on recommendations,” he said via an email response to Universe Today. “Old school. Why should the IAU be a traffic cop?”

Stern also said the new statement has several contradictions from the statement the IUA put out on April 12 of this year, such as that “these [naming]campaigns have no bearing on the official naming process — they will not lead to an officially-recognised exoplanet name, despite the price paid or the number of votes accrued.” It now would appear that contests that follow the IAU’s rules are OK.

Stern said he has received letters and emails of support from other astronomers, particularly on the “no revenue” provision, noting how astronomy publications and planetariums charge money for their magazines and sky shows.

“If they can do it, why can’t Uwingu — especially since Uwingu’s revenue is used (at least in part) to further the IAU’s own goals, namely, to advance the science of astronomy, and the public’s understanding of it, worldwide?,” Stern quoted one email he received.

Also, the April statement from the IAU said they were the single arbiter of the naming process of celestial objects, while the new August statement says, “The IAU does not consider itself as having a monopoly on the naming of celestial objects— anyone can in theory adopt names the way they choose.”

The statement goes on, “However, given the publicity and emotional investment associated with these discoveries, worldwide recognition is important and the IAU offers its unique experience for the benefit of a successful public naming process (which must remain distinct, as in the past, from the scientific designation issues).”

Since this is a public debate about the public’s involvement in providing popular names for astronomical objects, please add your thoughts in the comments.

August 15, 2013March 16, 2017 by Fraser Cain

Can You Really Name a Star?

There are services which will let you name a star in the sky after a loved one. You can commemorate a special day, or the life of an amazing person. But can you really name a star?

The answer is yes, and no.

Names of astronomical objects are agreed upon by the International Astronomical Union. If this name sounds familiar, it’s the same people who voted that Pluto is not a planet.

Them.

There are a few stars with traditional names which have been passed down through history. Names like Betelgeuse, Sirius, or Rigel. Others were named in the last few hundred years for highly influential astronomers.

These are the common names, agreed upon by the astronomical community.

Most stars, especially dim ones, are only given coordinates and a designation in a catalog. There are millions and millions of stars out there with a long string of numbers and letters for a name. There’s the Gliese catalog of nearby stars, or the Guide Star Catalog which contains 945 million stars.

The IAU hasn’t taken on any new names for stars, and probably won’t ever. The bottom line is that numbers are much more useful for astronomers searching and studying stars.

But what about the companies that will offer to let you name a star? Each of these companies maintains their own private database containing stars from the catalog and associated star names. They’ll provide you with a nice certificate and instructions for finding it in the sky, but these names are not recognized by the international astronomical community.

You won’t see your name appearing in a scientific research journal. In fact, it’s possible that the star you’ve named with one organization will be given a different name by another group.

So can you really name a star after yourself or a loved one?

Yes, you can, in the same way that you can name an already-named skyscraper after yourself. Everyone else might keep calling it the Empire State Building, but you’ll have a certificate that says otherwise.

There are a few objects that can be named, and recognized by the IAU.

Fragments of Shoemaker-Levy 9 on approach to Jupiter (NASA/HST)

If you’re the first person to spot a comet, you’ll have it named after you, or your organization. For example, Comet Shoemaker-Levy was discovered simultaneously by Eugene Shoemaker and David Levy.

If you discover asteroids and Kuiper Belt Objects, you can suggest names which may be ratified by the IAU. Asteroids, as well as comets, get their official numerical designation, and then a common name.

The amateur astronomer Jeff Medkeff, who tragically died of liver cancer at age 40, named asteroids after a handful of people in the astronomy, space and skeptic community.

Artist's impression of Eris — Artist’s impression of Eris

Kuiper Belt Objects are traditionally given names from mythology. And so, Pluto Killer Mike Brown’s Caltech team suggested the names for Eris, Haumea and Makemake.

So what about extrasolar planets? Right now, these planets are attached to the name of the star. For example, if a planet is discovered around one of the closer stars in the Gliese catalog, it’s given a letter designation.

An organization called Uwingu is hoping to raise funds to help discover new extrasolar planets, and then reward those funders with naming rights, but so far, this policy hasn’t been adopted by the IAU.

Personally, I think that officially allowing the public to name astronomical objects would be a good idea. It would spur the imagination of the public, connecting them directly to the amazing discoveries happening in space, and it would help drive funds to underfunded research projects.

And that would be a good thing.

Note: You can also visit a non-profit adopt-a-star program that supports Kepler research called the Pale Blue Dot Adopt-A-Star project!

August 15, 2013December 23, 2015 by Ken Kremer

Student Science Thunders to Space from NASA Wallops

A Terrier-Improved Malemute suborbital rocket carrying experiments developed by university students nationwide in the RockSat-X program was successfully launched at 6 a.m. EDT August 13. Credit: NASA/Allison Stancil
Watch the cool Video below
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WALLOPS ISLAND, VA – A nearly 900 pound complex payload integrated with dozens of science experiments created by talented university students in a wide range of disciplines and from all across America streaked to space from NASA’s beachside Wallops launch complex in Virginia on August 13 – just before the crack of dawn.

The RockSat-X science payload blasted off atop a Terrier-Improved Malemute suborbital sounding rocket at 6 a.m. from NASA’s Wallops Flight Facility along the Eastern Shore of Virginia.

As a research scientist myself it was thrilling to witness the thunderous liftoff standing alongside more than 40 budding aerospace students brimming with enthusiasm for the chance to participate in a real research program that shot to space like a speeding bullet.

“It’s a hands on, real world learning experience,” Chris Koehler told Universe Today at the Wallops launch pad. Koehler is Director of the Colorado Space Grant Consortium that manages the RockSat-X program in a joint educational partnership with NASA.

The hopes and dreams of everyone was flying along.

Here’s a cool NASA video of the RockSat-X Aug. 13 launch:

The students are responsible for conceiving, managing, assembling and testing the experiments, Koehler told me. Professors and industrial partners mentor and guide the students.

RockSat-X is the third of three practical STEM educational programs where the students master increasingly difficult skills that ultimately result in a series of sounding rocket launches.

“Not everything works as planned,” said Koehler. “And that’s by design. Some experiments fail but the students learn valuable lessons and apply them on the next flight.”

“The RockSat program started in 2008. And it’s getting bigger and growing in popularity every year,” Koehler explained.

August 13 launch of RockSat-X student science payload atop a Terrier-Improved Malemute suborbital at 6 a.m. EDT from NASA Wallops. Credit: Ken Kremer/kenkremer.com

The 2013 RockSat-X launch program included participants from seven universities, including the University of Colorado at Boulder; the University of Puerto Rico at San Juan; the University of Maryland, College Park; Johns Hopkins University, Baltimore, Md.; West Virginia University, Morgantown; University of Minnesota, Twin Cities; and Northwest Nazarene University, Nampa, Idaho.

We all watched as a group and counted down the final 10 seconds to blastoff just a few hundred yards (meters) away from the launch pad – Whooping and hollering as the first stage ignited with a thunderous roar. Then the second stage flash – and more yelling and screams of joy! – – listen to the video.

Moments later we saw the first stage plummeting and heard a loud thud as it crashed into the ocean just 10 miles or so offshore.

For most of the students -ranging from freshman to seniors – it was their first time seeing a rocket launch.

“I’m so excited to be here at NASA Wallops and see my teams experiment reach space!” said Hector, one of a dozen aerospace students who journeyed to Wallops from Puerto Rico.

Local Wallops area spectators and tourists told me they could hear the rocket booming from viewing sites more than 10 miles away.

Others who ‘overslept’ were awoken by the rocket thunder and houses shaking.

Suborbital rockets still make for big bangs!

The Puerto Rican students very cool experiment aimed at capturing meteorite particles in space using 6 cubes of aerogel that were extended out from the rocket as it descended back to Earth, said Oscar Resto, Science Instrument specialist and leader of the Puerto Rican team during an interview at the launch complex.

“Seeing this rocket launch was the best experience of my life,” Hector told me. “This was my first time visiting the mainland. I hope to come back again!”

Another team of 7 students from Northwest Nazarene University (NNU), Idaho aimed to investigate the durability of the world’s first physically flexible integrated chips.

“Our experiment tested the flexibility of integrated circuit chips in the cryogenic environment of space,” Prof Stephen Parke of NNU, Idaho, told Universe Today in an interview at the launch pad.

“The two year project is a collaboration with chipmaker American Semiconductor, Inc based in Boise, Idaho.”

“The chips were mechanically and electrically exercised, or moved, during the flight under the extremely cold conditions in space – of below Minus 50 C – to test whether they would survive,” Parke told me.

The 44 foot long, two stage rocket flew on a parabolic arc and a southeasterly trajectory. The 20 foot RockSat-X payload soared to an altitude of approximately 94 miles above the Atlantic Ocean.

More than 40 University students and mentors participating in the Aug. 13 RockSat-X science payload pose for post launch photo op at NASA Wallops Island, VA, launch complex that launched their own developed experiments to space. Credit: Ken Kremer/kenkremer.com

Telemetry and science data was successfully transmitted and received from the rocket during the flight.

The payload then descended back to Earth, deployed a 24 foot wide parachute and splashed down in the Atlantic Ocean some 90 miles offshore from Wallops Flight Facility. Overall the mission lasted about 20 minutes.

A commercial fishing boat hauled in the payload and brought it back to Wallops about 7 hours later.

By 2 p.m. the RockSat-X payload was back onsite at the Wallops ‘Rocket Factory’.

Rocket science university students get ready to tear apart the RockSat-X science payload after recovery from Atlantic Ocean splashdown following Aug. 13 rocket blastoff from NASA Wallops Flight Facility, VA. Credit: Ken Kremer/kenkremer.com

And I was on-hand as the gleeful students began tearing it apart to disengage their individual experiments to begin a week’s long process of assessing the outcome, analyzing the data and evaluating what worked and what failed. See my photos.

Rocket science university students from Puerto Rico pose for post flight photo op with their disengaged science experiment seeking to capture meteorite particles from space aboard Terrier-Improved Malemute sounding rocket that launched on Aug. 13 at 6 a.m. from NASA Wallops Flight Facility, VA. Credit: Ken Kremer/kenkremer.com

Included among the dozens of custom built student experiments were HD cameras, investigations into crystal growth and ferro fluids in microgravity, measuring the electron density in the E region (90-120km), aerogel dust collection on an exposed telescoping arm from the rockets side, effects of radiation damage on various electrical components, determining the durability of flexible electronics in the cryogenic environment of space and creating a despun video of the flight.

Indeed we already know that not every experiment worked. But that’s the normal scientific method – ‘Build a little, fly a little’.

New students are already applying to the 2014 RockSat program. And some of these students will return next year with thoughtful upgrades and new ideas!

The launch was dedicated in memory of another extremely bright young student named Brad Mason, who tragically passed away two weeks ago. Brad was a beloved intern at NASA Wallops this summer and a friend. Brad’s name was inscribed on the side of the rocket. Read about Brad at the NASA Wallops website.

Ken Kremer

…………….
Learn more about Suborbital science, Cygnus, Antares, LADEE, MAVEN and Mars rovers and more at Ken’s upcoming presentations

Sep 5/6/16/17: LADEE Lunar & Antares/Cygnus ISS Rocket Launches from Virginia”; Rodeway Inn, Chincoteague, VA, 8 PM

Oct 3: “Curiosity, MAVEN and the Search for Life on Mars – (3-D)”, STAR Astronomy Club, Brookdale Community College & Monmouth Museum, Lincroft, NJ, 8 PM

August 14, 2013December 23, 2015 by Bob King

Bright New Nova In Delphinus — You can See it Tonight With Binoculars

The new nova is located in Delphinus alongside the familiar Summer Triangle outlined by Deneb, Vega and Altair. This may shows the sky looking high in the south for mid-northern latitudes around 10 p.m. local time in mid-August. The new object is ideally placed for viewing. Stellarium

Looking around for something new to see in your binoculars or telescope tonight? How about an object whose name literally means “new”. Japanese amateur astronomer Koichi Itagaki of Yamagata discovered an apparent nova or “new star” in the constellation Delphinus the Dolphin just today, August 14. He used a small 7-inch (.18-m) reflecting telescope and CCD camera to nab it. Let’s hope its mouthful of a temporary designation, PNVJ20233073+2046041, is soon changed to Nova Delphini 2013!

This map shows Delphinus and Sagitta, both of which are near the bright star Altair at the bottom of the Summer Triangle. You can star hop from the Delphinus "diamond" to the star 29 Vulpecula and from there to the nova or center your binoculars between Eta Sagittae and 29 Vul. Stellarium — This map shows Delphinus and Sagitta, both of which are near the bright star Altair at the bottom of the Summer Triangle. You can star hop from the top of Delphinus to the star 29 Vulpeculae and from there to the nova. Or you can point your binoculars midway between Eta Sagittae and 29 Vul. The “5.7 star” is magnitude 5.7. Stellarium

Several hours later it was confirmed as a new object shining at magnitude 6.8 just under the naked eye limit. This is bright especially considering that nothing was visible at the location down to a dim 13th magnitude only a day before discovery. How bright it will get is hard to know yet, but variable star observer Patrick Schmeer of Germany got his eyes on it this evening and estimated the new object at magnitude 6.0. That not only puts it within easy reach of all binoculars but right at the naked eye limit for observers under dark skies. Wow! Since it appears to have been discovered on day one of the outburst, my hunch is that it will brighten even further.

I opened up the view a little more here and made a reverse "black stars on white" for clarity. Stars are shown to 9th magnitude. Magnitudes shown for 4 stars near the nova. The nova's precise position is RA 20 h 23' 31", Dec. +20 deg. 46'. Created with Chris Marriott's SkyMap — Here’s a reverse “black stars on white” map some observers prefer for greater clarity. Stars are shown to 9th magnitude. Tycho visual magnitudes shown for 4 stars near the nova. The nova’s precise position is RA 20 h 23′ 31″, Dec. +20 deg. 46′. Created with Chris Marriott’s SkyMap

The only way to know is to go out for a look. I’ve prepared a couple charts you can use to help you find and follow our new guest. The charts show stars down to about 9th magnitude, the limit for 50mm binoculars under dark skies. The numbers on the chart are magnitudes (with decimals omitted, thus 80 = 8.0 magnitude) so you can approximate its brightness and follow the ups and downs of the star’s behavior in the coming nights.

Despite the name, a nova is not truly new but an explosion on a star otherwise too faint for anyone to have noticed. A nova occurs in a close binary star system, where a small but extremely dense and massive (for its size) white dwarf grabs hydrogen gas from its closely orbiting companion. After swirling about in a disk around the dwarf, it’s funneled down to the star’s 150,000 degree F surface where gravity compacts and heats the gas until it detonates like a bazillion thermonuclear bombs. Suddenly, a faint star that wasn’t on anyone’s radar vaults a dozen magnitudes to become a standout “new star”.

Model of a nova in the making. A white dwarf star pulls matter from its bloated red giant companion into a whirling disk. Material funnels to the surface where it later explodes. Credit: NASA/CXC/M. Weiss

Novae can rise in brightness from 7 to 16 magnitudes, the equivalent of 50,000 to 100,000 times brighter than the sun, in just a few days. Meanwhile the gas they expel in the blast travels away from the binary at up to 2,000 miles per second. This one big boom! Unlike a supernova explosion, the star survives, perhaps to “go nova” again someday.

Closer view yet showing a circle with a field of view of about 2 degrees. Stellarium — Closer view yet of the apparent nova showing a circle with a field of view of about 2 degrees. Stellarium

I’ll update with links to other charts in the coming day or two, so check back.

See info on the Remanzacco Observatory website about their followup images of the nova.

August 14, 2013December 23, 2015 by Nancy Atkinson

Satellite Watches Dust from Chelyabinsk Meteor Spread Around the Northern Hemisphere

Model and satellite data show that four days after the bolide explosion, the faster, higher portion of the plume (red) had snaked its way entirely around the northern hemisphere and back to Chelyabinsk, Russia. Image Credit: NASA's Goddard Space Flight Center Scientific Visualization

When a meteor weighing 10,000 metric tons exploded 22.5 km (14 miles) above Chelyabinsk, Russia on Feb. 15, 2013, the news of the event spread quickly around the world. But that’s not all that circulated around the world. The explosion also deposited hundreds of tons of dust in Earth’s stratosphere, and NASA’s Suomi NPP satellite was in the right place to be able to track the meteor plume for several months. What it saw was that the plume from the explosion spread out and wound its way entirely around the northern hemisphere within four days.

The bolide, measuring 59 feet (18 meters) across, slipped quietly into Earth’s atmosphere at 41,600 mph (18.6 kilometers per second). When the meteor hit the atmosphere, the air in front of it compressed quickly, heating up equally as quick so that it began to heat up the surface of the meteor. This created the tail of burning rock that was seen in the many videos that emerged of the event. Eventually, the space rock exploded, releasing more than 30 times the energy from the atom bomb that destroyed Hiroshima. For comparison, the ground-impacting meteor that triggered mass extinctions, including the dinosaurs, measured about 10 km (6 miles) across and released about 1 billion times the energy of the atom bomb.

Atmospheric physicist Nick Gorkavyi from Goddard Space Flight Center, who works with the Suomi satellite, had more than just a scientific interest in the event. His hometown is Chelyabinsk.

“We wanted to know if our satellite could detect the meteor dust,” said Gorkavyi, who led the study, which has been accepted for publication in the journal Geophysical Research Letters. “Indeed, we saw the formation of a new dust belt in Earth’s stratosphere, and achieved the first space-based observation of the long-term evolution of a bolide plume.”

The team said they have now made unprecedented measurements of how the dust from the meteor explosion formed a thin but cohesive and persistent stratospheric dust belt.

About 3.5 hours after the initial explosion, the Ozone Mapping Profiling Suite instrument’s Limb Profiler on the NASA-NOAA Suomi National Polar-orbiting Partnership satellite detected the plume high in the atmosphere at an altitude of about 40 km (25 miles), quickly moving east at about 300 km/h (190 mph).

The day after the explosion, the satellite detected the plume continuing its eastward flow in the jet and reaching the Aleutian Islands. Larger, heavier particles began to lose altitude and speed, while their smaller, lighter counterparts stayed aloft and retained speed – consistent with wind speed variations at the different altitudes.

By Feb. 19, four days after the explosion, the faster, higher portion of the plume had snaked its way entirely around the Northern Hemisphere and back to Chelyabinsk. But the plume’s evolution continued: At least three months later, a detectable belt of bolide dust persisted around the planet.

Gorkavyi and colleagues combined a series of satellite measurements with atmospheric models to simulate how the plume from the bolide explosion evolved as the stratospheric jet stream carried it around the Northern Hemisphere.

“Thirty years ago, we could only state that the plume was embedded in the stratospheric jet stream,” said Paul Newman, chief scientist for Goddard’s Atmospheric Science Lab. “Today, our models allow us to precisely trace the bolide and understand its evolution as it moves around the globe.”

NASA says the full implications of the study remain to be seen. Scientists have estimated that every day, about 30 metric tons of small material from space encounters Earth and is suspended high in the atmosphere. Now with the satellite technology that’s capable of more precisely measuring small atmospheric particles, scientists should be able to provide better estimates of how much cosmic dust enters Earth’s atmosphere and how this debris might influence stratospheric and mesospheric clouds.

It will also provide information on how common bolide events like the Chelyabinsk explosion might be, since many might occur over oceans or unpopulated areas.

“Now in the space age, with all of this technology, we can achieve a very different level of understanding of injection and evolution of meteor dust in atmosphere,” Gorkavyi said. “Of course, the Chelyabinsk bolide is much smaller than the ‘dinosaurs killer,’ and this is good: We have the unique opportunity to safely study a potentially very dangerous type of event.”

Source: NASA

August 14, 2013April 8, 2018 by Nancy Atkinson

Two Beautiful Timelapse Videos of the 2013 Perseid Meteor Shower

Composite image of the Perseid Meteor Shower radiant, from the Mount Lemmon SkyCenter in Arizona. Credit and copyright: Adam Block.

We’re still swooning over the great images and videos coming in from this year’s Perseid Meteor Shower. Here are a couple of timelapse videos just in today: the first is from P-M Hedén showing 25 Perseid meteors, but you can also see Noctilucent clouds, a faint Aurora Borealis, airglow, satellites passing over and lightning. “It was a magic night!,” P-M said.

See another view from the Mount Lemmon SkyCenter in Arizona, below:

This timelapse was created by Adam Block and shows a few hours of the experience guests at the Mount Lemmon SkyCenter had on August 11/12, 2013 during the Perseids: they could look through the 0.8m Schulman telescope and enjoy being outside to see the meteors streaking overhead. Flashlights and other sources illuminate the ground and the observatory. Find out more about the observatory here.

August 14, 2013December 23, 2015 by David Dickinson

The USAF’s ‘Space Fence’ Surveillance System: Another Victim of Sequestration

Times are getting tougher in the battle to track space debris. A key asset in the fight to follow and monitor space junk is getting the axe on October 1st of this year. United States Air Force General and commander of Air Force Space Command William Shelton has ordered that the Air Force Space Surveillance System, informally known as Space Fence will be deactivated. The General also directed all related sites across the southern United States to prepare for closure.

This shutdown will be automatically triggered due to the U.S. Air Force electing not to renew its fifth year contract with Five Rivers Services, the Colorado Springs-based LLC that was awarded the contract for the day-to-day management of the Space Fence surveillance system in 2009.

To be sure, the Space Fence system was an aging one and is overdue for an upgrade and replacement.

The Space Fence system was first brought on line in the early days of the Space Age in the 1961. Space Fence was originally known as the Naval Space Surveillance (NAVSPASUR) system until passing into the custody of the U.S. Air Force’s 20^th Space Control Squadron in late 2004. Space Fence is a series of multi-static VHF receiving and transmitting sites strung out across the continental United States at latitude 33° north ranging from California to Georgia.

The Worldwide Space Surveillance Network, including Space Fence across the southern United States. (Credit: the U.S. Department of Defense).

Space Fence is part of the greater Space Surveillance Network, and comprises about 40% of the overall observations of space debris and hardware in orbit carried out by the U.S. Air Force. Space Fence is also a unique asset in the battle to track space junk and dangerous debris, as it gives users an “uncued” tracking ability. This means that it’s constantly “on” and tracking objects that pass overhead without being specifically assigned to do so.

Space Fence also has the unique capability to track objects down to 10 centimeters in size out to a distance of 30,000 kilometres. For contrast, the average CubeSat is 10 centimetres on a side, and the tracking capability is out to about 67% of the distance to geosynchronous orbit.

Exact capabilities of the Space Fence have always been classified, but the master transmitter based at Lake Kickapoo, Texas is believed to be the most powerful continuous wave facility in the world, projecting at 768 kilowatts on a frequency of 216.97927 MHz. The original design plans may have called for a setup twice as powerful.

A replacement for Space Fence that will utilize a new and upgraded S-Band radar system is in the works, but ironically, that too is being held up pending review due to the sequestration. Right now, the Department of Defense is preparing for various scenarios that may see its budget slashed by 150 to 500 billion dollars over the next 10 years.

The control center display of the prototype for the next generation Space Fence. (Credit: Lockheed Martin).

The U.S. Air Force has already spent $500 million to design the next generation Space Fence, and awarded contracts to Raytheon, Northrop Grumman and Lockheed Martin in 2009 for its eventual construction.

The eventual $3 billion dollar construction contract is on hold, like so many DoD programs, pending assessment by the Strategic Choices and Management Review, ordered by Secretary of Defense Chuck Hagel earlier this year.

“The AFSSS is much less capable than the space fence radar planned for Kwajalein Island in the Republic of the Marshall Islands,” stated General Shelton in a recent U.S. Air Force press release. “In fact, it’s apples and oranges in trying to compare the two systems.”

One thing’s for certain. There will be a definite capability gap when it comes to tracking space debris starting on October 1^st until the next generation Space Fence comes online, which may be years in the future.

In the near term, Air Force Space Command officials have stated that a “solid space situational awareness” will be maintained by utilizing the space surveillance radar at Eglin Air Force Base in the Florida panhandle and the Perimeter Acquisition Radar Characterization System at Cavalier Air Force Station in North Dakota.

We’ve written about the mounting hazards posed by space debris before. Just earlier this year, two satellites were partially damaged due to space debris. Space junk poses a grave risk to the residents of the International Space Station, which must perform periodic Debris Avoidance Maneuvers (DAMs) to avoid collisions. Astronauts have spotted damage on solar arrays and handrails on the ISS due to micro-meteoroids and space junk. And on more than one occasion, the ISS crew has sat out a debris conjunction that was too close to call in their Soyuz spacecraft, ready to evacuate if necessary.

In 2009, a collision between Iridium 33 and the defunct Cosmos 2251 satellite spread debris across low Earth orbit. In 2007, a Chinese anti-satellite missile test also showered low Earth orbit with more of the same. Ironically, Space Fence was crucial in characterizing both events.

Satellites, such as NanoSail-D2, have demonstrated the capability to use solar sails to hasten reentry at the end of a satellites’ useful life, but we’re a long ways from seeing this capability standard on every satellite.

Amateurs will be affected by the closure of Space Fence as well. Space Weather Radio relies on ham radio operators, who listen for the “pings” generated by the Space Fence radar off of meteors, satellites and spacecraft.

“When combined with the new Joint Space Operations Center’s high-performance computing environment, the new fence will truly represent a quantum leap forward in space situational awareness for the nation,” General Shelton said.

But for now, it’s a brave and uncertain world, as Congress searches for the funds to bring this new resource online. Perhaps the old system will be rescued at the 11^th hour, or perhaps the hazards of space junk will expedite the implementation of the new system. Should we pass the hat around to “Save Space Fence?”

August 14, 2013December 23, 2015 by Jason Major

An Occult Occurrence: Saturn’s Moon Iapetus Blocks a Background Star

Animation of Iapetus briefly blocking a distant bright object. (NASA/JPL-Caltech/SSI. Assembled by Jason Major.)

It’s a cosmic cover-up! No, don’t put your tinfoil* hats on, this isn’t a conspiracy — it’s just Saturn’s moon Iapetus drifting in front of the bright star Gamma Orionis (aka Bellatrix) captured on Cassini’s narrow-angle camera on August 10, 2013.

Such an event is called an occultation, a term used in astronomy whenever light from one object is blocked by another — specifically when something visually larger moves in front of something apparently smaller. (The word occult means to hide or conceal… nothing mystical implied!)

The animation above was assembled from 19 raw images publicly available on the JPL Cassini mission site, stacked in Photoshop and exported as a gif. They’ve been rotated 90º from the originals but otherwise they’re right from Cassini’s camera.

Iapetus, seen above as just a thin crescent, is best known for its two-toned appearance. One half of the 914-mile-wide moon is bright and icy, the other coated with a layer of dark reddish material, giving it a real “yin-yang” appearance. (Ok, I guess that’s a little mystical. But purely coincidental.)

The Tao of Iapetus (NASA/JPL-Caltech/SSI)

It’s thought that the dark material originates from a more distant moon, Phoebe, which is being pelted by micrometeorites and shedding its surface out into orbit around Saturn, which eventually gets scooped up by the backwards-orbiting Iapetus.

The difference in albedo affects how Iapetus absorbs solar radiation too, causing the water ice beneath the darker material to evaporate over the course of its 79-Earth-day rotation and migrate around its surface, creating a sort of positive feedback loop.

While neat to look at, occultations are important to science because they provide a way to briefly peer into a world’s atmosphere (or in a small moon’s case, exosphere). Watching how light behaves as it passes behind the limb of a planet or moon lets researchers learn details of the air around it — however tenuous — pretty much for free… no probes or flybys needed!

The occulted star above is Bellatrix, the 1.6-magnitude star that marks Orion’s left shoulder.

Iapetus orbits Saturn at the considerable distance of 2,212,889 miles (3,561,300 km). Learn more about Iapetus here, and as always you can find more fantastic Cassini images from Carolyn Porco’s team at the Space Science Institute in Boulder, Colorado at the CICLOPS site here.

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*Do they still make foil out of tin any more?

August 14, 2013December 23, 2015 by Elizabeth Howell

These 12 Asteroids Are The Easiest Ones To Bring Back To Earth

In February 2013, asteroid DA 2014 safely passed by the Earth. There are several proposals abounding about bringing asteroids closer to our planet to better examine their structure. Credit: NASA/JPL-Caltech

As NASA works through proposals for an asteroid retrieval mission, a new paper shows that there are other research groups considering which asteroids to pick first.

One scientific team has identified 12 “Easily Retrievable Objects” in our solar system that are circling the sun and would not cost too much to retrieve (in relative terms, of course!)

The definition of an ERO is an object that can be captured and brought back to a stable gravitational point near Earth (called a Lagrange point, or more specifically the L1/L2 points between the sun and the Earth.) The change in speed necessary in these objects to make them easily retrievable is “arbitrarily” set at 500 meters per second (1,641 feet/second) or less, the researchers stated.

Image of asteroid Vesta calculated from a shape model, showing a tilted view of the topography of the south polar region. This perspective shows the topography, but removes the overall curvature of Vesta, as if the giant asteroid were flat and not rounded. Credit: NASA

Catching the objects wouldn’t just be a technology demonstration, but also could shed some light into how the solar system formed. Asteroids are generally considered leftovers of the early days of the neighborhood; under our current understanding of the solar system’s history, a spinning disc of gas and dust gradually clumped into rocks and other small objects, which eventually crashed into each other and formed planets.

Also, steering these objects around has another benefit: teaching humans how to deflect potentially hazardous asteroids from smacking into the Earth and causing damage. As we were reminded about earlier this year, even smaller rocks such as the one that broke up over a portion of Russia can be hazardous.

Concept of NASA spacecraft with Asteroid capture mechanism deployed to redirect a small space rock to a stable lunar orbit for later study by astronauts aboard Orion crew capsule. Credit: NASA.

There are at least a couple of big limitations to the plan. The first is to make sure not to put the asteroid in a path that would hit the Earth. The second is that he L1 and L2 points are somewhat unstable, so over time the asteroid would drift from its spot. It would need a nudge every so often to keep it in that location.

That said, NASA is taking a serious look at the matter, as well as two groups that would like to mine asteroids: Planetary Resources and Deep Space Industries.

For the curious, this is the complete list of possible asteroids: 2006 RH120, 2010 VQ98, 2007 UN12, 2010 UE51, 2008 EA9, 2011 UD21, 2009 BD, 2008 UA 202, 2011 BL45, 2011 MD, 2000 SG344 and 1991 VG.

More details are available in the paper, “Easily retrievable objects among the NEO population“, which is published in the August 2013 edition of Celestial Mechanics and Dynamical Astronomy. A preprint version is also available on Arxiv.