Expedition 36/37 Soyuz Commander Fyodor Yurchikhin of the Russian Federal Space Agency (Roscosmos), top, Flight Engineers: Luca Parmitano of the European Space Agency, center, and Karen Nyberg of NASA, bottom, wave farewell as they board the Soyuz rocket ahead of their launch to the International Space Station, Wednesday, May 29, 2013, Baikonur, Kazakhstan. Credit: NASA/Bill Ingalls.
Three new International Space Station crew members are set to launch aboard the Soyuz TMA-09M spacecraft from the Baikonur Cosmodrome in Kazakhstan. Launch is scheduled for is 20:31 UTC (4:31 p.m. EDT) Tuesday (2:31 a.m. May 29, Baikonur time). The new Expedition 36 crew will take an accelerated four-orbit, 6-hour journey to Space Station. They will be docking at 02:17 UTC on May 29 (10:17 pm. EDT May 28). You can watch Live NASA TV coverage below, which begins an hour before launch (19:30 UTC, 3:30 p.m. EDT), and live coverage will return about 45 minutes before docking.
The new crew includes Soyuz Commander Fyodor Yurchikhin of the Russian Federal Space Agency (Roscosmos), NASA astronaut Karen Nyberg and European Space Agency (ESA) astronaut Luca Parmitano.
UPDATE: If you missed the launch live, you can watch a replay, below.
The crew will dock their Soyuz to the station’s Rassvet module. After the hatches open, the new trio will join Flight Engineer Chris Cassidy of NASA and Commander Pavel Vinogradov and Flight Engineer Alexander Misurkin of Roscosmos who docked with the orbital complex May 28. All six crew members will then participate in a welcome ceremony with family members and mission officials gathered at the Russian Mission Control Center in Korolev near Moscow.
In the past, Soyuz manned capsules and Progress supply ships were launched on trajectories that required about two days, or 34 orbits, to reach the ISS. The new fast-track trajectory has the rocket launching shortly after the ISS passes overhead. Then, additional firings of the vehicle’s thrusters early in its mission expedites the time required for a Russian vehicle to reach the Station.
This is the second Soyuz crew vehicle to make the accelerated trip, and three Progress resupply ships have also taken the fast track to the ISS.
The Service arms are raised into position around the Soyuz rocket, with the TMA-09M spacecraft, after arriving at the Baikonur Cosmodrome launch pad by train, Sunday, May 26, 2013, in Kazakhstan. Credit: NASA/Bill Ingalls.
You can see more images from the Expedition 36 launch and pre-launch activities at NASA HQ’s Flickr page.
The Southern Cross, the Milky Way, and the Large Magellanic Cloud shine above the Atacama Large Millimeter/submillimeter Array (ALMA) as it observes on a clear night sky during its Early Science phase. Image credit: C. Padilla, NRAO/AUI/NSF
Talk about an assembly line! Some early-stage galaxies created stars thousands of times faster than our Milky Way does today, according to new research. And it’s puzzling astronomers.
“We want to understand how and why these galaxies are forming stars at such incredibly fast rates, so soon after the Big Bang,” stated Scott Chapman of Dalhousie University, one of the researchers behind the discovery. “This could partially answer how our own galaxy, the Milky Way, was born billions of years ago.”
This is just a hint of the high-definition view we’ll receive from Chile’s Atacama Large Millimeter/submillimeter Array (ALMA), its astronomers promise, since the array of dozens of telescopes was officially inaugurated this spring. (ALMA has been working for years, but slowly adding telescopes and definition as it goes.)
There were actually three papers released today about ALMA. So what did the observatory find out this time? Here’s the nut graf:
Gravitational microlensing method requires that you have two stars that lie on a straight line in relation to us here on Earth. Then the light from the background star is amplified by the gravity of the foreground star, which thus acts as a magnifying glass.
– The observed galaxies are “gravitationally lensed”. Galaxies are so massive that they can bend light from other galaxies, if put in the right spot with respect to Earth. We’ve seen this effect over and over again with the Hubble Space Telescope, but observations are less well-known in the millimeter spectrum of light in which ALMA observes. “Models of lens geometries in the sample indicate that the background objects are ultra-luminous infrared galaxies, powered by extreme bursts of star formation,” stated a Nature paper on the discovery.
– These galaxies are further away than we thought. By measuring the time it takes light from carbon monoxide molecules to reach us, the astronomers concluded these galaxies are much further away than previously measured, with some reaching as far back as 12 billion light-years away. (That’s just 1.7 billion years after the Big Bang created the universe.)
– The galaxies put star creation on fast-forward. Looking back that far is like looking in a time machine — we can see things that were happening only 1 billion years after the Big Bang. At the time, those galaxies were as bright as 40 trillion suns and created new stars at an extreme rate of 4,000 suns per year. (That, by the way, is 4,000 times faster than what our own galaxy does.)
You can read more about these results in Nature and the Astrophysical Journal (here and here.)
Sometimes a trilogy needs four parts! The Astronomy Cast team of Fraser Cain and Pamela Gay have taken a look at the history and modern era of space stations, as well as peering into the future at some space station concepts still in the works. You can listen to this four-part series at the Astronomy Cast website, or at the links below:
And the podcast is also available as a video, as Fraser and Pamela now record Astronomy Cast as part of a Google+ Hangout. You can see their latest Hangouts at the Astronomy Cast YouTube page. They record most Mondays at 18:00 UTC (3:00 PM EDT, 12:00 PDT) at Google+.
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.
An artist's conception of two tidally locked objects orbiting the Sun from afar. The system: 2010 WG9 may likely look like this. Credit: zmescience
What if we could journey to the outer edge of the Solar System – beyond the familiar rocky planets and the gas giants, past the orbits of asteroids and comets – one thousand times further still – to the spherical shell of icy particles that enshrouds the Solar System. This shell, more commonly known as the Oort cloud, is believed to be a remnant of the early Solar System.
Imagine what astronomers could learn about the early Solar System by sending a probe to the Oort cloud! Unfortunately 1-2 light years is more than a little beyond our reach. But we’re not entirely out of luck. 2010 WG9 – a trans-Neptunian object — is actually an Oort Cloud object in disguise. It has been kicked out of its orbit, and is heading closer towards us so we can get an unprecedented look.
But it gets even better! 2010 WG9 won’t get close to the Sun, meaning that its icy surface will remain well-preserved. Dr. David Rabinowitz, lead author of a paper about the ongoing observations of this object told Universe Today, “This is one of the Holy Grails of Planetary Science – to observe an unaltered planetesimal left over from the time of Solar System formation.”
Now you might be thinking: wait, don’t comets come from the Oort Cloud? It’s true; most comets were pulled out of the Oort cloud by a gravitational disturbance. But observing comets is extremely difficult, as they are surrounded by bright clouds of dust and gas. They also come much closer to the Sun, meaning that their ices evaporate and their original surface is not preserved.
So while there is a surprisingly high number of Oort cloud objects hanging out within the inner solar system, we needed to find one that is easy to observe and whose surface is well preserved. 2010 WG9 is just the object for the job! It is not covered by dust or gas, and is believed to have spent most of its lifetime at distances greater than 1000 AU. In fact, it will never approach closer than Uranus.
Astronomers at Yale University have observed 2010 WG9 for over two years, taking images in different filters. Just as coffee filters allow ground coffee to pass through but will block larger coffee beans, astronomical filters allow certain wavelengths of light to pass through, while blocking all others.
Recall that the wavelength of visible light relates to color. The color red, for example, has a wavelength of approximately 650 nm. An object that is very red will therefore be brighter in a filter of this wavelength, as opposed to a filter of, say, 475 nm, or blue. The use of filters allow astronomers to study specific colors of light.
Astronomers observed 2010 WG9 with four filters: B, V, R, and I, also known as blue, visible, red, and infrared wavelengths. What did they see? Variation – a change in color over the course of just days.
The likely source is a patchy surface. Imagine looking at the Earth (pretend there’s no atmosphere) with a blue filter. It would brighten when an ocean came into view, and dim when that ocean left the field of view. There would be a variation in color, dependent on the different elements located on the surface of the planet.
The dwarf planet Pluto has patches of methane ice, which also show up as color variations on its surface. Unlike Pluto, 2010 WG9 is relatively small (100 km in diameter) and cannot hold on to its methane ice. It’s possible that part of the surface is newly exposed after an impact. According to Rabinowitz, astronomers are still unsure what the color variations mean.
Rabinowitz was very keen to explain that 2010 WG9 has an unusually slow rotation. Most trans-Neptunian objects rotate every few hours. 2010 WG9 rotates on the order of 11 days! The best reason for this discrepancy is that it exists in a binary system. If 2010 WG9 is tidally locked to another body — meaning that the spin of each body is locked to the rate of rotation — then 2010 WG9 will be slowed down in its rotation.
According to Rabinowitz, the next step will be to observe 2010 WG9 with larger telescopes — perhaps the Hubble Space Telescope — in order to better measure the color variation. We may even be able to determine if this object is in a binary system after all, and observe the secondary object as well.
Any future observations will help us further understand the Oort cloud. “Very little is known about the Oort cloud – how many objects are in it, what are its dimensions, and how it formed,” Rabinowitz explained. “By studying the detailed properties of a newly arrived member of the Oort cloud, we may learn about its constituents.”
2010 WG9 will likely hint at the origin of the Solar System in helping us further understand its own origin: the mysterious Oort cloud.
I’m just going to warn you, this is a controversial topic. Some people get pretty grumpy when you ask: how many planets are in the Solar System? Is it eight, ten, or more?
I promise you this, though, we’re never going back to nine planets… ever.
When many of us grew up, there were nine planets in the Solar System. It was like a fixed point in our brains.
As kids, memorizing this list was an early right of passage of nerd pride: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.
But then in 2005, Mike Brown discovered Eris, an icy object thought to be about the same size as Pluto, out beyond its orbit.
That would bring the total number of planets to ten. Right? There’s no turning back, textbooks would need to be changed.
In order to settle the dispute, the International Astronomical Union met in 2006, and argued for, and against Pluto’s planethood. Some astronomers advocated widening the number of planets to twelve, including Pluto, its moon Charon, the Asteroid Ceres, and the newly discovered Eris.
In the end, they changed the definition of what makes a planet, and sadly, Pluto doesn’t make the cut:
Here are the new requirements of planethood status:
A planet has to orbit the Sun. Okay fine, Pluto does that.
A planet needs enough gravity to pull itself into a sphere. Okay, spherical. Pluto’s fine there too.
A planet needs to have cleared out its orbit of other objects. Uh oh, Pluto hasn’t done that.
For example, planet Earth accounts for a million times the rest of the material in its orbit, while Pluto is just a fraction of the icy objects in its realm.
The final decision was to demote Pluto from planet to dwarf planet.
But don’t despair, Pluto is in good company.
Ceres. Image credit: NASAThere’s Ceres, the first asteroid ever discovered, and the smallest of the dwarf planets. The surface of Ceres is made of ice and rock, and it might even have a liquid ocean under its surface. NASA’s Dawn mission is flying there right now to give us close up pictures for the first time.
Haumea, named after the Hawaiian goddess of fertility, is about a third the mass of Pluto, and has just enough gravity to pull itself into an ellipsoid, or egg shape. Even though it’s smaller, it’s got moons of its own.
Makemake. Credit: NASAMakemake, a much larger Kuiper belt object, has a diameter about two-thirds the size of Pluto. It was discovered in 2005 by Mike Brown and his team. So far, Makemake doesn’t seem to have any moons.
Eris is the most massive known dwarf planet, and the one that helped turn our definition of a planet upside-down. It’s 27% more massive than Pluto and the ninth most massive body that orbits the Sun. It even has a moon: Dysnomia.
Pluto. Credit: ESOAnd of course, Pluto. The founding member of the dwarf family.
Want an easy way to remember the eight planets, in order? Just remember this mnemonic: my very excellent mother just served us noodles.
For all you currently writing angry tweets to Mike Brown, hold on a sec. Changing Pluto’s categorization is an important step that really needed to happen.
The more we discover about our Universe, the more we realize just how strange and wonderful it is. When Pluto was discovered 80 years ago, we never could have expected the variety of objects in the Solar System. Categorizing Pluto as a dwarf planet helps us better describe our celestial home.
So, our Solar System now has eight planets, and five dwarf planets.
1998 QE2 on closest approach to Earth this Friday on May 31st. (Credit: NASA/JPL-Caltech).
A large asteroid visits our fair corner of the solar system this week, and with a little planning you may just be able to spot it.
Near Earth Asteroid (NEA) 285263 (1998 QE2) will pass 5.8 million kilometres from the Earth on Friday, May 31st at 20:59 Universal Time (UT) or 4:59PM EDT. Discovered in 1998 during the LIncoln Near-Earth Asteroid Research (LINEAR) sky survey looking for such objects, 1998 QE2 will shine at magnitude +10 to +12 on closest approach. Estimates of its size vary from 1.3 to 2.9 kilometres, with observations by the Spitzer Space Telescope in 2010 placing the ballpark figure towards the high end of the scale at 2.7 kilometres in diameter.
1998 QE2 would fit nicely with room to spare in Oregon’s 8 kilometre-wide Crater Lake.
Though this passage is over 15 times as distant as the Earth’s Moon, the relative size of this space rock makes it of interest. This is the closest approach of 1998 QE2 for this century, and there are plans to study it with both the Arecibo and Goldstone radio telescopes to get a better description of its size and rotation as it sails by. Expect to see radar maps of 1998 QE2 by this weekend.
“Asteroid 1998 QE2 will be an outstanding radar imaging target… we expect to obtain a series of high-resolution images that could reveal a wealth of surface features,” said astronomer and principal JPL investigator Lance Benner.
An Amor-class asteroid, 1998 QE2 has an orbit of 3.77 years that takes it from the asteroid belt between Mars and Jupiter to just exterior of the Earth’s orbit. 1998 QE2 currently comes back around to our vicinity roughly every 15 years, completing about 4 orbits as it does so. Its perihelion exterior to our own makes it no threat to the Earth. This week’s passage is the closest for 1998 QE2 until a slightly closer pass on 0.038 Astronomical Units on May 27th, 2221. Note that on both years, the Earth is just over a month from aphelion (its farthest point from the Sun) which falls in early July.
Of course, the “QE2” designation has resulted in the inevitable comparisons to the size of the asteroid in relation to the Queen Elizabeth II cruise liner. Asteroid designations are derived from the sequence in which they were discovered in a given year. 1998 QE2 was the 55th asteroid discovered in the period running from August 1st to 16th 1998.
Perhaps we could start measuring asteroids in new and creative units, such as “Death Stars” or “Battlestars?”
But the good news is, you can search for 1998 QE2 starting tonight. The asteroid is currently at +12th magnitude in the constellation Centaurus and will be cruising through Hydra on its way north into Libra Friday on May 31st. You’ll need a telescope to track the asteroid as it will never top +10th magnitude, which is the general threshold for binocular viewing under dark skies. Its relative southern declination at closest approach means that 1998 QE2 will be best observed from northern latitudes of +35° southward. The farther south you are, the higher it will be placed in the sky after dusk.
A wide field view of the passage of 1998 QE2 this week, from May 27th through June 2nd. (Created by the author in Starry Night).
Still, if you can spot the constellation Libra, it’s worth a try. Many observers in the southern U.S. fail to realize that southern hemisphere sites like Omega Centauri in the constellation Centaurus are visible in the evening low to the south at this time of year. Libra sits on the meridian at local midnight due south for northern hemisphere observers, making it a good time to try for the tiny asteroid.
Visually, 1998 QE2 will look like a tiny, star-like point in the eye-piece of a telescope. Use low power and sketch or photograph the field of view and compare the positions of objects about 10 minutes apart. Has anything moved? We caught sight of asteroid 4179 Toutatis last year using this method.
A closeup look at the passage of 1998 QE2, covering a 48 hour span centered on closest approach on May 31st. (Created by the author in Starry Night).
1998 QE2 will also pass near some interesting objects that will serve as good “guideposts” to track its progress.
We find the asteroid about 5° north of the bright +2.5 magnitude star Iota Centauri on the night of May 28th. It then crosses the border into the constellation Hydra about 6° south of the +3 magnitude star Gamma Hydrae (Star Trek fans will recall that this star lies in the Neutral Zone) on May 29th. Keep a careful eye on 1998 QE2 as it passes within 30’ (about the diameter of a Full Moon) of the +8th magnitude galaxy Messier 83 centered on May 28th at 19:00 UT/3:00 PM EDT. This will provide a fine opportunity to construct a stop-motion animated .gif of the asteroid passing by the galaxy.
Another good opportunity to pinpoint the asteroid comes on the night on Thursday, May 30th as it passes within 30’ of the +3.3 magnitude star Pi Hydrae.
From there, it’s on to closest approach day. 1998 QE2 crosses into the constellation Libra early on Friday May 31st. The Moon will be at Last Quarter phase and won’t rise until well past local midnight, aiding in your quest.
At its closest approach, 1998 QE2 have an apparent motion of about 1 angular degree every 3 hours, or about 2/3rds the diameter of a Full Moon every hour. This isn’t quite fast enough to see in real time like asteroid 2012 DA14 was earlier this year, but you should notice its motion after about 10 minutes at medium power. Passing at ~465 Earth diameters distant, 1998 QE2 will show a maximum parallax displacement of just a little over 7 arc minutes at closest approach.
For telescopes equipped with setting circles, knowing the asteroid’s precise position is crucial. This allows you to aim at a fixed position just ahead of its path and “ambush” it as it drifts by. For the most precise positions in right ascension and declination, be sure to check out JPL’s ephemeris generator for 1998 QE2.
After its closest passage, 1998 QE2 will pass between the +3.3 & +2.7 magnitude stars Brachium (Sigma Librae) and Zubenelgenubi (Alpha Librae) around 4:00 UT on June 1st. Dedicated observers can continue to follow its northeastward trek into early June.
Slooh will also be carrying the passage of 1998 QE2 on Friday, May 31ststarting at 5:00 PM EDT/21:00 UT.
Of course, the hypothetical impact of a space rock the size of 1998 QE2 would spell a very bad day for the Earth. The Chicxulub impact basin off of the Yucatán Peninsula was formed by a 10 kilometre impactor about 4 times larger than 1998 QE2 about 65 million years ago. We can be thankful that 1998 QE2 isn’t headed our way as we watch it drift silently by this week. Hey, unlike the dinosaurs, WE have a space program… perhaps, to paraphrase science fiction author Larry Niven, we can hear the asteroid whisper as we track its progress across the night sky, asking humanity “How’s that space program coming along?”
Planets conjunction over Mont-Saint-Michel, Normandy, France on May 26. Credit: Thierry Legault -
www.astrophoto.fr
Triple planets (Venus/Jupiter/Mercury) conjunction over Mont-Saint-Michel, Normandy, France on May 26. Credit: Thierry Legault – www.astrophoto.fr Update: See expanded Conjunction astrophoto gallery below[/caption]
The rare astronomical coincidence of a spectacular triangular triple conjunction of 3 bright planets happening right now is certainly wowing the entire World of Earthlings! That is if our gallery of astrophotos assembled here is any indication.
Right at sunset, our Solar System’s two brightest planets – Venus and Jupiter – as well as the sun’s closest planet Mercury are very closely aligned for about a week in late May 2013 – starting several days ago and continuing throughout this week.
And, for an extra special bonus – did you know that a pair of spacecraft from Earth are orbiting two of those planets?
Have you seen it yet ?
Well you’re are in for a celestial treat. The conjunction is visible to the naked eye – look West to Northwest shortly after sunset. No telescopes or binoculars needed.
Triple conjunction shot on May 26 from a mile high in Payson,Az. 4 second exposure, ISO200, Canon 10D, 80mm f/5 lens. Credit: Chris Schur- http://www.schursastrophotography.com
Just check out our Universe Today collection of newly snapped astrophoto’s and videos sent to Nancy and Ken by stargazing enthusiasts from across the globe. See an earlier gallery – here.
Throughout May, the trio of wandering planets have been gradually gathering closer and closer.
On May 26 and 27, Venus, Jupiter and Mercury appear just 3 degrees apart as a spectacular triangularly shaped object in the sunset skies – which
adds a palatial pallet of splendid hues not possible at higher elevations.
And don’t dawdle if you want to see this celestial feast. The best times are 30 to 60 minutes after sunset – because thereafter they’ll disappear below the horizon.
The sky show will continue into late May as the planets alignment changes every day.
On May 28, Venus and Jupiter close in to within just 1 degree.
And on May 30 & 31, Venus, Jupiter and Mercury will form an imaginary line in the sky.
Triple planetary conjunctions are a rather rare occurrence. The last one took place in May 2011. And we won’t see another one until October 2015.
Indeed the wandering trio are also currently the three brightest planets visible. Venus is about magnitude minus 4, Jupiter is about minus 2.
While you’re enjoying the fantastic view, ponder this: The three planets are also joined by two orbiting spacecraft from humanity. NASA’s MESSENGER is orbiting Mercury. ESA’s Venus Express is orbiting Venus. And NASA’s Juno spacecraft is on a long looping trajectory to Jupiter.
Send Ken you conjunction photos to post here.
And don’t forget to “Send Your Name to Mars” aboard NASA’s MAVEN orbiter- details here. Deadline: July 1, 2013
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Learn more about Conjunctions, Mars, Curiosity, Opportunity, MAVEN, LADEE and NASA missions at Ken’s upcoming lecture presentations:
June 4: “Send your Name to Mars” and “CIBER Astro Sat, LADEE Lunar & Antares Rocket Launches from Virginia”; Rodeway Inn, Chincoteague, VA, 8:30 PM
June 11: “Send your Name to Mars” and “LADEE Lunar & Antares Rocket Launches from Virginia”; NJ State Museum Planetarium and Amateur Astronomers Association of Princeton (AAAP), Trenton, NJ, 730 PM.
May 25 conjunction over Malta. Canon 450D with a 55mm. lens and an exposure of 1/2 second at ISO 200 on a tripod. Credit: Leonard Ellul-MercerMay 26 triple conjunction from Warwick, NY snapped from Canon Rebel, 100mm – 300mm lens. Credit: Pietro CarboniTriple conjunction from Hondo, Texas taken with a Nikon D800 @ ISO 400 and a 2 second exposure with a Nikon 300mm Lens at F/4. Credit: Adrian New Sunset conjunction with fast moving clouds on May 26 through 10 x 50 binoculars from a seashore town -Marina di Pisa, Tuscany, Italy. Credit: Giuseppe Petricca
Caption: Taken on 2013-05-23 from Salem, Missouri. Canon T1i, Nikkor 105mm lens. 297 1/4s at 1s interval. Images assembled by QuickTime Pro. Credit: Joseph Shuster
May 26 sunset conjunction from Princeton, NJ. Credit: Ken Kremer -kenkremer.comTriple Planetary conjunction over Onset MA. Shot with a Nikon d7000 1/200 f 4 iso 100 at 110mm. Credit: Phillip DamianoPanoramic view over Almada City and Lisbon at the Nautical Twilight, with the Full moon rising above the Eastern horizon (right side of the image), while at the same time but in the opposite direction, the planets Venus, Mercury and Jupiter, are aligned in a triangle formation, setting in the Western horizon (left side of the image).In this panoramic picture is also visible the smooth light transition in the sky, with the end of Nautical Twilight and the beginning of Astronomical Twilight (almost night), at right. Facing to North, is visible the great lighted Monument Christ the King and at the left side of it, part of the 25 April Bridge that connects Almada to Lisbon. Canon 50D – ISO200; f/4; Exp. 1,6 Sec; 35mm. Panoramic of 10 images with about 200º, taken at 21h42 in 25/05/2013. Credit: Miguel Claro – www.miguelclaro.comThe triple conjunction of Venus, Mercury and Jupiter as seen over an Arizona desert landscape. Credit and copyright: Robert Sparks.Jupiter, Venus and Mercury triple conjunction seen here reflecting off Chatsworth Lake in Chatsworth, NJ. Jupiter (on the left) was 2.4° from Mercury (upper-right in the sky) and 2.0° from Venus (bottom right in the sky), while Venus and Mercury were 1.9° apart. Venus was at 2.6° altitude. Canon EOS 6D, 105 mm focal length, 1.3 seconds, f/6.3, ISO 800. Credit: Joe Stieber – sjastro.org/Triple conjunction on May 27 with WBZ radio towers south east of Boston. Hampton Hill, Hull, MA. Nikon D3x -iso200- 1.3 sec.at f2.8. Credit: Richard W. Green
This all-sky Fermi view includes only sources with energies greater than 10 GeV. From some of these sources, Fermi's LAT detects only one gamma-ray photon every four months. Brighter colors indicate brighter gamma-ray sources. Credit: NASA/DOE/Fermi LAT Collaboration
The universe, most cosmologists tell us, began with a bang. At some point, the lights turned on. How much light has the universe produced since it was born, 13.8 billion years ago?
It seems a difficult answer at first glance. Turn on a light bulb, turn it off and the photons appear to vanish. In space, however, we can track them down. Every light particle ever radiated by galaxies and stars is still travelling, which is why we can peer so far back in time with our telescopes.
A new paper in the Astrophysical Journal explores the nature of this extragalactic background light, or EBL. Measuring the EBL, the team states, “is as fundamental to cosmology as measuring the heat radiation left over from the Big Bang (the cosmic microwave background) at radio wavelengths.”
Turns out that several NASA spacecraft have helped us understand the answer. They peered at the universe in every wavelength of light, ranging from long radio waves to short, energy-filled gamma rays. While their work doesn’t go back to the origin of the universe, it does give good measurements for the last five billion years or so. (About the age of the solar system, coincidentally.)
Artist’s conception of how gamma rays (dashed lines) bump against photons of electromagnetic background light, producing electrons and positrons. Credit: Nina McCurdy and Joel R. Primack/UC-HiPACC; Blazar: Frame from a conceptual animation of 3C 120 created by Wolfgang Steffen/UNAM
It’s hard to see this faint background light against the powerful glow of stars and galaxies today, about as hard as it is to see the Milky Way from downtown Manhattan, the astronomers said.
The solution involves gamma rays and blazars, which are huge black holes in the heart of a galaxy that produce jets of material that point towards Earth. Just like a flashlight.
These blazars emit gamma rays, but not all of them reach Earth. Some, astronomers said, “strike a hapless EBL photon along the way.”
When this happens, the gamma ray and photon each zap out and produce a negatively charged electron and a positively charged positron.
More interestingly, blazars produce gamma rays at slightly different energies, which are in turn stopped by EBL photons at different energies themselves.
So, by figuring out how many gamma rays with different energies are stopped by the photons, we can see how many EBL photons are between us and the distant blazars.
Scientists have now just announced they could see how the EBL changed over time. Peering further back in the universe, as we said earlier, serves as a sort of time machine. So, the further back we see the gamma rays zap out, the better we can map out the EBL’s changes in earlier eras.
The Fermi Gamma-ray Space Telescope (formerly called GLAST). Credit: NASA
To get technical, this is how the astronomers did it:
– Compared the gamma-ray findings of the Fermi Gamma-ray Space Telescope to the intensity of X-rays measured by several X-ray observatories, including the Chandra X-Ray Observatory, the Swift Gamma-Ray Burst Mission, the Rossi X-ray Timing Explorer, and XMM/Newton. This let astronomers figure out what the blazars’ brightnesses were at different energies.
– Comparing those measurements to those taken by special telscopes on the ground that can look at the actual “gamma-ray flux” Earth receives from those blazars. (Gamma rays are annihilated in our atmosphere and produce a shower of subatomic particles, sort of like a “sonic boom”, called Cherenkov radiation.)
The measurements we have in this paper are about as far back as we can see right now, the astronomers added.
“Five billion years ago is the maximum distance we are able to probe with our current technology,” stated the paper’s lead author, Alberto Dominguez.
“Sure, there are blazars farther away, but we are not able to detect them because the high-energy gamma rays they are emitting are too attenuated by EBL when they get to us—so weakened that our instruments are not sensitive enough to detect them.”
Opportunity established a new American driving record for a vehicle on another world on May 15, 2013 (Sol 3309) and made history by driving ahead from this point at Cape York. This navcam mosaic shows the view forward to her next destinations of Solander Point and Cape Tribulation along the lengthy rim of huge Endeavour crater spanning 14 miles (22 km) in diameter. Opportunity discovered clay minerals at Cape York and stands as the most favorable location for Martian biology discovered during her entire nearly 10 year long mission to Mars. Credit: NASA/JPL/Cornell/Kenneth Kremer/Marco Di Lorenzo
NASA’s Opportunity Mars rover discovered clay minerals at Cape York ridge along the rim of Endeavour crater – seen in this photo mosaic – which stands as the most favorable location for Martian biology discovered during her entire nearly 10 year long mission to Mars. Opportunity also established a new American driving record for a vehicle on another world on May 15, 2013 (Sol 3309) and made history by driving ahead from this point at Cape York. This navcam photo mosaic shows the view forward to her next destinations of Solander Point and Cape Tribulation along the lengthy rim of huge Endeavour crater spanning 14 miles (22 km) in diameter.
Credit: NASA/JPL/Cornell/Ken Kremer (kenkremer.com)/Marco Di Lorenzo Updated: Illustrated below with a collection of imagery, mosaics and route maps[/caption]
Now nearly a decade into her planned 3 month only expedition to Mars, NASA’s longest living rover Opportunity, struck gold and has just discovered the strongest evidence to date for an environment favorable to ancient Martian biology – and she has set sail hunting for a motherlode of new clues amongst fabulous looking terrain!!
Barely two weeks ago in mid-May 2013, Opportunity’s analysis of a new rock target named “Esperance” confirmed that it is composed of a “clay that had been intensely altered by relatively neutral pH water – representing the most favorable conditions for biology that Opportunity has yet seen in the rock histories it has encountered,” NASA said in a statement.
The finding of a fractured rock loaded with clay minerals and ravaged by flowing liquid water in which life could have thrived amounts to a scientific home run for the golf cart sized rover!
“Water that moved through fractures during this rock’s history would have provided more favorable conditions for biology than any other wet environment recorded in rocks Opportunity has seen,” said the mission’s principal investigator Prof. Steve Squyres of Cornell University, Ithaca, N.Y.
Opportunity accomplished the ground breaking new discovery by exposing the interior of Esperance with her still functioning Rock Abrasion Tool (RAT) and examining a pristine patch using the microscopic camera and X-Ray spectrometer on the end of her 3 foot long robotic arm.
The pale rock in the upper center of this image, about the size of a human forearm, includes a target called “Esperance,” which was inspected by NASA’s Mars Exploration Rover Opportunity. Data from the rover’s alpha particle X-ray spectrometer (APXS) indicate that Esperance’s composition is higher in aluminum and silica, and lower in calcium and iron, than other rocks Opportunity has examined in more than nine years on Mars. Preliminary interpretation points to clay mineral content due to intensive alteration by water. Credit: NASA/JPL-Caltech/Cornell/Arizona State Univ
The robot made the discovery at the conclusion of a 20 month long science expedition circling around a low ridge called “Cape York” – which she has just departed on a southerly heading trekking around the eroded rim of the huge crater named “Endeavour.”
“Esperance was so important, we committed several weeks to getting this one measurement of it, even though we knew the clock was ticking.”
Esperance stems from a time when the Red Planet was far warmer and wetter billions of years ago.
“What’s so special about Esperance is that there was enough water not only for reactions that produced clay minerals, but also enough to flush out ions set loose by those reactions, so that Opportunity can clearly see the alteration,” said Scott McLennan of the State University of New York, Stony Brook, a long-term planner for Opportunity’s science team.
Close-Up of ‘Esperance’ After Abrasion by Opportunity This mosaic of four frames shot by the microscopic imager on the robotic arm of NASA’s Mars Exploration Rover Opportunity shows a rock target called “Esperance” after some of the rock’s surface had been removed by Opportunity’s rock abrasion tool, or RAT. The component images were taken on Sol 3305 on Mars (May 11, 2013). The area shown is about 2.4 inches (6 centimeters) across. Credit: NASA/JPL-Caltech/Cornell/USGS
Esperance is unlike any rock previously investigated by Opportunity; containing far more aluminum and silica which is indicative of clay minerals and lower levels of calcium and iron.
Most, but not all of the rocks inspected to date by Opportunity were formed in an environment of highly acidic water that is extremely harsh to most life forms.
Clay minerals typically form in potentially drinkable, neutral water that is not extremely acidic or basic.
Previously at Cape York, Opportunity had found another outcrop containing a small amount of clay minerals formed by exposure to water called “Whitewater Lake.”
“There appears to have been extensive, but weak, alteration of Whitewater Lake, but intense alteration of Esperance along fractures that provided conduits for fluid flow,” said Squyres.
Opportunity rover discovered phyllosilicate clay minerals and calcium sulfate veins at the bright outcrops of ‘Whitewater Lake’, at right, imaged by the Navcam camera on Sol 3197 (Jan. 20, 2013, coinciding with her 9th anniversary on Mars. “Copper Cliff” is the dark outcrop, at top center. Darker “Kirkwood” outcrop, at left, is site of mysterious “newberries” concretions. This panoramic view was snapped from ‘Matijevic Hill’ on Cape York ridge at Endeavour Crater. Credit: NASA/JPL-Caltech/Cornell/Marco Di Lorenzo/Ken Kremer
Cape York is a hilly segment of the rim of Endeavour crater which spans 14 miles (22 km) across – where the robot arrived in mid-2011 and will spend her remaining life.
Opportunity has now set sail for her next crater rim destination named “Solander Point”, an area about 1.4 miles (2.2 kilometers) away – due south from “Cape York.”
“Our next destination will be Solander Point,” Squyres told Universe Today.
Along the way, Opportunity will soon cross “Botany Bay” and “Sutherland Point”, last seen when Opportunity first arrived at Cape York.
Eventually she will continue further south to a rim segment named ‘Cape Tribulation’ which holds huge caches of clay minerals.
The rover must arrive at “Solander Point” before the onset of her 6th Martian winter so that she can be advantageously tilted along north facing slopes to soak up the maximum amount of sun by her power generating solar wings. She might pull up around August.
On the other side of Mars, Opportunity’s new sister rover Curiosity also recently discovered clay minerals on the floor of her landing site inside Gale Crater.
Curiosity found the clay minerals – and a habitat that could support life – after analyzing powdery drill tailings from the Yellowknife Bay basin worksite with her on board state-of-the-art chemistry labs.
Just a week ago on May 15 (Sol 3309), Opportunity broke through the 40 year old American distance driving record set back in December 1972 by Apollo 17 astronauts Eugene Cernan and Harrison Schmitt.
But she is not sitting still resting on her laurels!
This past week the robots handlers’ back on Earth put the pedal to the metal and pushed her forward another quarter mile during 5 additional drives over 7 Sols, or Martian days. Thus her total odometry since landing on 24 January 2004 now stands at 22.45 miles (36.14 kilometers).
Opportunity will blast through the world record milestone of 23 miles (37 kilometers) held by the Lunokhod 2 lunar rover (from the Soviet Union), somewhere along the path to “Solander Point” in the coming months.
Opportunity captures the eerie Martian scenery looking south across Botany Bay from the southern tip of Cape York to her next destination – Solander Point, about 1 mile (1.6 km) away. This navcam photo mosaic was taken on Sol 3317, May 23, 2013. Credit: NASA/JPL/Cornell//Marco Di Lorenzo/Ken Kremer (kenkremer.com)
Endeavour Crater features terrain with older rocks than previously inspected and unlike anything studied before by Opportunity. It’s a place no one ever dared dream of reaching prior to Opportunity’s launch in the summer of 2003 and landing on the Meridiani Planum region in 2004.
Signatures of clay minerals, or phyllosilicates, were detected at several spots at Endeavour’s western rim by observations from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) aboard NASA’s Mars Reconnaissance Orbiter (MRO).
“The motherlode of clay minerals is on Cape Tribulation. The exposure extends all the way to the top, mainly on the inboard side,” says Ray Arvidson, the rover’s deputy principal investigator at Washington University in St. Louis.
Stay tuned for the continuing breathtaking adventures of NASA’s sister rovers Opportunity and Curiosity!
And don’t forget to “Send Your Name to Mars” aboard NASA’s MAVEN orbiter- details here. Deadline: July 1, 2013
Traverse Map for NASA’s Opportunity rover from 2004 to 2013 to Record Setting Drive on May 15. This map shows the entire path the rover has driven during more than 9 years and over 3318 Sols, or Martian days, since landing inside Eagle Crater on Jan 24, 2004 to current location heading south to Solander Point from Cape York ridge at the western rim of Endeavour Crater. On May 15, 2013 Opportunity drove 263 feet (80 meters) southward – achieving a total traverse distance on Mars of 22.22 miles (35.76 kilometers) – and broke the driving record by any NASA vehicle that was previously held by the astronaut-driven Apollo 17 Lunar Rover in 1972. Credit: NASA/JPL/Cornell/ASU/Marco Di Lorenzo/Ken KremerOpportunity Heads Toward Next Destination, ‘Solander Point’ -This map of a portion of the western rim of Endeavour Crater on Mars shows the area where NASA’s Mars Exploration Rover Opportunity worked for 20 months, “Cape York,” in relation to the area where the rover team plans for Opportunity to spend its sixth Martian winter, “Solander Point.” Credit: NASA/JPL-Caltech/Univ. of Arizona
