Universe Today

February 25, 2014December 23, 2015 by Ken Kremer

Next SpaceX Falcon 9 Rocket Gets Landing Legs for March Blastoff to Space Station – Says Elon Musk

1st stage of SpaceX Falcon 9 rocket equipped with landing legs and now scheduled for launch to the International Space Station on March 16, 2014 from Cape Canaveral, FL. Credit: SpaceX/Elon Musk

1st stage of SpaceX Falcon 9 rocket newly equipped with landing legs and now scheduled for launch to the International Space Station on March 16, 2014 from Cape Canaveral, FL. Credit: SpaceX/Elon Musk
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The next commercial SpaceX Falcon 9 rocket that’s set to launch in March carrying an unmanned Dragon cargo vessel will also be equipped with a quartet of landing legs in a key test that will one day lead to cheaper, reusable boosters, announced Elon Musk, the company’s founder and CEO.

The attachment of landing legs to the first stage of SpaceX’s new and more powerful, next-generation Falcon 9 rocket counts as a major step towards the firm’s eventual goal of building a fully reusable rocket.

Before attempting the use of landing legs “SpaceX needed to gain more confidence” in the new Falcon 9 rocket, Musk told me in an earlier interview.

Blastoff of the upgraded Falcon 9 on the Dragon CRS-3 flight is currently slated for March 16 from Cape Canaveral Air Force Station, Florida on a resupply mission to bring vital supplies to the International Space Station (ISS) in low Earth orbit for NASA.

“Mounting landing legs (~60 ft span) to Falcon 9 for next month’s Space Station servicing flight,” Musk tweeted, along with the up close photos above and below.

All four landing legs now mounted on Falcon 9 rocket being processed inside hanger at Cape Canaveral, FL for Mar 16 launch. Credit: SpaceX/Elon Musk — All four landing legs now mounted on Falcon 9 rocket being processed inside hanger at Cape Canaveral, FL for March 16 launch. Credit: SpaceX/Elon Musk

“SpaceX believes a fully and rapidly reusable rocket is the pivotal breakthrough needed to substantially reduce the cost of space access,” according to the firm’s website.

SpaceX hopes to vastly reduce their already low $54 million launch cost when a reusable version of the Falcon 9 becomes feasible.

Although this Falcon 9 will be sprouting legs, a controlled soft landing in the Atlantic Ocean guided by SpaceX engineers is still planned for this trip.

“However, F9 will continue to land in the ocean until we prove precision control from hypersonic thru subsonic regimes,” Musk quickly added in a follow-up twitter message.

In a prior interview, I asked Elon Musk when a Falcon 9 flyback would be attempted?

“It will be on one of the upcoming missions to follow [the SES-8 launch],” Musk told me.

“What we need to do is gain more confidence on the three sigma dispersion of the mission performance of the rocket related to parameters such as thrust, specific impulse, steering loss and a whole bunch of other parameters that can impact the mission.”

“If all of those parameters combine in a negative way then you can fall short of the mission performance,” Musk explained to Universe Today.

When the upgraded Falcon 9 performed flawlessly for the SES-8 satellite launch on Dec 3, 2013 and the Thaicom-6 launch on Jan. 6, 2014, the path became clear to attempt the use of landing legs on this upcoming CRS-3 launch this March.

Atmospheric reentry engineering data was gathered during those last two Falcon 9 launches to feed into SpaceX’s future launch planning, Musk said.

That new data collected on the booster stage has now enabled the approval for landing leg utilization in this March 16 flight.

SpaceX engineers will continue to develop and refine the technology needed to accomplish a successful touchdown by the landing legs on solid ground back at the Cape in Florida.

Extensive work and testing remains before a land landing will be attempted by the company.

Ocean recovery teams will retrieve the 1st stage and haul it back to port much like the Space Shuttle’s pair of Solid Rocket Boosters.

This will be the second attempt at a water soft landing with the upgraded Falcon 9 booster.

SpaceX founder and CEO Elon Musk briefs reporters including Universe Today on Sunday (Nov. 24) in Cocoa Beach, FL prior to planned SpaceX Falcon 9 rocket blastoff with SES-8 communications satellite set for Nov. 25, 2013 from Cape Canaveral, FL. Credit: Ken Kremer/kenkremer.com — SpaceX founder and CEO Elon Musk briefs reporters including Universe Today in Cocoa Beach, FL prior to December 2013 SpaceX upgraded Falcon 9 rocket blastoff with SES-8 communications satellite from Cape Canaveral, FL. Credit: Ken Kremer/kenkremer.com

The two stage Falcon 9 rocket and Dragon cargo carrier are currently in the final stages of processing by SpaceX technicians for the planned March 16 night time liftoff from Space Launch Complex 40 at 4:41 a.m. that will turn night into day along the Florida Space Coast.

“All four landing legs now mounted on Falcon 9,” Musk tweeted today, Feb. 25.

SpaceX has carried out extensive landing leg and free flight tests of ever increasing complexity and duration with the Grasshopper reusable pathfinding prototype.

SpaceX is under contract to NASA to deliver 20,000 kg (44,000) pounds of cargo to the ISS during a dozen Dragon cargo spacecraft flights over the next few years at a cost of about $1.6 Billion.

SpaceX Falcon 9 landing leg. Credit: SpaceX

To date SpaceX has completed two cargo resupply missions. The last flight dubbed CRS-2 blasted off a year ago on March 1, 2013.

The Falcon 9 and Dragon were privately developed by SpaceX with seed money from NASA in a public-private partnership.

The goal was to restore the cargo up mass capability the US completely lost following the retirement of NASA’s space shuttle orbiters in 2011.

SpaceX along with Orbital Sciences Corp are both partnered with NASA’s Commercial Resupply Services program.

Orbital Sciences developed the competing Antares rocket and Cygnus cargo spacecraft.

This extra powerful new version of the Falcon 9 dubbed v1.1 is powered by a cluster of nine of SpaceX’s new Merlin 1D engines that are about 50% more powerful compared to the standard Merlin 1C engines. The nine Merlin 1D engines 1.3 million pounds of thrust at sea level rises to 1.5 million pounds as the rocket climbs to orbit.

The Merlin 1 D engines are arrayed in an octaweb layout for improved efficiency.

Next Generation SpaceX Falcon 9 rocket blasts off with SES-8 communications satellite on Dec. 3, 2013 from Pad 40 at Cape Canaveral, FL. Credit: Ken Kremer/kenkremer.com

Therefore the upgraded Falcon 9 can boost a much heavier cargo load to the ISS, low Earth orbit, geostationary orbit and beyond.

The next generation Falcon 9 is a monster. It measures 224 feet tall and is 12 feet in diameter. That compares to a 130 foot tall rocket for the original Falcon 9.

Stay tuned here for Ken’s continuing SpaceX, Orbital Sciences, commercial space, Orion, Chang’e-3, LADEE, Mars rover, MAVEN, MOM and more planetary and human spaceflight news – and upcoming launch coverage at Cape Canaveral & the Kennedy Space Center press site.

Ken Kremer

February 25, 2014December 23, 2015 by Jason Major

Does Free Will Exist? Ancient Quasars May Hold the Clue.

Artist’s interpretation of ULAS J1120+0641, a very distant quasar with a supermassive black hole at its heart. Credit: ESO/M. Kornmesser

Do you believe in free will? Are people able to decide their own destinies, whether it’s on what continent they’ll live, who or if they’ll marry, or just where they’ll get lunch today? Or are we just the unwitting pawns of some greater cosmic mechanism at work, ticking away the seconds and steering everyone and everything toward an inevitable, predetermined fate?

Philosophical debates aside, MIT researchers are actually looking to move past this age-old argument in their experiments once and for all, using some of the most distant and brilliant objects in the Universe.

Rather than ponder the ancient musings of Plato and Aristotle, researchers at MIT were trying to determine how to get past a more recent conundrum in physics: Bell’s Theorem. Proposed by Irish physicist John Bell in 1964, the principle attempts to come to terms with the behavior of “entangled” quantum particles separated by great distances but somehow affected simultaneously and instantaneously by the measurement of one or the other — previously referred to by Einstein as “spooky action at a distance.”

The problem with such spookiness in the quantum universe is that it seems to violate some very basic tenets of what we know about the macroscopic universe, such as information traveling faster than light. (A big no-no in physics.)

(Note: actual information is not transferred via quantum entanglement, but rather it’s the transfer of state between particles that can occur at thousands of times the speed of light.)

Then again, testing against Bell’s Theorem has resulted in its own weirdness (even as quantum research goes.) While some of the intrinsic “loopholes” in Bell’s Theorem have been sealed up, one odd suggestion remains on the table: what if a quantum-induced absence of free will (i.e., hidden variables) is conspiring to affect how researchers calibrate their detectors and collect data, somehow steering them toward a conclusion biased against classical physics?

“It sounds creepy, but people realized that’s a logical possibility that hasn’t been closed yet,” said David Kaiser, Germeshausen Professor of the History of Science and senior lecturer in the Department of Physics at MIT in Cambridge, Mass. “Before we make the leap to say the equations of quantum theory tell us the world is inescapably crazy and bizarre, have we closed every conceivable logical loophole, even if they may not seem plausible in the world we know today?”

What are Quasars — A color composite image of the quasar in HE0450-2958 obtained using the VISIR instrument on the Very Large Telescope and the Hubble Space Telescope. Image Credit: ESO

So in order to clear the air of any possible predestination by entangled interlopers, Kaiser and MIT postdoc Andrew Friedman, along with Jason Gallicchio of the University of Chicago, propose to look into the distant, early Universe for sufficiently unprejudiced parties: ancient quasars that have never, ever been in contact.

According to a news release from MIT:

…an experiment would go something like this: A laboratory setup would consist of a particle generator, such as a radioactive atom that spits out pairs of entangled particles. One detector measures a property of particle A, while another detector does the same for particle B. A split second after the particles are generated, but just before the detectors are set, scientists would use telescopic observations of distant quasars to determine which properties each detector will measure of a respective particle. In other words, quasar A determines the settings to detect particle A, and quasar B sets the detector for particle B.

By using the light from objects that came into existence just shortly after the Big Bang to calibrate their detectors, the team hopes to remove any possibility of entanglement… and determine what’s really in charge of the Universe.

“I think it’s fair to say this is the final frontier, logically speaking, that stands between this enormously impressive accumulated experimental evidence and the interpretation of that evidence saying the world is governed by quantum mechanics,” said Kaiser.

Then again, perhaps that’s exactly what they’re supposed to do…

The paper was published this week in the journal Physical Review Letters.

Source: MIT Media Relations

Want to read more about the admittedly complex subject of entanglement and hidden variables (which may or may not really have anything to do with where you eat lunch?) Click here.

February 25, 2014December 23, 2015 by Elizabeth Howell

Pushy Black Holes Stop Elliptical Galaxies From Forming Stars

Multi-wavelength view of the elliptical galaxy NGC 5044. Credit: Digitised Sky Survey/NASA Chandra/Southern Observatory for Astrophysical Research/Very Large Array (Robert Dunn et al. 2010)

Contradicting past theories, cold gas has been found in abundance in some elliptical galaxies — showing that there must be some other explanation why these types of galaxies don’t form new stars. Astronomers believe that the jets from supermassive black holes in these galaxies’ center must push around the gas and prevent stars from forming.

Researchers spotted the gas for the first time using old data from the recently retired Herschel space observatory, which was able to peer well into the infrared — where it spotted carbon ions and oxygen atoms. This find stands against the previous belief that these galaxies were “red and dead”, referring to their physical appearance and the fact that they form no new stars.

“We looked at eight giant elliptical galaxies that nobody had looked at with Herschel before and we were delighted to find that, contrary to previous belief, six out of eight abound with cold gas”, stated Norbert Werner, a researcher at Stanford University in California who led the study.

“These galaxies are red, but with the giant black holes pumping in their hearts, they are definitely not dead,” added Werner.

NGC 1399, an elliptical galaxy about 65 million light years from Earth. Credit: NASA, Chandra

Previously, scientists thought that the galaxies got rid of their cold gas or had used it all up during a burst of earlier star formation. With cold gas found in the majority of the sample, researchers then used other observatories to try to find warmer gas up to tens of millions of Kelvin (or Fahrenheit or Celsius).

X-ray information from NASA’s Chandra X-ray Observatory revealed that there is hot gas cooling in six of the eight galaxies, but not in the remaining two of the sample.

“This is consistent with theoretical expectations: once cooled, the hot gas would become the warm and cold gas that are observed at longer wavelengths. However, in these galaxies the cooling process somehow stopped, and the cold gas failed to condense and form stars,” the European Space Agency stated.

“While the six galaxies with plenty of cold gas harbour moderately active black holes at their centres,” ESA added, “the other two show a marked difference. In the two galaxies without cold gas, the central black holes are accreting matter at frenzied pace, as confirmed by radio observations showing powerful jets of highly energetic particles that stem from their cores.”

You can read more about the research in the Monthly Notices of the Royal Astronomical Society or in preprint version on Arxiv.

Source: European Space Agency

February 25, 2014December 23, 2015 by Jason Major

New Technique Finds Water in Exoplanet Atmospheres

Artist's concept of a hot Jupiter exoplanet orbiting a star similar to tau Boötes (Image used with permission of David Aguilar, Harvard-Smithsonian Center for Astrophysics)

As more and more exoplanets are identified and confirmed by various observational methods, the still-elusive “holy grail” is the discovery of a truly Earthlike world… one of the hallmarks of which is the presence of liquid water. And while it’s true that water has been identified in the thick atmospheres of “hot Jupiter” exoplanets before, a new technique has now been used to spot its spectral signature in yet another giant world outside our solar system — potentially paving the way for even more such discoveries.

Researchers from Caltech, Penn State University, the Naval Research Laboratory, the University of Arizona, and the Harvard-Smithsonian Center for Astrophysics have teamed up in an NSF-funded project to develop a new way to identify the presence of water in exoplanet atmospheres.

Previous methods relied on specific instances such as when the exoplanets — at this point all “hot Jupiters,” gaseous planets that orbit closely to their host stars — were in the process of transiting their stars as viewed from Earth.

This, unfortunately, is not the case for many extrasolar planets… especially ones that were not (or will not be) discovered by the transiting method used by observatories like Kepler.

Watch: Kepler’s Universe: More Planets in Our Galaxy Than Stars

So the researchers turned to another method of detecting exoplanets: radial velocity, or RV. This technique uses visible light to watch the motion of a star for the ever-so-slight wobble created by the gravitational “tug” of an orbiting planet. Doppler shifts in the star’s light indicate motion one way or another, similar to how the Doppler effect raises and lowers the pitch of a car’s horn as it passes by.

The two Keck 10-meter domes atop Mauna Kea. (Rick Peterson/WMKO)

But instead of using visible wavelengths, the team dove into the infrared spectrum and, using the Near Infrared Echelle Spectrograph (NIRSPEC) at the W. M. Keck Observatory in Hawaii, determined the orbit of the relatively nearby hot Jupiter tau Boötis b… and in the process used its spectroscopy to identify water molecules in its sky.

“The information we get from the spectrograph is like listening to an orchestra performance; you hear all of the music together, but if you listen carefully, you can pick out a trumpet or a violin or a cello, and you know that those instruments are present,” said Alexandra Lockwood, graduate student at Caltech and first author of the study. “With the telescope, you see all of the light together, but the spectrograph allows you to pick out different pieces; like this wavelength of light means that there is sodium, or this one means that there’s water.”

Previous observations of tau Boötis b with the VLT in Chile had identified carbon monoxide as well as cooler high-altitude temperatures in its atmosphere.

Now, with this proven IR RV technique, the atmospheres of exoplanets that don’t happen to cross in front of their stars from our point of view can also be scrutinized for the presence of water, as well as other interesting compounds.

“We now are applying our effective new infrared technique to several other non-transiting planets orbiting stars near the Sun,” said Chad Bender, a research associate in the Penn State Department of Astronomy and Astrophysics and a co-author of the paper. “These planets are much closer to us than the nearest transiting planets, but largely have been ignored by astronomers because directly measuring their atmospheres with previously existing techniques was difficult or impossible.”

Once the next generation of high-powered telescopes are up and running — like the James Webb Space Telescope, slated to launch in 2018 — even smaller and more distant exoplanets can be observed with the IR method… perhaps helping to make the groundbreaking discovery of a planet like ours.

“While the current state of the technique cannot detect earthlike planets around stars like the Sun, with Keck it should soon be possible to study the atmospheres of the so-called ‘super-Earth’ planets being discovered around nearby low-mass stars, many of which do not transit,” said Caltech professor of cosmochemistry and planetary sciences Geoffrey Blake. “Future telescopes such as the James Webb Space Telescope and the Thirty Meter Telescope (TMT) will enable us to examine much cooler planets that are more distant from their host stars and where liquid water is more likely to exist.”

The findings are described in a paper published in the February 24, 2014 online version of The Astrophysical Journal Letters.

Sources: Caltech and EurekAlert press releases.

February 25, 2014December 23, 2015 by Elizabeth Howell

Yesterday’s Mammoth Solar Flare Is The Biggest Of 2014 So Far

NASA's Solar Dynamics Observatory captured these images of a large flare erupting from the sun Feb. 21, 2014. Credit: NASA/SDO

She’s a rainbow! You can see the first moments of a huge flare belching off the sun in the picture above. The so-called X-class flare erupted a few hours ago (at 7:25 p.m. EST Feb. 24, or 12:25 a.m. UTC Feb. 25) and was captured by several spacecraft. If you have a pictures of the sun yourself to share, feel free to post them in the Universe Today Flickr pool.

NASA’s Solar Dynamics Observatory saw the flare growing in at least six different wavelengths of light, which are visible in the image above. This is classified this as an X4.9-class flare, which shows that it is pretty strong. X-flares are the most powerful kind that the sun emits, and each X number is supposed to be twice as intense as the previous one (so an X-2 flare is twice as powerful as X-1, for example).

SpaceWeather.com says this is the most powerful flare of the year so far, emitted from sunspot AR1967 (or more properly speaking, AR1990; sunspots are renamed if they survive a full rotation of the sun, as this one has done twice already!) While solar flares can lead to auroras, in this case it appears the blast was pointed in the wrong direction, the site added.

“Although this flare is impressive, its effects are mitigated by the location of the blast site–near the sun’s southeastern limb, and not facing Earth,” SpaceWeather stated. “Indeed, a bright coronal mass ejection (CME) which raced away from the sun shortly after the flare appears set to miss our planet.”

This image from the Solar and Heliospheric Observatory illustrates increased solar activity between Feb. 18-20, 2014. Credit: ESA/NASA/SOHO/GSFC

The sun goes through an 11-year cycle of sunspot and solar activity, which is supposed to be at its peak right now. This particular peak has been very muted, but lately things have been picking up. The European Space Agency noted that between Feb. 18 and 20, the sun sent out six CMEs in three days, with most of them moving in different directions.

“This level of activity is consistent with what we might expect as the Sun is near its maximum period of activity in the 11-year solar cycle,” ESA stated.

You can see the sun changing on this SDO page, showing the latest views of the sun in different wavelengths. And for more information on sunspots, check out this NASA page explaining a little more about how they work.

February 25, 2014December 29, 2015 by Susie Murph

Carnival of Space #342

Carnival of Space. Image by Jason Major.

The tent is up! This week’s Carnival of Space is hosted by Pamela Hoffman at the Everyday Spacer blog.

Click here to read Carnival of Space #342.

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.

February 24, 2014December 23, 2015 by Jason Major

Watch Saturn Slip Behind the Moon

Occultation of Saturn on Feb. 22, 2014 by Colin Legg

Or, more accurately, watch the Moon pass in front of Saturn. Either way you get the same result: a beautiful video of planetary motion in action!

On the morning of Saturday, Feb. 22, the Moon drifted in front of the planet Saturn from the point of view of certain locations on Earth. Luckily one of those locations was Perth, Australia, where astrophotographer Colin Legg happens to be, and thus we all get to enjoy the fantastic results of his photographic and astronomical acumen.

Check out the video below:

The occultation — as such events are called whenever one celestial object passes in front of, or “hides,” another (the root of the word means “to conceal”) — may make it look like a tiny Saturn is getting absorbed by a giant Moon. But (obviously) they are separated by a vast distance: at the time of the occultation, 9.658 AU, or about 1,444,816,000 kilometers (897.7 million miles).

These sort of events will become a bit more common as the Moon is “headed towards a ‘shallow’ year in 2015 relative to the ecliptic; it will then begin to slowly open back up and ride high around 2025,” according to a recent Universe Today article by David Dickinson.

For those of you interested, Colin lists his equipment as a Celestron C8, f/10, prime focus. His camera is a Canon 5D2, running Magic Lantern RAW video firmware in 3x crop mode @ 1880 x 1056 resolution. Footage was taken at 1/60 sec exposure, ISO 200, 10 fps.

See more of Colin’s work on his Facebook page here.

February 24, 2014April 26, 2016 by David Dickinson

Watch the Moon Meet Venus in the Dawn this Wednesday

The view of Wednesday's conjunction from selected sites based on four separate continents. Credit: Created by the author using Stellarium.

Are you ready for some lunar versus planetary occultation action? One of the best events for 2014 occurs early this Wednesday morning on February 26^th, when the waning crescent Moon — sometimes referred to as a decrescent Moon — meets up with a brilliant Venus in the dawn sky. This will be a showcase event for the ongoing 2014 dawn apparition of Venus that we wrote about recently.

This is one of 16 occultations of a planet by our Moon for 2014, which will hide every naked eye classical planet except Jupiter and only one of two involving Venus this year.

An occultation occurs when one celestial body passes in front of another, obscuring it from our line of sight. The term is used to refer to planets or asteroids blocking out distant stars or the Moon passing in front of stars or planets.

Wednesday’s event has a central conjunction time of 5:00 Universal. Viewers in northwestern Africa based in Mali and southern Algeria and surrounding nations will see the occultation occur in the dawn sky before sunrise, while viewers eastward across the Horn of Africa, the southern Arabian peninsula, India and southeast Asia will see the occultation occur in the daylight.

A comparison of Venus versus the Moon in the daytime taken by Sharin Ahmad (@shahgazer) from Malaysia during the last lunation on January 29th, 2014.

Observers worldwide, including those based in Australia, Europe and the Americas will see a near miss, but early risers will still be rewarded with a brilliant dawn pairing of the second and third brightest objects in the night sky. This will also be a fine time to attempt to spot Venus in the daytime, using the nearby crescent Moon as a guide. It’s easier than you might think! In fact, Venus is actually brighter than the Moon per apparent square arc second of surface area, owing to its higher average reflectivity (known as albedo) of 80% versus the Moon’s dusky 14%.

The International Occultation Timing Association also maintains a chart of ingress and egress times for specific locations along the track of the occultation.

Credit: Created using Occult 4.0.11. — The footprint of the Wednesday occultation of Venus by the Moon. Solid lines indicate where the occultation occurs before sunrise, while the dashed area denotes where the occultation occurs after sunrise. Credit: Created using Occult 4.1.0.11.

The Moon occults Venus 21 times in this decade. The last occultation of Venus by the Moon occurred on September 8^th, 2013, and the next occurs October 23rd 2014 over the South Pacific in daylight skies very close to the Sun, and is unobservable.

Wednesday’s event also offers a unique opportunity to catch a crescent Venus emerging from behind the dark limb of the Moon. On Wednesday, Venus presents a 34” diameter disk that is 35% illuminated and shining at magnitude -4.3, while the Moon is a 12% illuminated crescent three days from New. Fun fact: February 2014 is missing a New Moon, meaning that both January and March will each contain two!

Apparent path of Venus in relation to the Moon Wednesday morning as seen from a theoretical geocentric (Earth-centered) location. Created using Starry Night Education software.

This also means that a well positioned observer in northwestern Africa would be able to see able to catch the dark limb of Venus creeping out from behind the nighttime side of the Moon against a dark sky. Such favorable occurrences only happen a handful of times per decade, and this week would be a great time to try and briefly spot – or perhaps even video or photograph – a phenomenon know as the ashen light of Venus as the dazzling crescent daytime side of the planet lay obscured by the Moon. Is this effect reported by observers over the years a fanciful illusion, or a real occurrence?

Perhaps, due to the remote location, this chance to spy and record this elusive effect will go unnoticed this time ‘round. The next chance with optimal possibilities to catch a crescent Venus occulted by the Moon against a dark sky occurs next year on October 8th, 2015, favoring the Australian outback. Anyone out there down for an observing expedition to prove or disprove the ashen light of Venus once and for all? Astronomy road trip!

Photo by Author — April 22nd, 2009 conjunction of Venus and the Moon as seen from Hudson, Florida. The Photo by author.

This event also provides optimal circumstances as Venus heads towards greatest elongation west of the Sun on March 22^nd and the Moon-Venus pair lay 43 degrees west of the Sun during Wednesday’s event. Compare this to the impossible to observe occultation this October, when the pairing is only one degree east of the Sun! The next occultation of Venus for North America occurs next year on December 7th, 2015 and will be visible in the daytime across the extent of the track except for Alaska and Northwestern Canada.

Vexillographers may also want to take note: this week’s Venus-Moon pairing will closely emulate the familiar crescent Moon plus star pairing seen on many national flags worldwide. Did an ancient and unrecorded occultation of Venus by the Moon inspire this meme? Tradition has it that Sultan Alp Arslan settled on the star and crescent for the flag of the Turks after witnessing a close conjunction after the defeat of the Byzantine Army at the Battle of Manzikert on August 26^th, 1071 A.D. This tale, however, is almost certainly apocryphal, as no occultations of planets or bright stars by the Moon occurred on or near that date, and only two occultations of Venus by the Moon occurred that year. And Venus was less than two degrees from the Sun on that date, yet another strike against it. In fact, the only occultations of Venus by the Moon in 1071 occurred on June 29^th and November 27^th. Perhaps Arslan just took a while to decide…

Still, this week’s event provides a great photo-op to have “Fun with Flags” and capture the pair behind your favorite astronomical conjunction-depicting banner. And be sure to send those pics into Universe Today… methinks there’s a good chance of us running a post occultation photo-essay later this week!

February 24, 2014December 23, 2015 by Elizabeth Howell

‘Green Valley’ Of Galaxies Shows Off Gas And Star Formation

M33, the Triangulum Spiral Galaxy, seen here in a 4.3 hour exposure image. Astronomers used JWST to examine a section of its south spiral arm to search out and find nearly 800 newly forming stars. Credit and copyright: John Chumack.

We keep saying this: the universe is more complex than it appears. Conventional thinking in galaxy research postulates that spiral galaxies have star-forming areas, while ellipticals do not due to a lack of gas. While this thinking has been debunked, there’s now emerging research showing a “green valley” of galaxies somewhat in between these two types.

Basically, the research (which includes participation from citizen scientists in the Galaxy Zoo project) is showing that there are two different populations of “green” galaxies, between ellipticals and spirals. Further, what happens to star formation based upon gas in the area.

“In this paper, we take a look at the most crucial event in the life of a galaxy: the end of star formation. We often call this process ‘quenching’ and many astrophysicists have slightly different definitions of quenching. Galaxies are the place where cosmic gas condenses and, if it gets cold and dense enough, turns into stars. The resulting stars are what we really see as traditional optical astronomers,” wrote Kevin Schawinski, a Ph.D. student at the University of Oxford who is on the Galaxy Zoo team, in a blog post.

“Not all stars shine the same way though: stars much more massive than our sun are very bright and shine in a blue light as they are very hot. They’re also very short-lived. Lower mass stars take a more leisurely pace and don’t shine as bright (they’re not as hot). This is why star-forming galaxies are blue, and quiescent galaxies (or ‘quenched’ galaxies) are red: once star formation stops, the bluest stars die first and aren’t replaced with new ones, so they leave behind only the longer-lived red stars for us to observe as the galaxy passively evolves.”

You can read more information in the blog post. The study, which has been accepted for publication in the Monthly Notices of the Royal Astronomical Society, is available on preprint site Arxiv.

February 24, 2014December 23, 2015 by Nancy Atkinson

Watch a Car-Sized Asteroid Slam Into the Moon

An image of the flash resulting from the impact of a large meteorite on the lunar surface on 11 September 2013, obtained with the MIDAS observatory. Credit: J. Madiedo / MIDAS

Hey, all you astro-photographers/videographers out there: were you shooting the Moon back on September 11, 2013? You may want to review your footage and see if you captured a bright flash which occurred at about 20:07 GMT. Astronomers say a meteorite with the mass of a small car slammed into the Moon at that time and the impact produced a bright flash, and it even would have been easy to spot from the Earth.

According to astronomers Jose M. Madiedo, from the University of Huelva and Jose L. Ortiz, from the Institute of Astrophysics of Andalusia both in Spain, this impact was the longest and brightest confirmed lunar impact flash ever observed, as the “afterglow” of the impact remained visible for 8 seconds.

The astronomers think the bright flash was produced by an impactor of around 400 kg with a width of between 0.6 and 1.4 meters. The rock hit may have hit Mare Nubium at about 61,000 kilometers per hour (38,000 miles per hour) — although the uncertainty of the impact is fairly high, the team says in their paper. But if it is as high as they think, it may have created a new crater with a diameter of around 40 meters. The impact energy was equivalent to an explosion of roughly 15 tons of TNT.

This beats the previous largest impact seen – which occurred just six months earlier in March 2013 – which was estimated to pack as much punch as 5 tons of TNT. Astronomers that explosion was caused by a 40 kg meteoroid measuring 0.3 to 0.4 meters wide, traveling about 90,000 km/hr (56,000 mph.)

How often does an asteroid hit the Moon? Astronomers actually aren’t very sure.

On average, 33 metric tons (73,000 lbs) of meteoroids hit Earth every day, the vast majority of which harmlessly ablates or burns up high in Earth’s atmosphere, never making it to the ground. The Moon, however, has little or no atmosphere, so meteoroids have nothing to stop them from striking the surface.

The lunar impact rate is so uncertain because observations for objects in the mass range of visible impacts from Earth are quite few. But now, astronomers have set up networks of telescopes that can detect them automatically. NASA has the Automated Lunar and Meteor Observatory (ALaMO) at Marshall Space Flight Center, and the Spanish telescopes are part of the Moon Impacts Detection and Analysis System (MIDAS) system.

Lunar meteors hit the ground with so much kinetic energy that they don’t require an oxygen atmosphere to create a visible explosion. The flash of light comes not from combustion but rather from the thermal glow of molten rock and hot vapors at the impact site.

This thermal glow can be detected from Earth as short-duration flashes through telescopes. Generally, these flashes last just a fraction of a second. But the flash detected on September 11, 2013 was much more intense and longer than anything observed before.

Mosaic of zoomed images showing the flash evolution from the Sept. 11, 2013 impact during the first 2 seconds. Time increases from left to right in each row, starting from the upper left. The time interval between two consecutive images in the same row is 0.1 s. Credit: Madiedo, Ortiz, et al. 2014.

“Our telescopes will continue observing the Moon as our meteor cameras monitor the Earth’s atmosphere,” said Madiedo and Ortiz in a press release. “In this way we expect to identify clusters of rocks that could give rise to common impact events on both planetary bodies. We also want to find out where the impacting bodies come from.”

You can read the team’s paper here.