Astronomy Archives

October 1, 2013December 23, 2015 by David Dickinson

Uranus: A Guide to its 2013 Opposition

Up for a challenge? Got a big 12” light bucket of a Dobsonian telescope and looking for something new to point it at? This week, as the Moon reaches New phase on October 4^th and stays safely out of the late evening sky, why not check out Uranus and its retinue of moons. And yes, we’ve heard just about ALL the Uranus jokes —its pronounced yer-in-us, thank you very much — but feel free to attempt to pen an original if you must.

Now, back to astronomy. Uranus reaches opposition for 2013 on Thursday, October 3^rd at 14:00 Universal Time. Opposition is the point in time that an outer planet rises as the Sun sets. In the case of Uranus, its opposition dates advance forward by about 4-5 days each year.

This also marks the start of the best time to hunt for the planet among the star fields of the constellation Pisces. Uranus will reach its maximum elevation above the southern horizon for northern hemisphere viewers for early October around local midnight. For observers south of the equator, Uranus will transit to the north. Incidentally, Uranus also currently sits near the equinoctial point occupied by the Sun during the March equinox, making viewing opportunities nearly equal for both hemispheres.

Uranus is 19.04 astronomical units distant during opposition 2013, or about 158 light minutes away. Shining at magnitude +5.8, Uranus presents a tiny blue-green disk just under 4” across at opposition.

Uranus currently lies six degrees SW of the +4.4 magnitude star Delta Piscium, on the border of the constellations Pisces and Cetus. Uranus will actually be crossing once again into the non-zodiacal constellation of Cetus later this year.

Discovered in 1781 by Sir William Herschel, Uranus has only completed 2 full orbits (2.75 to be precise) in its 84.3 year trips about the Sun. We can be thankful that William’s proposal to name the planet Geogium Sidus after his benefactor King George the III didn’t stick!

The path of Uranus into Cetus. Created by the author using Starry Night Education software.

At opposition, Uranus will be located at;

Right Ascension: 0h 40’

Declination: +3° 25’

Five of the 27 known moons of Uranus are also within the grasp of a moderate-sized backyard scope as well. The trick is to catch ‘em near greatest elongation, when they appear farthest from the “glare of Uranus” (hey, there’s a freebie for a snicker or two). An eyepiece equipped with an occulting bar, or simply nudging Uranus out of the field of view can also help.

With magnitudes ranging from +13 to +16, the moons of Uranus are similar in brightness to Neptune’s large moon Triton or the tiny world Pluto.

The five brightest moons of Uranus and their respective maximum elongations are:

And here’s a handy finder chart for the coming month, showing maximum elongations for each:

A corkscrew graph featuring the greatest elongations for the five brightest moons of Uranus. (Created by Ed Kotapish using PDS Rings Node). — A corkscrew graph featuring the greatest elongations for the five brightest moons of Uranus through October. (Created by Ed Kotapish using PDS Rings Node).

The first two moons were named Titania and Oberon by William’s son John after characters from William Shakespeare’s A Mid-Summer Night’s Dream. William discovered the first two moons of Uranus on the night of January 11^th, 1787 using his 49.5” reflector. His scopes were so advanced for his day, that it wasn’t until over a half a century later that William Lassell discovered Umbriel and Ariel using the Liverpool Observatory’s 24” reflector in 1851.

Gerard Kuiper would later add tiny Miranda to the list, nabbing it with the McDonald Observatory’s 82” Otto Struve Telescope in 1948. We would then have to wait until Voyager 2’s 1986 flyby of Uranus in 1986 to add more. To date, Voyager 2 remains the only spacecraft to visit Uranus and Neptune.

The current convention established by the International Astronomical Union is to name the moons of Uranus after characters from the plays of Shakespeare or Alexander Pope’s Rape of the Lock.

There’s still a wide range of names in said literature to choose from!

It’s interesting to note that the orbits of the moons of Uranus are also currently tipped open about 25 degrees to our line of sight and widening. They were edge on in December 2007, and will be perpendicular to our Earthly view come 2029, after which they’ll head back to edge on in 2049. This is because Uranus and the orbits of its moons are tipped at a 97 degree angle relative to the planet’s orbit. This is why elongations for its moons are often quoted it terms of “north and south” of the planet, rather than the familiar east and west. Shadow transits of the moons can occur with about a year and a half during plane-crossing seasons, but they’re ~42 years apart and tough to spot on the tiny disk of Uranus!

October 4th Starry Night Education — An example of the orientation of Uranus’s moons on October 4th, with Oberon at greatest elongation. Note that Miranda is the tiny unlabeled moon with the interior orbit. (Created by the author using Starry Night Education software).

Uranus also reached aphelion in 2009 at 20.099 AU from the Sun —we’re still at the farther end of the spectrum, as oppositions of Uranus can range from 19.09 to 17.28 AU distant.

Uranus will rise earlier on each successive evening until it reaches quadrature at the end of the year on December 30^th. At this point, it’ll be roughly due south at local sunset. Keep in mind, there’s also another ice giant worth hunting for in the adjacent constellation of Aquarius named Neptune.

So ignore those bad puns, and be sure to take out that 10” (scope, that is) and point it at Uranus!

October 1, 2013December 23, 2015 by Jason Major

Navigating the Cosmos by Quasar

A quasar resides in the hub of the nearby galaxy NGC 4438. Credit: NASA/ESA, Jeffrey Kenney (Yale University), Elizabeth Yale (Yale University)

50 million light-years away a quasar resides in the hub of galaxy NGC 4438, an incredibly bright source of light and radiation that’s the result of a supermassive black hole actively feeding on nearby gas and dust (and pretty much anything else that ventures too closely.) Shining with the energy of 1,000 Milky Ways, this quasar — and others like it — are the brightest objects in the visible Universe… so bright, in fact, that they are used as beacons for interplanetary navigation by various exploration spacecraft.

“I must go down to the seas again, to the lonely sea and the sky,

And all I ask is a tall ship and a star to steer her by.”

– John Masefield, “Sea Fever”

Deep-space missions require precise navigation, especially when approaching bodies such as Mars, Venus, or comets. It’s often necessary to pinpoint a spacecraft traveling 100 million km from Earth to within just 1 km. To achieve this level of accuracy, experts use quasars – the most luminous objects known in the Universe – as beacons in a technique known as Delta-Differential One-Way Ranging, or delta-DOR.

Delta-DOR uses two antennas in distant locations on Earth (such as Goldstone in California and Canberra in Australia) to simultaneously track a transmitting spacecraft in order to measure the time difference (delay) between signals arriving at the two stations.

Unfortunately the delay can be affected by several sources of error, such as the radio waves traveling through the troposphere, ionosphere, and solar plasma, as well as clock instabilities at the ground stations.

Delta-DOR corrects these errors by tracking a quasar that is located near the spacecraft for calibration — usually within ten degrees. The chosen quasar’s direction is already known extremely well through astronomical measurements, typically to closer than 50 billionths of a degree (one nanoradian, or 0.208533 milliarcsecond). The delay time of the quasar is subtracted from that of the spacecraft’s, providing the delta-DOR measurement and allowing for amazingly high-precision navigation across long distances.

“Quasar locations define a reference system. They enable engineers to improve the precision of the measurements taken by ground stations and improve the accuracy of the direction to the spacecraft to an order of a millionth of a degree.”

– Frank Budnik, ESA flight dynamics expert

So even though the quasar in NGC 4438 is located 50 million light-years from Earth, it can help engineers position a spacecraft located 100 million kilometers away to an accuracy of several hundred meters. Now that’s a star to steer her by!

Read more about Delta-DOR here and here.

Source: ESA Operations

October 1, 2013December 23, 2015 by Elizabeth Howell

This Very Old Cosmic Light Has A Bend To It

Artist's impression of how huge cosmic structures deflect photons in the cosmic microwave background (CMB). Credit: ESA and the Planck Collaboration

Leftover radiation from the Big Bang — that expansion that kick-started the universe — can be bent by huge cosmic structures, just like other light that we see in the universe. While the finding seems esoteric at first glance, scientists say the discovery could pave the way for finding a similar kind of signal that indicate the presence of gravitational waves in the moments after the universe was born.

That light is called the cosmic microwave background and is the radiation that was visible when the universe became transparent to radiation, 380,000 years after the Big Bang. A tiny bit of the CMB is polarized. There are two types of polarized light in the CMB: E-modes (first detected in 2002) and B-modes (which were just detected using a telescope in Antarctica and ESA’s Herschel space observatory.

“[B-modes] can arise in two ways,” the European Space Agency wrote in a press release.

“The first involves adding a twist to the light as it crosses the Universe and is deflected by galaxies and dark matter – a phenomenon known as gravitational lensing. The second has its roots buried deep in the mechanics of a very rapid phase of enormous expansion of the Universe, which cosmologists believe happened just a tiny fraction of a second after the Big Bang – ‘inflation’.”

More results are on the way from ESA’s Planck telescope in 2014, at which point scientists hope to see this B-mode of the second type. For now, check out the full study in Physical Review Letters. There is also a preprint version available on Arxiv.

Sources: ESA and ESA Herschel

October 1, 2013December 23, 2015 by Elizabeth Howell

What Does The Government Shutdown Mean For NASA?

The MAVEN missions ‘Going to Mars’ campaign invites the public to submit names and poems which will be included on a special DVD. The DVD will be adhered to the MAVEN spacecraft and launched to Mars on Nov. 18, 2013. Credit: NASA/GSFC

A forthcoming NASA launch to Mars could be in danger of losing its launch window should a shutdown in the United States federal government that began today (Oct. 1) continue for a while. That’s just one of the ways in which NASA is affected amid a lapse of funding that is affecting all government agencies and an untold number of government contractors.

Around 97% of NASA’s 18,000 employees are off the job. Twitter, Facebook, Google Plus and other social media accounts are going dark. NASA’s website is being pulled offline. NASA Television has also ceased broadcasting.

Beyond the agency’s public face, activities ranging from certain commercial crew payouts, to conference attendance, to scientific work will cease. Awards and scholarship approvals will be delayed.

“NASA will shut down almost entirely,” said President Barack Obama in a speech late Monday (Sept. 30).

In addition to the agency’s public relations activities, NASA is planning to launch the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft to Mars in November to examine the Red Planet’s atmosphere. There are all sorts of questions vexing scientists concerning that planet, with one of the most prominent ones being why the atmosphere thinned over the years.

Media reports indicate that if the shutdown is lengthy, MAVEN could miss the launch window and have to try again in 2016.

“A shutdown could delay the pre-launch processing currently under way with a possible impact to the scheduled Nov. 18 launch date,” Dwayne Brown, a NASA senior public affairs officer at NASA, told The Planetary Society in a story published yesterday (Sept. 30). The launch window extends for several weeks beyond that time, however.

The 3% of NASA employees who are deemed essential will work without pay until the situation is resolved. These are some of the things that will continue:

The International Space Station. Credit: NASA

International Space Station monitoring will be maintained, but with the bare minimum of ground crew. (NASA will cease regular updates of the astronauts’ activities during the furlough, although we presume if something urgent happened there would be an update.)
Robotic missions that are already in operation — think the Cassini spacecraft circling Saturn, or the Lunar Atmosphere and Dust Environment Explorer (LADEE) winging its way to the moon — will have small crews making sure that they are functioning properly. No scientific analysis will be conducted, though.
Certain other programs will continue if a shutdown would be detrimental to their performance. Space News reports that the much-delayed James Webb Space Telescope will be among them, as some of its instruments are undergoing cryogenic vacuum testing at the Goddard Space Flight Center.
Update, 1:09 p.m. EDT: Several missions run out of the Jet Propulsion Laboratory and Applied Physics Laboratory are running as usual for at least the next week because these facilities are running under contracted money from NASA and still have funds in the bank. According to the Planetary Society’s Emily Lakdawalla: “At JPL, that includes: Curiosity; Opportunity; Odyssey; Mars Reconnaissance Orbiter; Cassini; Dawn; Juno; Spitzer; the Voyagers; and WISE, among many others. At APL, that includes MESSENGER and New Horizons. It also includes the Deep Space Network.”

Additional Update, 2:09 p.m. EDT: The HiRISE twitter account just replied to inquiries from several space journalists that they will be “open for business” as usual, which is great news since the Mars Reconnaissance Orbiter made an audacious attempt to take images of Comet ISON during the comet’s closest approach to Mars today. We’ll provide any news and updates on images as they become available, but the HiRISE team said getting the images back to Earth and processing them may take a day or two.

HiRISE is still open for business and updates will continue as usual.

— HiRISE (@HiRISE) October 1, 2013

Many observers noted that NASA is marking its 55th anniversary today by shutting down its activities. There’s no word yet on when the deadlock in Congress will be resolved. The last two shutdowns in 1995 and 1996 (which began in the middle of the STS-74 shuttle mission to Mir) lasted several weeks.

October 1, 2013December 23, 2015 by Elizabeth Howell

First Cloudy Alien Planet Spotted From Earth

Cloud map of Kepler-7b (left) in comparison to Jupiter (right). Credit: NASA/JPL-Caltech/MIT

Call it cloudy with a low chance of meatballs. The alien world Kepler-7b — a very reflective world in big telescopes — has clouds in its upper atmosphere. And scientists have actually been able to map those out, despite the planet’s great distance from Earth (at least 1,000 light-years away.)

It’s the first time scientists have been able to map out clouds on a world outside of the solar system. If we can see clouds, then we can begin to think about what a planet’s climate will be, making this an important milestone in understanding the conditions on other worlds.

“Kepler-7b reflects much more light than most giant planets we’ve found, which we attribute to clouds in the upper atmosphere,” stated Thomas Barclay, Kepler scientist at NASA’s Ames Research Center. “Unlike those on Earth, the cloud patterns on this planet do not seem to change much over time — it has a remarkably stable climate.”

Illustration of the Kepler spacecraft (NASA/Kepler mission/Wendy Stenzel)

Here’s how scientists got it done:

Preliminary observations with the Kepler space telescope –which was designed to hunt planets until a second reaction wheel failed earlier this year — found “moon-like phases” on Kepler-7b. These showed a bright spot on the western hemisphere.
NASA’s Spitzer Space Telescope measured Kepler-7b’s temperature using infrared light, calculating it at between 1,500 and 1,800 degrees Fahrenheit (815 and 982 degrees Celsius.)
Something was clearly going on, as the planet is extremely close to its star; only 0.06 Earth-sun distances away. The temperature was too cool. They figured out that the light was reflected off cloud tops on the planet’s west side.

Another cool fact — Kepler-7b, like Saturn, would float if it was put in a big enough tub of water!

You can read more details in the technical paper online here. The study, which was led by the Massachusetts Institute of Technology, has been accepted to the Astrophysical Journal, but not published yet.

Source: NASA

October 1, 2013December 23, 2015 by Carnival of Space

Carnival of Space #321

Carnival of Space. Image by Jason Major.

This week’s Carnival of Space is hosted by Stefan Lamoureux at his Links Through Space blog.

Click here to read Carnival of Space #321.

And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, sign up to be a host. Send an email to the above address.

September 30, 2013April 26, 2016 by Elizabeth Howell

Are Black Holes Hairy, Or Better Described By Clean Physics?

Black holes are a spot in the universe where you won’t see the sun shine in, to paraphrase that 1960s rock-musical Hair. But speaking of “hair”, a group of scientists says these singularities may have matter (sometimes referred to as “hair”) that could affect how they appear.

This is a tangled concept to figure out (so to speak), so let’s unpack what the new study in Physical Review Letters means.

When black hole understanding was still in its infancy in the scientific literature, physicist John Wheeler wrote a phrase that is now famous among scientists in that field: “Black holes have no hair.” His phrase referred to how black holes are defined, which he believed came down to only two factors: their mass, and their angular momentum, or the rotation velocity of the hole. (Some sources also say electric charge was included as a third factor.)

Say you have a black hole that was created out of a huge star that imploded. Even though the star itself had distinctive properties, this theory says they would vanish in a black hole. So to take that to a generality, Wheeler’s phrase said all black holes are essentially the same.

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

This understanding of black holes dates back to 1963, arising back to a “clean” black hole model first published by Roy Kerr. The new study agrees that Kerr’s work from 50 years ago works with general relativity, a theory from Einstein that (in very simple terms) says the laws of nature are consistent throughout the universe. (More at this past Universe Today article.) As the theory pertains to black holes, strong sources of gravity bend space and time.

Kerr’s theory, however, does not agree with extensions of Einstein’s work, the scientists said. These extensions are known as scalar-tensor theories and there are several variations on this topic. The physics deals with the interactions between two different types of fields, scalar and tensor. Scalar fields, according to this Massachusetts Institute of Technology paper, assign values for every point of space observed. (Think a temperature map of Mars). Tensor fields measure these variables with relation to each other.

This artist’s impression shows the surroundings of the supermassive black hole at the heart of the active galaxy NGC 3783 in the southern constellation of Centaurus (The Centaur). New observations using the Very Large Telescope Interferometer at ESO’s Paranal Observatory in Chile have revealed not only the torus of hot dust around the black hole but also a wind of cool material in the polar regions. Credit: ESO/M. Kornmesser — This artist’s impression shows the surroundings of the supermassive black hole at the heart of the active galaxy NGC 3783 in the southern constellation of Centaurus (The Centaur). Credit: ESO/M. Kornmesser

The science team included Thomas Sotiriou, a physicist at the International School for Advanced Studies in Italy.

His team, Sotiriou said in a statement, “focused on the matter that normally surrounds realistic black holes, those observed by astrophysicists. This matter forces the pure and simple black hole hypothesized by Kerr to develop a new ‘charge’ (the hair, as we call it) which anchors it to the surrounding matter, and probably to the entire universe.

“According to our calculations,” he added, “the growth of the black hole’s hair is accompanied by the emission of distinctive gravitational waves.”

This model hasn’t been proved yet in by measurements, so this will be something for astronomical instruments to watch for in the coming decades. It also should be noted that other scientists have found different problems with the clean black-hole theory, which you can check out if you’re so inclined.

In the meantime, you can read the new study at this link. There is also a prepublished version available.

Source: Scuola Internzaionale Superiore di Studi Avanzati

September 28, 2013December 23, 2015 by Bob King

Comet ISON Goes Green

Comet ISON, photographed with a 3-inch (80mm) telescope on this morning Sept. 28 shows a circular green coma and short dust tail pointing northwest. Click to enlarge. Credit: Michael Jaeger

As NASA and the European Space Agency prepare their remote photojournalists – Mars Express, Mars Reconnaissance Orbiter and the Curiosity and Opportunity rovers – to capture photos of Comet ISON’s flyby of Mars early next week, amateur astronomers continue to monitor and photograph the comet from backyard observatories across the blue Earth. Several recent color photos show ISON’s bright head or nucleus at the center of a puffy, green coma. Green’s a good omen – a sign the comet’s getting more active as it enters the realm of the inner solar system and sun’s embrace.

Another photo of a "greening" Comet ISON taken on Sept. 24 with a 17-inch (43-cm) telescope. Click to enlarge. Credit: Damian Peach — *Another great photo of the “greening” of Comet ISON taken on Sept. 24 with a 17-inch (43-cm) telescope. Click to enlarge. Credit: Damian Peach*

Sunlight beating down on the comet’s nucleus (core) vaporizes dust-impregnated ice to form a cloud or coma, a temporary atmosphere of water vapor, dust, carbon dioxide, ammonia and other gases. Once liberated , the tenuous haze of comet stuff rapidly expands into a huge spherical cloud centered on the nucleus. Comas are typically hundreds of thousands of miles across but are so rarified you could wave your hand through one and not feel a thing. The Great Comet of 1811 sported one some 864,000 miles (1.4 million km) across, nearly the same diameter as the sun!

Among the materials released by solar heating are cyanogen and diatomic carbon. Both are colorless gases that fluoresce a delicious candy-apple green when excited by energetic ultraviolet light in sunlight.

*Sounds like a plan. Newspaper clipping from 1910.*

Cyanogen smells pleasantly of almonds, but it’s a poisonous gas composed of one atom each of carbon and nitrogen. Diatomic carbon or C2 is equally unpleasant. It’s a strong, corrosive acid found not only in comets but also created as a vapor in high-energy electric arcs. But nature has a way of taking the most unlikely things and fashioning them into something beautiful. If you’re concerned about the effects of cometary gas and dust on people, rest easy. They’re spread too thinly to touch us here on Earth. That didn’t stop swindlers from selling “comet pills” and gas masks to protect the public from poisoning during the 1910 return of Halley’s Comet. Earth passed through the tail for six hours on May 19 that year. Amazingly, those who took the pills survived … as did everyone else.

Comet ISON's location and approximate appearance on October 1 seen from the Curiosity Rover. ISON will pass only 6.7 million miles (10.8 million km) from Mars on Tuesday Oct. 1. Stellarium — *Comet ISON’s location and approximate appearance on October 1 seen from the Curiosity Rover. ISON will pass only 6.7 million miles (10.8 million km) from Mars on Tuesday Oct. 1. Stellarium*

While Comet ISON is still too faint for visual observers to discern its Caribbean glow, that will change as it beelines for the sun and brightens. If you could somehow wish yourself to Mars in the next few days, I suspect you’d easily see the green coma through a telescope. The comet – a naked eye object at magnitude 2.5-3 – glows low in the northern sky from the Curiosity rover’s vantage point 4.5 degrees south of the Martian equator.

Comet Hale-Bopp shows off its whitish dust tail and fainter, blue ion tail in early 1997. Credit: Bob King — *Comet Hale-Bopp shows off its bright dust tail and fainter, blue ion tail in early spring 1997. Credit: Bob King*

I’ve noticed that when a comet reaches about 7th magnitude, the green coloration becomes apparent in 8-inch (20 cm) and larger telescopes. Bright naked eye comets often display multiple subtle colors that change chameleon-like over time. Dust tails, formed when sunlight pushes dust particles downwind from the coma, glow pale yellow. Gusty solar winds sweep back molecules from the coma into a second “ion” tail that glows pale blue from jazzed up carbon monoxide ions fluorescing in solar UV.

The highlight of seeing the comet through the telescope was its brilliant, pea-like false nucleus glowing yellow from sunlit dust. The real comet nucleus – the actual comet – lies within the false nucleus and shrouded by dust. Drawing: Bob King — One of the highlights of seeing Comet L4 PANSTARRS through a small telescope was its brilliant, pea-like false nucleus glowing yellow from sunlit dust. The real comet nucleus – the actual comet – lies within the false nucleus and hidden by dust. Drawing: Bob King

During close encounters with the sun, millions of pounds of dust per day boil off a comet’s nucleus, forming a small, intensely bright, yellow-orange disk in the center of the coma called a false nucleus. Earlier this year, when Comet C/2011 L4 PANSTARRS emerged into the evening sky after perihelion, not only was its yellow tail apparent to binocular users but the brilliant false nucleus glowed a lovely shade of lemon in small telescopes.

With ISON diving much closer to the sun than L4 PANSTARRS, expect a full color palette in the coming weeks. While it may not be easy being green for Sesame Street’s Kermit the Frog, comets do it with aplomb.

September 26, 2013December 23, 2015 by David Dickinson

Bazinga: Mysterious Earth Orbiting Asteroid Turns Out to be Space Junk

The launch of Chan'ge-2 with 3rd stage (arrowed) now known as 2010 Q (Credit CALT).

Can’t find asteroid 2010 QW1 in the Minor Planet Database? No, the “Men in Black” didn’t secretly remove this Earth-orbiting asteroid from the listing… but recent top-notch detective work by astronomers did.

The mystery of this object all started back on August 23^rd of this year, when the PanSTARRS sky survey based on the summit of Haleakala on the island of Maui in Hawai’i spotted an asteroid that was given the provisional designation of 2013 QW1.

The object was in a wide-ranging orbit around the Earth, leading astronomers to wonder if it was a naturally captured asteroid or perhaps space debris from a previous launch. Either solution to the dilemma would be fascinating. Our large Moon keeps the Earth pretty well swept clear of debris, though a “second Moon,” however small, would be an interesting find. And if 2013 QW1 were to prove artificial, it just might be a piece of history.

The European Space Agency’s NEO Coordination Centre decided to take up the challenge. A call went out to track and observe the 2013 QW1, and a team led by Elisabetta Dotto of INAF-Observatorio di Roma & Maria Barucci & Davide Perna of the Observatoire de Paris managed to get time on the Italian Telescopio Nazaionale Galileo based at La Palma to obtain a spectrum of the object.

“It was a bit of a challenge, because the object was moving fast with respect to a typical NEO,” said Dr. Perna in a recent ESA press release.

The team used an instrument known as DOLORES to make the crucial measurements. DOLORES stands for the Device Optimized for LOw RESolution. The spectrum obtained in the early morning hours of August 25^th shows something much brighter than your typical asteroid, but is characteristic of a painted metallic object.

And thus, 2013 QW1 was removed from the ledger of NEO asteroids maintained by the IAU Minor Planet Center (MPEC). And the leading suspect? The third stage booster of a Chinese Long March 3C rocket that launched the Chang’e 2 spacecraft from Xichang, China on October 1^st, 2010.

Chang’e-2 entered lunar orbit 8 days after launch, and departed on June 8^th of the following year after studying and mapping the Moon. Chang’e-2 then went on to become the first spacecraft to directly reach the L2 Lagrange point 1.5 million kilometres beyond Earth from lunar orbit. The spacecraft also made the first flyby of NEO asteroid 4179 Toutatis on December 13^th of last year. The probe is estimated to continue functioning into 2014, and will be used to hone China’s ability to track objects in deep space.

The NORAD tracking identification assigned to the 3^rd stage booster that launched Chan’ge-2 is 2010-50B.

This sort of discovery is not without precedent.

The launch of Apollo 12, with the 2nd stage arrowed. (Credit: NASA). — The launch of Apollo 12, with the 3rd stage (arrowed) would one day be “asteroid Joo2E3”. (Credit: NASA).

On September 3^rd, 2002, amateur astronomer Bill Yeung discovered an asteroid tentatively designated J002E3. Subsequent studies revealed that the asteroid had a spectrum consistent with that of titanium oxide paint, a decidedly unasteroid-like coating for a space rock to sport. This was, however, a common veneer in use during the Apollo era, and it is now known that J002E3 is the S-IVB third stage booster that launched the second mission to land men on the Moon on November 14^th, 1969. Unlike other boosters, such as the one that launched Apollo 14, the Apollo 12 3^rd stage did not impact the Moon as part of seismic experiments. After a brief period as a “pseudo-moon” of the Earth, J002E3 was kicked out into solar orbit in June 2003 and may return to our neighborhood once again in the 2040s.

NASA’s Lunar Reconnaissance Orbiter has documented the lunar crash sites of these historic boosters. It’s of note that the Apollo 10 Lunar Module Snoopy remains discarded out in solar orbit as well, having been used as a dress rehearsal for the historic Apollo 11 landing. Apollo 10 never landed on the Moon. Efforts have been made by UK astronomer Nick Howes to recover it as well.

And there are more relics of the Space Age awaiting discovery. One of the first things we always check in the case of a pass by a newly discovered NEO closer than the Moon to the Earth is its history, to see if it matches up with any launches headed out beyond Earth orbit in the past.

And the upcoming Mars launches of MAVEN and India’s Mars Orbiter Mission in October & November will be the first to depart Earth orbit since 2011. These will give future generations of asteroid hunters new human-made space hardware to ponder.

The B612 Foundation’s asteroid-hunting Sentinel Space Telescope will also “up the game,” scouting for asteroids from a vantage point interior to the Earth’s orbit. Sentinel is slated for launch in 2016 atop a SpaceX Falcon 9 rocket.

And no, the fabled “Black Knight” satellite of UFO conspiracy buffs’ dreams is nowhere to be found.

What other fascinating relics of the Space Age lie are out there in the solar system, waiting to tell their tale?

September 26, 2013December 23, 2015 by Elizabeth Howell

This Neutron Star Behaves Just Like The Hulk

The Hulk (Bruce Banner), as portrayed in The Avengers. Credit: Marvel & Subs

When Bruce Banner gets angry, he gets big and green and strong and well, vengeful. The Hulk is the stuff of comic book legend and as Mark Ruffalo recently showed us in The Avengers, Banner’s/Hulk’s personality can transform on a dime.

Turns out rapid transformations are the case in astronomy, too! Scientists found a peculiar neutron star that can change from radio pulsar, to X-ray pulsar, back and forth. In the Hulk’s case, a big dose of gamma rays likely fuelled his ability to transform. This star’s superpowers, however, likely come from a companion star.

“What we’re seeing is a star that is the cosmic equivalent of ‘Dr. Jekyll and Mr. Hyde,’ with the ability to change from one form to its more intense counterpart with startling speed,” stated Scott Ransom, an astronomer at the National Radio Astronomy Observatory.

“Though we have known that X-ray binaries — some of which are observed as X-ray pulsars — can evolve over millions of years to become rapidly spinning radio pulsars, we were surprised to find one that seemed to swing so quickly between the two.”

A neutron star and its companion flipping between accretion (when it emits X-rays) and when accretion has stopped (when it emits radio pulses). Credit: Bill Saxton; NRAO/AUI/NSF. Animation by Elizabeth Howell

The star’s double personality came to light after astronomers made an accidental double-discovery. IGR J18245-2452, as the star is called, was flagged as a millisecond radio pulsar in 2005 using the National Science Foundation’s Robert C. Byrd Green Bank Telescope. Then this year, another team found an X-ray pulsar in the same region of the star cluster M28.

It took a little while to sort out the confusion, we’re sure, but eventually astronomers realized it was the same object behaving differently. That said, they were mighty confused: “This was particularly intriguing because radio pulses don’t come from an X-ray binary and the X-ray source has to be long gone before radio signals can emerge,” stated lead researcher Alessandro Papitto, who is with of Institute of Space Sciences in Catalunya (Institut d’Estudis Espacials de Catalunya) in Spain.

The key, it turns out, comes from the interplay with the star’s companion. Material doesn’t flow continuously, as astronomers previously believed is true of these system types, but in bunches. Starting and stopping the flow then led to swings in the behavior, making the star alternate between X-ray and radio emissions.

So to sum up what is happening:

– Neutron stars like IGR J18245-2452 are superdense star remnants that formed after supernovas. A teaspoon of this material is often cited as being as heavy as a mountain (but be careful, as mass and weight are different). Still, we can all understand this stuff is very dense and would take a superhero (Hulk?) to move.

– A neutron star that has a normal star nearby forms an X-ray binary, which happens when the neutron star poaches starstuff off its companion. When the material hits the neutron star, the stuff gets really hot and emits X-rays.

– When the material stops, magnetic fields on the neutron produce radio waves. These appear to blink on and off from the perspective of Earth, as the neutron rotates super-fast (several times a second).

In the case of IGR J18245-2452, it behaved like an X-ray binary star for about a month, stopped suddenly, and then sent out radio waves for a while before flipping back again. (A month is less than a blink in astronomical terms, when you recall the universe is 13.8 billion years old.)

To take the longer view, astronomers used to believe that X-ray binaries could evolve into radio emitters over time. Now, though, it appears a star can be these two things at almost the same time.

“During periods when the mass flow is less intense, the magnetic field sweeps away the gas and prevents it from reaching the surface and creating X-ray emission,” NASA stated. “With the region around the neutron star relatively gas free, radio signals can easily escape and astronomers detect a radio pulsar.”

A whole suite of telescopes in Earth and space contributed to this discovery, but of note: the X-ray source was first spotted with the International Gamma-Ray Astrophysics Laboratory (INTEGRAL). You can read more details in the paper published in Nature.

Sources: National Radio Astronomy Observatory and NASA